Carbohydrate Polymers 125(2015)16–25
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Carbohydrate
Polymers
j o u r n a l h o m e p a g e :w w w.e l s e v i e r.c o m /l o c a t e /c a r b p o
l
Characterization of an exopolysaccharide produced by Lactobacillus plantarum YW11isolated from Tibet Ke?r
Ji Wang a ,b ,Xiao Zhao a ,Zheng Tian a ,Yawei Yang a ,Zhennai Yang a ,b ,?
a Beijing Laboratory of Food Quality and Safety,Beijing Technology and Business University,Beijing,China b
School of Biological and Agricultural Engineering,Jilin University,Changchun,China
a r t i c l e
i n f o
Article history:
Received 12September 2014
Received in revised form 27February 2015Accepted 2March 2015
Available online 9March 2015
Keywords:
Exopolysaccharide
Lactobacillus plantarum Rheology
Structural characterization
Chemical compounds studied in this article:Glucose (PubChem CID:79025)Fructose (PubChem CID:5984)Rhamnose (PubChem CID:25310)Glycerol (PubChem CID:753)
Glucuronic acid (PubChem CID:444791)Sodium nitrate (PubChem CID:24268)Sodium chloride (PubChem CID:5234)Calcium chloride (PubChem CID:21226093)
Tri?uoroacetic acid (PubChem CID:6422)Phenol (PubChem CID:996)
Sulfuric acid (PubChem CID:1118)
a b s t r a c t
An exopolysaccharide (EPS)-producing strain YW11isolated from Tibet Ke?r was identi?ed as Lacto-bacillus plantarum ,and the strain was shown to produce 90mg L ?1of EPS when grown in a semi-de?ned medium.The molecular mass of the EPS was 1.1×105Da.The EPS was composed of glucose and galactose in a molar ratio of 2.71:1,with possible presence of N -acetylated sugar residues in the polysaccharide as con?rmed by NMR spectroscopy.Rheological studies showed that the EPS had higher viscosity in skim milk,at lower temperature,or at acidic pH.The viscous nature of the EPS was con?rmed by observa-tion with scanning electron microscopy that demonstrated a highly branched and porous structure of the polysaccharide.The atomic force microscopy of the EPS further revealed presence of many spherical lumps,facilitating binding with water in aqueous solution.The EPS had a higher degradation temperature (287.7?C),suggesting high thermal stability of the EPS.
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1.Introduction
Exopolysaccharides (EPSs)are extracellular biopolymers that are produced during the metabolic process of microorganisms such as bacteria,fungi,and blue-green algae (Amjres et al.,2014).The EPSs could be either covalently associated with the cell surface forming a capsule,or be loosely attached,or totally secreted into the surrounding environment during the cell growth (Yang et al.,2010).Among the wide variety of EPS-producing microorganisms,lactic acid bacteria (LAB)are generally regarded as safe due to their long history of safe use in human consumption (Nikolic et al.,2012).In
?Corresponding author at:Beijing Laboratory of Food Quality and Safety,Bei-jing Technology and Business University,No.11Fu-Cheng Road,Hai-Dian District,Beijing,100048China.Tel.:+861068984870;fax:+861068985456.
E-mail address:yangzhennai@https://www.doczj.com/doc/4411416972.html, (Z.Yang).
recent years,owing to the unique physicochemical properties and biological activities,the EPSs produced by LAB have been used in a wide range of applications including food products,pharmaceut-icals,bio?occulants,bioemulsi?ers,and chemical products (Ismail &Nampoothiri,2010;Liu et al.,2010;Ye,Liu,Wang,Wang,&Zhang,2012).In the fermented food industry,LAB EPSs are usually used as natural alternatives to commercial stabilizers because of their viscosifying,stabilizing,emulsifying or gelling properties for improving the rheology,texture and mouth-feel of the fermented products including yoghurt and cheese (Ahmed,Wang,Anjum,Ahmad,&Khan,2013).In addition,extensive research has revealed that some EPSs produced by LAB may be correlated with promoting human health and preventing diseases due to their pharmacolog-ical activities,such as immunostimulatory,immunomodulatory,antitumor,antibio?lm,antioxidant,and cholesterol lowering activ-ities (Kanmani et al.,2011;Liu,Chu,Chou,&Yu,2011;Lindstr?m,Holst,Nilsson,?ste,&Andersson,2012;Li et al.,2014a ).Since,
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J.Wang et al./Carbohydrate Polymers125(2015)16–2517
bacterial EPS are generally of protective nature,production of EPS may increase the resistance of the bacteria against unfavorable environmental factors,e.g.,resistance to high acidity and bile salts (de los Reyes-Gavilán et al.,2011).
In the last decade,a large number of EPS-producing LAB have been isolated from a variety of fermented foods such as yoghurt, cheese,sausages,ke?r,wine,and sauerkraut.These LAB strains belong to the species of Streptococcus,Lactobacillus,Pediococcus, Lactococcus,and Bi?dobacterium(Costa et al.,2010;Ramchandran &Shah,2010;Song,Jeong,Cha,&Baik,2013;Prasanna,Bell, Grandison,&Charalampopoulos,2012;Zhang et al.,2013).Among EPS-producing LAB,Lactobacillus plantarum is famous for its poten-tial probiotic properties and has received considerable attention in recent years(Wang et al.,2010,2014;Zhang et al.,2013).It has been shown that the EPS yield,monosaccharide composition and structure are greatly dependent on the producing microor-ganisms,their culture conditions and media compositions(Salazar et al.,2009).L.plantarum C88,an isolate from fermented dairy tofu, is able to synthesize a high molecular mass capsular polysaccha-ride(1.15×106Da)composed of galactose and glucose(1:2)when grown in a semi-de?ned medium(Zhang et al.,2013).L.plantarum 70810isolated from Chinese Paocai could produce two released EPSs with average molecular weights of204.6and202.8kDa,and composed of glucose,mannose,and galactose with molar ratios of18.21:78.76:3.03and12.92:30.89:56.19,respectively(Li et al., 2014b).Besides,L.plantarum KF5isolated from Tibet Ke?r was reported to compose of mannose,glucose,and galactose in an approximate ratio of1:4.99:6.90(Wang et al.,2010).
EPSs produced by L.plantarum will be increasingly applied in the fermented products due to their safe,healthy and desired physicochemical properties in the future,and thus more research is required on the physicochemical,structural,and rheological parameters of the EPS.However,so far most of the reports about EPS are focused on the functional characteristics of the EPS-producing L.plantarum strains.Therefore,in the present study,the EPS from L.plantarum YW11was prepared and characterized by gas chromatography–mass spectrometer(GC–MS),nuclear magnetic resonance(NMR),scanning electron microscopy(SEM),atomic force micrograph(AFM),thermogram analysis(TGA),and differ-ential scanning calorimeter(DSC)in order to evaluate its potential application in food industry.
2.Materials and methods
2.1.Bacterial strain and media
The EPS-producing strain YW11used in this study was isolated from Ke?r grains collected from Tibet.The strain was main-tained as frozen(?80?C)stocks in MRS broth(de Man,Rogosa, &Sharpe,1960)supplemented with20%(v/v)glycerol.The ster-ile semi-de?ned medium(SDM)broth contained(per1L):10g of bactocasitone(Difco),5g of yeast nitrogen base(Difco),2g of ammonium citrate,5g of sodium acetate,0.1g of MgSO4·7H2O, 0.05g of MnSO4,2g of K2HPO4,20g of glucose,and1.0ml of Tween 80,adjusted to pH6.6with1M acetic acid(Kimmel&Roberts, 1998).
2.2.Identi?cation of strain YW11
Strain YW11was primarily identi?ed based on Gram reaction,catalase tests,and cell morphology.Then,the strain was further identi?ed to the species level by API50 CHL test(bio-Mérieux,France)and16S rDNA sequencing analysis.The primers with the following sequences:A27F(5 -AGCGGATCACTTCACACAGGACTACGGCTACCTTGTTACGA-3 )and A1495R(5 -GCAGAGTTCTCGGAGTCACGAAGAGTTTGATCCTGGCTC AG-3 ),were provided by China Agricultural University(Beijing, China).The nucleotide sequences were compared with standard strains for the sequence similarity through BLAST(http://www. https://www.doczj.com/doc/4411416972.html,/blast).
2.3.Analysis of bacterial growth and EPS production
Strain YW11was inoculated in2000-ml Erlenmeyer?asks con-taining1000ml of SDM broth as mentioned above and incubated at37?C.Samples(50ml)were withdrawn at different time inter-vals from0to56h.The pH was determined with a pH meter(FE20, Mettler Toledo,Switzerland).The cell viability was determined by dilution plating with MRS agar medium incubated at37?C for48h. EPS yield(expressed as mg L?1)was estimated by phenol–sulfuric acid method using glucose as a standard(DuBois,Gilles,Hamilton, Rebers,&Smith,1956).
2.4.Isolation and puri?cation of EPS
The EPS was isolated by using the method of Zhang et al.(2013). The crude EPS solution(20mg ml?1,5ml)was fractionated with an anion exchange chromatography on a DEAE-cellulose column (26mm×40cm),eluted with deionized water,0.2and0.5M NaCl solution at a?ow rate of1ml min?1.Every5ml of elution was collected automatically and the carbohydrate content was deter-mined by phenol–sulfuric acid method.Peak fractions containing polysaccharides were pooled,dialyzed,and lyophilized.Further puri?cation of the EPS was performed by a Sepharose CL-6B col-umn(25mm×50cm)and eluted with0.9%(w/v)NaCl at a?ow rate of0.5ml min?1.The polysaccharide fractions were detected, pooled,dialyzed,and lyophilized.
