Magnetically Dominated Strands of Cold Hydrogen in the Riegel-Crutcher Cloud

认知衰弱的研究进展马雅军;刘惠;胡志灏;李晓东;李淑娟【摘要】衰弱已被公认为老年不良事件的危险因素之一.然而目前对于衰弱的定义与筛查多只体现了身体生理因素方面,与衰弱相关的认知及社会心理方面的概念与研究仍需完善.本文介绍了由国际营养与衰老研究所和国际老年医学和老年医学协会于2013年首次提出的认知衰弱的概念,即同时存在身体衰弱和认知损害,并排除老年痴呆或其他类型痴呆,叙述了认知衰弱概念的提出及完善,并简述了认知衰弱可能的机制及可能造成认知衰弱的危险因素,还归纳了涉及认知衰弱的一些流行病学研究.分析表明,认知衰弱的提出是衰弱研究进程中重要的一部分,个人和社会应对这一新兴概念予以足够的重视,最终为制定预防老年人认知衰弱的策略做出贡献.此外,根据生物-心理-社会模型的假设,衰弱作为一种综合概念,还应该包括社会心理方面,未来应将与衰弱相关的社会心理因素作为下一步的研究方向.【期刊名称】《中国全科医学》【年(卷),期】2019(022)015【总页数】6页(P1778-1783)【关键词】认知;衰弱;综述【作者】马雅军;刘惠;胡志灏;李晓东;李淑娟【作者单位】100020北京市,首都医科大学附属北京朝阳医院神经内科;100020北京市,首都医科大学附属北京朝阳医院神经内科;100020北京市,首都医科大学附属北京朝阳医院神经内科;100020北京市,首都医科大学附属北京朝阳医院神经内科;100020北京市,首都医科大学附属北京朝阳医院神经内科【正文语种】中文【中图分类】R741当今世界上高龄老年人（80岁及以上）的比例增长快于其他任何年龄段人群，并且高龄老年人的比例预计在2015—2050年增加3倍［1］。

为了预防未来老龄化的危害，各种老年综合征引起了全世界的关注，老年人衰弱也成为近年来的热门话题。

衰弱是老年不良结局的危险因素之一，也是其先兆。

根据病因，衰弱可分为身体衰弱、认知衰弱和社会心理衰弱3种类型［1-2］。

微纳米流动和核磁共振技术英文回答：Microfluidics and nuclear magnetic resonance (NMR) are two important technologies that have revolutionized various fields of science and engineering.Microfluidics refers to the study and manipulation of fluids at the microscale level, typically in channels or chambers with dimensions ranging from micrometers to millimeters. It allows precise control and manipulation of small volumes of fluids, enabling a wide range of applications such as chemical analysis, drug delivery systems, and lab-on-a-chip devices. Microfluidic devices are often fabricated using techniques such as soft lithography, which involve the use of elastomeric materials to create microchannels and chambers.NMR, on the other hand, is a powerful analytical technique that utilizes the magnetic properties of atomicnuclei to study the structure and dynamics of molecules. It is based on the principle of nuclear spin, which is the intrinsic angular momentum possessed by atomic nuclei. By subjecting a sample to a strong magnetic field and applying radiofrequency pulses, NMR can provide information about the chemical composition, molecular structure, and molecular interactions of the sample. NMR has diverse applications in fields such as chemistry, biochemistry, medicine, and materials science.Microfluidics and NMR can be combined to create powerful analytical tools for studying various biological and chemical systems. For example, microfluidic devices can be used to precisely control the flow of samples and reagents, while NMR can provide detailed information about the composition and structure of the samples. This combination has been used in the development ofmicrofluidic NMR systems, which allow rapid and sensitive analysis of small sample volumes. These systems have been applied in areas such as metabolomics, drug discovery, and environmental monitoring.中文回答：微纳米流体力学和核磁共振技术是两种重要的技术，已经在科学和工程的各个领域引起了革命性的变化。

2020年考研英语词汇《疾病类》：查多克征Chaddoch sign查多克征Chamberlain's line硬腭枕大孔(张伯伦)线Charcot's foot夏科氏足(脊髓痨性关节病患者的畸形足)barylalia 言语不清basal plate 基板basiarachnitis 颅底蛛网膜炎basicranial 颅底basilar cistern 基底池basilar fracture 颅底骨折basilar impression 颅底凹陷basilar invagination 颅底陷入症basilar sinus 基底窦basilar suleus 基底沟basinasial 颅底鼻根的basioccipital 枕骨底部的basis pontis 基底部(脑桥)basophil 嗜碱性细胞Bassen-Kornzweig syndrome 棘状红细胞-β-脂蛋白缺乏症Bastian-Bruns Sign 巴斯欣-布伦斯征(从头部到腰膨大部的脊髓有完全横贯性损害，下肢键反射就消失)bathrocephaly 梯头bathyanesthesia 深部感觉缺失bathyesthesia 深部感觉bathyhyperesthesia 深部感觉过敏bathyhypesthesia 深部感觉迟钝Batten-Mayou disease 少年型黑蒙性白痴Bayle's disease 贝尔病(精神错乱者的实行性全身性麻痹) Beale's ganglion cells 比尔神经节细胞(双极细胞)Beard's disease 神经衰弱Behcet syndrome 白塞综合征Bekhterev's layer 别赫捷列夫层(大脑皮层外粒层的纤维层) Bekhterev's nucleus 别赫捷列夫核(前庭神经上核) Bekhterev's reaction 别赫捷列夫反应Abaptiston安全开颅圆锯abarognosis压觉缺失abasia astasia立行不能abasia步行不能abdominal reflex腹壁反射abduction外展abiotrophy生活力缺失。

