ORIGINAL PAPER
Natural 15N abundance of paddy rice (Oryza sativa L.)grown with synthetic fertilizer,livestock manure compost,and hairy vetch
Soek-In Yun &Sang-Sun Lim &Gwang-Sung Lee &Sang-Mo Lee &Han-Yong Kim &Hee-Myong Ro &Woo-Jung Choi
Received:8February 2011/Revised:17March 2011/Accepted:30March 2011/Published online:12April 2011#Springer-Verlag 2011
Abstract Nitrogen isotope abundance (δ15N)of paddy rice (Oryza sativa L.)grown for 110days after transplanting (DAT)under field conditions with ammonium sulfate (AS with ?0.4‰as a synthetic fertilizer),pig manure compost (PMC with 15.3‰as a livestock manure compost),and hairy vetch (HV with ?0.5‰as a green manure)was investigated to test the possible use of δ15N technique in discriminating organically grown from conventionally grown rice.At 15DAT,the δ15N of whole rice decreased (P <0.05)in the order of 10.5‰for PMC >5.5‰for control (without N input)>4.0‰for HV >1.8‰for AS.This difference seemed to reflect primarily the δ15N signal of N sources.Although differences in δ15N of rice grown with isotopically distinct N inputs (i.e.PMC vs.AS and PMC vs.HV)became smaller over time,the difference (2.8
and 3.0‰difference at harvest on 110DAT,respectively)was still significant (P <0.05).However,there was no distinguishable difference between AS and HV treatment after 42DAT.Such effect of N inputs on δ15N of whole rice was also observed for root,shoot,and grain at harvest.Therefore,our study suggests that it is possible to distinguish rice grown with manure composts from that grown with synthetic fertilizers.However,if green manure of preceding N 2-fixing plants is used as the N source,δ15N of rice may not be a good surrogate of N sources.Keywords δ15N technique .Green manure .N sources .Organic produce certification .Temperate rice
Introduction
As organic farming practices without the use of synthetic fertilizers and pesticides produce safer food with mini-mum environmental impacts,market and social forces have created price premiums on organic produce (Mann 2003).To be labeled as organic products,the absence of synthetic pesticide and fertilizer use needs to be certified by qualified inspecting authorities (Codex Committee on Food Labelling 2001).The use of synthetic pesticides can be detected by pesticide residue analysis on soil and agricultural products.However,discriminating organic foods grown with non-synthetic fertilizers from those conventionally grown with synthetic fertilizers is not straightforward (Choi et al.2002).Food companies are putting more efforts to strength-en reliability of their organic produce certification by adopting extra inspection systems that are not regulated by relevant laws (in the case of Korea,the Agricultural Products Quality Management Act).
S.-I.Yun :H.-Y .Kim
Department of Applied Plant Science,Chonnam National University,
Gwangju 500–757,Republic of Korea
S.-S.Lim :G.-S.Lee :W.-J.Choi (*)
Department of Rural and Biosystems Engineering,Chonnam National University,
Gwangju 500–757,Republic of Korea e-mail:wjchoi@chonnam.ac.kr
S.-M.Lee
National Instrumentation Center for Environmental Management,Seoul National University,
Seoul 151–921,Republic of Korea
H.-M.Ro (*)
Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences,Seoul National University,Seoul 151–921,Republic of Korea e-mail:hmro@snu.ac.kr
Biol Fertil Soils (2011)47:607–617DOI 10.1007/s00374-011-0571-3
One of the extra inspection systems potentially adoptable is using natural15N abundance(15N/14N,expressed as δ15N)of plant tissues to identify the use of synthetic fertilizers(Ro and Choi2010).Choi et al.(2002)proposed the possible use of theδ15N technique in the certification of organic products by showing a higherδ15N of maize(Zea mays L.)grown with organic input(composted pig manure) than with synthetic fertilizer(urea).This technique is based on the fact that theδ15N of synthetic fertilizers manufac-tured from atmospheric N2using the Haber–Bosch process (<2.0‰)is usually lower than that of organic sources of N fertilizers(>5.0‰; e.g.,manure/manure-based composts, seaweed-based materials,non-manure wastes of livestock, and fish-based materials)that are permitted in organic farming(Bateman et al.2005;Bateman and Kelly2007; Choi et al.2003a;Choi et al.2006;Rogers2008;Schmidt et al.2005).
Previous reports have shown that the application of organic fertilizers results in a higherδ15N of crop than synthetic fertilizers application(Bateman et al.2005;Choi et al.2003a;Choi et al.2006;Rogers2008;Schmidt et al. 2005).Theδ15N of crops ranged from0‰to5‰for synthetic fertilizers and3‰to15‰for organic fertilizers. However,discriminating organic crops against conventional crops using a criticalδ15N range is not yet a straightforward task because there is sometimes an overlap inδ15N values between organic and conventional crops.To improve the feasibility of theδ15N technique for identifying organic vs. conventional crops,a cropδ15N database encompassing a variety of crop species,N inputs,and soil types needs to be constructed(Bateman et al.2007;Yun et al.2006).In this context,δ15N of paddy rice(Oryza sativa L.)grown with synthetic fertilizer and organic inputs should be added to the current cropδ15N databases because rice is a staple food for more than half of the world’s population,particularly in many Asian countries,where the organic rice market is increasing(Coats2003).However,to date,most studies have been conducted on vegetables such as Chinese cabbage,lettuce,tomato,and carrot(Bateman et al.2005; Lim et al.2007;Nakano et al.2003;Rogers2008;Schmidt et al.2005;?turm et al.2011;Yun et al.2006)and upland grain crops such as maize,canola,barley,and wheat(Choi et al.2002,2006).
Another gap in our current knowledge is the kind of organic N input used.Although various kinds of organic N sources are permitted in organic farming,most studies have been conducted with livestock manure including pig manure compost(Choi et al.2002,2003a;Yun et al. 2006),liquid pig manure(Lim et al.2007),solid pig manure(Choi et al.2006),chicken manure(Bateman et al. 2005),and cattle manure(Choi et al.2006),which has distinctly higherδ15N than synthetic fertilizers.Green manure plants that fix atmospheric N2have served as a traditional N source for summer crops including paddy rice (Asagi and Ueno2009;Ashraf et al.2004).Due to the N2-fixing ability of green manure plants,we cannot eliminate the possibility of similarδ15N signals to synthetic fertilizer, which may produce indistinguishableδ15N signals between crops receiving green manure and synthetic fertilizer. Despite widespread organic crop rotation with green manure as a winter crop,there is little attention given to δ15N of crops including rice grown with green manure.
Ideally,to test N isotopic response of rice to N inputs with variousδ15N,a long-term experiment employing different fertilization treatments needs to be conducted as various organic inputs are applied a couple of times in a single cropping season and return of plant residues including straw may influenceδ15N of rice in the next cropping season(Choi et al.2006).However,for such a large-scale experiment,a preliminary study to obtain fundamental information on the variations inδ15N of rice as affected by N inputs with variousδ15N may be helpful. Therefore,this study was conducted to test if the applica-tion of isotopically different N sources(i.e.,synthetic fertilizer https://www.doczj.com/doc/af7409341.html,posted manure)results in distinguishable δ15N of paddy rice and to investigate if paddy rice grown with isotopically similar N sources(i.e.,synthetic fertilizer vs.green manure)will show analogousδ15N in a single cropping season.
Materials and methods
Nitrogen inputs
In this study,three kinds of N inputs were used,which were ammonium sulfate(AS)as synthetic fertilizer,pig manure compost(PMC)as livestock manure compost, and hairy vetch(HV)as green manure.Ammonium sulfate was purchased from a fertilizer manufacturing company(Namhae Chemical Ltd.,Yeosu,Korea),and compost was obtained from the experimental livestock farming station at Chonnam National University.Before the initiation of the experiment,seeds of hairy vetch (Vicia villosa Roth.)were sown at the plots allocated for HV treatment(see the Experimental settings for details)at the recommended rate(10gm?2).Five months later,hairy vetch(including roots)was harvested,weighed,and stored at4°C until field application.The compost had aδ15N value of15.3‰which was significantly(P<0.05)higher than those of AS(?0.4‰)and HV(?0.5‰;Table1). Experimental settings
The experiment was conducted in the experimental rice paddy at Chonnam National University(126°53′E,35°10′N),
Gwangju,Republic of Korea.The climate is temperate with an annual mean temperature of 13.7°C over the past 30years.Annual mean precipitation was approxi-mately 1,520mm,with over 60%of the annual precipitation occurring during the monsoon rainy season (June to August).The soil of the paddy field was classified as fine loamy,mesic family of Typic Hapludults in the USDA Soil Taxonomy.The δ15N of soil was 6.4±0.6‰for total N,4.1±1.6‰for NH 4+,and 5.3±0.4‰for NO 3-(Table 2).
Four treatments were laid out in a randomized complete block design with four replicates:control without N inputs (code:control),synthetic fertilizer with AS,livestock manure compost with PMC,and green manure with HV .In each block (4×15m),plots were located 2m apart,and each plot (1.5×1.5m)was confined by inserting flexible plastic barriers (40cm in height)into the plow pan layer of
the soil (around 20cm in depth)to minimize cross-contamination.Seven days before rice transplanting,N inputs,together with fused phosphate of which chemical composition is P 2O 519%,SiO 227%,CaO 30%,and MgO 12%(4.5g P 2O 5m ?2)and KCl (5.7g K 2O m ?2),were mixed thoroughly with the soil surface layer (0～20cm).The total amount of N applied was 11g m ?2(the recommend rate for rice cultivation)for AS,22g m ?2for PMC,and 9.3g m ?2for HV treatments.For PMC,N was doubled to compensate the low N availability of livestock manure compost (Lim et al.2010),and the lower HV application was due to low dry matter production of the green manure.
The total amounts of PMC and HV were applied as basal fertilization,but AS was applied in three dressings (5.5g m ?2at transplanting,3.3gm ?2at tillering stage on 16days after transplanting (DAT)and 2.2g m ?2at panicle initiation stage on 43DAT following the conventional fertilization practices.Rice cultivation and sampling
Three 30-day-old rice seedlings (O.sativa L.subsp.Japonica)were transplanted into each plot with a hill spacing of 15cm and a row spacing of 30cm (a total of 50hills per plot).The same rice seedlings were transplanted in the remaining spaces of the field to create canopy conditions.The plots were kept waterlogged (water depth,3cm)throughout the growing season except for a 7-day summer drainage period in the middle of July.