The purity of the?nal puri?ed EPS sample was checked.The total carbohydrate content of the sample was determined by the phenol–sulfuric acid method using glucose as standard.The total protein content of the sample was determined by the method of binding of Coomassie Brilliant Blue G-250to protein,using bovine serum albumin as a standard(Bradford,1976).The uronic acid con-tent was determined by the Dische method,using glucuronic acid as standard(Dische,1947).
The moisture content of the sample was measured by the method of Vijayendra,Palanivel,Mahadevamma,and Tharanathan (2008).The EPS taken in a dish,which was previously dried and weighed,was placed along with its lid in an oven maintained at 105?C for5h and cooled in a desiccator.Drying was repeated till a constant weight was obtained and the percentage of moisture content was calculated.
2.5.Molecular mass determination of EPS
The molecular mass of the puri?ed EPS was measured by gel-permeation chromatography(GPC).The GPC system consisted of a Shodex SB-806m-HQ13?m,300×8.0mm column,connected with a SB-G10?m,50×6.0mm guard column.The EPS were detected using a refractive index detector(RI)(Optilab Wyatt,USA) and a multi angle laser-light scattering detector(MALLS)(DAWN HELEOS-II Wyatt,USA),at an internal temperature of40?C.The column was eluted with0.1M NaNO3solution at a?ow rate of 0.5ml min?1,and the injection volume of sample was200?l,and dn/dc of0.146as a refractive index increment was used for polysac-charides solution(Ai et al.,2008).Data processing was performed with Wyatt Astra software(Version5.3.4.14,Wyatt Technology, USA).
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2.6.Determination of monosaccharide composition of EPS
A total of5mg of the puri?ed EPS were hydrolyzed with2ml (2M)tri?uoroacetic acid(TFA)at120?C for2h.The hydrolysates were then subjected to GC–MS analysis.GC–MS was performed on an Agilent7890A GC?tted with a?ame ionization detector (FID)and a DB-WAX column(30m length×0.25mm inner diam-eter×0.25?m?lm thickness;J&W Scienti?c,Folsom,CA).The operating conditions were determined according to Li et al.(2014a). Sugar identi?cation was done by comparison with standard rham-nose,arabinose,galactose,glucose,mannose,and fructose.
2.7.UV–vis and FTIR spectral analysis of EPS
Ultraviolet–visible(UV–vis)spectroscopy analyses of the EPS were conducted on UV–vis spectrophotometer(U-3900,Hitachi Ltd.,Japan).The EPS solution was prepared by suspending the sam-ple in distilled water for UV–vis measurement in the wavelength range of190–550nm.
The major structural groups of the puri?ed EPS were detected using Fourier transform infrared(FTIR)spectroscopy,and the spectrum of the EPS was obtained using a KBr method.The polysac-charide samples were pressed into KBr pellets at sample:KBr ratio 1:100.The FTIR spectra were recorded on a Bruker Tensor27instru-ment(Germany)in the region of4000–400cm?1.FTIR spectrum was determined in transmission mode and the number of scans was32.The infrared spectral resolution was4cm?1.
2.8.Nuclear magnetic resonance(NMR)spectroscopy analysis of EPS
NMR spectrum of the EPS from strain YW11were obtained using a Bruker AVANCE600MHz spectrometer(Bruker Group,F?llan-den,Switzerland)operated at27?C with a5mm inverse probe. Prior to analysis,samples were exchanged twice in D2O(99.9at %D,Cambridge Isotope Laboratories,Inc.,Andover,MA,USA)with intermediate lyophilization,and then dissolved in D2O at concen-trations of5mg ml?1(for1H NMR)and40mg ml?1(for13C NMR). Chemicals shifts(?)were expressed in parts per million(ppm).The 2D1H13C HSQC experiment was recorded with decoupling during acquisition of the1H FID and used to assign signals.
2.9.Rheological properties of EPS
The rheological behavior of the EPS solutions was carried out in a Brook?eld DV-III ultra-programmable rheometer(Brook?eld Engi-neering Laboratories Inc.,Stoughton,Massachusetts,USA)with a SC4-18spindle that rotated in chamber equipped with tempera-ture control system.The lyophilized EPS sample was dissolved in 0.1M CaCl2,0.1M NaCl solutions,11%(w/v)skim milk,and distilled water at a concentration of2mg ml?1,respectively.To investigate the effect of pH on the viscosity of EPS,the pH of EPS solution was adjusted at levels of4.0,6.0,and7.0by1N HCl and NaOH solu-tions.To investigate the effect of temperature on the viscosity of EPS,the EPS solution was exposed to different temperatures(25, 35,and45?C).The rheological behavior of the EPS was studied by measuring viscosity as a function of shear rate from10to300s?1.
2.10.Scanning electron microscopy(SEM)analysis of EPS
The lyophilized samples of the puri?ed EPS(5mg)were?xed to the SEM stubs with double sided tape,then coated with a layer of gold,～10nm thick.The samples were observed in a scanning electron microscope(S-4800,Hitachi Ltd.,Japan)at an accelerating voltage of3.0kV.2.11.Atomic force micrograph(AFM)analysis of EPS
A stock solution(1mg ml?1)was prepared by adding the puri-?ed EPS into distilled H2O.The aqueous solution was stirred for about1h at40?C in a sealed bottle under N2stream so that EPS dis-solved completely.After cooling to room temperature,the solution was continuously diluted to the?nal concentration of0.01mg ml?1. About5?l of diluted EPS solution was dropped on the surface of a mica sample carrier,allowed to dry at a room temperature.The AFM images were obtained using a Dimension?Icon instrument (Bruker Instruments Co.,Germany)in tapping mode.
2.12.Thermogram analysis(TGA)
The pyrolysis and combustion were carried out in TA SDT-Q600 thermal analyzer operating at atmospheric pressure.The puri?ed sample of EPS(3mg)was placed in an Al2O3crucible and heated at a linear heating rate of10?C min?1over a temperature range of 25–800?C.The experiments were performed in air atmosphere at a?ow rate of100ml min?1.
2.1
3.Differential scanning calorimeter(DSC)
The thermal property of the EPS was analyzed using a DSC(DSC Model Q100,TA instruments).The puri?ed EPS sample(5mg)was placed in an aluminum pan,which was sealed and analyzed using empty pan as a reference.The melting point and enthalpy changes were determined by increasing the heating rate at10?C min?1from 10to400?C(Wang et al.,2010).
3.Results and discussion
3.1.Identi?cation of strain YW11
Strain YW11was primarily identi?ed as L.plantarum by API 50CHL test.Further identi?cation by16S rRNA sequencing con-?rmed that the sequence of strain YW11(Acc.No.KM265361)was identical to those of L.plantarum lp-15(Acc.No.FJ763580),L.plan-tarum LW4(Acc.No.KJ779096)and L.plantarum TW57-4(Acc.No. KJ026699).Therefore,the strain was designated as L.plantarum YW11.
3.2.Bacterial growth and EPS production
Change of pH of the medium and EPS production by L.plan-tarum YW11during growth are shown in Fig.1.L.plantarum YW11 exhibited a fast growth with a rapid decrease in pH of the medium during the?rst8h of incubation,and the viable cell count reached a maximum of9.77log cfu ml?1at16h with pH about4.0.In the late stationary phase of growth(after32h),the viable count decreased gradually to about8.60log cfu ml?1,with a slight decrease in pH to about3.90at56h.EPS production by strain YW11increased rapidly during the initial phase of growth,and continued to increase to 90mg L?1at56h.It seemed that the EPS was not degraded dur-ing the late stationary phase of L.plantarum YW11although the bacterial growth decreased,as previously reported with other EPS-producing L.plantarum strain(Yang et al.,2010).However,EPS production by L.plantarum C88,L.plantarum70810,and L.helveti-cus MB2-1decreased after prolonged incubation,probably due to presence of glycohydrolases in the culture that catalyzed the degra-dation of polysaccharides(Li et al.,2014a;Wang et al.,2014;Zhang et al.,2013).
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Fig.1.Kinetics of growth and EPS production by L.plantarum YW11in a semi-de?ned medium at37?C showing changes of the bacterial cell counts,EPS yield and pH of the medium during the incubation.Each value represents the average of triplicate measurements.
3.3.Isolation and puri?cation of EPS
The crude EPS obtained by ethanol precipitation of the culture supernatant of L.plantarum YW11was?rst separated by anion-exchange chromatography of DEAE-52.Fractions corresponding to the major peak eluted with0.2M NaCl were found to contain polysaccharides.These fractions that contain the EPS,being an acidic polysaccharide as it was eluted with NaCl(Gan,Ma,Jiang, Xu,&Zeng,2011),were further puri?ed by Sepharose CL-6B gel permeation chromatography.A single elution peak was generated, and the corresponding fractions were collected and lyophilized to obtain the puri?ed form of the EPS that was used for the follow-ing physicochemical characterization.Analysis of the puri?ed EPS sample showed that it contained92.35±2.38%of carbohydrate, 2.52±0.12%of moisture,1.38±0.25%of protein,and1.56±0.09% of uronic acids.