APT Attached Proton Test 质子连接实验ASIS Aromatic Solvent Induced Shift 芳香溶剂诱导位移BBDR Broad Band Double Resonance 宽带双共振BIRD Bilinear Rotation Decoupling 双线性旋转去偶（脉冲）COLOC Correlated Spectroscopy for Long Range Coupling 远程偶合相关谱COSY ( Homonuclear chemical shift ) COrrelation SpectroscopY （同核化学位移）相关谱CP Cross Polarization 交叉极化CP/MAS Cross Polarization / Magic Angle Spinning 交叉极化魔角自旋CSA Chemical Shift Anisotropy 化学位移各向异性CSCM Chemical Shift Correlation Map 化学位移相关图CW continuous wave 连续波DD Dipole-Dipole 偶极-偶极DECSY Double-quantum Echo Correlated Spectroscopy 双量子回波相关谱DEPT Distortionless Enhancement by Polarization Transfer 无畸变极化转移增强2DFTS two Dimensional FT Spectroscopy 二维傅立叶变换谱DNMR Dynamic NMR 动态NMRDNP Dynamic Nuclear Polarization 动态核极化DQ(C) Double Quantum (Coherence) 双量子（相干）DQD Digital Quadrature Detection 数字正交检测DQF Double Quantum Filter 双量子滤波DQF-COSY Double Quantum Filtered COSY 双量子滤波COSY DRDS Double Resonance Difference Spectroscopy 双共振差谱EXSY Exchange Spectroscopy 交换谱FFT Fast Fourier Transformation 快速傅立叶变换FID Free Induction Decay 自由诱导衰减H,C-COSY 1H,13C chemical-shift COrrelation SpectroscopY 1H,13C 化学位移相关谱H,X-COSY 1H,X-nucleus chemical-shift COrrelation SpectroscopY1H,X-核化学位移相关谱HETCOR Heteronuclear Correlation Spectroscopy 异核相关谱HMBC Heteronuclear Multiple-Bond Correlation 异核多键相关HMQC Heteronuclear Multiple Quantum Coherence异核多量子相干HOESY Heteronuclear Overhauser Effect Spectroscopy 异核Overhause效应谱HOHAHA Homonuclear Hartmann-Hahn spectroscopy 同核Hartmann-Hahn谱HR High Resolution 高分辨HSQCHeteronuclear Single Quantum Coherence 异核单量子相干INADEQUATE Incredible Natural Abundance Double Quantum Transfer Experiment 稀核双量子转移实验（简称双量子实验，或双量子谱）INDOR Internuclear Double Resonance 核间双共振INEPT Insensitive Nuclei Enhanced by Polarization 非灵敏核极化转移增强INVERSE H,X correlation via 1H detection 检测1H的H,X核相关IR Inversion-Recovery 反（翻）转回复JRES J-resolved spectroscopy J-分解谱LIS Lanthanide (chemical shift reagent ) Induced Shift 镧系（化学位移试剂）诱导位移LSR Lanthanide Shift Reagent 镧系位移试剂MAS Magic-Angle Spinning 魔角自旋MQ(C) Multiple-Quantum ( Coherence ) 多量子（相干）MQF Multiple-Quantum Filter 多量子滤波MQMAS Multiple-Quantum Magic-Angle Spinning 多量子魔角自旋MQS Multi Quantum Spectroscopy 多量子谱NMR Nuclear Magnetic Resonance 核磁共振NOE Nuclear Overhauser Effect 核Overhauser效应（NOE）NOESY Nuclear Overhauser Effect Spectroscopy 二维NOE谱NQR Nuclear Quadrupole Resonance 核四极共振PFG Pulsed Gradient Field 脉冲梯度场PGSE Pulsed Gradient Spin Echo 脉冲梯度自旋回波PRFT Partially Relaxed Fourier Transform 部分弛豫傅立叶变换PSD Phase-sensitive Detection 相敏检测PW Pulse Width 脉宽RCT Relayed Coherence Transfer 接力相干转移RECSY Multistep Relayed Coherence Spectroscopy 多步接力相干谱REDOR Rotational Echo Double Resonance 旋转回波双共振RELAY Relayed Correlation Spectroscopy 接力相关谱RF Radio Frequency 射频ROESY Rotating Frame Overhauser Effect Spectroscopy 旋转坐标系NOE谱ROTO ROESY-TOCSY Relay ROESY-TOCSY 接力谱SC Scalar Coupling 标量偶合SDDS Spin Decoupling Difference Spectroscopy 自旋去偶差谱SE Spin Echo 自旋回波SECSY Spin-Echo Correlated Spectroscopy自旋回波相关谱SEDOR Spin Echo Double Resonance 自旋回波双共振SEFT Spin-Echo Fourier Transform Spectroscopy (with J modulation)（J-调制）自旋回波傅立叶变换谱SELINCOR Selective Inverse Correlation 选择性反相关SELINQUATE Selective INADEQUATE 选择性双量子（实验）SFORD Single Frequency Off-Resonance Decoupling 单频偏共振去偶SNR or S/N Signal-to-noise Ratio 信 / 燥比SQF Single-Quantum Filter 单量子滤波SR Saturation-Recovery 饱和恢复TCF Time Correlation Function 时间相关涵数TOCSY Total Correlation Spectroscopy 全（总）相关谱TORO TOCSY-ROESY Relay TOCSY-ROESY接力TQF Triple-Quantum Filter 三量子滤波WALTZ-16 A broadband decoupling sequence 宽带去偶序列WATERGATE Water suppression pulse sequence 水峰压制脉冲序列WEFT Water Eliminated Fourier Transform 水峰消除傅立叶变换ZQ(C) Zero-Quantum (Coherence) 零量子相干ZQF Zero-Quantum Filter 零量子滤波T1 Longitudinal (spin-lattice) relaxation time for MZ 纵向（自旋-晶格）弛豫时间T2 Transverse (spin-spin) relaxation time for Mxy 横向（自旋-自旋）弛豫时间tm mixing time 混合时间τc rotational correlation time 旋转相关时间。

极端酶研究进展及其在食品工业中的应用现状刘欣;魏雪;王凤忠;辛凤姣【摘要】酶是一种高效的生物催化剂,因其反应条件温和、能耗低、特异性强、绿色环保等优势而广泛应用于食品、纺织、饲料、医药、能源等各个领域中.随着食品工业的迅猛发展,食品制造绿色化的需求急剧增加,食品酶在整个酶制剂市场中所占的份额日益越大.大部分食品加工工艺都涉及高温、高压等较为严苛的条件,因此极端酶在食品工业中显示出了极大优势.综述了嗜热酶、嗜冷酶等极端酶的研究进展,主要从结构生物学的角度阐明了其耐热、耐冷等适应机制,并对其在食品工业中的应用现状进行了详细阐述.【期刊名称】《生物产业技术》【年(卷),期】2017(000)004【总页数】8页(P62-69)【关键词】食品酶;极端酶;食品加工;晶体结构【作者】刘欣;魏雪;王凤忠;辛凤姣【作者单位】中国农业科学院农产品加工研究所,北京 100193;中国农业科学院农产品加工研究所,北京 100193;中国农业科学院农产品加工研究所,北京 100193;中国农业科学院农产品加工研究所,北京 100193【正文语种】中文辛凤姣，博士，博士生导师，研究员，中国农业科学院农产品加工研究所食品酶研究与应用创新团队首席科学家，中国农业科学院青年英才，中国农学会食物与营养专业委员会副秘书长。

长期从事农产品加工领域关键酶的生化性质及晶体结构研究，微生物代谢调控研究，酶制剂等生物制品开发等。

主持创新工程、自然科学基金面上项目等项目5项；发表高水平论文10余篇，申请国家发明专利6项。

E-mail:*******************2017年初，国家发展和改革委员会、工业和信息化部关于促进食品工业健康发展的指导意见（发改产业［2017］19号）中多次强调要“绿色制造”、“提升科技创新能力”、“促进食品工业发生质的转变”。