Rice samples (both above-and below-ground)were collected on 15(the day before second fertilization),42(the day before third fertilization),72,and 110DAT (at maturity)from three randomly selected hills.Above-ground plants were collected,and the soils (a cylindrical shape with 5cm in hill direction×15cm in row direction×20cm in depth with the hill as a center)were excavated intact with a shovel.Rhizosphere soils were separated from the excavated soils –roots mixture as much as possible by
Table 2Properties of the soil used for the experiment Variables a
Values Texture Loam pH water
5.84(0.1)Total N (g kg ?1)0.92(0.02)NH 4+(mg N kg ?1)9.1(2.1)NO 3-(mg N kg ?1)7.2(0.7)Total C (g kg ?1)
9.4(0.2)Available P (mg P 2O 5kg ?1)32.5(3.7)δ15N of N (‰)
Total N 6.4(0.6)NH 4+ 4.1(1.6)NO 3-
5.3(0.4)
Values are the means of triplicate measurements with standard errors in parentheses
a
Texture as USDA classification after particle size separation with pipette method;pH water with a pH meter at a 1:5(soil-to-water)ratio;total N and C using a combustion method;NH 4+and NO 3-with Kjeldhal distillation method after extracting with 2M KCl at 1:5(soil-to-extractant)ratio;available P with Bray #1method.Method of δ15N analysis is described in the text
Table 1Nitrogen concentration and corresponding δ15N of ammonium sulfate,pig manure compost,and hair vetch used as N sources N sources
Total N
2M KCl extractable mineral N Concentration (g N kg ?1)
δ15N (‰)
Concentration (mg N kg ?1)δ15N (‰)NH 4+
NO 3-NH 4+NO 3-
Ammonium sulfate (AS)211.9(0.1)b ?0.4(0.1)a NA
NA
NA
NA
Pig manure compost (PMC)23.1(1.2)a 15.3(0.2)b 327.2(13.5)125.4(7.9)12.5(1.3)22.6(0.1)Hairy vetch (HV)
29.4(0.3)a
?0.5(0.1)a
NA
NA
NA
NA
Values are the means of triplicate measurements with standard errors in parentheses
Values in the same column followed by different lowercase letters are significantly different at α=0.05NA not applicable
hands,and all the broken roots found during the separation were placed in plastic bags.The separated soils were mixed homogenously with hands,and around100g of the rhizosphere soils was used for chemical analysis,and the remaining was backfilled to each sampling pit.The roots including those in the plastic bags were covered with a net, and all visible root tissue was collected by washing soil particles out with tap water.
Plant samples collected on15,42,and72DAT were treated as single samples(i.e.,not separated into each plant part),and those on110DAT were separated into grain(i.e., panicle),shoot(including green and dead leaves,leaf sheath and culm,and rootstocks)and root.Half of the grain was polished by hand removal of hull followed by milling.All the plant samples were oven-dried at60°C to a constant weight.After dry weight measurement,plant samples were ground to coarse particles.
Chemical analyses and calculation
For the determination of total N concentration andδ15N, each sample(soil,PMC,AS,and HV)was dried in different manners considering their NH4+concentration that is susceptible to volatilization.Soil samples with a relatively low NH4+concentration(9.1mg N kg?1,see Table2)were air-dried;PMC samples which have an NH4+concentration as high as327.2mg N kg?1(see Table1)were freeze-dried(to minimize N loss during drying),and AS and HV samples oven-dried at65°C to facilitate water removal.All the samples were ground to a fine powder with a ball mill(MM200,Retsch GmbH, Haan,Germany)and analyzed for concentration and the correspondingδ15N using a continuous-flow stable iso-tope ratio mass spectrometer(CF-IRMS)linked to an elemental analyzer(IsoPrime-EA,Micromass,UK).
Mineral N(NH4+and NO3-)concentrations of compost and soil samples were analyzed with the steam distillation method after extraction with2M KCl at1:10(w/v)ratio (Hauck1982;Keeney and Nelson1982).The N content in the distillates was potentiometrically determined by titration with0.01mol L?1NaOH.After titration,the solution containing NH4+was adjusted to pH3using0.05mol L?1 H2SO4and evaporated to dryness at65°C in an oven and analyzed forδ15N using the CF-IRMS.Nitrogen isotope compositions were calculated as
(‰)sample
= [(R/R standard)-1] 1000
where R sample and R standard are the ratio of15N/14N for sample and standard(atmospheric N2),respectively.The reproducibility(n=10)of the analytical procedure was checked with IAEA-N2(ammonium sulfate,20.3‰)for NH4+and an internal reference material(6.8‰for soil,13.5‰for compost,and4.8‰for plant samples)for total N as reference materials following the above-mentioned procedures,and it was better than0.1‰.
For the sample collected at harvest(the final sampling), the integratedδ15N values of the whole rice plant consisting of root,shoot,and grain were calculated using the following isotope mass balance equations(Karamanos and Rennie1981):
d15N whole?d15N root N roottd15N shoot N shoottd15N grain N grain
àá
=N whole
where N root,N shoot,N grain,and N whole are the N content of root,shoot,unpolished grain,and whole rice plant, respectively,andδ15N root,δ15N shoot,δ15N grain,andδ15N whole are their correspondingδ15N,respectively.
Statistical analysis
All the statistical analyses were performed with PASW Statistics18package(SPSS Inc.,Chicago,IL,USA). For statistical analysis,data were tested for homogeneity of variance and normality of distribution.Dry matter data were normally distributed(P>0.05)but N uptake at 72and110DAT,andδ15N of rice at42DAT were not. These data were log-transformed to achieve normal distribution and homogeneity of variance,and back-transformed means with95%confidence limit are reported.Analysis of variance was performed to examine the effects of N inputs using the general linear model. When the treatment effects were significant,the means were separated by the Tukey's honestly significant differ-ence test.The significance level was set atα=0.05for the mean separation.
Results
Dry matter and N uptake of rice
In all the treatments,the dry matter(DM)of rice increased linearly(r2>0.98and P<0.01,regression equation of DM with DAT was not shown)with elapse of days after transplanting(Table3).Comparing among the treatments, application of AS and HV resulted in a greater DM production than the control with varying statistical signif-icance depending on sampling time(Table3),meanwhile the effect of PMC application on increasing DM production over the control was not significant atα=0.05.Overall,AS application produced the greatest DM,followed by HV and PMC applications(except at15DAT).At the final sampling time point(110DAT),the DM of rice was in the order of AS(2,382.2g m?2)>HV(1,744.0g m?2)> PMC(1,183.9g m?2)≥control(1,011.7g m?2)atα=0.05.
Temporal and inter-treatment variations in the amount of N assimilated by rice showed similar patterns to DM (Table 3).At 110DAT,the amount of N uptake was greatest in AS (15.2g m ?2),followed by HV (9.3g m ?2),then PMC (7.5g m ?2),and finally the control (6.1g m ?2;P <0.05).
Temporal change and intra-plant variations in δ15N of rice At 15DAT,the δ15N of rice was significantly (P <0.05)different among treatments,10.5‰for PMC >5.5‰for control >4.0‰for HV >1.8‰for AS (Fig.1).However,at 42DAT,differences in δ15N of rice among treatments became smaller and that between AS and HV treatments
was insignificant (P >0.05),as a result of a decrease in δ15N of rice in the PMC treatment (8.5‰)and a concomitant increase in δ15N in the AS treatment (4.6‰).Thereafter,the δ15N of rice in PMC and AS treatments showed very small fluctuation and the final δ15N values at 110DAT were 8.2‰and 5.4‰,respectively.Meanwhile,the δ15N of rice grown without N input (control)and with HV did not change dramatically at 42DAT but showed gradual increasing patterns with time from 5.5‰(15DAT)to 6.7‰(110DAT)for control and from 4.0‰to 5.2‰for HV treatment during the same period.
At 110DAT (harvest),the δ15N (8.2‰)of whole rice with PMC was significantly (P <0.05)higher than that (6.7‰)of the control.Meanwhile,application of AS and HV resulted in similar δ15N of whole rice (5.4‰for AS and 5.2‰for HV)that is lower than the control.The effect of N inputs on δ15N of each rice part was similar to that on whole rice,and the value for each part was highest in PMC and lowest in AS and HV treatments (Fig.2).Comparing the δ15N of rice parts,grain δ15N ranged from 5.3‰to 7.1‰for unpolished and from 4.6‰to 6.1‰for polished,and those of shoot and root were between 7.8‰and 8.6‰and between 7.7‰and 9.7‰,respectively.Within the same N treatments,δ15N of grain for control and PMC in which N availability was relatively low as shown by the low N uptake (Table 3)was significantly (P <0.05)lower than those of shoot and root but not for AS and HV treatments (Table 3).