3.4.Molecular mass and monosaccharide composition of EPS
The molecular mass of the EPS of L.plantarum YW11was deter-mined by GPC-MALLS-RI(Fig.2).The chromatogram of the EPS appeared as a single symmetrical narrow peak,con?rming the homogeneity of the puri?ed EPS sample.The molecular mass of the EPS was determined to be1.1×105Da(error3.2%),which was similar to that(169.6kDa)of the acidic EPS from L.plantarum70810 (Wang et al.,2014),lower than that(1.15×106Da)of the neutral EPS of L.plantarum C88(Zhang et al.,2013),but higher than that (4.4×104Da)of the EPS of L.plantarum EP56(Tallon,Bressollier,& Urdaci,2003).The polydispersity index of the EPS of L.plantarum YW11was determined to be1.2(error2.5%),which was generally low,indicating no large aggregates formed upon dispersion of this EPS in aqueous solution.The polydispersity index,as a measure of the width of molecular mass distribution,was thought to be impor-tant due to the relevance and signi?cant in?uence of molecular mass distribution on the functional properties of EPS(Zheng et al., 2014).
GC–MS analysis of the monosaccharide composition of the EPS of L.plantarum YW11showed that the EPS was composed of glu-cose and galactose in a molar ratio of2.71:1.Previously,the EPS from L.plantarum C88was shown to contain glucose and galactose, but in different molar ratio(Zhang et al.,2013).Other L.plantarum strains,e.g.,both EP56and KF5produced EPSs consisted of glucose and galactose,and additionally N-acetylgalactosamine(Tallon et al.,2003)and mannose(Wang et al.,2010),respectively.The monosac-charide composition of EPS produced by LAB can be affected by the type of strains,culture conditions,and medium compositions (Wang et al.,2014).
3.5.Spectra analysis of the EPS functional groups
The UV–vis spectrum of the puri?ed EPS from strain YW11 showed no absorption at260nm or280nm,indicating no nucleic acid present in the EPS sample.The FTIR spectrum(Fig.3)of the EPS indicated that the polysaccharide contained a signi?cant number of hydroxyl groups as it displayed a broad and intense stretching peak around3408cm?1(Wang et al.,2010).The stretching band around 2933cm?1was due to C H stretching vibration(Melo,Feitosa, Freitas,&de Paula,2002).The absorptions at1726and1646cm?1 were due to the stretch vibration of C O bond(Ye et al.,2014),and a peak at1550cm?1could be assigned to N H bending of amides II of protein(Lin et al.,2005).The absorption at1384cm?1was pos-sibly due to symmetric CH3bending(Pan&Mei,2010).The bands within the900–1150cm?1region were attributed to the vibration of C O C bond(Ye et al.,2014).
3.6.NMR analysis of EPS
The1H NMR and13C NMR spectroscopy of the EPS from strain YW11are shown in Fig.4.Three major chemical shift signals in the anomeric region(?4.8–5.5ppm)were found at?5.22,5.07,and 4.97ppm in1H NMR(Fig.4A).This indicates that the EPS from strain YW11mainly consists of three monosaccharide residues. Based on their chemical shift and the value of the coupling con-stant for anomeric signals in the1H NMR spectrum,three signals were corresponds to C-1of?-type con?gurations.The13C NMR spectrum(Fig.4B)of EPS from strain YW11included anomeric car-bons regions(95–110ppm)and ring carbons(50–85ppm)regions. Based on the data reported previously(Li et al.,2014;Wang et al., 2014),the three main signals in the anomeric carbons regions at?104.58,104.05,and101.21ppm were corresponded to the ?-linkages.Although no amino sugars were detected by monosac-charide analysis of the EPS as described above,the13C NMR spectrum demonstrated two signals between50and60ppm,and several signals at22.85,174.82,175.30ppm that were probably from C-2and N-acetyl group of the amino sugar,respectively,indi-cating possible presence of this sugar in the EPS of strain YW11.
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Fig.2.GPC-MALLS-RI chromatogram of EPS from L.plantarum YW11.
The single-bond correlations between the protons and the cor-responding carbons obtained from 2D 1H 13C HSQC spectrum (Fig.4C)of the EPS from strain YW11in D 2O demonstrated three crosspeaks in the anomeric region resulted from cross link of the C-1signals at ?104.58,104.05,and 101.21ppm to the proton signals at ?5.22,5.07,and 4.97ppm,respectively,con?rming presence of three monosaccharide residues in the repeating unit of the polysac-charide.Detailed chemical structure of the EPS from strain YW11needs to be further studied.
3.7.Rheological properties of EPS
The rheological behavior of the EPS from strain YW11was studied in water,skim milk,different salt solutions (NaCl and CaCl 2),and at different pH (4,6,and 7)and temperatures (25,35,and 45?C)(Fig.5).All the EPS solutions showed a shear thin-ning behavior,a decrease of viscosity with increasing shear rates that was caused mainly by breakdown of structural units in the EPS by hydrodynamic forces generated during shear (Kavita,Singh,Mishra,&Jha,2014).This property was considered to be impor-tant for yielding desired sensory properties such as mouth-feel and ?avor release properties,as well as some processing opera-tions such as stirring,pouring,pumping,spray drying (Zhou et al.,
2014).The EPS in skim milk was shown to be more viscous than in water over the whole shear rate range (Fig.5A).However,no obvious difference in viscosity was observed with the EPS in 0.1M NaCl solution or in 0.1M CaCl 2solution at all the shear rates tested (Fig.5B).The higher viscosity of the EPS solution at acidic pH (4,6)than at a neutral pH (7.0)(Fig.5C)would be bene?-cial to the use of this EPS-producing strain to improve texture of fermented milk that usually has pH values between 4.0and 4.5.Ahmed et al.(2013)also reported that an EPS produced by L.ke?ranofaciens ZW3was more viscous at acidic pH than alka-line pH.Studies on the effect of temperature (Fig.5D)showed that increasing temperature from 25to 35?C did not affect the vis-cosity of the EPS solution over the whole shear rate range,but further increasing to 45?C resulted in decreased viscosity.Sim-ilarly,an acidic EPS produced by Streptococcus phocae PI80had decreased viscosity with increasing temperature from 25to 45?C (Kanmani et al.,2011).This decrease in viscosity of EPS solution might be attributed to the decreased interactions between the EPS molecules when temperature was increased,thus leading to a loos-ened polymer structure.Therefore,the rheological behavior of the EPS produced by L.plantarum YW11as described above would make it particular suitable as a potential stabilizer used in dairy
foods.
Fig.3.UV spectrum of the puri?ed EPS from L.plantarum YW11in the range of 190–550nm (A);FTIR spectrum of the puri?ed EPS in the range of 400–4000cm ?1(B).
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Fig.4.The1H NMR(A),13C(B),and1H13C HSQC(C)NMR spectra of the puri?ed EPS from L.plantarum YW11recorded on Bruker AVANCE600MHz spectrometer in D2O.
3.8.Scanning electron microscopic(SEM)analysis of EPS
The microstructures of the EPS from strain YW11and xan-than gum as a reference material are represented by SEM(Fig.6). The EPS showed a relatively stable three dimensional structure that appeared to be a porous web(Fig.6A),whereas the xan-than gum showed a dispersive structure with irregular lumps of different size(Fig.6C).At a higher magni?cation(Fig.6B and D),additional details of the microstructure of the EPS and xan-than gum were visible.The EPS had a smooth and glittering surface,but xanthan gum presented a coarse surface.Similar porous structures were also reported with the puri?ed EPSs of Bi?dobacterium longum subsp.infantis CCUG52486and Bi?dobac-terium infantis NCIMB702205(Prasanna et al.,2012).However, Wang et al.(2010)observed a sheet-like compact morphology of the EPS from L.plantarum KF5.The highly branched and porous structure of the EPS from strain YW11as observed in this study may facilitate its application in foods to improve the physical properties, e.g.,viscosity,water-holding capacity of the prod-uct.
3.9.Atomic force micrograph(AFM)analysis of EPS
In recent years exopolysaccharide has been studied extensively by using atomic force microscopy that provides a powerful tool to characterize the morphological features of polymers(Admed et al., 2013).Images of the strain YW11EPS deposited from0.01mg ml?1 aqueous solution were obtained by AFM(Fig.7).There was pres-ence of many spherical lumps with the height ranged from3.0 to13.5nm.Some regions formed?brous network,whereas other regions were relatively sparse,suggesting that the structure of the EPS might be tangled networks,which was in agreement with its ?brous morphology in dry solid form.This structural property of the EPS was also observed earlier with another viscous polysac-charide from Mesona blumes gum that had irregular worm-shaped structure(Feng,Gu,Jin,&Zhuang,2008).The viscous nature of the
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Fig.5.Rheological behavior of the EPS from L.plantarum YW11in distilled water and skim milk (11%,w/v)(A),in 0.1M NaCl and CaCl 2(B),at different pH values (4,6,and 7)(C),and at different temperatures (25,35,and 45?C)(D).
EPS from strain YW11described above might also be caused by its capability of binding with water in the aqueous solution.
3.10.Thermogravimetric analysis (TGA)
The thermogravimetric analysis (TGA)of the EPS from L.plan-tarum YW11was carried out dynamically between weight loss vs.
temperatures.As shown in Fig.8A,the EPS showed an initial weight loss of approximately 11.64%between about 25and 100?C.This ini-tial weight loss may be associated with the loss of moisture (Wang et al.,2010),suggesting high content of carboxyl groups in the EPS molecules.Kumar,Joo,Choi,Koo,and Chang (2004)reported that the high level of carboxyl group in the EPS increased the degrada-tion of the ?rst phase as carboxyl groups were bound to more
water
Fig.6.Scanning electron micrograph images of the puri?ed EPS from L.plantarum YW11(A:1000×,B:5000×)as compared to a reference material xanthan gum (C:1000×,D:5000×).
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Fig.7.Atomic force microscopy images of the puri?ed EPS from L.plantarum YW11(A)planar,(B)
cubic.