酶作为“绿色制造”的核心工具，在推动食品工业发展中扮演着至关重要的角色。

酶是一类具有高催化效率、高专一性、高多样性、反应条件温和的生物催化剂，除了具有催化活性的RNA（核酶）之外，几乎均为蛋白质。

BMBreports338BMB reports*Corresponding author. T el: 82-31-201-2688; Fax: 82-31-202-2687;E-mail: dcyang@khu.ac.krReceived 17 October 2007, Accepted 26 December 2007K eywords: Abiotic stress, Codonopsis lanceolata , Dehydrin (DHN), Semi-quantitative RT-PCRIsolation of a novel dehydrin gene from Codonopsis lanceolata and analysis of its response to abiotic stressesRama Krishna Pulla 1,2, Yu-Jin Kim 1, Myung Kyum Kim 1, Kalai Selvi Senthil 3, Jun-Gyo In 4 & Deok-Chun Yang 1,*1Korean Ginseng Center and Ginseng Genetic Resource Bank, Kyung Hee University, Seocheon-dong, Kiheung-gu Yongin, Kyunggi-do, South Korea, 2Kongunadu Arts and Science College, Coimbatore, Tamil Nadu, 641029, India. 3Avinashilingam University for Women, Coimbatore, 641043, India. 4Biopia Co., Ltd., Yongin, KoreaDehydrins (DHNs) compose a family of intrinsically unstructured proteins that have high water solubility and accumulate during late seed development at low temperature or in water-deficit conditions. They are believed to play a protective role in freez-ing and drought-tolerance in plants. A full-length cDNA encod-ing DHN (designated as ClDhn ) was isolated from an oriental medicinal plant Codonopsis lanceolata , which has been used widely in Asia for its anticancer and anti-inflammatory properties. The full-length cDNA of ClDhn was 813 bp and contained a 477 bp open reading frame (ORF) encoding a polypeptide of 159 amino acids. Deduced ClDhn protein had high similarities with other plant DHNs. RT-PCR analysis showed that different abiotic stresses such as salt, wounding, chilling and light, trig-gered a significant induction of ClDhn at different time points within 4-48 hrs post-treatment. This study revealed that ClDhn assisted C. lanceolata in becoming resistant to dehydration. [BMB reports 2008; 41(4): 338-343]INTRODUCTIONPlants have developed defensive strategies against various stresses that arise from frequent environmental fluctuations to which they are exposed. Drought and low temperatures are the most severe factors limiting plant growth and yield. More than 100 genes have been shown to be responsive to such conditions and they are believed to function either during the physiological protection of cells from water-deficiencies or temperature-changes or in the regulation of gene expression (1-3).DHNs are proteins that are known to accumulate in vegetative plant tissues under stress conditions, such as low temperature, drought, or salt-stress (2, 4-6). These proteins have been catego-rized as late embryogenesis abundant (LEA) proteins (7, 8).DHNs have been subdivided into five classes according to thepresence of highly conservative segments: YnSK 2, Kn, KnS, SKn and Y 2Kn. The K-segment (EKKIGIMDKIKEKLPG) is a conserved 15-mer lysine-rich sequence characteristic of DHNs, which may be present in one or several copies (5). The K-segment can form an amphiphathic α-helix structure that may interact with lipid components of bio-membranes and partially denatured proteins like chaperones (6, 9). The S-segment consists of contiguous ser-ine residues in the centre of the protein, which may be phosphorylated. They are involved in nuclear transport through their binding to nuclear localization signal peptides (6). The Y-segment with the consensus sequence DEYGNP, shares some similarities to the nucleotide-binding site of chaperones in plants and bacteria (5, 10). Another conserved domain contained in many DHNs is ϕ-segment (repeated Gly and polar amino acids), which interacts with and stabilizes membranes and macro-molecules, preventing structural damage and maintaining the activity of essential enzymes (11).DHNs have been found in the cytoplasm (12), nucleus (12, 13), mitochondria (14), vacuole (15), and chloroplasts (16). They are known to associate with membranes (17, 18), pro-teins (19) and excess salt ions (15, 20). Several DHN genes have been isolated and characterized from different species, including cor47, erd10 and erd14 from Arabidopsis thaliana ; Hsp90, BN59, BN115 and Bnerd10 from Brassica napus ; cor39 and wcs19 from Triticum aestivum (bread wheat); and cor25 from Brassica rapa subsp. Pekinensis (21). Many studies have reported a positive correlation between the accumulation of DHN transcripts or proteins and tolerance to freezing, drought, and salinity (12, 17, 22-24). Moreover, mod-ulation of transcripts by light has been reported for many DHN-encoding genes in drought- or cold-stressed plants (25-28). Although the biochemical functions and physiological roles of DHNs are still unclear, their sequence character-izations and expression patterns suggest that they may play a positive role in plant-response and adaptation to abiotic stress that leads to cellular dehydration. Indeed, many studies have indicated that transgenic plants with DHNs have a better stress-tolerance, recovery or re-growth after drought and freez-ing stress than that of the control (8, 29, 30).Thus far, there are no reports on isolation of the DHN gene from the oriental medicinal plant Codonopsis lanceolata . ThisCodonopsis lanceolata dehydrin geneRama Krishna Pulla, et al.339BMBreportsFig. 1. Nucleotide sequence and de-duced amino acid sequence of a ClDhn cDNA isolated from C. lanceolata . Num-bers on the left represent nucleotide positions. The deduced amino acid se-quence is shown in a single-letter code below the nucleotide sequence. The as-terisk denotes the translation stop signal.Amino acids in two double boxes repre-sent the Y-segment and amino acids in a single box the S-segment, respectively.The two underlined sequences represent the K-segments.plant belongs to the family of Campanulaceae (bellflower fam-ily), which contains many famous oriental medicinal plants such as Platycodon grandiflorum (Chinese bellflower or balloon flow-er), Codonopsis pilosula and Adenophora triphylla (nan sha shen). The roots of these plants have been used as herbal drugs to treat bronchitis, cough, spasm, macrophage-mediated immune responses and inflammation, and has also been administered as a tonic (31). C. lanceolata grows in North-eastern china, Korea, and far eastern Siberia. Despite their medicinal importance, little genomic study of this plant has been carried out. In this study, we characterized an Y 2SK 2 type DHN gene from C. lanceolata and analyzed its expression in response to various abiotic stresses.RESULTS AND DISCUSSIONIsolation and characterization of the full length cDNA of the ClDhn geneAs part of a genomic project to identify genes in the medicinal plant C. lanceolata , a cDNA library consisting of about 1,000 cDNAs was previously constructed. A cDNA encoding a dehy-drin (DHN), designated ClDhn was isolated and sequenced. The sequence data of ClDhn has been deposited in GenBank under accession number AB126059. As shown in Fig. 1, ClDhn is 813 bp in length and it has an open reading frame (ORF) of 477 bp nucleotide with an 87-nucleotide upstream sequence and a 248-nucleotide downstream sequence. The ORF of ClDhn starts at nucleotide position 88 and ends at position 565. ClDhn encodes a precursor protein of 159 amino acids resi-dues with no predicted signal peptide at the N-terminal. The calculated molecular mass of the protein is approximately 16.7kDa with a predicated isoelectric point of 6.87. In the deduced amino acid sequence of ClDhn protein, the total number of neg-atively charged residues (Asp +Glu) amounted to 21 while the total number of positively charged residues (Arg +Lys) was 20. In addition, transmembrane helix prediction (TMHMMv2.0) did not identify any transmembrane helices in the deduced protein, implying that the protein did not function in the membrane but might function within the cytosolic or nuclear compartment.Homology analysisA GenBank Blastp search revealed that ClDhn had the highest sequence homology to the carrot (Daucus carota ) DHN (BAD86644) with 51% identity and 61% similarity. ClDhn also shared homology with ginseng (Panax ginseng ) DHN5 (ABF48478, 50% identity and 60% similarity), wild potato (Solanum commersonii ) DHN (CAA75798, 50% identity and 58% similarity), robusta coffee (Coffea canephora ) DHN1α (ABC55670, 47% identity and 55% similarity), grape (Vitis vin-ifera ) DHN (ABN79618, 47% identity and 57% similarity), American beech (Fagus sylvatica ) DHN (CAE54590, 46% iden-tity and 56% similarity), tobacco (Nicotiana tabacum ) DHN (BAD13498, 45% identity and 56% similarity), sunflower (Helianthus annuus ) DHN (CAC80719, 45% identity and 52% similarity), and soybean (Glycine max ) DHN (AAB71225, 44% identity and 52% similarity). The DHNs showing the highest similarities were Y 2SK 2 type DHNs except grape (Vitis vinifera ) DHN (YSK 2 type) (32). Thus ClDhn might belong to Y 2SK 2 type DHNs based on the two Y-segments, one S-segment, and two K-segments present in its amino acid sequence. Phylogenetic analysis of ten of the plant DHNs were carried out using theCodonopsis lanceolata dehydrin gene Rama Krishna Pulla, et al.340BMB reportsFig. 2. A phylogenetic tree based on DHN amino acid sequence, showing the phylogenetic relationship between ClDhn and other plant DHNs . The tree was constructed using the Clustal X method (Neighbor-joining method) and a bar represents 0.1 substitutions peramino acid position.Fig. 3. Alignment of ClDhn with the most closely related DHNs from carrot (Daucus carota , BAD86644), ginseng (Panax ginseng DHN5, ABF48478), com-merson’s wild potato (Solanum commer-sonii , CAA75798), robusta coffee (Coffea canephora , ABC55670), grape (Vitis vin-ifera , ABN79618), American beech (Fagus sylvatica , CAE54590), tobacco (Nicotiana tabacum , BAD13498), sunflower (Helian-thus annuus , CAC80719) and soybean (Glycine max , AAB71225). Gaps are marked with dashes. The conserved ami-no acid residues are shaded and Y-, S-, and K-segments are shown.Clustal X program (Fig. 2). Fig. 3 is a sequence alignment result of ClDhn and other closely related DHNs .The differential expression of ClDhn in different organs of C . lanceolataThe expression patterns of ClDhn in different C . lanceolata or-gans were examined using RT-PCR analysis. Almost similar levels of ClDhn -mRNA expression were observed in leaves and roots, whereas ClDhn was expressed in slightly higher lev-els in the stems. (Data was not shown).Expression of ClDhn in response to various stressesExpression patterns of ClDhn under various conditions were ex-amined using RT-PCR analysis. Fig. 4A showed the accumu-lation of ClDhn -mRNA in response to 100 mM ABA in MS agar. ABA is a hormone secreted when environmental conditions be-come dry. Expression of ClDhn was induced and reached a maximum level after 12 hrs, and then gradually decreased. When plants are submitted to dehydration the endogenous con-tent of ABA increases, with ABA mediating the closure of the stomata. Several studies have identified ABA as a key hormone in the induction pathway of many inducible genes including DHN , in response to drought (33-36). 