Concentrations and δ15N of soil mineral N
Across the treatments,the concentration of NH 4+varied between 3.4and 6.4mg kg ?1during the sampling time
3
6
9
12
Days after treatment
δ15N o f r i c e p l a n t s (‰)
Fig.1Temporal changes in δ15N of whole rice plants grown with different N sources.Values are the means of four replicates with standard errors (vertical bars ).Treatment effects were all significant at α=0.05.Data on the same days after treatment (DAT)with different lowercase letters are significantly different at α=0.05
Table 3Dry matter and N uptake amount of rice grown with different N inputs at different sampling time Treatments
Dry matter (g m ?2)N uptake (g m ?2)
Days after transplanting 15
42
72
110
154272110
Control
21.1(2.1)a 241.1(33.1)a 687.2(53.3)a 1011.7(127.0)a 0.6(0.1)ab 3.0(0.2)a 4.2(0.2)a 6.1(0.5)a Pig manure compost
25.6(2.1)a
248.9(14.6)a 738.9(61.0)ab 1183.9(136.1)a 0.5(0.1)a 3.7(0.5)ab 5.3(0.4)a 7.5(0.7)ab Ammonium sulfate 34.4(4.6)b 491.1(51.3)c 1521.1(132.1)c 2382.2(198.7)c 1.0(0.1)b 8.5(0.9)c 14.2(0.4)c 15.2(0.9)c Hairy vetch 21.1(3.3)a 353.5(31.3)b 1107.9(92.8)b 1744.0(194.2)b 0.5(0.1)a 5.2(0.)b 9.0(0.9)b 9.3(0.5)b ANOV A (Probability>F )Treatment effect 0.039a
0.001c
<0.001c
<0.001c
0.004b
<0.001c
<0.001c
<0.001c
Values are the means with standard errors in parentheses (n =4)
Values in the same column followed by different lowercase letters are significantly different at α=0.05
a Significant at α=0.05
b Significant at α=0.01c
Significant at α=0.001
(Fig.3a ).Significant treatment effect was observed during the growth period until 72DAT,and NH 4+concentration was consistently (P <0.05)higher in AS than in other treatments.Meanwhile,NO 3-concentration was consistent-ly lower than 2mg kg ?1during the course of the experiment (Fig.3b ).
The δ15N of soil NH 4+fluctuated from 5.4‰to 9.6‰(Fig.4).Overall,soil amended with PMC had a relatively higher (P <0.05)δ15N than those amended with other treatments throughout the experiment (Fig 4).However,differences in δ15N among other N inputs were not significant (P >0.05).The δ15N of NO 3-was not determined due to a sustained low concentration of below 2mg kg ?1.
Discussion
Dry matter production and N uptake of rice
The percent increment of DM and N uptake relative to the control were 17.0%and 24.2%for PMC,135.5%and 150.6%for AS,and 72.4%and 54.1%for HV ,respectively (calculated with the data in Table 3).The significant greater DM yield and N uptake of rice grown with AS than those with PMC and HV seemed to reflect their different N availability.The amounts of plant N derived from inputs calculated by using difference method (Cassman et al.1998),i.e.,the difference in N uptake between control and each N input treatment,were 1.5,9.1,and 3.3gN m ?2for PMC,AS,and HV treatments,respectively.These amounts correspond to 6.7%,83.1%,and 35.3%of the applied N inputs,respectively.Apparently,lower uptake efficiency of
livestock manure compost-N by rice than that of chemical fertilizer-N was consistent with the result of Nishida et al.(2005),reporting 17%of N uptake efficiency for swine manure compost and 34%for ammonium sulfate,and this is generally ascribed to low mineralization of compost-N due to stabilization of organic compost-N via humification
Days after treatment
δ15
N o f N H 4+
(‰)
Fig.4Changes in δ15N of NH 4+of paddy rice soils treated with different N inputs.Vertical bars are the standard errors of the means (n =4).The δ15N of NO 3-were not determined due to low concentration (<2mg kg ?1)
N H 4+
c o n c e n t r a t i o n (m g N k g -1
)
N H 3-
c o n c e n t r a t i o n (m g N k g -1
)
Days after treatment
(b)(a)
Fig.3Changes in a NH 4+concentration and b NO 3-concentration of paddy rice soils treated with different N inputs.Vertical bars are the standard errors of the means (n
=4)
Rice parts
Pig manure compost δ15N o f r i c e p a r t s (‰)
Fig.2δ15
N of root,shoot,unpolished grain (rough rice),and polished grain of rice sampled at harvest (110DAT).Values are the means of four replicates with standard errors (vertical bars ).Treatment effects were all significant at α=0.05.Data on the same days after treatment (DAT)with different lowercase letters are significantly different at α=0.05
during composting(Kim et al.2008).The N uptake efficiency of PMC observed in this study(6.7%)is relatively low but within the ranges of percent N mineral-ization(1.2%to65.0%)of a variety of livestock manure compost(Lim et al.2010;Miller et al.2008;Nendel et al. 2004).Meanwhile,the relatively high N uptake efficiency of AS in this study than the values(less than50%)reported for chemical fertilizer(Bronson et al.2000)could be attributed both to split application and to the confined experimental conditions that can minimize loss of applied N.The difference method used in this study could also lead to over-estimation of N uptake efficiency as N fertilization can stimulate uptake of soil N over the control due to so-called“priming effect”(Jenkinson et al.1985).
Compared with AS,however,low uptake efficiency of HV by rice was different from other studies(Asagi and Ueno2009;Diekmann et al.1993)that reported no significant difference between chemical fertilizer and green manure.In this study,HV application was conducted at 7days before transplanting(i.e.,6days earlier than AS application)as recommended by Korean government to avoid gas damage to young seedling that is in contrast with other studies in which green manure and chemical fertilizer were applied at the same time.The early incorporation of HV into soil could lower N uptake efficiency because green manure is easily decomposable and thus some portion of N derived from HV might have been lost before rice transplanting(Thorup-Kristensen1994).Magid et al. (2001)reported that most mineralization of green manure estimated by CO2evolution occurred rapidly during the first4days of incorporation into soil.
Temporal changes in riceδ15N
Plantδ15N is determined byδ15N of the N source(soil and N inputs)and isotopic fractionation associated with N transformation and subsequent loss that results in15N enrichment of the substrate(i.e.,mineral N)for plant uptake (Evans2001).Due both to isotope mixing of added N with indigenous soil N and to the isotopic fractionation,plant δ15N is likely to deviate from the15N signature of applied N(Choi et al.2002;H?gberg1997).In our study,the significantly(P<0.05)different isotope signatures among treatments at15DAT(Fig.1)show that the N source effect is greater than the N isotopic fractionation effect in the early growth period,leading to greaterδ15N difference among treatments(10.5‰for PMC>5.5‰for control>4.0‰for HV>1.8‰for AS)than in the later growth period(Fig.1).
When the plantδ15N at15DAT was compared with the δ15N of the N source,rice grown with PMC had a lower δ15N(10.5‰)than the applied N input(15.3‰)while that receiving AS or HV had a higherδ15N(1.8‰and4.0‰, respectively)than the applied N inputs(?0.4‰and?0.5‰,respectively)due primarily to isotope mixing with soil N, which has an intermediateδ15N(6.4‰).In spite of the similar isotope signature of AS and HV,δ15N of rice grown with AS showed a lowerδ15N than that with HV,possibly due to a greater contribution of15N-depleted N input to total plant N in AS treatment than that in HV treatment,as indicated by greater N uptake in AS(1.0g m?2)than in HV (0.5g m?2)treatments at15DAT(Table1).
At42DAT,δ15N of rice grown with compost decreased by 2.0‰and that with AS increased by 2.8‰,and thereafter their values remained almost constant(Fig.1). These temporal changes inδ15N of crop grown with compost and synthetic fertilizer have been reported by Choi et al.(2002)who ascribed the pattern primarily to increasing contribution of soil-derived N of whichδ15N is lower than that of compost but higher than that of synthetic fertilizer to total plant N with time(Tables1and2). Meanwhile,15N enrichment of plant-available mineral N due to N isotopic fractionation associated with N transfor-mation and loss might also play a critical role in temporal increases of riceδ15N particularly for AS treatment in which mineral N availability was higher than other treatment(Fig.3)as15N enrichment of the remaining soil N due to N loss is proportional to N availability(Choi et al. 2003b;H?gberg1997).Besides,changed N turnover rates by different N inputs(inorganic https://www.doczj.com/doc/af7409341.html,anic)might have influencedδ15N of mineral N and subsequent plantδ15N,e.
g.,Billings et al.(2002)reported that increased microbial activity due to sufficient C substrate under elevated CO2 resulted in15N-enrichment of soil mineral N and plant tissue.In the present study,therefore,the higherδ15N of NH4+(Fig.4)and rice(Fig.1)treated with PMC could be attributed partially to increased N turnover by the applica-tion of organic-C enriched compost.However,such effect was not observed for HV treatment,suggesting thatδ15N rather than chemical composition(e.g.,organic-C content) of N inputs might influenceδ15N of available N and subsequent that of rice more greatly.
Theδ15N of plant is often correlated with that of available N(mineral N)for root uptake(Billings et al. 2002;Choi et al.2003a).However,in our study,the temporal pattern ofδ15N of NH4+which is the predomi-nant mineral N form available for plant uptake in paddy soils did not match with that of rice,suggesting that the δ15N signal of mineral N is not always a conservative surrogate of the N source because the mineral N pool is very dynamic,and thus itsδ15N is susceptible to change by many processes including volatilization and nitrifica-tion(for NH4+)and denitrification(for NO3-;Choi and Ro 2003;Choi et al.2003b).Although microbial immobili-zation–remineralization of N(Billings et al.2002;Monaco et al.2010)and physico-chemical fixation of NH4+ (Nieder et al.2011)are also important fates of NH4+in
soils,N isotopic fractionation associated with these processes are generally negligible(H?gberg1997).For example,N isotopic fractionation factors(α)associated with N mineralization,immobilization,and ion exchange are generally lower than 1.002,but those with NH3 volatilization,nitrification,and denitrification are as high as1.035(H?gberg1997).In an incubation study without plants,Choi and Ro(2003)investigated the changes in δ15N of NH4+and NO3-in water-saturated and unsaturated soils after adding(NH4)2SO4(δ15N=?2.6‰)and found thatδ15N of NH4+sharply increased to around50.0‰with a rapid decrease of NH4+concentration within7days under water-unsaturated nitrifying conditions.Mean-while,under water-saturated conditions,NH4+concen-tration decreased at a slower rate,andδ15N of the remaining NH4+increased to around20.0‰at most during the36-day incubation due to retardation of nitrification under anaerobic conditions as in paddy soils. Another reason for the discrepancy of the temporal pattern ofδ15N between plant and NH4+is that plantδ15N is an integratedδ15N value for the whole plant growth period butδ15N of mineral N is an instantaneous value at the time of soil sampling.For example,theδ15N of NH4+in AS-
treated soil represents the value of the remaining NH4+ after rice uptake of applied AS because soil sampling(i.e., on15and42DAT)was made the day before next fertilization in our study.