Fig.8.Thermogravimetric mass loss spectrum (A,left hand ordinate ordinate axis),and differential thermogravimetric mass loss spectrum (B,right hand ordinate axis)of the puri?ed EPS from L.plantarum YW11.
molecules.A degradation temperature (Td)of 287.7?C and a large weight loss of approximately 69.93%could be observed from the differential thermogravimetric mass loss spectrum (Fig.8B)and thermogravimetric mass loss spectrum (Fig.8A)for strain YW11EPS between about 200and 300?C.Then the weight loss gradually
decreased to leave a ?nal residue of ca.16.07%of the total EPS.Ahmed et al.(2013)and Wang et al.(2010)showed that the degra-dation temperatures of ZW3EPS,KF5EPS,xanthan,and locust gum were 299.62,278.53,282.65,and 278.46?C,respectively.The degra-dation temperature of the EPS from strain YW11in the
present
Fig.9.DSC thermogram of the puri?ed EPS from L.plantarum YW11.
24J.Wang et al./Carbohydrate Polymers125(2015)16–25
study was within the range of the KF5EPS and ZW3EPS,but slightly higher than xanthan gum and locust gum.The different thermal stability and degradation behavior of these EPSs proba-bly attributed to their different carbohydrate compositions.Due to the relatively higher degradation temperature of the EPS from strain YW11,it would be safe for use of this EPS in dairy indus-try where in most of the processes temperature seldom overpasses 150?C.
3.11.DSC analysis
Commercial application of an EPS is crucially dependent on its thermal and rheological behavior.DSC analysis of the EPS from strain YW11showed an exothermic peak with heat?ow from10to 400?C(Fig.9).The melting point of the EPS exothermic peak started at about143.6?C,and the enthalpy change( H)needed to melt1g of EPS was217.8J.Different results were reported previously for different EPSs.Wang et al.(2010)showed that the melting point and enthalpy change of KF5EPS isolated from L.plantarum KF5 were88.35?C and133.5J g?1,respectively.Kanmani et al.(2011) reported that the melting point of the EPS from S.phocae PI80 endothermic peak started at120.09?C and the enthalpy change was about404.6J g?1.Thus the EPS from strain YW11showed a different thermal behavior from these EPSs.
4.Conclusion
In this study,an EPS-producing strain YW11isolated from Tibet Ke?r was identi?ed as L.plantarum.The EPS from YW11was com-posed of glucose and galactose in a molar ratio of2.71:1,with possible presence of N-acetylated sugar residues in the polysaccha-ride.The EPS had a molecular mass of1.1×105Da.It exhibited a shear thinning behavior under different conditions and had higher viscosity in skim milk,at lower temperature and acidic pH.The SEM images of the EPS demonstrated a porous structure that was highly branched,while the AFM images of the EPS revealed presence of many spherical lumps.Furthermore,the EPS had a higher degra-dation temperature.These characteristics of the EPS produced by L.plantarum YW11would make it a promising candidate for its exploitation in food industry.
Acknowledgment
This work was?nancially supported by The Key Project of the Educational Committee of Beijing City(KZ201310011011),Natu-ral Science Foundation of China(31371804),and National Public Bene?t Research(Agriculture)Foundation(201303085). References
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西藏自治区劳动合同 编号甲方（用人单位）名称：法定代表人（委托代理人）：联系电话：地址：乙方（劳动者）姓名：性别： 家庭住址：身份证号码：联系电话：根据《中华人民共和国劳动法》、《中华人民共和国劳动合同法》和《西藏自治区关于全面实行劳动合同制度的意见》，甲乙双方在平等自愿、协商一致、诚实信用的基础上，签订本劳动合同，共同遵守执行。 一、劳动合同期限 第一条甲乙双方约定按下列种方式确定劳动合同期限： （一）有固定期限：自年月日起至年月日止。 （二）无固定期限：自年月日起至甲乙双方约定的劳动合同终止条件出现时止。 （三）以完成一定的工作为期限:自年月日起至。 其中，试用期自年月日起至年月日止。 二、工作内容及工作地点 第二条根据甲方工作需要，乙方同意从事工作。经甲乙双方协商同意，可以变更工作岗位。 第三条乙方应按照甲方的要求，按时完成规定的工作数量，达到规定的质量标准。 第四条乙方的工作地点。 三、工作时间和休息休假 第五条甲方安排乙方执行工时制。 （一）实行标准工时工作制的，甲方安排乙方每日工作时间不超过8小时，每周不超过40小时。甲方由于工作需要，经与工会和乙方协商后可以延长工作时间，一般每日不得超过1小时，因特殊原因需要延长工作时间的，在保障乙方身体健康的条件下延长工作时间不得超过3小时，每月不得超过36小时。 （二）实行综合计算工时工作制的，平均每日工作时间不得超过8小 时，平均每周工作时间不得超过40小时。 （三）实行不定时工作制的，工作时间和休息休假由乙方自行安排。实行综合计算工时或不定时工作制的，要经当地人力资源和社会保障行政部门批准。 第六条甲方安排乙方延长工作时间、休息日、法定节假日工作的，按照《劳动法》第四十四条执行。 第七条乙方在合同期内享受国家规定的各项休息、休假的权利，甲方应保证乙方每周至少休息1天。 四、劳动保护、安全卫生和劳动条件 第八条甲方必须执行国家和自治区有关劳动安全卫生的法规标准，采取劳动保护措施，提供和改善劳动条件，建立安全生产规章制度，保证安全生产和劳动者健康。 第九条甲方应根据国家有关规定，给乙方发放劳动保护用品，保健食品。 第十条甲方应对乙方进行安全生产教育和技术培训，乙方从事特种作业的，必须经专业训练，并经地、市及其以上人力资源和社会保障行政部门考核合格发证后持证上岗。 第十一条甲方不得安排未成年工从事矿山井下，有毒有害国家规定的第四级体力劳动强度的劳动和其他禁忌从事的劳动。 第十二条甲方应按国家有关规定，不得安排女职工禁忌从事的劳动和工作岗位。