100 μM of ABA in sprayCodonopsis lanceolata dehydrin geneRama Krishna Pulla, et al.341BMBreportsFig. 4. RT-PCR analyses of the expressions of ClDhn gene in the leaves of C. lanceolata at various time points (h) post-treatment with various stresses: A, 100 mM ABA; B, 100 mM NaCl; C, wounding; D, chilling and E, light treatment. Actin was used as an internal control.induced DHN-levels in Brassica napus and increased its ex-pression up to 48 hrs after treatment with ABA (37). 100 μM of ABA in MS agar induced DHN -levels in rice and cause a max-imum expression level at 1 hr post-treatment (10).Fig. 4B shows the accumulation of ClDhn mRNA in re-sponse to salt stress (100 mM NaCl). ClDhn expression was in-duced at 4 hrs post-treatment and gradually increased until 48 hrs. In Brassica napus , 250 mM NaCl added in the nutrient medium induced DHN-expression and reached a maximum at 48 hrs post-treatment (37). The application of NaCl to soil brought on a progressive decrease of the pre-dawn leaf water potential, a decrease of stomatal-conductance and a growth- reduction. Osmotic potential increase during salt treatmentcould result from Na ＋ or Cl −absorption and from the synthesis of compatible compounds (38).Under wounding stress, ClDhn gene transcription was in-duced at 4 hrs post-treatment and gradually increased until 48 hrs (Fig. 4C). Richard et al . (39) discussed that the cumulative effect of wounding on transcript accumulation could also be associated with greater water-loss through more open surfaces arising from the wounding treatment.Under cold treatment, increase of ClDhn transcripts was ob-served at 4 hrs post-treatment and gradually increased until 48 hrs (Fig. 4D). Induction of DHN by low temperatures has been observed in numerous plants (17, 38). Overexpression of citrus DHN improved the cold tolerance in tobacco (18). Overexpre-ssion of multiple DHN genes in Arabidopsis resulted in accu-mulation of the corresponding DHNs to levels similar or higher than in cold-acclimated wild-type plants (24). Another example showed that overexpression of the acidic DHN WCOR410 could improve freezing tolerance in transgenic strawberry leaves (29). Fig. 4E shows that ClDhn gene expression was induced bylight stress and increased continuously until 48 hrs post-treat-ment. Natali et al . (40) showed that the G-box (CACGTGGC), a motif found in the promoter region of many light regulated genes, was found in the DHN gene promoter of helianthus and that DHN was responsive to light stress (41).In conclusion, we isolated a new dehydrin gene (ClDhn ) from C. lanceolata and characterized its expression in response to various stresses. ClDhn was induced by various stresses related to wa-ter-deficiency (ABA, salt, wounding and cold) and was induced by light, similar to other DHN genes isolated from other plants.MATERIALS AND METHODSPlant materialsCodonopsis lanceolata were grown in vitro on MS medium supplemented with 3% sucrose and 0.8% agar under the 16 hrs light and 8 hrs dark period. Its growth was maintained by regular subculture every 4 weeks. Abiotic stress studies were carried out on plants that were subcultured for one month. To analyze gene expression in different organs, samples were col-lected from leaves, roots and stem of C. lanceolata plants.Sequence analysesThe full-length ClDhn gene was analyzed using the softwares BioEdit, Clustal X, Mega 3 and other databases listed below; NCBI (http://www.ncbi.nlm.nih), SOPMA (http://npsa-pbil.ibcp /npsaautomat.pl?page=npsopma.html).Stress assaysTo investigate the response of the ClDhn gene to various stress-es, the third leaves with petioles from C. lanceolata were used. For treatment with ABA (100 mM) and NaCl (100 mM), leaf samples were incubated in media containing each compound at 25o C for 48 hrs. For mechanical wounding stress, excised leaves were wounded with a needle puncher (42). Chilling stress was applied by exposing the leaves to a temperature of 4o C (43). To investigate the ClDhn gene-expressions in light, leaves were incubated under an electrical lamp with a light in-tensity of 24 mol m-2 s-1 for 48 hrs. All treatments were carried out on MS media with or without the treatment solution (ABA, NaCl). All treated plant materials were immediately frozen in liquid nitrogen and stored at -70o C until further analysis.Semi-quantitative RT-PCR analysisTotal RNA was extracted from various whole plant tissues (leaves, stem, roots) of C. lancolata using the Rneasy mini kit (Qiagen, Valencia, CA, USA). For RT-PCR (reverse tran-scriptase-PCR), 800 ng of total RNA was used as a template for reverse transcription using oligo (dT) primer (0.2 mM)(INTRON Biotechnology, Inc., South Korea) for 5 mins at 75oC. The reaction mixture was then incubated with AMV Reverse Transcriptase (10 U/μl) (INTRON Biotechology, Inc., SouthKorea) for 60 mins at 42oC. The reaction was inactivated byheating the mixture at 94oC for 5 mins. PCR was then per-Codonopsis lanceolata dehydrin gene Rama Krishna Pulla, et al.342BMB reportsformed using a 1 μl aliquot of the first stand cDNA in a final volume of 25 μl containing 5 pmol of specific primers for cod-ing of ClDhn gene (forward, 5'-AAA GAG AGA GAA AAT GGC AGG TTA C-3'; reverse, 5'-GGA GTA GTT GTT GAA GTT CTC TGC T-3') were used. As a control, the primers spe-cific to the C. lanceolata actin gene were used (forward, 5'-CAA GAA GAG CTA CGA GCT ACC CGA TGG-3'; reverse, 5'-CTC GGT GCT AGG GCA GTG ATC TCT TTG CT-3'). PCR was carried out using 1 μl of taq DNA polymerase (Solgent Co., South Korea) in a thermal cycler programmed as follows:an initial denaturation for 5 mins at 95oC, 30 amplification cy-cles [30 s at 95o C (denaturation), 30 s at 53o C (annealing), and90 s at 72oC (polymerization)], followed by a final elongation for 10 mins at 72o C. Actin was used as an internal control to normalize each sample for variations in the amount of RNA used.AcknowledgementsThis work was supported by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (MOST) (No. R01-2006-000-11178-0).REFERENCES1.Bray, E. A. (2002) Classification of the genes differentially expressed during water-deficit stress in Arabidopsis thali-ana : An analysis using micro array and differential ex-pression data. Ann. Bot. 89, 803-811.2.Ingram, J. and Bartels, D. (1996) The molecular basis of dehydration tolerance in plants. Annu. Rev. Plant Physiol. Plant Mol. Biol. 47, 377-403.3.Kim, S. J., Jeong, D. H., An, G. and Kim, S. R. (2005) Characterization of a drought-responsive gene, OsTPS1, identified by the T-DNA gene-trap system in rice. J. Plant Biol. 48, 371-379.4.Allagulova, Ch. R., Gimalor, F. R., Shakirova, F. M. and Vakhitov, V. A. (2003) The plant dehydrins: Structure and putative functions. 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核磁共振英语词汇英文回答：Nuclear magnetic resonance (NMR) is a powerfulanalytical tool that utilizes magnetic fields and radio waves to investigate the properties of atoms and molecules. It offers a non-destructive and versatile technique for characterizing materials at the atomic and molecular level. NMR has various applications across multiple scientific disciplines, including chemistry, physics, biology, and medicine.The basic principle of NMR involves the interaction between atomic nuclei with a magnetic field. Certain nuclei, such as 1H (proton), 13C, 15N, and 31P, possess anintrinsic magnetic moment due to their nuclear spin. When placed in a magnetic field, these nuclei align with or against the field, resulting in two distinct energy states. By applying radio waves to the sample at specific frequencies, it is possible to induce transitions betweenthese energy states.The absorption of radio waves by the nuclei leads to the resonance phenomenon, which forms the basis of NMR. The resonant frequency for a particular nucleus depends on its chemical environment, including the electron density and surrounding atoms. By analyzing the resonance frequencies and patterns, NMR provides detailed information about the structure, dynamics, and interactions of molecules.NMR spectroscopy is a widely used technique for identifying and quantifying different atoms and functional groups within molecules. It plays a crucial role in determining the molecular structure of organic and inorganic compounds, as well as studying chemical reactions and reaction mechanisms. NMR also finds applications in drug discovery and development, protein structure determination, and metabolomics.In medical imaging, NMR is employed as a non-invasive tool for obtaining detailed anatomical and functional information about the human body. Magnetic resonanceimaging (MRI) utilizes NMR techniques to create high-resolution images of organs, tissues, and blood vessels. MRI is particularly valuable for diagnosing and monitoring a wide range of medical conditions, including brain disorders, cardiovascular diseases, and musculoskeletal injuries.NMR also has applications in other fields, such as materials science, polymer characterization, and geological studies. It is a versatile technique that provides valuable insights into the structure, dynamics, and properties of various materials and systems.In summary, nuclear magnetic resonance (NMR) is a powerful analytical tool that offers a non-destructive and versatile approach for investigating the properties of atoms and molecules. Its applications span multiple scientific disciplines, including chemistry, physics, biology, and medicine, providing insights into molecular structure, dynamics, and interactions.中文回答：核磁共振（NMR）是一种强大的分析工具，利用磁场和射频波来研究原子和分子的性质。