Riceδ15N with N inputs at harvest
Theδ15N of various N inputs have been reported by Bateman and Kelly(2007);the mean value was?0.2‰for synthetic fertilizer,8.1‰for manure/compost,2.5‰for seaweed-based materials,5.9‰for non-manure wastes of livestock,and7.1‰for fish-based materials in their study. Among the various N inputs,the types of N inputs tested for cropδ15N are classified into liquid manure(LM),solid manure(SM),manure compost(MC),synthetic fertilizer (SF),and non-synthetic fertilizer/non-manure(NSF/NM) type such as hornmeal and corn steep liquor(Bateman et al. 2005;Choi et al.2002,2003a,2006;Georgi et al.2005; Lim et al.2007;Nakano et al.2003;Yun et al.2006).
Summarizing the previous studies onδ15N variations of crops as affected by various types of N inputs,theδ15N of crops ranged from5.6‰to14.9‰for LM,from6.0‰to 12.0‰for MC,from5.7‰to10.0‰for NSF/NM,from
2.2‰to6.0‰for SM,from0.7‰to7.7‰for no N input
(i.e.control in the experiments),and from?4.0‰to5.5‰for SF(Fig.5).Theδ15N of rice in our study are within(for control,PMC,and AS)or adjacent to(for HV)the range reported for the corresponding N input regime as depicted in Fig.5.The wide variations inδ15N of crops grown with non-synthetic N inputs are ascribed primarily to different N availability andδ15N of N inputs.Therefore,when other experimental conditions are the same,application of LM (highδ15N and high N availability)is likely to result in highest cropδ15N followed by MC(highδ15N and low N availability),NSF/NM(intermediateδ15N and high N availability),and SM(lowδ15N and high N availability; Bateman et al.2005;Choi et al.2006;Georgi et al.2005; Lim et al.2007).Meanwhile,a wide range ofδ15N of crops grown with the same type of N input is attributed to many factors,such as fertilization rate,N availability of inputs, weather conditions,soil characteristics,crop species,and other management practices(Bateman and Kelly2007; Choi et al.2006;Rogers2008;Yun et al.2006).
In our study,the difference inδ15N of whole rice between treatments with PMC(8.2‰)and AS(5.4‰)at harvest was2.8‰,suggesting thatδ15N of rice can be exploited in discriminating rice grown with manure compost and synthetic fertilizer.Fortunately,we observed higherδ15N of soil NH4+in PMC treatment than in AS treatment(Fig.4).The difference between manure-based N inputs and synthetic fertilizer(2.8‰)detected in our study is within the range(around2‰to6‰difference)reported for other crops,for example,less than that for Chinese cabbage(Brassica campestris L.)and chrysanthemum (Chrysanthemum morifolium Ramatuelle)grown with liquid pig manure and urea(>6.0‰difference)(Lim et al. 2007),similar for carrot(Daucus carota L.)grown with chicken manure and NH4NO3(3‰to4‰difference; Bateman et al.2005),and greater for maize grown with pig manure compost and urea(<2‰difference;Choi et al.
Nitrogen inputs
δ
1
5
N
o
f
c
r
o
p
s
(
‰
)
Fig.5Distribution ofδ15N in crops as affected by the type of N inputs applied(LM liquid manure,MC manure compost,SM solid manure,NI no input,SF synthetic fertilizer,NSF/NM non-synthetic fertilizer/non-manure).Data adopted from Choi et al.(2002;2003a), Bateman et al.(2005),Choi et al.(2006),Yun et al.(2006),Nakano et al.(2003),Lim et al.(2007),Georgi et al.(2005).Error bars indicate the range ofδ15N and boxes correspond to the most frequently observed range of values.Solid circle represents theδ15N of whole rice based on the N input category observed in this study
2002).This variation is due primarily to differences in N availability and δ15N of N inputs as previously mentioned.In general,the higher the δ15N and N availability of the organic fertilizer,the higher the δ15N in crop tissues (Choi et al.2006).
Meanwhile,the δ15N of whole rice grown with AS and HV was not different although the amount of rice N derived from AS (9.1gN m ?2)was higher than that from HV (3.3gN m ?2),and both are not isotopically different.This result suggests that the δ15N technique is not applicable in discriminating conventional farming with synthetic fertilizer from organic farming with green manure.The δ15N of N derived from inputs (δ15N NDFI )was calculated by using the isotope mass balance equations (Karamanos and Rennie 1981).
d 15N NDFI ?TN T d 15N T àTN control d 15N control àá
=TN T àTN control eT
where TN T and TN control are the N content of rice treated with N inputs and the control,respectively,and δ15N T and δ15N control are the corresponding δ15N of rice.The δ15N of N derived from AS (δ15N NDFAS )and HV (δ15N NDFHV )were 4.6‰and 2.6‰,respectively.The higher δ15N NDFAS and δ15N NDFHV than the corresponding δ15N of N inputs (?0.4‰for AS and ?0.5‰for HV,see Table 1)could be attributed to 15N enrichment of the remaining N via N isotopic fractionation during N loss,and such patterns have been widely reported for several crop species (e.g.,Choi et al.2002,2003a ,2006).However,for AS treatment,the “priming effect ”seemed to contribute to the higher δ15N NDFAS as root DM at the harvest was significantly (P <0.001,data not shown)higher in AS treatment (592.8g m ?2)than others (204.4,236.7,and 428.5g m ?2for control,PMC,and HV,respectively).According to the “priming effect ”theory (Jenkinson et al.1985),chemical fertilizer enhances root proliferation and thus uptake of soil N particularly when the root growth is not restricted as in the present study (Choi et al.2001).In this study,δ15N of total soil and rice in control was 6.4‰and 8.2‰(Table 2;Fig.1)and thus increased uptake of soil-derived N which is more enriched with 15N compared with AS-derived N could lead to estimation of δ15N NDFAS at a higher value than the real δ15N of N derived from AS.All the rice parts (root,shoot,and grain)showed similar δ15
N patterns to the total rice plant,with the highest δ15N in PMC treatments followed by the control and then HV or AS (Fig.2).Among the rice parts,grain showed the smallest isotopic difference (1.8‰for unpolished and 1.1‰for polished)between PMC and AS treatments compared with other parts (3.7‰for root and 3.5‰for shoot).This seemed to be related with rice organ development and associated N uptake and use patterns.Rice plants assimilate N from soils and store N in shoot during the active growing
period,and at the grain filling stage (i.e.,reproductive growth stage),parts of N are supplied from N stored in the shoot (internal N reservoir)through remobilization and the other parts from the soil through root uptake (external soil N;Kano 1995;Thorup-Kristensen 1994).Since N avail-ability of PMC-treated soil was much lower than that of AS-treated soil as indicated by N uptake data (Table 3),reliance of rice on an internal N source (shoot N)for grain filling might have been greater when it was grown with PMC than that with AS.Remobilization and redistribution of stored N in the plant causes 15N depletion in the sink (grain for rice)due to N isotopic fractionation associated with enzymatic remobilization of stored N (Choi et al.2002;Shearer and Kohl 1986).In our study,the lower δ15N of grain than shoot in relatively N-limited soils as in the control and PMC treatments evidenced N isotopic fraction-ation during the N allocation from shoot to grain,and Choi et al.(2002)also reported similar pattern with maize.Therefore,the smallest isotopic difference of grain between PMC and AS treatments could be ascribed to the greater contribution of intra-plant redistribution of N to grain N of PMC treatment that led to a lower δ15N of grain.
Not only δ15N of N sources (fertilizer-N and soil N)but also N assimilation pattern can influence intra-plant patterns of δ15N (Choi et al.2002).For example,a significant intra-plant variation of δ15N can be found when NO 3-rather than NH 4+is the predominant N source because primary NO 3-assimilation can occur in both roots and leaves and NO 3-not assimilated in the root and thus translocated to leaves would be enriched in 15N because it experienced N isotopic fractionation during the assimilation mediated by nitrate reductase in the root (Evans et al.1996;Yoneyama and Kaneko 1989).Meanwhile,little intra-plant variations of δ15N are observed when NH 4+is the predominant N source as in this study (paddy conditions),because NH 4+is likely to be assimilated immediately after entering roots due to its toxic accumulation within the plant (Bloom 1988).Because the predominant mineral N species in our study is NH 4+due to the waterlogged soil conditions (Fig.3),therefore,the contribution of the N assimilation pattern to the intra-plant variations of δ15N could be assumed to be negligible.In conclusion,although this study was conducted for a single cropping season,the results suggest a possibility of using δ15N analysis in discriminating rice grown with manure composts from that with synthetic fertilizers;however,when organic N input (HV in our study)of which δ15N signal is similar to synthetic fertilizers (AS)is used,rice δ15N may not serve as a surrogate of N sources.We believe that our study provides fundamental data on δ15N variations of rice plants as affected by different N inputs,and these data can be considered in designing a long-term experiment.Although small isotopic difference of grain,the commercial product of rice cultivation,
between PMC and AS treatments was observed in this single cropping experiment,this may need to be further tested in a long-term experiment as continuous applica-tions of organic inputs may enrich soil N with15N and thus lead to annual increases of plantδ15N.It may also be necessary to consider investigatingδ15N of other rice parts (i.e.,whole rice,root,and shoot)samples for more reliable certification.
Acknowledgments This work was supported by the Korea Research Foundation Grant funded by the Korean Government(MOEHRD; KRF-2008-313-F00005).