保护生态环境-建设美丽西藏
浅谈保护生态环境、建设美丽西藏 作者：旦增格桑曲古 地球是我们共同的母亲，大自然是我们赖以生存的环境，而丰富的自然资源是大自然赐给我们的财富。可是近几年来，由于科学的飞速发展，在一定程度上也造成了对生态环境的破坏，使很多资源濒临灭绝。这一点已引起了全世界的关注。科技的发展，对人类来说当然是好事，可是在一定意义上来说，也是对生态环境的破坏。自然资源的减少；动植物的灭绝；对环境的破坏…… 西藏自治区位于青藏高原的主体，地势高峻，地理特殊，野生动植物资源、水资源和矿产资源丰富，素有“世界屋脊”和“地球第三极”之称。这里不仅是南亚、东南亚地区的“江河源”和“生态源”，还是中国乃至东半球气候的“启动器”和“调节区”。 政府高度重视西藏的生态建设与环境保护，为加强西藏的生态建设与环境保护，促进西藏经济、社会可持续发展，提高各族人民的生活质量，做出了巨大的努力。半个多世纪以来，西藏的生态建设与环境保护作为西藏现代化建设的一项重要内容，与经济发展、社会进步、人民生活的提高同步推进，取得了重大成就。 一、西藏生态环境的现状
（1）西藏高原气候寒冷、干旱、缺氧，90%以上国土处在高寒下，自然环境严酷导致生态系统具有不稳定性、敏感性、易变性等脆弱性特征。 (2)西藏生态环境的多样性。由于地形地貌类型多样且地域差异很大，形成了从热带到寒带、从低山谷地到高原高山等多样性生态环境。 (3)西藏高原是全球独特的生态地域，生态安全阈值幅度窄，环境人口容量低，生态系统一旦破坏，很难恢复甚至成为荒漠、裸地。 (4)西藏地区的生态环境受全球气候变暖和人类活动的综合影响, 呈现出生态系统稳定性降低、资源环境压力增大等问题,突出表现为:冰川退缩显著、土地退化形势严峻、水土流失加剧、生物多样性威胁加大与珍稀生物资源减少、自然灾害增多等。 青藏高原地区是我国冰川的集中分布区，冰川储量5590立方千米，近30年冰川消融明显，面积减小15%以上；西藏全区沙漠化呈现不断发展的态势，沙化与潜在沙化土地达21万平方公里，荒漠化面积达43万平方公里，分别占全区总土地面积的18.1%和36.1；2西藏的草原总面积12.44亿亩,其中一半以上的草场严重退化，1/10的草场明显沙化，西藏全区已经退化而不能放牧的草场面积达1.7亿亩3。随着工业化进程的推进、公路铁路等交通条件的改善、社会经济的发展和人口的持续增长, 生态环境问题日益突出，生态安全形势依然严峻 二、保护生态环境对西藏建设的重要性
金家律师修订 本协议或合同的条款设置建立在特定项目的基础上，仅供参考。实践中，需要根据双方实际的合作方式、项目内容、权利义务等，修改或重新拟定条款。本文为Word格式，可直接使用、编辑或修改 外聘人员合同 甲方：____________________________________________ 乙方（以下简称乙方）：_____________________________ 身份证：___________________________________________ 家庭住址：_________________________________________ 经甲乙双方协商达成聘用合同，条款好下： 一、试用期及录用 （一）甲方依照合同条款聘用乙方为员工，乙方工作部门为财务部，职位记账会计，乙方经过一个月的试用期间，在此期间，甲乙任何一方有权终止合同，但必须提前七天通知对方。 （二）试用期满，双方无异议，乙方成为甲方的正式合同制劳务工，甲方将以书面方式给予确认。 （三）乙方试用合格后被正式录用，试用期应计算在合同有效期内。 二、工资及其它补助奖金。 甲方根据国家有关规定，经双方协商甲方发给乙方工资标准3000元/月，甲方负责给乙方购买五险一金。 、甲方根据本企业利润情况设立年终奖金，可根据员工劳动表现及在单位服务年限发放奖金。 甲方根据政府的有关规定和企业状况，向乙方提供津贴和补助金。 除法律、法规、规章明确提出的要求补助外，甲方将不再有义务向乙方提供其它补助津贴。 三、工作时间及公假 （一）乙方的工作时间每天为7小时，每星期工作五天。 （二）乙方有权享受法定节假日以及婚假，丧假等有薪假期。甲方如要求乙
编号：12320923MB0087484Y -0004 江苏省事业单位 聘用合同书 （2009版） 聘用单位(甲方)：板湖镇人民政府 地址：板湖镇振兴路1号 法定代表人:戴斌 (或委托代理人) 受聘人员(乙方)： 身份证号码：□□□□□□□□□□□□□□□□□□江苏省人力资源和社会保障厅印制
填写说明 1．填写聘用合同书一律用蓝、黑墨水书写，字迹清晰、工整，涂改处必须加盖校对章，否则无效。 2．本聘用合同书须由甲方法定代表人或具合法授权的委托代理人与受聘人员双方亲自签订。乙方因故确需代签的，须经本人书面委托，否则代签无效。代签合同委托函由甲方收执。 3．本聘用合同书内的年、月、日一律用公历和阿拉伯数字填写，工资报酬等金额一律使用大写。
根据《国务院办公厅转发人事部关于在事业单位试行人员聘用制度意见的通知》和《江苏省事业单位人员聘用制暂行办法》的有关规定，甲乙双方在平等自愿、协商一致的基础上，签订本合同并遵照执行。 第一条聘用期限 本聘用合同期限按下列第项确定: 1．聘用期限为年，自年月日起，至年月日止。其中试用期为个月，自年月日起，至年月日止。 2．聘用期限自签订之日起，至乙方达到国家规定的退休年龄之日终止。 3．甲方聘用乙方完成工作任务，聘用期限自年月日起至该项工作完成。 第二条聘用岗位 1．甲方聘用乙方在部门工作。本岗位名称为，类别和等级为下列第项： （1）专业技术级岗位；（2）管理（职员）级岗位；（3）工勤技能级技术工岗位；（4）普通工岗位。 2．甲方根据工作需要和乙方所具备的工作能力、岗位任职条件，聘用乙方在本岗位工作。本岗位工作职责、工作任务、工作标准、聘用条件等见《岗位说明书》。《岗位说明书》作为本合同的附件。乙方已知悉《岗位说明书》内容。 3．甲方根据工作需要和乙方的工作能力及表现等情况可以调整乙方的工作岗位，但应征得乙方的同意并签订聘用合同变更书。 第三条岗位纪律 1．甲方应当制定具体、明确的单位内部岗位职责，建立健全考核制度，做到职权清楚、责任明确、考核公正、奖惩分明。 2．甲方有权在不违反国家现行有关法律、法规和人事管理政策的前提下，制定本单位具体的内部管理规章制度；乙方若有违反，甲方可以按规定给予相应的处理。 3．甲方依法制定的内部规章制度须经职工代表大会或职工大会通过，并向乙方履行告知义务。 4．乙方应当遵守国家的法律、法规、规章和甲方依法制定的各项规章制度，严格遵守岗位职责要求的工作规范和各项安全操作规程，服从甲方的领导和管理，诚信守职，努力完成本职工作。 5．乙方对工作中涉及到甲方的商业秘密或岗位秘密的，应履行保密义务。乙方若有泄密行为，应承担相应责任并按双方的约定支付违约金，给甲方造成损失的，须赔偿损失。
西藏民族文化旅游资源的保护性开发 基于产权经济理论和关联博弈理论双重视角 唐 剑 贾秀兰2 [内容摘要]本文以巴泽尔产权经济模型为理论基础,分析了西藏民族文化旅游资源的 特殊产权属性,指出西藏民族文化旅游资源在开发中受到破坏的制度经济学根源,并 提出以关联博弈为基础健全社会声誉机制,规范利益博弈强势方的开发行为,基于产 业发展的三大维度原则,构建西藏民族文化旅游资源的保护性开发体系。 [关键词]西藏民族文化;旅游资源;产权经济理论;关联博弈理论 在独特的地理位置、气候条件、资源环境和宗教习俗的约束下,西藏地区经济相对落后,但拥有丰富的自然旅游资源和民族文化旅游资源,尤其是藏民族灿烂辉煌的文化资源。由于地理环境因素使西藏地区的行为文化、宗教文化和艺术文化表现出相当的完整性和充分的独特性,这些独特的文化传统和行为方式形成了西藏旅游业快速发展的持续竞争优势。进入21世纪,西藏已成为全国乃至全世界的著名旅游目的地。西藏旅游业以其强劲的发展势头在六大支柱产业中的重要地位越来越突出,成为西藏经济跨越式发展的动力。2006年,随着青藏铁路的开通,进藏旅客首次突破250万人次,旅游业总收入突破27亿元人民币,全区共有2 9万名农牧民参与旅游服务,同比增长49%,人均增收5318元,同比增长153%。[1]近年来,以西藏为目的地主题旅游持续升温,据统计数据显示,从2006年到2009年,西藏旅游业总收入年均增长率超过40%。旅游开发促进了西藏经济的发展,提高了居民的生活水平。 项目基金:2009国家社科基金西部项目(09XMZ007)阶段性研究成果;西南民族大学中央高校基本业务专项基金(10SZY ZJ15)阶段性研究成果。 作者简介:唐 剑(1977 ),男,西南民族大学政治学院(成都,610041)。研究方向:中国经济改革与发展。 贾秀兰(1956 ),女,西南民族大学政治学院(成都,610041),教授。研究方向:马克思主义经济 理论与现实。
( 管理体系 ) 单位：_________________________ 姓名：_________________________ 日期：_________________________ 精品文档 / Word文档 / 文字可改 安全标准化和6S管理(新版) Safety management system is the general term for safety management methods that keep pace with the times. In different periods, the same enterprise must have different management systems.