地球磁场在减弱的证据英文回答：Evidence of Earth's Weakening Magnetic Field.The Earth's magnetic field, also known as the geomagnetic field, is generated by the movement of molten iron in the outer core of the planet. This magnetic field is crucial for protecting the Earth from harmful solar radiation and maintaining a stable climate. However, there is mounting evidence that the Earth's magnetic field is weakening.One piece of evidence is the observation of the South Atlantic Anomaly (SAA). The SAA is an area in the South Atlantic Ocean where the Earth's magnetic field is significantly weaker than in other regions. Satellites passing through this anomaly experience higher levels of radiation, which can affect their electronic systems. This anomaly has been expanding over the past few decades,indicating a weakening of the Earth's magnetic field.Another piece of evidence comes from studies of ancient rocks. Rocks contain tiny magnetic minerals that align with the Earth's magnetic field at the time of their formation. By analyzing these rocks, scientists can determine the strength and direction of the Earth's magnetic field in the past. These studies have revealed that the Earth's magnetic field has been weakening over the past few centuries.Furthermore, researchers have found that the rate of decline in the Earth's magnetic field has been accelerating in recent years. This rapid decline suggests that the weakening of the magnetic field is not a gradual process but rather a more significant and concerning phenomenon. If this trend continues, it could have significantimplications for our planet.The weakening of Earth's magnetic field has several potential consequences. One of the most significant is the increased exposure to solar radiation. The magnetic field acts as a shield, deflecting charged particles from the Sunaway from the Earth. Without a strong magnetic field, more solar radiation would reach the Earth's surface, increasing the risk of skin cancer and other health issues.Additionally, a weakened magnetic field could have implications for navigation systems that rely on magnetic compasses. The accuracy of compasses could be compromised, leading to errors in navigation. This could be particularly problematic for ships and aircraft that heavily rely on magnetic compasses for direction.In conclusion, there is compelling evidence that the Earth's magnetic field is weakening. The South Atlantic Anomaly, studies of ancient rocks, and the accelerating rate of decline all point to this concerning phenomenon. The implications of a weakened magnetic field range from increased exposure to solar radiation to potential navigation issues. It is crucial for scientists to continue monitoring and studying this phenomenon to better understand its implications for our planet.中文回答：地球磁场减弱的证据。