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本科毕业论文外文翻译 外文译文题目（中文）：再生建筑垃圾作为混凝土骨料用于 可持续建筑材料的探究 学院: 城市建设学院 专业: 土木工程 学号: 201308141162 学生姓名: 郑健 指导教师: 唐红 日期: 二○一七年六月
InternationalConferenceonSustainableDesign,Engineeringan dConstruction Recycled Construction Debris as Concrete Aggregate for Sustainable Construction Materials ShahidKabir*,AmmarAl-ShayebandImranM.Khan ProcediaEngineering145(2016)1518–1525 （可持续设计、工程与建筑国际会议） 再生建筑垃圾作为混凝土骨料用于可持续建筑材料的探究ShahidKabir*,AmmarAl-ShayebandImranM.Khan （土木与环境工程系，费萨尔国王大学，沙乌地阿拉伯王国）能源与工程145(2016)1518–1525
摘要 为了比较各种来源有差异的再生混凝土骨料废料拆除的工程性质，笔者专门为此做了一个实验：实验室从一个已知的工程性质商业预拌混凝土公司得到样品来测试混凝土废物，通过一些关于样品的工程性质的信息具体，并从结合市场规则的前提出发将其作为实验的控制样品。本研究探讨了潜在的建筑废物的可持续建筑材料的发展，以获得建筑废物的经济回报。将建筑垃圾处理成砾石后，计算出废料的再生材料量，进行骨料试验。实验室样品的制作是对各种废物来源进行混合设计与骨料回收的基础上完成的，得到控制样品后，最后进行抗压强度，拉伸强度，抗弯强度，以及一些非破坏性试验（NDT），如脉冲速度和锤击试验。从不同的测试得到的结果之间的相关性进行了分析，在这个实验程序中，指出样品之间的线性相关性以及其他机械性能的评价，如抗压强度，劈裂抗拉强度，弯曲强度，脉冲速度等。 关键词 可持续混凝土设计；再生骨料，建筑拆除混凝土，混凝土工程性能 一、引言 固体废物管理是全球面临的严峻挑战，而这也是海湾地区的一个特殊问题 ，其中大多数国家有着世界上最高的人均废物产生量。工业增长、建设繁荣、快速城市化、生活方式的改变和不可持续的消费模式，都对这一日益严重的浪费问题有着不小的影响。城市化建设的加速导致了数十亿美元的建设公共基础设施部门的建设项目的支出，这导致了建筑材料与相关建筑废弃物的管理不断增长的物质人力需求。拆除旧建筑物，成吨的建筑废料被丢弃；这些拆除的混凝土也常常被认为是没有价值的，作为拆卸废物处置。然而，大多数建筑垃圾被认为是有利用价值的，可以可用于再生建筑材料。 自然资源通常由建筑业大量消耗，同时还生产大量的建筑和拆除废物。碳废物构成最大的固体废物量。例如，美国建筑业每年产生超过1亿吨的碳废物，而大约有29%的固体废物流是由建筑业产生的。此外，英国的碳废物废物贡献率超过50%，每年有着7000万吨的碳废物被丢弃。克莱文等人在1994年的报道说，建筑活动产生的约20-30%的废物在澳大利亚，这是弃置垃圾的填埋场。而在1993-2004年间，则是中国香港建筑垃圾的巅峰年代，建筑垃圾的制造量翻了一番，达到2000万吨。2004年。在香港近23%的固体废物来自建筑业活动。大量的建筑垃圾在不同的国家揭示了地方行动的重要性，同时，回收和再利用建筑废物在整个建筑行业的生命周期中有着显著的意义。 建筑废物的产生和建筑材料消耗以及自然资源的不可持续使用也与建筑业的不利环境影响有关。在全球范围内，据估计，约30%的废物处置堆填区来源于建筑和拆除活动。此外，自然资源的过度使用，如碎石生产、爆破土石的山区，已成为一个日益严重的环境问题，这些工业生产的废物需要通过创新思想来加以解决，同时改善可持续发展的综合管理方案来获得经济回报。
本科生毕业设计（论文）外文科技文献译文 译文题目(外文题目)学院(系)Socket网络编程的设计与实现A Design and Implementation of Active Network Socket Programming 机械与能源工程学院 专学业 号 机械设计制造及其自动化 071895 学生姓名李杰林 日期2012年5月27日指导教师签名日期
摘要：编程节点和活跃网络的概念将可编程性引入到通信网络中，并且代码和数据可以在发送过程中进行修改。最近，多个研究小组已经设计和实现了自己的设计平台。每个设计都有其自己的优点和缺点，但是在不同平台之间都存在着互操作性问题。因此，我们引入一个类似网络socket编程的概念。我们建立一组针对应用程序进行编程的简单接口，这组被称为活跃网络Socket编程（ANSP）的接口，将在所有执行环境下工作。因此，ANSP 提供一个类似于“一次性编写，无限制运行”的开放编程模型，它可以工作在所有的可执行环境下。它解决了活跃网络中的异构性，当应用程序需要访问异构网络内的所有地区，在临界点部署特殊服务或监视整个网络的性能时显得相当重要。我们的方案是在现有的环境中，所有应用程序可以很容易地安装上一个薄薄的透明层而不是引入一个新的平台。 关键词：活跃网络；应用程序编程接口；活跃网络socket编程
1 导言 1990年，为了在互联网上引入新的网络协议，克拉克和藤农豪斯[1]提出了一种新的设 计框架。自公布这一标志性文件，活跃网络设计框架[2，3，10]已经慢慢在20世纪90 年代末成形。活跃网络允许程序代码和数据可以同时在互联网上提供积极的网络范式，此外，他们可以在传送到目的地的过程中得到执行和修改。ABone作为一个全球性的骨干网络，开 始进行活跃网络实验。除执行平台的不成熟，商业上活跃网络在互联网上的部署也成为主要障碍。例如，一个供应商可能不乐意让网络路由器运行一些可能影响其预期路由性能的未知程序，。因此，作为替代提出了允许活跃网络在互联网上运作的概念，如欧洲研究课题组提出的应用层活跃网络（ALAN）项目[4]。 在ALAN项目中，活跃服务器系统位于网络的不同地址，并且这些应用程序都可以运行在活跃系统的网络应用层上。另一个潜在的方法是网络服务提供商提供更优质的活跃网络服务类。这个服务类应该提供最优质的服务质量（QOS），并允许路由器对计算机的访问。通过这种方法，网络服务提供商可以创建一个新的收入来源。 对活跃网络的研究已取得稳步进展。由于活跃网络在互联网上推出了可编程性，相应 地应建立供应用程序工作的可执行平台。这些操作系统平台执行环境（EES），其中一些已 被创建，例如，活跃信号协议（ASP）[12]和活跃网络传输系统（ANTS）[11]。因此，不 同的应用程序可以实现对活跃网络概念的测试。 在这些EES 环境下，已经开展了一系列验证活跃网络概念的实验，例如，移动网络[5]，网页代理[6]，多播路由器[7]。活跃网络引进了很多在网络上兼有灵活性和可扩展性的方案。几个研究小组已经提出了各种可通过路由器进行网络计算的可执行环境。他们的成果和现有基础设施的潜在好处正在被评估[8，9]。不幸的是，他们很少关心互操作性问题，活跃网络由多个执行环境组成，例如，在ABone 中存在三个EES，专为一个EES编写的应用程序不能在其他平台上运行。这就出现了一种资源划分为不同运行环境的问题。此外，总是有一些关键的网络应用需要跨环境运行，如信息收集和关键点部署监测网络的服务。 在本文中，被称为活跃网络Socket编程（ANSP）的框架模型，可以在所有EES下运行。它提供了以下主要目标： ??通过单一编程接口编写应用程序。 由于ANSP提供的编程接口，使得EES的设计与ANSP 独立。这使得未来执行环境的发展和提高更加透明。
BPMN2.0标准业务流程建模简介 Thomas Allweyer著2.1最初的BPMN模型 一个简单的BPMN流程模型被认为是一个起点。在图1中所示的模型工作可以被大多数先前已经涉及任何种类的过程建模的人所直接理解。建模的方式类似于公知的流程图和活动图。 图1 一个简单的BPMN模型 营业部和人力资源部门参与的过程为“发布职位”。当需要雇员的过程开始。该营业部报告该职位空缺。然后，人力资源部写一份招聘启事。该营业部的评论此招聘启事。 在这一点上，有两种可能性：要么招聘启事是好的，否则是不行的。如果不行的，它是由人力资源部返工。这是一次，其次是营业部审查招聘启事。同样，其结果可能是好还是不好吧。因此，它可能在招聘启事发生时需要检讨多次。如果它是好的，它是由人力资源管理部门公布的，在这个过程结束时。 在现实中，用于创建和发布招聘启事可以更加复杂和广泛。所提出的例子是（像在这本书中所有例子）为了具有小的和容易理解的模型的简化，可用于说明不同的BPMN元素。 2.2 BPMN构建的使用 下面，将模型图1中的每个元件更加紧密地说明。整个过程被包含在一个池。这是一个完整的过程的一般种类的容器。在上面的例子中，池标有包含进程的名称。 每一道工序都坐落在池内。如果该集合对于过程来说是不重要的，它不要求将其拉在图中。在不显示一个池的过程中，整个过程都包含在一个无形的，隐含的池。池是特别有趣的当数个池用来模拟一个协作使用，即几个合作伙伴的过程的相互作用。每个合作伙伴的过
程在一个单独的游泳池显示。这将在第5章描述。 从图1中的池分隔成两个道。道可用于各种用途，例如用于分配组织单位，如在这个例子中，或用于技术系统内代表不同的组件。在这个例子中，道显示的过程的活动由营业部和人力资源部门进行。 被池和道也被称为“泳道”。他们像游泳池划分成的道。比赛的每一个参与者只游在自己道。过程本身开始的第一个活动为“要求员工”。流程通常有这样一个启动事件。其标志是一个简单的圆形。在大多数情况下是有意义的只使用一个起始事件，而不是几个的。 一个圆角矩形代表活动。在一个活动得到的东西做的。这是由活动的名称表示，比如“报告工作机会”或“审查职位发布”。 连接箭头用于模拟的顺序流。它们表示，其中不同的事件，活动，和其它元件的遍历顺序。通常，这被称为控制流，但在BPMN有第二类型的流，该消息流，从而影响一个过程的控制，以及，因此，某种控制流，太。出于这个原因，术语“序列流”被使用。用于从其它种类的流区分开来，这是很重要的绘制顺序用实线和填充箭头流动。 这个过程“发布职位”包含了拆分：活动“审查招聘启事”后面的网关。一个空白的菱形代表了一个独特的网关。这意味着，从几个外向顺序流向，只有一个必须选择。在招聘启事进程正确网关到达每一次，一个决定必须。无论顺序流向右后跟，导致活动“发布作业发布”，或一到左侧被选择，触发活动“返修作业发布”。因此不可能同时遵循两条路径。 这样的决定的逻辑也被称为“异或”，缩写为“异或”。在输出路径的条件决定选择哪条路径。如果建模工具的使用量和处理已被执行或由软件程序进行模拟，则通常可以正式定义确切条件。这种正式的描述，其可以表示在一种编程语言，可以存储在该序列流动的特殊属性。 如果，在另一方面，模型的目的是要说明一个过程到其它人，那么最好是写非正式的，但可以理解的，语句直接进入图，旁边的顺序流。的意思是“好”与“不行”后，被称为“审查职位发布”活动是明确到人- 一个程序无法使用它。 网关还用于合并替代路径。在示例过程中，对活动“评论作业发布”左侧网关合并两个输入序列流动。再次，这是一个唯一网关。该公司预计，无论是活动“写入招聘发布”或“返修职位发布”进行网关到达之前- 在同一时间，但不能同时使用。它应为使用网关或者用于分离或用于接合被照顾，但不能用于二者的组合。在示例过程中