安全标准化和6S管理(新版) 安全标准化，就是将标准化工作引入和延伸到安全工作中来，它是企业全部标准化工作中最重要的组成部分。其内涵就是企业在生产经营和全部管理过程中，要自觉贯彻执行国家和地区、部门的安全生产法律、法规、规程、规章和标准，并将这些内容细化，依据这些法律、法规、规程、规章和标准制定本企业安全生产方面的规章、制度、规程、标准、办法，并在企业生产经营管理工作的全过程、全方位、全员中、全天候地切实得到贯彻实施，使企业的安全生产工作得到不断加强并持续改进，使企业的本质安全水平不断得到提升，使企业的人、机、环始终处于和谐和保持在最好的安全状态下运行，进而保证和促进企业在安全的前提下健康快速的发展。 “6S”（整理、整顿、清扫、清洁、素养、安全）管理是通过现场现物的规范，明确“场所、方法、标识”、确定“定点、定容、定
量”及大量使用“目视”“看板”管理等方法、手段，构筑一个整洁、明了、一目了然的工作现场，确保空间有效利用，减少各种“寻找”的时间，提高效率，创造明朗、有序的工作环境。让员工养成革除马虎之心、认真对待每一件小事、有规定按规定去做的良好习惯，最终达成全体员工不断寻求改善的职业素养的目的。整理就是把生产现场要与不要的东西分开，去除不要的东西；整顿就是把用的东西用最易于使用的方式放好；清扫就是保持，不断提升；清洁就是用制度保证以上的成果；素养就是使人们养成认真对待每一件小事，尊重他人劳动，严格遵守既定要求的习惯；安全就是努力实现“零”事故。“6S”管理是追求完美的精益生产方式成功导入的基础。 开展安全标准化和“6S”工作的好处： 1、建章立制，形成标准化管理模式； 大家普遍认识到，没有规矩，不成方圆。建章立制是企业管理的基础性工作，是开展安全质量标准化和搞好安全生产工作的前提。“6S”管理标准包括规章、制度、规程、标准等，只有抓好这些基础工作，搞好基础业务建设，才能为开展安全质量标准化工作搞好
外聘人员劳动合同 甲方：_____________________________________ 乙方：_____________________________________ 按照《中华人民共和国劳动法》和《合同法》的有关规定，甲方因生产（工作）需要与乙方在平等自愿、协商一致的基础上签订本劳动合同，建立劳动关系。劳动合同依法订立即具有法律约束力，甲、乙双方必须严格履行。 一、劳动合同期限 本合同自年月日起至年月日为止，试用期三个月。 二、生产（工作）内容 1、甲方根据生产（工作）需要，安排乙方在岗位（部门）从事生产（工作）。 2、甲方根据生产（工作）需要，在劳动合同期限内可以调换乙方的生产（工作）岗位或部门。 三、劳动保护和劳动条件 1、甲方应合理安排乙方进行生产（工作），并提供相关的劳动工具和生产设备。 2、甲方按照国家职业安全卫生等规定，向乙方提供必要的生产（工作）环境及条件，提供劳动保护用品、卫生健康、防暑降温和冬季取暖等。 3、甲方按照国家法律规定保证乙方的工作时间和休息（休假）时间。 四、劳动报酬及保险福利待遇 1、甲方参照社会、行业工资水平，实行谈判工资制，确定乙方的月薪。 2、甲方以按劳分配为主、效率优先、兼顾公平的分配原则，实行以岗定薪、岗变薪变，根据乙方完成的劳动数量和质量，以货币形式按月向乙方支付工资。 3、甲方支付的谈判工资，包含乙方的基本养老、医疗、工伤、失业、生育和住房 公积金单位和个人部分，均由乙方自行缴纳。 员工因工伤亡（患职业病）的各项待遇，按国家和企业的有关规定办理。 5、员工患病或非因工负伤的医疗期，按劳动部和的企业的规定执行。医疗期内的病假工资和有关待遇，按国家和企业的规定办理。 6、女职工孕期、产期、哺乳期的各种待遇，按国家和企业有关规定办理。 五、教育培训
西藏的生态环境保护 西藏自治区环境保护局 西藏日报20030326第2版 西藏自治区位于中国西南边陲，土地总面积120多方平方公里，约占中国国土总面积的l/8为中国第二次省区。西藏是青藏高原的主体，拥有独特的地理和自然环境，有着极为丰富的野生动植物资源和矿产资源，是世界上环境质量最好的地区之一。西藏不仅是我国、南亚、东南亚地区的“江河源”和“生态源”，还是我国乃至东半球气候的“启动器”和“调节区”，全球生态战略地位十分重要。 一、西藏的生态环境特征 西藏的生态环境具有鲜明、突出的地方特色，其原始性、多样性、特殊性、地域差异性、自然与人文的融合性在我国乃至世界具有独特的优势。同时，由于地处高原，我区的生态环境也存在脆弱性、干燥性和不稳定性等劣势。 (一)西藏生态环境的优势 l、西藏生态环境的高原性与特殊性西藏作为青藏高原的重要组成部分，具有地质历史最年轻和海拔高度最大的特点，是世界上特殊的地理环境单元。由此而形成的特殊的生态与环境的组合体，使得生态环境具有较强的高原性，产生世界上所没有的许多特殊的优势环境资源和生态资源，为西藏高原特色经济的形成与发展提供了许多有利的条件。 2、西藏生态环境的原始性 西藏幅员辽阔，人口密度低，是我国地广人稀，面积最大的一个地区，人类活动对生态环境的影响较小，许多地方迄今仍是人迹罕至的处女地，生态环境处于原始状态；还有不少地方，虽有人类活动，但活动强度小，基本上处于自然状态。生态环境的原始性有利于建设国家级和世界级水平的自然保护区和生态功能保护区。 3、西藏生态环境的多样性 西藏地势变化明显，地貌类型多样，自然条件地域差异很大，由此形成了各种各样和形形色色的生态环境类型，既有从热带到寒带的生态环境类型，又有从低山谷地到高原高山的生态环境类型，同时还有多样性的人工生态环境类型和原始状态下的自然生态环境类型。多样性的生态环境类型为多样性的生态系统类型和多样性生物物种资源的形成与发育提供了非常良好的条件，为西藏生物资源的开发利用和生态旅游资源的开发提供了有力的基础。 4、西藏特殊自然生态环境与特殊人文环境的融合性。 西藏的高山自然神奇风光与藏传佛教文化艺术和文化胜迹的有机融合，成为世界上独一无二的天人合璧的壮丽而又神秘的旅游瑰宝，为建立具有世界水平的旅游圣地提供了十分优越的条件，也为西藏经济社会的发展提供了巨大的潜力。 5、西藏生态环境资源的地域差异性 复杂的地形和强烈的地理分异，使西藏生态环境资源(主要为农、林、牧)的地区差异明显。耕地集中在藏中南部地区的河谷地带，而广大北部和西北部地区形成了几乎清一色的牧业；东部和东南部山地区是林地集中分布区。这种强烈的生态环境资源的地区反差有利于地区专业化的发展，有利于在自然分异基础上形成完善的劳动地域分工。这种生态环境资源地域差异性是西藏生产力布局调整和资源合理配置的基础。 此外，作为生态环境资源的高原强光照和强太阳辐射形成有利于植物和作物生长的“热岛效应”，表现为西藏高原温度、积温有效性和太阳有效辐射等比同纬度东部地区相同高度高，其结果有利于生态系统生物生产力的提高，农作物单位面积产量高达1．5万kg／hm2，森林平均生长量达4．46m3／hm2·a，这些现象均为其它地区所少见。 上述生态环境上的优势，可以形成具有鲜明地方特色的经济优势，进而促进全区生态环境和经济社会可持续发展。
日照市中小学安全管理规范化标准 （试行） 为加强学校安全管理，确保校园和谐、师生平安，根据《山东省中小学幼儿园安全管理暂行办法》及有关法律法规，特制定日照市中小学安全管理规范化标准。 一、设立安全组织机构 1.学校建立由校长任组长、副校长任副组长，相关人员和家长委员会代表为成员的学校安全工作领导小组。 2.学生规模300人以上的学校必须有专职安全工作人员，300人以下学校可安排安全工作人员。 3.建立安全工作例会制度，定期汇总情况、查找问题、整改隐患，会议记录健全。 二、安全责任制落实 4. 校长为学校安全第一责任人，分管安全工作的副校长为安全工作的直接责任人。其他学校领导成员根据工作分工承担相应安全责任。 5.实施全员安全责任制。明确各岗位和每个教职工的安全工作职责。校长与所有教职工签订岗位安全年度工作目标责任书。 6.安全工作列入学校工作重点，年度有计划、有总结。 7.安全工作重点部位、重点区域有明确责任人员和工作职责。 三、安全制度制定和实施
8.学校应建立相关安全制度，内容包括教育教学安全、校园及周边安全、消防安全、饮食卫生安全、校车安全、传染病防控、自然灾害预防、突发事件应急等管理制度。 9.重点部位的安全制度和职责应张贴上墙，师生对各项安全管理制度知晓率高。 10.建立学校安全项目定期检查制度。对学生宿舍、食堂、教学场所等重点部位的检查次数和标准符合规定。安全项目检查和整改档案完整。对检查发现的重大安全问题，要及时上报有关部门。 11.建立学校岗位安全责任制考核奖惩办法，考核结果与绩效工资挂钩。 12.设立学校安全隐患举报信（邮）箱，建立举报表彰制度。 四、安全教育 13.加强对教职工安全知识技能培训。内容包括：岗位职责、安全法规、安全制度、应急预案，及指导学生开展事故预防、避险、自救等活动的能力。 14.开设学生安全教育课程，完成规定的教学任务。学生掌握防火、防震、防溺水、防突发伤害、防拐骗诈骗、防交通事故、防饮食卫生事故和防传染病事故等有关技能知识，熟记急救、报警等求助电话。 15.开展丰富多彩的安全教育活动。学期初、放假前及安全教育日要对学生集中进行安全教育；利用班会、晨会、广播、黑板报、学生大会等形式，对学生进行日常安全教育；开展“每日一案例”安全
外聘人员协议样本 Effectively restrain the parties’ actions and ensure that the legitimate rights and interests of the state, collectives and individuals are not harmed ( 协议范本 ) 甲方：______________________ 乙方：______________________ 日期：_______年_____月_____日 编号：MZ-HT-068943
外聘人员协议样本 甲方： 乙方：姓名：性别：出生日： 身份证号码：民族： 为实现投资经营与职业经理人的有效结合，经甲乙双方友好协商，通过相互了解、达成共识、就甲方聘用乙方为江西鹰潭浪淘沙美食水疗会总经理事宜，组建管理队伍，实施经营管理，达成如下协议，并共同信守协议各项条款。 第一条：甲方聘请乙方出任江西*淘沙美食水疗会总经理，由乙方配备管理人员2名，专职营销经理1-2名，全面经营该会所，负责市场策划、市场营销、日常经营管理，其工作绩效向董事长及董事会负责。 第二条：江西*淘沙美食水疗会会馆的企业运营实施职业经理人