Contents01.02.03.04.05.06.07.08.09.10.11.12.13.14.15.16.17.18.19.20.21.22.23.24.25.26.27.28.29.30.31.32.33.34.35.36.37.38.39.40. THE ELEMENTS AND THE PERIODIC TABLE...................................................... - 3 - THE NONMETAL ELEMENTS .................................................................................. - 5 - GROUPS IB AND IIB ELEMENTS ............................................................................ - 7 - GROUPS IIIB—VIIIB ELEMENTS ............................................................................ - 9 - INTERHALOGEN AND NOBLE GAS COMPOUNDS ........................................... - 11 - THE CLASSIFICATION OF INORGANIC COMPOUNDS .................................... - 13 - THE NOMENCLATURE OF INORGANIC COMPOUNDS.................................... - 15 - BRONSTED'S AND LEWIS' ACID-BASE CONCEPTS.......................................... - 19 - THE COORDINATION COMPLEX.......................................................................... - 22 - ALKANES .................................................................................................................. - 25 - UNSATURATED COMPOUNDS ............................................................................. - 28 - THE NOMENCLATURE OF CYCLIC HYDROCARBONS ................................... - 30 - SUBSTITUTIVE NOMENCLATURE....................................................................... - 33 - THE COMPOUNDS CONTAINING OXYGEN ....................................................... - 37 - PREPARATION OF A CARBOXYLiC ACID BY THE GRIGNARD METHOD .. - 39 - THE STRUCTURES OF COVALENT COMPOUNDS ............................................ - 41 - OXIDATION AND REDUCTION IN ORGANIC CHEMISTRY ............................ - 44 - SYNTHESIS OF ALCOHOLS AND DESIGN OF ORGANIC SYNTHESIS .......... - 47 - ORGANOMETALLICS—METAL π COMPLEXES ................................................ - 49 - THE ROLE OF PROTECTIVE GROUPS IN ORGANIC SYNTHESIS................... - 52 - ELECTROPHILIC REACTIONS OF AROMATIC COMPOUNDS ........................ - 54 - POLYMERS................................................................................................................ - 57 - ANALYTICAL CHEMISTRY AND PROBLEMS IN SOCIETY ............................ - 61 - VOLUMETRIC ANALYSIS ...................................................................................... - 63 - QUALITATIVE ORGANIC ANALYSIS .................................................................. - 65 - VAPOR-PHASE CHROMATOGRAPHY ................................................................. - 67 - INFRARED SPECTROSCOPY.................................................................................. - 70 - NUCLEAR MAGNETIC RESONANCE (I) .............................................................. - 72 - NUCLEAR MAGNETIC RESONANCE(II).............................................................. - 75 - A MAP OF PHYSICAL CHEMISTRY...................................................................... - 77 - THE CHEMICAL THERMODYNAMICS ................................................................ - 79 - CHEMICAL EQUILIBRIUM AND KINETICS ........................................................ - 82 - THE RATES OF CHEMICAL REACTIONS ............................................................ - 85 - NATURE OF THE COLLOIDAL STATE................................................................. - 88 - ELECTROCHEMICAL CELLS ................................................................................. - 90 - BOILING POINTS AND DISTILLATION ............................................................... - 93 - EXTRACTIVE AND AZEOTROPIC DISTILLATION ............................................ - 96 - CRYSTALLIZATION ................................................................................................ - 98 - MATERIAL ACCOUNTING ................................................................................... - 100 - THE LITERATURE MATRIX OF CHEMISTRY................................................... - 102 -01. THE ELEMENTS AND THE PERIODIC TABLEThe number of protons in the nucleus of an atom is referred to as the atomic number, or proton number, Z. The number of electrons in an electrically neutral atom is also equal to the atomic number, Z. The total mass of an atom is determined very nearly by the total number of protons and neutrons in its nucleus. This total is called the mass number, A. The number of neutrons in an atom, the neutron number, is given by the quantity A-Z.The term element refers to, a pure substance with atoms all of a single kind. To the chemist the "kind" of atom is specified by its atomic number, since this is the property that determines its chemical behavior. At present all the atoms from Z = 1 to Z = 107 are known; there are 107 chemical elements. Each chemical element has been given a name and a distinctive symbol. For most elements the symbol is simply the abbreviated form of the English name consisting of one or two letters, for example:oxygen==O nitrogen == N neon==Ne magnesium == MgA complete listing of the elements may be found in Table 1.Beginning in the late seventeenth century with the work of Robert Boyle, who proposed the presently accepted concept of an element, numerous investigations produced a considerable knowledge of the properties of elements and their compounds1. In 1869, D.Mendeleev and L. Meyer, working independently, proposed the periodic law. In modern form, the law states that the properties of the elements are periodic functions of their atomic numbers. In other words, when the elements are listed in order of increasing atomic number, elements having closely similar properties will fall at definite intervals along the list. Thus it is possible to arrange the list of elements in tabular form with elements having similar properties placed in vertical columns2. Such an arrangement is called a periodic Each horizontal row of elements constitutes a period. It should be noted that the lengths of the periods vary. There is a very short period containing only 2 elements, followed by two short periods of 8 elements each, and then two long periods of 18 elements each. The next period includes 32 elements, and the last period is apparently incomplete. With this arrangement, elements in the same vertical column have similar characteristics. These columns constitute the chemical families or groups. The groups headed by the members of the two 8-element periods are designated as main group elements, and the members of the other groups are called transition or inner transition elements.In the periodic table, a heavy stepped line divides the elements into metals and nonmetals. Elements to the left of this line (with the exception of hydrogen) are metals, while those to the right are nonmetals. This division is for convenience only; elements bordering the line—the metalloids-have properties characteristic of - both metals and nonmetals. It may be seen that most of the elements, including all the transition and inner transition elements, are metals.Except for hydrogen, a gas, the elements of group IA make up the alkali metal family. They are very reactive metals, and they are never found in the elemental state in nature. However, their compounds are widespread. All the members of the alkali metal family, form ions having a charge of 1+ only. In contrast, the elements of group IB —copper, silver, and gold—are comparatively inert. They are similar to the alkali metals in that they exist as 1+ ions in many of their compounds. However, as is characteristic of most transition elements, they form ions having other charges as well.The elements of group IIA are known as the alkaline earth metals. Their characteristic ionic charge is 2+. These metals, particularly the last two members of the group, are almost as reactive as the alkali metals. The group IIB elements—zinc, cadmium, and mercury are less reactive than are those of group II A5, but are more reactive than the neighboring elements of group IB. The characteristic charge on their ions is also 2+.With the exception of boron, group IIIA elements are also fairly reactive metals. Aluminum appears to be inert toward reaction with air, but this behavior stems from the fact that the metal forms a thin, invisible film of aluminum oxide on the surface, which protects the bulk of the metal from further oxidation. The metals of group IIIA form ions of 3+ charge. Group IIIB consists of the metals scandium, yttrium, lanthanum, and actinium.Group IVA consists of a nonmetal, carbon, two metalloids, silicon and germanium, and two metals, tin and lead. Each of these elements forms some compounds with formulas which indicate that four other atoms are present per group IVA atom, as, for example, carbon tetrachloride, GCl4. The group IVB metals —titanium, zirconium, and hafnium —also forms compounds in which each group IVB atom is combined with four other atoms; these compounds are nonelectrolytes when pure.The elements of group V A include three nonmetals —nitrogen, phosphorus, and arsenic—and two metals —antimony and bismuth. Although compounds with the formulas N2O5, PCl5, and AsCl5exist, none of them is ionic. These elements do form compounds-nitrides, phosphides, and arsenides — in which ions having charges of minus three occur. The elements of group VB are all metals. These elements form such a variety of different compounds that their characteristics are not easily generalized.The elements of groups ⅥB, ⅦB, and VIIIB are all metals. They form such a wide Variety of compounds that it is not practical at this point to present any examples as being typical of the behavior of the respective groups.The periodicity of chemical behavior is illustrated by the fact that. excluding the first period, each period begins with a very reactive metal. Successive element along the period show decreasing metallic character, eventually becoming nonmetals, and finally, in group ⅦA, a very reactive nonmetal is found. Each period ends with a member of the noble gas family.02. THE NONMETAL ELEMENTSWe noted earlier. that -nonmetals exhibit properties that are greatly different from those of the metals. As a rule, the