车床 用于车外圆、端面和镗孔等加工的机床称作车床。车削很少在其他种类的机床上进行，因为其他机床都不能像车床那样方便地进行车削加工。由于车床除了用于车外圆还能用于镗孔、车端面、钻孔和铰孔，车床的多功能性可以使工件在一次定位安装中完成多种加工。这就是在生产中普遍使用各种车床比其他种类的机床都要多的原因。 两千多年前就已经有了车床。现代车床可以追溯到大约1797年，那时亨利?莫德斯利发明了一种具有把主轴和丝杆的车床。这种车床可以控制工具的机械进给。这位聪明的英国人还发明了一种把主轴和丝杆相连接的变速装置，这样就可以切削螺纹。 车床的主要部件：床身、主轴箱组件、尾架组件、拖板组、变速齿轮箱、丝杆和光杆。 床身是车床的基础件。它通常是由经过充分正火或时效处理的灰铸铁或者球墨铸铁制成，它是一个坚固的刚性框架，所有其他主要部件都安装在床身上。通常在球墨铸铁制成，它是一个坚固的刚性框架，所有其他主要部件都安装在床身上。通常在床身上面有内外两组平行的导轨。一些制造厂生产的四个导轨都采用倒“V”，而另一些制造厂则将倒“V”形导轨和平面导轨结合。由于其他的部件要安装在导轨上并（或）在导轨上移动，导轨要经过精密加工，以保证其装配精度。同样地，在操作中应该小心，以避免损伤导轨。导轨上的任何误差，常常会使整个机床的精度遭到破坏。大多数现代车床的导轨要进行表面淬火处理。以减少磨损和擦伤，具有更大的耐磨性。 主轴箱安装在床身一端内导轨的固定位置上。它提供动力。使工件在各种速度下旋转。它基本上由一个安装在精密轴承中的空心轴和一系列变速齿轮---类似于卡车变速箱所组成，通过变速齿轮，主轴可以在许多中转速的旋转。大多数车床有8～18中转速，一般按等比级数排列。在现代车床上只需扳动2～4个手柄，就能得到全部挡位的转速。目前发展的趋势是通过电气的或机械的装置进行无级变速。 由于车床的精度在很大程度上取决于主轴，因此主轴的结构尺寸较大，通常安装在紧密配合的重型圆锤滚子轴承或球轴承中。主轴中有一个贯穿全长的通孔，长棒料可以通过该孔送料。主轴孔的大小是车床的一个重要尺寸，因为当工件必须通过主轴孔供料时，它确定了能够加工棒料毛坯的最大外径尺寸。 主轴的内端从主轴箱中凸出，其上可以安装多种卡盘、花盘和挡筷。而小型的车床长带有螺纹截面供安装卡盘之用。很多大车床使用偏心夹或键动圆锥。这
温州医学院 本科毕业论文外文翻译资料 （2018届> 译文题目1劳伦斯《儿子与情人》中地异化 <中文） 译文题目2人地异化：海明威短篇小说研究 <中文） 译文总字数6069 学院仁济专业英语 班级06英语2班学号0606041058 作者姓名张苗苗完稿时间2018-04-27 指导老师陈勇合作老师无劳伦斯《儿子与情人》中地异化b5E2RGbCAP 第6-14页第一章异化地意义拉丁语异化地意思是产权转让，一种麻木、精神错乱地状态和有敌意或疏远倾向地行动.英语用法中地“异化”和法语用法中地“异化”保留着疏远地意思.作为一种文学主题地异化，它可以被描述为文学角色或人物与他或她以前或本来应有地本性或者是想要地一种谐和和一致地疏离.相反,关于异化问题地解决方法，一个有悖于它地是和解主题.异化关系以及孤独主题就是一体地，常常摈弃异化形象地环境背景?但是,孤独也可以从积极地方面被展示，比如说和平，与自然或上帝交流地机会以及助长创造性地条件 .这些可以与 异化无关.p1EanqFDPw 基于个人脱离不同地本质，我们可以确立六种基本地异化类型.异化可能来自于自然环境：来自于海洋,如贺拉斯地《布兰诗歌》所述<1.3或1.4 ;颂 Si—Chuan, Meng. Alienated in Sons and Lovers by D.H. Lawrence. Sichuan Normal University, May. 2008 诗,C.23 B.C ）或来自于现代都市,比如波德莱尔地《巴黎塑像》< 巴黎场
景,1861）.它也可能来自某人自己生活地时代，正如艾略特地诗《荒原》所写 <1922）.文学人物经历地往往是与他人交流或和他们所生活地社会地价值和道德观念地疏离.尽管异化主题也可以在早期地作品中找到，但是一些社会异化形式可以被认作是自浪漫主义盛行到目前地西方文学地准则.第四种异化是与上 帝和宇宙秩序地脱离?自我或人格分裂地异化概念，彻底源于拉丁语精神错乱地意思，但是也吸收了相当多地现代哲学和心理学观点.文学里地这种异化是靠一贯以来地象征性独白和重复或隐喻这样地手段来传达地.可能最深刻地一种异 化类型是存在主义，那就是与人类自身条件地疏远?这不仅是与外界世界一些方面地疏远或者是自身寻求某种出路地失败?更是一种无能协调和适应于人自身 本性以及调节人类弱点地表现.后者地异化类型可能更多地在克尔凯郭尔，陀思妥耶夫斯基和萨特等所谓地存在主义者地作品中得以探究.广义上说,异化可能 在信神或理性信仰动摇或在易变性<情绪不稳定或者是衰退）地时期成为一个 盛行地主题.< 塞涅雷31— 32）DXDiTa9E3d 根据《新牛津英语字典》，异化地意思是：1 一种脱离群体地感受或者是某人本应归宿或参与地行为.<1 ）丧失同情心；疏离他人.<2）<在马克思异化理论中）处在资本主义经济下地工人现状是由于缺失对他们自己劳动产品地衡量和一种被控制和剥削感?精神病学上来讲，是一种人格分裂或丧失个人本真地状态这被认为是与社会相关地困境和长时间情绪压抑地结果 .RTCrpUDGiT 从以上我们可以得到异化地基本定义.但是为了提供更精确地信息和提供分析莫雷尔家庭异化关系地理论基础，本章将从以下代表人物马克思、卡夫卡和艾略特来阐释必要地异化概念.5PC Z VD7H X A 1.1马克思异化理论中地异化劳动 马克思认识到异化地概念反映了社会生活最有意义地方面.他也意识到黑格尔 地理想主义和费尔巴哈地抽象人文主义阻碍了真正历史条件和社会矛盾下产生地异化形 式.jLBHrnAlLg 在他后来地论作中 <资本论），马克思将商品看作是资本主义制度地组成部分， 并且指出作为核心概念地异化劳动.他甚至把私有财产看做是异化劳动之外地. 他写道：这是异化劳动地结果，并且也阐释了与劳动相异化地方式.XHAQX74J0X 在确定了异化劳动作为资本生产地基础和源起之后，马克思接着推断出了所产生地结果.劳动在生产者工作后开始异化.这并不是直接为了他自己或者是一个享有共同利益地团体，而是为异于自己地利益和目地而工作.LDAYtRyKfE 这样对抗性地生产关系在很多方面损害了工人地利益 .1.他与自身相异化，而必须作为一个机械工具.这不是因为他是他自身地一部分，而是为了便于作为生产过程中地要素能够起作用.2.自从自然物质被认识到具有广泛地作用后，他与自然相异化了?但这并不是作为满足他自身和文化需求地方式，而仅仅只是为了获利生产地物质手段3由于特别地品质和能力得不到施展，而是参与并发展了他地经济活动能力，他与自身作为一个人特有地本质相异化了?这最终使他沦为了体力4最后是他与其他人地异化?“当一个人与自身相异化后，他
核桃（核桃L.）水解蛋白的抗氧化肽的分离纯化和鉴定 陈宁a,b杨红梅a,b孙毅a,b牛军a,b刘淑莹a,c a张俊应用化学研究所，中国科学院研究所，人民街5625号，长春130022，中华人民共和国 b中国社科院研究生院，北京100039，中国人民共和国 c长春中医大学，长春，中国人民共和国 文章信息： 二零一二年八月二十八日收到稿件 二零一二年九月十四日收到修改稿件 二零一二年九月十四日得到公认 二零一二年九月二十六日在线可用 关键词： 核桃蛋白水解物、清除自由基的活性、纯化、抗氧化肽 摘要： 通过使用三种不同的蛋白酶水解核桃中的蛋白质，来得到抗氧化剂。使用1,1 - 二苯基-2 - 苦肼（DPPH）法来测水解物的抗氧化活性。 其中胃蛋白酶水解物，水解3小时获得具有最高的抗氧化活性，因此可以抑制羟基自由基，亚铁离子螯合物，具有还原性与抑制过氧化脂质的能力。 然后，3小时的胃蛋白酶水解产物顺序通过超滤，凝胶过滤和反相高效液相色谱法纯化。具有最高的抗氧化活性的肽序列被检测为丙氨酸- 天冬氨酸- 丙氨酸- 苯丙氨酸（423.23 Da）的RP-HPLC-ESI-MS，这首次被认定为来自核桃蛋白水解物。 最后，肽对脂质过氧化抑制作用类似于对还原型谷胱甘肽（GSH）的作用。这些结果也表明蛋白水解产物和/或其有效分离的肽可以用作食品添加剂。 1介绍 生物分子的氧化一直被被认为是自由基介导的过程，在所有生物体都是一个重要的反应。自由基是原子，分子或离子的未成对电子或开壳层结构，如羟基自由基（?OH），超氧阴离子自由基（O2?- ）[6,34]。过量自由基的合成，可导致细胞损伤和死亡，从而导致许多疾病，如癌症，中风，心肌梗死，糖尿病和主要障碍[2,4,21]。因此，重要的是要抑制的过度自由基形成。 许多合成抗氧化剂如丁基化羟基苯甲醚（BHA），丁基羟基甲苯（BHT），没食子酸丙酯已被用来清除自由基[28,32]。然而，使用合成抗氧化剂已很可能威胁健康造成肝损伤和致癌作用[9,23]。因此，人们在从源代码中发现的天然抗氧化剂的兴趣与日俱增。许多蛋白质水解物中的肽合物，如大豆蛋白[5,15]，鹰嘴豆蛋白[12,34]，小麦蛋白[18,35]，油菜籽蛋白质[17]，水稻胚乳中的蛋白质[33]，鱼蛋白[10,23,24,29,32]，蛋清蛋白[4,7]和牛蛙的皮肤[20]的抗氧化能力已得到评估。这些水解物的抗氧化性能归于许多性能的共同作用。包括他们清除自由基的能力，作为金属离子螯合剂，氧淬灭剂或供氢，抑制脂质过氧化的能力[4,12,15]。一般肽包括3-20个氨基酸残基，并且它们的活性依赖于组成，结构和疏水性[4,5,19,26,27]。 核桃（核桃L.）是世界上最普遍坚果树[14]。这是营养密集的食物，主要是由于其脂肪含量以及蛋白质，维生素和矿物质的比例构成。一些生物活性，如抗动脉粥样硬化，抗炎和