总经理负责制，按董事会的经营指导方针，做好企业的正常经营，安全保障，资产的保值保全；以获取最大经营利润为经营中心；以创造企业持续发展的品牌经营为己任。享受董事长及董事会特许的福利待遇，明确所授权的责任和权力。 第三条：因甲方投资项目为特殊行业，经友好协商，乙方除享受国家规定的法定节假日外，每月公休为四天，乙方如因工作需要不能休息，可按公司规定给予补休。 第四条：因乙方管理绩效所需甲方聘用乙方的薪资实行“年工薪制度”及绩效利润分成方式；a：甲方支付乙方劳动报酬为税后工资年薪24万元人民币，以月形式支付1.8万元/月，支付日期为每月五号（其中包括：基本工资、、职务补贴、岗位补贴、高温补贴。通讯费用。）；余薪2万4000元在每年元月五号以十三个月薪资的形式发放。b：绩效考核工资为全年的纯利润的分红模式执行；具体方式如下：全年的纯利润的10%归乙方分红所得。如中途解聘分红为去年纯利润的5%为补偿。 第五条：为提高办事效率及对外经营需要，甲方为乙方配备办
Both parties jointly acknowledge and abide by their responsibilities and obligations and reach an agreed result. 甲方：___________________ 乙方：___________________ 时间：___________________ 事业单位聘用合同书
编号：FS-DY-20893 事业单位聘用合同书 甲方（聘用单位）：_____ 法定代表人：_____ 地址：_____ 乙方（受聘人员）：_____ 性别：_____ 民族：_____ 出生年月：_____ 参加工作时间：_____ 学历：_____ 专业技术职务任职资格：_____ 身份证号码：_____ 住址：_____ 根据有关法律、法规、规章和《浙江省事业单位人员聘用制度试行细则》（浙政办发（XX）117号），甲乙双方在平
等、自愿、协商一致的基础上，签订本聘用合同。 一、聘用合同期限 按下列第_____项执行： （一）本合同为有固定期限合同。合同期自_____年_____月_____日起至_____年_____月_____日止。 （二）本合同为无固定期限合同。合同期自年_____月_____日起至法定或约定的终止（解除）合同的条件出现时止。 （三）本合同为以完成一定工作为期限的合同。合同期自_____年_____月_____日起至_____年_____月_____日止。 本合同约定试用期（大中专应届毕业生见习期）自_____年_____月_____日起至_____年_____月_____日止。 二、聘用岗位和职责要求 甲方根据工作需要和乙方的岗位意向，决定聘用乙方从事岗位工作。乙方同意在该岗位工作，并按甲方岗位职责要求履行义务，完成工作任务。 因工作需要，经双方协商，甲方可以重新安排乙方的工作岗位，乙方也可选择其他岗位。双方就岗位变更事宜作如下约定：_____。
《上海建设工程造价信息》网上查询功能介绍 根据本市建筑建材管理体制改革总体要求，自2006年12月起, 原由上海市建筑建材业市场管理总站编制的《上海建设工程造价与交易信息》(月刊)内部会员刊物中造价信息，改为在上海建筑建材业网(https://www.doczj.com/doc/4411416972.html, )上发布。为便于网上查询，我们编写《上海建设工程造价信息》网上查询功能介绍，供参考使用。主要功能及操作步骤如下： 一、上网查询: 1、用户登入“上海市建筑建材业网站”(https://www.doczj.com/doc/4411416972.html, )； 2、单击［专题专栏］中的标准定额，如图1所示; 督上海建抗連斜业■ ■让匱巧?瑰Internet E EP I IVE cf 图1 3、单击标准定额标题栏中造价信息，如图2所示;
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合同编号：YT-FS-2166-14 外聘人员协议范本(完整 版) Clarify Each Clause Under The Cooperation Framework, And Formulate It According To The Agreement Reached By The Parties Through Consensus, Which Is Legally Binding On The Parties. 互惠互利共同繁荣 Mutual Benefit And Common Prosperity
外聘人员协议范本(完整版) 备注：该合同书文本主要阐明合作框架下每个条款，并根据当事人一致协商达成协议，同时也明确各方的权利和义务，对当事人具有法律约束力而制定。文档可根据实际情况进行修改和使用。 聘用协议 甲方：江西鹰潭浪淘沙美食水疗会 乙方：姓名: 性别：出生日： 身份证号码：民族： 为实现投资经营与职业经理人的有效结合，经甲乙双方友好协商，通过相互了解、达成共识、就甲方聘用乙方为江西鹰潭浪淘沙美食水疗会总经理事宜，组建管理队伍，实施经营管理，达成如下协议，并共同信守协议各项条款。 第一条：甲方聘请乙方出任江西浪淘沙美食水疗会总经理，由乙方配备管理人员2名，专职营销经理1-2名，全面经营该会所，负责市场策划、市场营销、日常经营管理，其工作绩效向董事长及董事会负责。 第二条：江西浪淘沙美食水疗会会馆的企业运营
实施职业经理人总经理负责制，按董事会的经营指导方针，做好企业的正常经营，安全保障，资产的保值保全；以获取最大经营利润为经营中心；以创造企业持续发展的品牌经营为己任。享受董事长及董事会特许的福利待遇，明确所授权的责任和权力。 第三条：因甲方投资项目为特殊行业，经友好协商，乙方除享受国家规定的法定节假日外，每月公休为四天，乙方如因工作需要不能休息，可按公司规定给予补休。 第四条：因乙方管理绩效所需甲方聘用乙方的薪资实行“年工薪制度”及绩效利润分成方式;a:甲方支付乙方劳动报酬为税后工资年薪24万元人民币，以月形式支付1.8万元/月，支付日期为每月五号（其中包括：基本工资、、职务补贴、岗位补贴、高温补贴.通讯费用。）；余薪2万4000元在每年元月五号以十三个月薪资的形式发放。b:绩效考核工资为全年的纯利润的分红模式执行;具体方式如下:全年的纯利润的10%归乙方分红所得.如中途解聘分红为去年纯利润的5%
合同编号：YT-FS-8509-12 事业单位合同(完整版) Clarify Each Clause Under The Cooperation Framework, And Formulate It According To The Agreement Reached By The Parties Through Consensus, Which Is Legally Binding On The Parties. 互惠互利共同繁荣 Mutual Benefit And Common Prosperity
事业单位合同(完整版) 备注：该合同书文本主要阐明合作框架下每个条款，并根据当事人一致协商达成协议，同时也明确各方的权利和义务，对当事人具有法律约束力而制定。文档可根据实际情况进行修改和使用。 房屋租赁合同 出租方(甲方)： 承租方(乙方)： 根据《中华人民共和国合同法》、《湖北省行政事业单位国有资产管理实施办法》、《随县人民政府办公室关于印发随县行政事业单位国有资产收益征收与使用管理暂行办法的通知》等有关规定，甲乙双方经平等协商，就房屋租赁事宜签订本合同。 一、租赁房屋地址及设施、设备情况： 1、租赁房屋地址：____ 。面积 ____ 平方米。 2、现有装修及设施、设备情况： ①门窗情况： ②地板及墙壁装修情况： ③水电设施情况及其他：
上述房屋属甲方所有(或甲方依法使用，有权出租)，甲方将其出租给乙方使用，用途为。 二、租赁期限：从年月日至年月日止。(原则上为1年，最长期限不超过3年，承租方享有续签合同的优先权。) 三、租金及保证金： 年\月租金为人民币元。租金支付方式为：一次性交清\按年支付\按季支付，先交租金后使用，租金支付时间为。 乙方于本合同签定之日开始，每年向甲方交付设施设备等使用保证金元。保证金不计利息，合同期满，甲方经验收确认房屋无毁损等情形且乙方付清全部租赁费用后，将保证金退还乙方。 四、交付房屋期限：乙方交付保证金及首期租金后，于日内甲方将房屋交付给乙方，房屋租赁期限从甲方向乙方交付房屋之日起计算。 五、甲方责任： 1、实行本合同约定的租赁期限、租金标准、租赁
浅谈西藏民俗文化旅游资源及其开发 【摘要】西藏民俗文化是西藏文化的重要组成部分，它以其厚重的文化内蕴和特有的高原风采深受世人的瞩目和关注。然而在旅游这一产业中，旅游产业的性质正在发生变化。西藏民俗文化资源的开发在取得很大成绩。本论文除了介绍了西藏特有的民俗文化之外，还就西藏的民俗文化资源的旅游开发做了一些讨论很提出相关意见，希望西藏的民俗文化在开发中必须更新开发理念，使得经济、社会、坏境效益兼得，保护好西藏的民俗文化资源以及推动西藏旅游的可持续发展。 关键字：西藏民俗文化西藏民俗文化旅游资源 一文献综述 民俗是生活于某一特定地域的民族或人们共同体在长期的历史发展过程中形成的习俗惯制，文化是指人类在社会历史实践过程中创造的物质财富和精神财富的总和，是人类的活动方式。显然，民俗是一种重要的社会文化现象。 民俗文化，是指民间民众的风俗生活文化的统称。也泛指一个国家、民族、地区中集居的民众所创造、共享、传承的风俗生活习惯。民俗文化一般分为物质民俗、社会民俗和精神民俗几大类别。物质民俗指人们日常的衣、食、住、行等生产生活方式及相关的习俗礼仪；社会民俗包含家族村社、婚丧嫁娶及人生礼仪等相关内容；精神民俗则以信仰、节日、民间文学和游艺为其代表。 可持续发展是一种注重长远发展的经济增长模式，最初于1972年提出，指既满足当代人的需求，又不损害后代人满足其需求的能力，是科学发展观的基本要求之一。 二西藏民俗文化的形成与发展 （一）西藏民俗文化的形成 考古学和地理学资料表明，青藏高原是人类的故乡之一。至迟在1万至5 万年前，西藏高原便有古人类的活动足迹。发现于藏南定日县苏热、藏北申扎县珠各勒、多格则和各听、阿里日土县扎布等五处地点的达200余件旧石器便是明证。距今四五千年前，西藏各地已普遍进入了新石器时代。如果说混沌之初人类之始以至旧石器时代民俗文化的具体情形我们还无从知晓，那么，西藏民俗文化的滥觞则有据可考于四五千年前的新石器时代。昌都卡若原始村落遗址的发掘为我们提供了一幅西藏远古先民生活的图景。卡若遗址位于西藏东部昌都西南约