nonmetals are poor conductors of electricity (graphitic carbon is an exception) and heat; they are brittle, are often intensely colored, and show an unusually wide range of melting and boiling points. Their molecular structures, usually involving ordinary covalent bonds, vary from the simple diatomic molecules of H2, Cl2, I2, and N2 to the giant molecules of diamond, silicon and boron.The nonmetals that are gases at room temperature are the low-molecular weight diatomic molecules and the noble gases that exert very small intermolecular forces. As the molecular weight increases, we encounter a liquid (Br2) and a solid (I2) whose vapor pressures also indicate small intermolecular forces. Certain properties of a few nonmetals are listed in Table 2.Table 2- Molecular Weights and Melting Points of Certain NonmetalsSimple diatomic molecules are not formed by the heavier members of Groups V and VI at ordinary conditions. This is in direct contrast to the first members of these groups, N2 and O2. The difference arises because of the lower stability of π bonds formed from p orbitals of the third and higher main energy levels as opposed to the second main energy level2. The larger atomic radii and more dense electron clouds of elements of the third period and higher do not allow good parallel overlap of p orbitals necessary for a strong π bond. This is a general phenomenon —strong π bonds are formed only between elements of the second period. Thus, elemental nitrogen and oxygen form stable molecules with both σ and π bonds, but other members of their groups form more stable structures based on σ bonds only at ordinary conditions. Note3 that Group VII elements form diatomic molecules, but π bonds are not required for saturation of valence.Sulfur exhibits allotropic forms. Solid sulfur exists in two crystalline forms and in an amorphous form. Rhombic sulfur is obtained by crystallization from a suitable solution, such as CS2, and it melts at 112°C. Monoclinic sulfur is formed by cooling melted sulfur and it melts at 119°C. Both forms of crystalline sulfur melt into S-gamma, which is composed of S8 molecules. The S8 molecules are puckered rings and survive heating to about 160°C. Above 160°C, the S8 rings break open, and some of these fragments combine with each other to form a highly viscous mixture of irregularly shaped coils. At a range of higher temperatures the liquid sulfur becomes so viscous that it will not pourfrom its container. The color also changes from straw yellow at sulfur's melting point to a deep reddish-brown as it becomes more viscous.As4 the boiling point of 444 °C is approached, the large-coiled molecules of sulfur are partially degraded and the liquid sulfur decreases in viscosity. If the hot liquid sulfur is quenched by pouring it into cold water, the amorphous form of sulfur is produced. The structure of amorphous sulfur consists of large-coiled helices with eight sulfur atoms to each turn of the helix; the overall nature of amorphous sulfur is described as3 rubbery because it stretches much like ordinary rubber. In a few hours the amorphous sulfur reverts to small rhombic crystals and its rubbery property disappears.Sulfur, an important raw material in industrial chemistry, occurs as the free element, as SO2 in volcanic regions, asH2S in mineral waters, and in a variety of sulfide ores such as iron pyrite FeS2, zinc blende ZnS, galena PbS and such, and in common formations of gypsum CaSO4• 2H2O, anhydrite CaSO4, and barytes BaSO4• 2H2O. Sulfur, in one form or another, is used in large quantities for making sulfuric acid, fertilizers, insecticides, and paper.Sulfur in the form of SO2 obtained in the roasting of sulfide ores is recovered and converted to sulfuric acid, although in previous years much of this SO2 was discarded through exceptionally tall smokestacks. Fortunately, it is now economically favorable to recover these gases, thus greatly reducing this type of atmospheric pollution. A typical roasting reaction involves the change:2 ZnS +3 O2—2 ZnO + 2 SO2Phosphorus, below 800℃ consists of tetratomic molecules, P4. Its molecular structure provides for a covalence of three, as may be expected from the three unpaired p electrons in its atomic structure, and each atom is attached to three others6. Instead of a strictly orthogonal orientation, with the three bonds 90° to each other, the bond angles are only 60°. This supposedly strained structure is stabilized by the mutual interaction of the four atoms (each atom is bonded to the other three), but it is chemically the most active form of phosphorus. This form of phosphorus, the white modification, is spontaneously combustible in air. When heated to 260°C it changes to red phosphorus, whose structure is obscure. Red phosphorus is stable in air but, like all forms of phosphorus, it should be handled carefully because of its tendency to migrate to the bones when ingested, resulting in serious physiological damage.Elemental carbon exists in one of two crystalline structures — diamond and graphite. The diamond structure, based on tetrahedral bonding of hybridized sp3orbitals, is encountered among Group IV elements. We may expect that as the bond length increases, the hardness of the diamond-type crystal decreases. Although the tetrahedral structure persists among the elements in this group — carbon, silicon, germanium, and gray tin — the interatomic distances increase from 1.54 A for carbon to 2.80 A for gray tin. Consequently .the bond strengths among the four elements range from very strong to quite weak. In fact, gray tin is so soft that it exists in the form of microcrystals or merely as a powder. Typical of the Group IV diamond-type crystalline elements, it is a nonconductor and shows other nonmetallic properties7.03. GROUPS IB AND IIB ELEMENTSPhysical properties of Group IB and IIBThese elements have a greater bulk use as metals than in compounds, and their physical properties vary widely. Gold is the most malleable and ductile of the metals. It can be hammered into sheets of 0.00001 inch in thickness; one gram of the metal can be drawn into a wire 1.8 mi in length1. Copper and silver are also metals that are mechanically easy to work. Zinc is a little brittle at ordinary temperatures, but may be rolled into sheets at between 120° to 150℃; it becomes brittle again about 200℃-The low-melting temperatures of zinc contribute to the preparation of zinc-coated iron .galvanized iron; clean iron sheet may be dipped into vats of liquid zinc in its preparation. A different procedure is to sprinkle or air blast zinc dust onto hot iron sheeting for a zinc melt and then coating.Cadmium has specific uses because of its low-melting temperature in a number of alloys. Cadmium rods are used in nuclear reactors because the metal is a good neutron absorber.Mercury vapor and its salts are poisonous, though the free metal may be taken internally under certain conditions. Because of its relatively low boiling point and hence volatile nature, free mercury should never be allowed to stand in an open container in the laboratory. Evidence shows that inhalation of its vapors is injurious.The metal alloys readily with most of the metals (except iron and platinum) to form amalgams, the name given to any alloy of mercury.Copper sulfate, or blue vitriol (CuSO4• 5H2O) is the most important and widely used salt of copper. On heating, the salt slowly loses water to form first the trihydrate (CuSO4• 3H z O), then the monohydrate (CuSO4• H2O), and finally the white anhydrous salt. The anhydrous salt is often used to test for the presence of water in organic liquids. For example, some of the anhydrous copper salt added to alcohol (which contains water) will turn blue because of the hydration of the salt.Copper sulfate is used in electroplating. Fishermen dip their nets in copper sulfate solution to inhibit the growth of organisms that would rot the fabric. Paints specifically formulated for use on the bottoms of marine craft contain copper compounds to inhibit the growth of barnacles and other organisms.When dilute ammonium hydroxide is added" to a solution of copper (I) ions, a greenish precipitate of Cu(OH)2 or a basic copper(I) salt is formed. This dissolves as more ammonium hydroxide is added. The excess ammonia forms an ammoniated complex with the copper (I) ion of the composition, Cu(NH3)42+. This ion is only slightly dissociated; hence in an ammoniacal solution very few copper (I) ions are present. Insoluble copper compounds, execpt copper sulfide, are dissolved by ammonium hydroxids. The formation of the copper (I) ammonia ion is often used as a test for Cu2+ because of its deep, intense blue color.Copper (I) ferrocyanide [Cu2Fe(CN)6] is obtained as a reddish-brown precipitate on the addition of a soluble ferrocyanide to a solution of copper ( I )ions. The formation of this salt is also used as a test for the presence of copper (I)ions.3Ag + 4HNO3—3AgNO3 + NO + 2H2OThe salt is the starting material for most of the compounds of silver, including the halides used in photography. It is readily reduced by organic reducing agents, with the formation of a black deposit of finely divided silver; this action is responsible for black spots left on the fingers from the handling of the salt. Indelible marking inks and pencils take advantage of this property of silver nitrate.The halides of silver, except the fluoride, are very insoluble compounds and may be precipitated by the addition of a solution of silver salt to a solution containing chloride, bromide, or iodide ions.The addition of a strong base to a solution of a silver salt precipitates brown silver oxide (Ag2G). One might expect the hydroxide of silver to precipitate, but it seems likely that silver hydroxide is very unstable and breaks down into the oxide and water — if, indeed, it is ever formed at all3. However, since a solution of silver oxide js definitely basic, there must be hydroxide ions present in solution.Ag2O + H2O = 2Ag+ + 2OH-Because of its inactivity, gold forms relatively few compounds. Two series of compounds are known — monovalent and trivalent. Monovalent (aurous) compounds resemble silver compounds (aurous chloride is water insoluble and light sensitive), while the higher valence (auric) compounds tend to form complexes. Gold is resistant to the action of most chemicals —air, oxygen, and water have no effect. The common acids do not attack the metal, but a mixture of hydrochloric and nitric acids (aqua regia) dissolves it to form gold( I ) chloride or chloroauric acid. The action is probably due to free chlorine present in the aqua regia.3HCl + HNO3----→ NOCl+Cl2 + 2H2O2Au + 3Cl2 ----→ 2AuCl3AuCl3+HCl----→ HAuCl4chloroauric acid (HAuCl4-H2O crystallizes from solution).Zinc is fairly high in the activity series. It reacts readily with acids to produce hydrogen and displaces less active metals from their salts. 