连续色谱和电喷雾电离质谱分析法对草鱼肌肉水解物的抗氧化肽的 纯化和鉴定 任娇燕a,赵眸明a,*, John Shi b,王金水a,江月明c,催春a，Yukio Kakuda a , Sophia Jun Xue b a轻工与食品科学学院，中国科技大学，广州510640，中国 b圭尔夫食品研究中心，农业和农业食品,加拿大圭尔夫，安大略省，加拿大N1G5C9 c华南植物园，中国科学院研究所，广州，乐意居510650，中国 d食品科学研发部，圭尔夫大学，圭尔夫，安大略省,加拿大N1G2W1 2007年5月9日收到，2007年11月5日收到修订表格，2007年11月7日接受。 摘要 用多种蛋白酶（木瓜蛋白酶，菠萝蛋白酶，牛胰酶6.0，中性蛋白酶为1.5mg和碱性蛋白酶2.4L）水解草鱼肌肉以提取抗氧化肽。用羟自由基的清除能力和抑制脂质过氧化活性的方法来评估水解能力。准备过程中发现，用2.4L碱性蛋白酶的水解具有最高的抗氧化活性。使用超滤和连续的色谱法来纯化，包括离子交换色谱法，多层线圈高速逆流色谱法，凝胶过滤色谱法。纯化的多肽，作为一种强有力的抗氧化剂，可以使用在线RP-HPLC的电喷雾电离质谱确定丝氨酸-赖氨酸-色氨酸- 谷氨酸-脯氨酸-苯丙氨酸- 缬氨酸（966.3 Da）。当然，才发现基本肽比酸性或中性肽有更大的清除羟自由基的能力，水解的疏水肽比亲水性肽贡献更多的抗氧化活动。此外，氨基酸中其抗氧化活性的肽序列可能发挥重要作用。 关键词 草鱼肌肉抗氧化肽，高速逆流色谱，电喷雾电离质谱分析。 1介绍 氧化在所有活的生物体中都是一种重要的反应。氧化代谢过程中自由基和其他活性氧（ROS）的形成是不可避免。这些活性自由基，起到重要的信号转导作用（汉考克，Desikan，奥尼尔，2001年）。然而，过剩的自由基对生物组织和食品能造成破坏性的影响（王，赵，赵江，2007）。在所有ROS中，羟基自由基被认为是最活泼的，并能在接触到活细胞的过程中破坏几乎任何化合物（卡斯特罗弗里曼，2001）。自由基链式反应可以启动膜脂质过氧化作用，这已被证明与许多疾病相关（哈勒威尔，2001年哈利维尔及怀特曼，2004）。脂质过氧化导致食品风味和口感变坏，保质期减少并形成潜在的毒性产品（Pihlanto，2006年）。合成抗氧化剂：如叔丁基对羟基茴香醚（BHA），丁基化的羟基甲苯（BHT），叔丁基氢醌（TBHQ），没食子酸丙酯已被广泛应用于延迟食品因氧化引起的变质（Wanita & Lorenz, 1996）。然而，由于其潜在的健康危害，他们被限制在一些国家（贝克尔，1993;膜，1975）。其结果是，安全和自然存在的抗氧化剂作为人造替代品的需求已经稳步发展了许多年。 近年来，各种蛋白质的消化产生的生物活性肽的抗氧化活性已经吸引了很多注意。从牛奶中的肽（布兰卡安娜·卢尔德＆Isidra，2007年），大豆（吉布斯，Zougman，穆利根，2004），米糠（帕拉多等，2006），油的种子（阿鲁科MONU 2003），鸡蛋（坂橘石原慎太郎Juneja，2004）和猪（赛加羚羊的，2003年）都被证明具有抗氧化活性。此外，水产品和副产物已被证明是良好的抗氧化肽来源。例如，来自蛋白（Amarowicz沙希迪，1997），鲭鱼蛋白（吴，陈，萧，2003），巨型鱿鱼皮（门迪斯，拉贾帕克萨，卞金，2005年），无须鳕帧蛋白（JE，
译文 交通拥堵和城市交通系统的可持续发展 摘要：城市化和机动化的快速增长，通常有助于城市交通系统的发展，是经济性，环境性和社会可持续性的体现，但其结果是交通量无情增加，导致交通拥挤。道路拥挤定价已经提出了很多次，作为一个经济措施缓解城市交通拥挤，但还没有见过在实践中广泛使用，因为道路收费的一些潜在的影响仍然不明。本文首先回顾可持续运输系统的概念，它应该满足集体经济发展，环境保护和社会正义的目标。然后，根据可持续交通系统的特点，使拥挤收费能够促进经济增长，环境保护和社会正义。研究结果表明，交通拥堵收费是一个切实有效的方式，可以促进城市交通系统的可持续发展。 一、介绍 城市交通是一个在世界各地的大城市迫切关注的话题。随着中国的城市化和机动化的快速发展，交通拥堵已成为一个越来越严重的问题，造成较大的时间延迟，增加能源消耗和空气污染，减少了道路网络的可靠性。在许多城市，交通挤塞情况被看作是经济发展的障碍。我们可以使用多种方法来解决交通挤塞，包括新的基础设施建设，改善基础设施的维护和操作，并利用现有的基础设施，通过需求管理策略，包括定价机制，更有效地减少运输密度。 交通拥堵收费在很久以前就已提出，作为一种有效的措施，来缓解的交通挤塞情况。交通拥堵收费的原则与目标是通过对选择在高峰拥挤时段的设施的使用实施附加收费，以纾缓拥堵情况。转移非高峰期一些出行路线，远离拥挤的设施或高占用车辆，或完全阻止一些出行，交通拥堵收费计划将在节省时间和降低经营成本的基础上，改善空气中的质量，减少能源消耗和改善过境生产力。此计划在世界很多国家和地方都有成功的应用。继在20世纪70年代初和80年代中期挪威与新加坡实行收费环，在2003年2月伦敦金融城推出了面积收费;直至现在，它都是已经开始实施拥挤收费的大都市圈中一个最知名的例子。 然而，交通拥堵收费由于理论和政治的原因未能在实践中广泛使用。道路收费
计算机学院2011届 毕业设计译文的格式要求 根据教务处的相关文件的规定，2011 届毕业设计译文格式规范如下： 1）封皮： 译文的封皮采用学校统一的模板，模板的格式见“08届毕业设计指导手册及模板”要求，各位同学将封皮各项全部填写好以后用A4纸张打印出来，到经管学院文印室（D区组团2楼）加土黄色封皮（理工科统一封皮）进行装订； 2）内容： a.译文部分的格式要求： 前面附翻译好的中文部分，按照学校的要求，可以打印或手写。装订时在中文译文后面增加一空白页，供 指导老师写评语用。 手写的格式要求如下： （1）采用“中原工学院毕业设计（论文）译文专用纸”，到计算机学院统一购买（由教务处统一印 发）； （2）书写工整，必须用黑色钢笔（或黑色签字笔）书写； （3）翻译的汉字部分要求3000字以上 打印的格式要求如下： （1）采用W ord 格式排版 （2）中文：正文采用宋体小4号 （3）英文：采用新罗马体12 （4）题目用黑体小2号字 （5）纸张大小：A4
（6）行间距为2倍行距，便于老师批改 （7）页边距：采用A4默认的格式 （8）页眉： 中间标明：中原工学院毕业设计（论文）译文专用纸 右上角标明：第页 b.原文部分的格式要求 后面附英文原文，可以打印，或原件复印。打印时，W ord 排版格式如下： （1）英文：采用新罗马体12，1.5倍行距，内封题目用黑体小2号字； （2）纸张大小：A4 （3）页边距：采用A4默认的格式 （4）页眉： 中间标明：中原工学院毕业设计（论文）译文专用纸 右上角标明：第页 （5）原文出处：在英文的首页注明原文出处 二O一O年十二月
外文翻译 Coagulation and flocculation 14.1 Introduction Coagulation and flocculation provide the water treat-ment process by which finely divided suspended and colloidal matter in the water is made to agglomerate and form flocs. This enables their removal by sedi-mentation, dissolved air flotation or filtration. Colloidal particles (colloids) are midway in size 1 between dissolved solids and suspended matter. Colloids are kept in suspension (stabilised) by electrostatic repulsion and hydration.Electrostatic repulsion occurs because colloids usually have a surface charge due to the presence of a double layer of ions around each particle. Thus, the colloid has an electric charge, mostly a negative one. Hydration is the reaction of particles at their surface with the surrounding water. The resulting particle-water agglomerates have a specific gravity, which differs little from that of water itself. The substances that frequently are to be removed by coagulation and flocculation are those that cause turbidity and colour. Surface waters in tropical countries often are turbid and contain colouring material. Turbidity may result from soil erosion, algal growth or animal/vegetable debris carried by surface run-off. Substances leached from decomposed organic matter, leaves, or soil such as peat may impart colour. Both turbidity and colour are mostly present as colloidal particles. The electrostatic repulsion between colloidal particles effectively cancels out the electronic attraction forces (Van der Waals?