武汉建设工程造价信息网 2011年第5期武汉地区主要建材市场价格变化动态及 浅析 东莞网站建设一、武汉地区主要建材市场价格总体走势浅析受宏观经济形势变化、原材料价格变化、人工成本及运输费增加等综合因素的影响，近期武汉地区建筑材料市场价格总体呈现上涨的走势。其中，水泥、商品砼、成品油、沥青及沥青混凝土市场价格呈现大幅上涨的态势；建筑钢材及制品、钢纤维、预拌砂浆、复合管材及园林苗木市场价格小幅上涨；铸铁、铜、铝、锌材及电线电缆等材料价格走势趋于稳定。 二、武汉地区主要建材市场价格具体变化动态 1、近期武汉地区水泥市场价格呈现大幅上涨的趋势，本期 水泥市场信息预算价平均每吨上调25元左右。 2、由于近期水泥市场价格大幅上涨，砂、石料以及粉煤灰 等原材料价格以及人工成本都有不同程度的上涨，导致商品砼生产成本大幅增加，由此引起武汉地区商品砼市场价格大幅上涨，本期商品砼市场指导价格平均每立方上调20元。3、近期由于原材料沥青市场价格继续大幅上涨导致沥青防 水卷材生产成本增加，本期市政工程改性沥青防水卷材市场
参考价格继续小幅上调。 4、近期国际原油价格继续高位运行，国家发改委出台了成品油价格上调政策。省物价局出台湖北市场汽、柴油销售价格政策：90#、93#、97#汽油以及0#柴油最高批发价（不送货）分别为9000、9540、10080、8150元/吨；最高零售价分别为7.0 5、7.45、7.90、7.35元/升。武汉地区主营汽柴油批零价格全面上涨，本期汽柴油市场参考价格进行了较大幅度上调。由于影响国际原油价格走势的因素仍不稳定，后期国内汽柴油市场价格继续上涨的可能性较大。 5、在资源供应偏紧、市场需求向好、成本高位支撑以及厂家调价推动等综合因素影响下，近期国内及武汉地区沥青市场价格呈现大幅上涨的走势。本期重交AH-70、SBS改性沥青市场参考价格大幅上调。后期沥青价格受国内市场需求变化及国际原油价格变化的影响较大。 6、由于沥青、柴油等原材料价格大幅上涨导致沥青砼生产成本大幅增加，本期武汉地区沥青砼指导价格每立方上调 20-25元左右，10公里以内运输费指导价格每立方上调2元。 7、近期武汉地区建筑钢材市场价格总体呈现小幅上涨的走势。本期信息价作如下调整：圆钢价格每吨上调150元；螺纹钢平均每吨上调200元；工字钢、槽钢、角钢平均每吨上调50元左右；镀锌钢板平均每吨上调50元左右；中厚钢板平均每吨上调150元左右；无缝钢管平均每吨下调100元左
学校消防安全标准化管理 一、消防设施： 1、灭火器：首先对原有的灭火器进行检查，不合格的必须换。 A、设置在教室、宿舍、办公楼的走廊上，实验室、多功能教室、会场、厨房等特殊场所室内，以及其他需要的重要部位。 B、标准：一般是4KG或大于4KG的ABC干粉灭火器，两个灭火器为一组，厨房必须配备一具手推式干粉灭火器。 C、固定在位置明显的墙体上或摆放在灭火器箱内，并在上方用明显的标识标注“灭火器”“灭火器使用指南”与“灭火器检查表”（卡片可以取、换，换下的卡片需要归档）；下方用黄、橙、红等颜色鲜明线条等标出警示线。 2、消火栓：对所有消火栓进行试水检查，并检查箱内的消防卷盘、水带、水枪等设施，不合格的产品必须换。 A、消火栓下方地板上应画出长方形警示线，尺寸为50cm*80cm（学校可根据本校实际情况适度调整警示线尺寸，但本校内尺寸应统一）。警示线内不应堆放物品。 B、消火栓箱上贴消防知识宣传画，宣传画上除必须用红色醒目大字标注“消火栓、火警119”外，其余可自行设计。（备注：需留出小口，方便打开消火栓箱。） C、消火栓旁边配备“消火栓操作方法”与“灭火器检查表”（卡片可以取、换，换下的卡片需要归档）。每月至少检查一次，检查完毕，贴
封条，封条上盖公章、写明日期。 3、应急灯：安全出口正上方、疏散楼梯的每一层、疏散通道等位置，均应设置应急照明灯。 4、安全疏散标志：疏散走道、转角处等均应设置“安全疏散指示”标志，安全出口处设置“安全出口”标志，标志必须可直接接电源。 二、各室设置： 1、校门口值班室、宿舍值班室 A、均有“消防器材柜”，器材柜上标注“消防器材柜”，柜内配备“手电筒、过滤式自救呼吸器、头盔、战斗服、灭火器”等，各学校可按本校实际情况增加器材，按值班人数配备。每周检查一次，并在旁边的“器材检查表”上标明（卡片可以取、换，换下的卡片需要归档）。 B、墙上有“义务消防队结构图”“义务消防队组织管理规定”“学校室外消火栓平面图”“学校室内消火栓平面图”。（备注：建筑物较多的学校可将“学校室内消火栓平面图”装订成册，放在校门口值班室。） C、设有“每周消防安全检查登记本”，内容包括每周对校园内消防设施检查的记录。 2、教学楼 A、每层均有“教学楼疏散示意图”，可在每层的教学楼疏散示意图中标注本层室内消火栓位置。 3、宿舍楼 A、每层均有“宿舍楼疏散示意图”，可在每层的宿舍楼疏散示意图中标注本层室内消火栓位置。 B、每一间宿舍门口用带箭头的卡片表明疏散方向，或者在每间宿舍
安徽****有限公司 外聘协议书 甲方（用人单位）名称：安徽****有限公司 单位住所： ***经济开发区* 法定代表人： 乙方（劳动者）姓名： 住址： 身份证号码： 联系电话：
根据《中华人民共和国劳动法》、《中华人民共和国劳动合同法》和有关法律、法规、规章的规定，甲乙双方在平等自愿协商一致的基础上，签订本合同 第一条合同期限 合同期从2018 年10 月20 日至2021 年10 月19日，试用期一个月，合同期满双方希望继续维持合同关系时，则须另行订立新合同。 第二条聘用岗位 甲方因工作需要聘用乙方从事技术研发工作，主要工作职责为：为企业工艺创新、产品研发提供技术支撑 乙方根据甲方的时间安排，在乙方无客观原因的情况下，按照甲方的工作时间上班。 第三条劳动时间 乙方在被聘用期间执行一周3天上班，每天的上班时间按照甲方的工作时间。甲方若有紧急或重要事情需要乙方履行相关职责，乙方需同意。 第四条薪资福利 一、聘用期内，甲方的工资发放为每月5000 元。 二、甲方按月以货币形式支付给乙方。 第五条权利义务 一、甲方可以根据实际工作需要调整乙方的岗位或工种、工作地点及工作内容，其劳动报酬做出相应的调整和变更。
二、乙方必须严格遵守和执行甲方公司的规章制度，认真履行岗位职责，完成相应的工作内容。 第七条保密协议 乙方任职期间必须严格遵守甲方保密及竞业限制相关规定，乙方必须对工作中所接触到的甲方的资料予以保密，不得向第三方泄露；不得使用甲方资料为甲方以外的其他任何人或单位谋取利益，损害甲方利益。 第八条合同的解除 一、经双方协商一致，可以解除劳动合同； 二、乙方有下列情形之一的，甲方可以解除劳动合同： 1、每周上班时间少于2天； 2、甲方认为乙方不能很好履行工作职责或缺乏合作精神； 3、在试用期间被证明不符合录用条件的； 2、有打架斗殴、偷窃、赌博等违法、违纪行为的； 3、严重失职，营私舞弊，对甲方造成重大损害的； 4、被劳动教养或被追究刑事责任的； 三、甲方有下列情形之一的，乙方可以解除劳动合同： 1、甲方以暴力、威胁、监禁、或者非法限制人身自由的手段强迫 劳动的； 2、甲方不能提供安全的劳动条件或者无故不按照本合同规定支付劳动报酬的； 第九条其他
编号： 机关、事业单位临时聘用人员劳动合同书 (示范文本) 甲方： 乙方： 签订日期：年月日
劳动合同 甲方（用人单位）名称: 法定代表人（主要负责人）: 地址: 乙方（劳动者）姓名: 性别: 出生年月: 民族: 文化程度: 身份证号码： 住址: 联系电话： 根据《中华人民共和国劳动合同法》以及有关法律、法规的规定，经甲、 乙双方平等协商，共同签订并履行本合同所列条款。 一、劳动合同期限 本合同为固定期限劳动合同。合同期从年月日起至 年月日止。其中试用期从年月日起至 年月日止。 二、工作内容 乙方同意根据甲方工作需要，在岗位 从事临时辅助性工作。甲乙双方可另行明确岗位具体职责和要求。 三、工作时间和休息休假 1.甲、乙双方必须严格遵守国家规定的工作时间制度，甲方根据工作需 要，安排乙方加班的，应安排调休或给予加班费。 2.甲方依法保证乙方的休息权利。乙方依法享受法定节假日等休假。 四、劳动报酬 乙方的月工资为元，其中试用期间的月工资为元。 乙方工资的增减、补贴、加班费的发放，以及特殊情况下的工资支付等均 按有关法律、法规规定执行。
五、社会保险及福利 1.甲、乙双方依法参加社会保险，缴纳社会保险费。甲方为乙方办理有关社会保险手续，乙方负担的部分由甲方负责代扣代缴。 2.甲方可根据其实际情况为乙方提供其他保险和福利待遇。 六、劳动纪律 甲、乙双方必须严格遵守法律、法规、规章、政策。乙方应服从甲方的管理，并严格遵守政府的有关规定及甲方依法制定的规章制度。 七、劳动保护、劳动条件和职业危害防护 甲、乙双方都必须严格执行国家有关生产安全、劳动保护、卫生健康等规定。甲方应为乙方提供符合规定的劳动保护设施、劳动防护用品及其他劳动保护条件。乙方必须严格遵守甲方的劳动安全制度。 八、劳动合同变更、解除和终止 1.甲乙双方变更、解除、终止劳动合同依照《中华人民共和国劳动合同法》和有关法律法规规定执行。甲乙双方就劳动合同变更、解除另有约定的，可在本合同书第十项中约定。 2.本合同解除或者终止时，甲方为乙方出具解除或者终止劳动合同的证明，并在十五日内为乙方办理档案和社会保险关系转移等手续。 3.乙方按照双方约定，及时办理工作交接等有关手续。应当支付经济补偿的，在乙方办结工作交接等有关手续时支付。 九、当事人约定的其他事项 经协商一致，甲、乙双方约定以下内容：