1 he action of acids on impure zinc is much more rapid than on pure zinc, since bubbles of hydrogen gas collect on the surface of pure zinc and slow down the action. If another metal is present as an impurity, the hydrogen is liberated from the surface of the contaminating metal rather than from the zinc. An electric couple to facilitate the action is probably Set up between the two metals.Zn + 2H+----→ Zn2+ + H2Zinc oxide (ZnO), the most widely used zinc compound, is a white powder at ordinary temperatures, but changes to yellow on heating. When cooled, it again becomes white. Zinc oxide is obtained by burning zinc in air, by heating the basic carbonate, or by roasting the sulfide. The principal use of ZnO is as a filler in rubber manufacture, particularly in automobile tires. As a body for paints it has the advantage over white lead of not darkening on exposure to an atmosphere containing hydrogen sulfide. Its covering power, however, is inferior to that of white lead.04. GROUPS IIIB—VIIIB ELEMENTSThe predominant group oxidation number of the lanthanide series is +3, but some of the elements exhibit variable oxidation states. Cerium forms cerium( III )and cerium ( IV ) sulfates, Ce2 (SO4 )3 and Ce(SO4 )2, which are employed in certain oxidation-reduction titrations. Many rare earth compounds are colored and are paramagnetic, presumably as a result of unpaired electrons in the 4f orbitals.All actinide elements have unstable nuclei and exhibit radioactivity. Those with higher atomic numbers have been obtained only in trace amounts. Actinium (89 Ac), like lanthanum, is a regular Group IIIB element.Group IVB ElementsIn chemical properties these elements resemble silicon, but they become increasingly more metallic from titanium to hafnium. The predominant oxidation state is +4 and, as with silica (SiO2), the oxides of these elements occur naturally in small amounts. The formulas and mineral names of the oxides are TiO2, rutile; ZrO2, zirconia; HfO2, hafnia. Titanium is more abundant than is usually realized. It comprises about 0.44% of the earth's crust. It is over 5.0% in average composition of first analyzed moon rock. Zirconium and titanium oxides occur in small percentages in beach sands.Titanium and zirconium metals are prepared by heating their chlorides with magnesium metal. Both are particularly resistant to corrosion and have high melting points.Pure TiO2 is a very white substance which is taking the place of white lead in many paints. Three-fourths of the TiO2 is used in white paints, varnishes, and lacquers. It has the highest index of refraction (2.76) and the greatest hiding power of all the common white paint materials. TiO2 also is used in the paper, rubber, linoleum, leather, and textile industries.Group VB Elements: Vanadium, Niobium, and TantalumThese are transition elements of Group VB, with a predominant oxidation number of + 5. Their occurrence iscomparatively rare.These metals combine directly with oxygen, chlorine, and nitrogen to form oxides, chlorides, and nitrides, respectively. A small percentage of vanadium alloyed with steel gives a high tensile strength product which is very tough and resistant to shock and vibration. For this reason vanadium alloy steels are used in the manufacture ofhigh-speed tools and heavy machinery. Vanadium oxide is employed as a catalyst in the contact process of manufacturing sulfuric acid. Niobium is a very rare element, with limited use as an alloying element in stainless steel. Tantalum has a very high melting point (2850 C) and is resistant to corrosion by most acids and alkalies.Groups VIB and VIIB ElementsChromium, molybdenum, and tungsten are Group VIB elements. Manganese is the only chemically important element of Group VIIB. All these elements exhibit several oxidation states, acting as metallic elements in lower oxidation states and as nonmetallic elements in higher oxidation states. Both chromium and manganese are widely used in alloys, particularly in alloy steels.Group VIIIB MetalsGroup VIIIB contains the three triads of elements. These triads appear at the middle of long periods of elements in the periodic table, and are members of the transition series. The elements of any given horizontal triad have many similar properties, but there are marked differences between the properties of the triads, particularly between the first triad and the other two. Iron, cobalt, and nickel are much more active than members of the other two triads, and are also much more abundant in the earth's crust. Metals of the second and third triads, with many common properties, are usually grouped together and called the platinum metals.These elements all exhibit variable oxidation states and form numerous coordination compounds.CorrosionIron exposed to the action of moist air rusts rapidly, with the formation of a loose, crumbly deposit of the oxide. The oxide does not adhere to the surface of the metal, as does aluminum oxide and certain other metal oxides, but peelsCorrosion of iron is inhibited by coating it with numerous substances, such as paint, an aluminum powder gilt, tin, or organic tarry substances or by galvanizing iron with zinc. Alloying iron with metals such as nickel or chromium yields a less corrosive steel. "Cathodic protection" of iron for lessened corrosion is also practiced. For some pipelines and standpipes zinc or magnesium rods in the ground with a wire connecting them to an iron object have the following effect: with soil moisture acting as an electrolyte for a Fe — Zn couple the Fe is lessened in its tendency to become Fe2+. It acts as a cathode rather than an anode.2 205. INTERHALOGEN AND NOBLE GAS COMPOUNDSInterhalogen and noble gas compounds comprise a relatively limited family of highly reactive and unstable molecules whose primary importance is their role in testing chemical bonding theory 1. At first it may seem rather strange to treat the chemistry of the halogens and the noble gases, two groups that represent the extremes of chemical activity and inertia, in the same section. The superficial differences between the halogens and the noble gases are much reduced, however, if we focus our attention on the comparison of halide ions (particularly F -) with the isoelectronic noble gas atoms and the noble gas compounds with halogen atoms or the halogens in their higher positive-oxidation states. Noble gases are exceptional in their reluctance to either gain or lose an electron. Halide ions — because of their excess negative charge, relative to the isoelectronic noble gas atoms — have both a lower ionization energy and a lesser electron affinity. On the other hand, noble gas cations have greater electron affinities and greater ionization energies than do isoelectronic halogen atoms. From such considerations, it is obvious that inert gases should be less reactive than are halide ions, but their compounds should show even higher reactivity than the halogens. The big question remaining is : Are there any chemically significant conditions under which noble gases can be persuaded to yield electrons sufficiently to produce stable compounds? The answer is definitely , yes! (The same question can be asked of halogen atoms, which have ionization energies comparable to those of the inert gases.)Another obvious point of similarity between halogen and noble gas compounds is the characteristically large number of electrons that must be accommodated in the valence shell. For a noble gas atom bonded to any number of other atoms, the octet rule must be exceeded; for a halogen atom to be bonded to more than one other atom, the same must be true. It is a curious historical fact that the mythical inertia of a closed shell did much to diminish the energy expended in the search for noble gas compounds, long after numerous examples of superoctet valence shells were known, particularly among interhalogen compounds.We may roughly classify the interhalogen compounds into two categories: those in oxidation state zero (the binary analogs of the elementary diatomics 2) and those in which one of the halogens is in a formally positive oxidation state. Heterodiatomic halogens are generally formed readily on mixing the required pair of halogens in a 1:1 ratio. The bond energies are always higher in the heteropolar molecules than are the average bond energies of the two constituents and in some cases higher than either. It is this factor that drives the reactions. All heterodiatomics 2 are more or less stable under ambient conditions except for BrF, which spontaneously disproportionates to BrF 3 and Br 2. The bonding in the halogen diatomics can be attributed to a single a bond, formed by overlap of p orbitals. In the heterodiatomics, the principal new features are the poorer orbital overlaps that are possible between atoms of widely different principal quantum number (n ), the polarity arising from the difference in electronegativity, the contribution of ionic terms to increase bond energy, and the relief in interelectronic repulsion in the fluorides. relative to difluorine.Dihalogens (except for F 2) usually react by dissociation into atoms or by heterolytic dissociation under the influenceof an attacking reagent. Thus, reaction of Cl with hydroxide may be viewed as displacement of Cl - from Cl by OH -: Cl 2+OH - -----→HOCl + Cl -The tendency to undergo heterolytic fission increases on descending the group, and the I 2 molecule can actually be cleaved to two stable species:I 2 + 2C 5H 5N+AgNO 3-----→ [C 5H 5N)2I]NO 3 + AgI。