ˉforces) that would attach the particles together. Certain chemicals (called coagulating agents, coagulants) have the capacity to compress the double layer of ions around the colloidal particles. They reduce the range of the electrostatic repulsion, and thus enable the particles to flocculate, i.e. to form flocs. These flocs can grow to a sufficient size and specific weight to allow their removal by settling, flotation or filtration. Generally water treatment processes involving the use of chemicals are not so suitable for small community water supplies. They should be avoided whenever possible. Chemical coagulation and flocculation should only be used when the needed treatment result cannot be achieved with another treatment process using no chemicals. If the turbidity and colour of the raw water are not much higher than is permissible for drinking water, it should be possible to avoid chemical coagulation in the treatment of the water. A process such as slows and filtration or multi-stage filtration would serve both to reduce the turbidity and colour to acceptable levels, and to improve the other water quality characteristics, in a single unit.A roughing filter can serve to reduce the turbidity load on the slow sand filter, if necessary. . 14.2Coagulants Alum (Al2(SO4)3.nH20) where n=14, 16, or 18, depends on the form of alum supplied. This may be in liquid solution, broken crystalline granules 2-5 cm size (kibbled) or crystalline blocks. It is by far the most widely used coagulant. Iron salts (e.g. ferric chloride (FeCl3), orferric sulphate (Fe2(SO4)3.9H2O) can be used as well
届本科毕业设计(论文)外文 文献翻译 学院： 专业： 姓名： 学号： 外文出处：Automating Manufacturing Systems with PLCs 附件：1、外文翻译2、外文原文
附录1：外文资料翻译译文 基于PLC的自动化制造系统 15.梯形图逻辑函数 主题： ?数据处理、数学运算、数据转换、阵列操作、统计、比较、布尔量运算等函数?设计实例 宗旨： ?理解基本函数,允许计算和比较 ?了解使用了内存文件的数组函数 15.1介绍 梯行图逻辑输入触点和输出线圈之间允许简单的逻辑判断。这些函数把基本的梯形图逻辑延伸到其他控制形式中。例如，附加的定时器和计数器允许基于事件的控制。在下图15.1中有一个较长的关于这些函数的表。这包括了组合逻辑和事件函数。本章将会研究数据处理和数值的逻辑。下一章将介绍表、程序控制和一些输入和输出函数。剩下的函数会在后面的章节中讨论 图15.1 基本PLC函数分类
大多数的函数会使用PLC 的存储单元获取值、储存值和跟踪函数状态。一般大部分函数当输入值是“真”时，会被激活。但是，有些函数，如延时断开定时器，可以在无输入时，保持激活状态。其它的函数仅当输入由“假”变“真”时，才会被执行，这就是所谓的上升沿触发。想想，一计数器仅仅是输入由“假”变“真”时才会计数，输入为“真”状态的持续时间并不影响函数动作。而下降沿触发函数仅当输入由“真”变“假”时才会触发。多数函数并非边沿触发：除非有规定说明函数不是边沿触发。 15.2数据处理 15.2.1传递函数 有两种基本的传递函数； MOV(值,操作数) -把值传递到指定的存储位置。 MVM(值,标号,操作数) -把值传递到指定的存储位置，但是用标号来指定一个传递的位。 这个MOV 函数从一个存储空间取出一个值放置到另外一个存储空间里。下图15.2给出了MOV 的基本用法。当A 为“真”，MOV 函数把一个浮点数从原操作数传递到操作数存储位置。原操作数地址中的数据没有改变。当B 为“真”时，原操作数中的浮点数将被转换成整数存储在操作数存储区中。浮点数会被四舍五入成整数。当C 为“真”时，整数“123”将被存储在整数文件N7:23中。 MOV 原操作数F8:07操作数N7:23MOV 原操作数123操作数N7:23 MOV 原操作数F8:07操作数 F8:23
机械工程英语 第1课现代制造工程 A.什么是制造业 也许你从来没有想过这个问题之前，但它是你周围的一切。它影响着你生活的一部分。是什么呢？在这种情况下，“它”是制造业。其实“制造”是不是你周围的一切。而是人为制造的产品。现在看看你周围。名称有些事情你看到这些制造。椅子，笔记本电脑，蓝色牛仔裤，书籍，地板砖，黑板，灯泡，铅笔，眼镜，近周围的一切你是制造。 制造业是香港的重要的社会。这对于我们的经济。一个经济体是生产和销售的产品和服务体系。许多人工作在制造业。他们帮助生产的产品。他们用这些钱购买他们赚的产品。人们购买的产品越多，越产品的生产。这让更多的人来工作。 制造业也是重要的另一种方式的经济。甲片的材料后，更是值得它被改变成一个有用的产品。这就是附加值。价值是增加了生产过程。
二现代制造 一个制造业的资源需要三个基本类型：物质资源，人力资源，资本资源。 工业的七个关键要素是组织生产步骤：研究，开发，生产模具，生产计划与控制，质量控制，人事管理，制造，营销。 研发新产品，工艺或材料，旧技术的改进计划。R＆D是这么大，工业世界的重要组成部分，需要与不同的人才很多人。 生产工具是工业元素与这些工具有关。在PT获得的工具，机器和设备需要做出的产品。 生产计划与控制最重要的部分是路由，调度，调度，并规划布局。机械及设备，必须使生产安排，可以进行顺利，没有浪费时间和精力。
质量控制可以被定义为那些活动，防止缺陷的文章。在尝试这种方式管理，以确保产品将可以接受的买家。 营销是让那些谁使他们对那些谁使用它们，有助于提供各种货物的权利给我们，在正确的方式和数额，时间及价格，产品的过程。 第2课机械工程设计 机械工程设计是工程的主要部分，它涉及的概念，设计，开发，改进和应用机器及各种机械设备。对于许多学生，机械工程设计是他们的第一个专业的工程课程之一。专业工程关注的是获得解决实际问题，工程师们能够设计出更好的解决实际问题。在机械工程设计中的大多数问题没有唯一正确的答案。因此，现代机械工程师能够产生显着更好的解决方案，以满足今天的需要。工程师必须使用现有的最佳科学信息的理解以及经验，良好的判断力。当考虑一个完整的机器，工程师都认为，要求和约束是相互关联的各个组成部分。现代工程师已越来越多地安全，生态，更广泛的考虑和整体有关“生活质量”。好的设计需要尝试新的想法并愿意采取了一定的风险，因为他们知道如果新的观点并不工作中存在的方法可以恢复。因此，设计者必须要有耐心，因为没有时间和扩大的努力取得成功的保证。创建一个全新的设计，通常需要许多旧的和行之有效的方法，将重点放在一边。这并不容易，因为许多人抱着熟悉的想法，技巧和态度。设计工程师必须不断寻找方法来改进现有产品，必须决定哪些旧的，成熟的概念，应使用什么新的，未经试验的想法应该被纳入。
本科毕业设计外文翻 译 外文译文题目(中文) ：中间包覆盖剂对钢水纯净度的影响 学院: 材料与冶金学院 专业: 冶金工程 学号: 201002126072 学生姓名: 陈维涛 指导教师: 李光强教授 日期: 二〇一四年六月
近年来，对薄板和涂层钢板质量的要求越来越高。在这方面所面临的一项重要挑战便是如何减少钢水中的非金属夹杂物。 保护中间包中钢液免受污染不仅对提高钢产品的质量尤为重要，而且在避免浸入式水口堵塞和增加连续浇铸的炉数方面有重要作用。为了以稳定的方式供给高洁净度的钢液，对中间包内钢液的去污行为进行了研究，并对保持中间包内钢液洁净机制进行了定量研究。基于所取得的成果，对如何保持中间包中钢液洁净度的工艺进行了研究。 关键词：连铸，炼钢，铸造，夹杂物，洁净钢，空气氧化。 1 前言 确保中间包内钢液的洁净度不仅对生产洁净钢的产品非常重要，而且对防止浸入式水口堵塞有重要影响。中间包具有将钢液分流并通过促进非金属夹杂物的上浮、去除来清洁钢液的功能[1-4]。但中间包冶金也会使钢液中产生新的夹杂物。因此传统研究认为改善中间包内夹杂物的上浮去除工艺以及防止钢液二次污染工艺经是制造洁净钢的先决条件[10-21]。为了充分利用中间包促进夹杂物上浮和去除功能稳定地生产高纯度的洁净钢，联合通过确定某些特殊因素的影响对中间包内污染物的去除的工艺和通过采取适当的措施阻止中间包内新生污染的生成的工艺有着至关重要的作用。 本实验对一实际生产连铸机上中间包中钢液夹杂物进行了研究，并对其形成原因进行了阐述。根据实验的结果，研究了防止钢液被空气氧化工艺及在钢包中使用无污染钢包引流砂工艺在提高中间包中钢液洁净度方面的效果。 2 中间包内夹杂物行为分析结果 在新日铁公司，八幡厂，第三炼钢厂，1号连铸机（两流，60吨中间包）上，浇铸了三炉含铝0.05%的铝镇静钢。在长水口（中间包入口）和浸入式水口（中间包出口）的位置分别用快速冷却取样器对钢液取样。用光学显微镜观察粒径在10μm以上夹杂物的形状（簇状，丛状或球状），并在电子探针显微镜（EPMA）下观察夹杂物的组成。