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Background The mental health of employees in railway enterprises is related to the safety and stability of railway transportation. As an important factor affecting occupational mental health, job characteristics have attracted the attention of researchers. However, there exists a lack of job characteristic scales with occupational specificity in current researches relevant to the railway industry.Objective To develop a job characteristics questionnaire oriented to railway employees that takes both Job Demands-Resources Model（JD-R） and Chinese actual conditions into essential consideration, so as provide guidance for the research on the mental health of railway employees.Methods Purposive and theoretical samplings were used to select 77employees across 9 railway units as research objects, and interview method was used to conduct qualitative research in order to determine the structural dimensions and items of the questionnaire. The 612 subjects randomly selected from the railway maintenance system went through the preliminary test, then exploratory factor analysis and confirmatory factor analysis were employed to test the questionnaire. After forming a formal questionnaire on the job characteristics of railway employees, it is extended to the other four main industry systems of railway enterprises, responsible for locomotive maintenance, vehicle depot, signal and communication maintenance, and power supply respectively, to verify the stability and effectiveness.Results（1）Exploratory factor analysis showed that the questionnaire included two factors, job demands and job resources, with a total of 14 items. The factor loading of each item ranged from 0. 761 to 0. 916, and the two factors accounted for 71. 02% of the total variance. The results of confirmatory factor analysis indicated good fitting of the two-factor model （χ²/df=3. 310, RMSEA=0. 087, GFI=0. 892, CFI=0. 932, NFI=0. 905, IFI=0. 932）.（2） Confirmatory factor analysis was carried out in four extended samples of locomotive maintenance, vehicle depot, signal and communication maintenance, and power supply, and each result indicated a satisfactory model fit（χ~2/df=2. 678, 4. 741, 4. 868, 3. 502, RMSEA=0. 109, 0. 096, 0. 093, 0. 084,GFI=0. 832, 0. 878, 0. 894, 0. 904,NFI=0. 874, 0. 935, 0. 902, 0. 928,IFI=0. 917, 0. 948, 0. 920, 0. 947）.（3）Job demands in five sub-samples can positively predict job burnout and turnover intention（β =0. 564～0. 686, 0. 425～0. 554, P＜0. 01）. Job resources in five sub-samples can positively predict job performance and job satisfaction（β=0. 594～0. 752, 0. 731～0. 807, P＜0. 01）, and it can also negatively predict job burnout and turnover intention（β =-0. 247～-0. 186,-0. 357～-0. 175,P＜0. 05 or 0. 01）. In sub-samples of locomotive maintenance and power supply, job demands can positively predict job performance（β=0. 242,0. 261, P＜0. 01）. In sub-samples of railway maintenance and signal and communication maintenance, job demands can negatively predict job satisfaction（β =-0. 065,-0. 091, P＜0. 01）.Conclusion The questionnaire has good reliability and validity, and is applicable for the study of occupational mental health research on railway employees. [ABSTRACT FROM AUTHOR]

Polysaccharide is one of the effective components of apple pomace. The effects of enzymatic extraction on the structure and antioxidant activity of polysaccharide were studied in this paper. The structures of enzymatic polysaccharides from enzymatic apple pomace (PEAP) and non enzymatic polysaccharides from apple pomace (PAP) were compared, and their antioxidant activities in vitro were evaluated. Fourier infrared spectroscopy and monosaccharide analysis showed that PAP and PEAP were acidic heteropolysaccharides, mainly composed of arabinose, rhamnose, galactose, glucose, xylose and galacturonic acid with different molar ratios; The molecular weight of PAP is greater than that of PEAP.AFM analysis showed that PEAP had more branched chains than PAP. Compared with PAP,PEAP has stronger antioxidant activity, which can be attributed to the differences in uronic acid content, molecular weight and branching structure between PAP and PEAP. This study provides theoretical data for the application of apple pomace and its polysaccharide. [ABSTRACT FROM AUTHOR]

In order to solve the tunnel construction problems such as low efficiency and high consumption of rock tunnel boring ma, chine (TBM) in high-strength and high abrasion hard rock stratum, cutter head trapped in fault fracture zone stratum, and shield stuck in high stress extrusion stratum. Based on the interaction between TBM disc cutter, cutter head, shield and tunnel surrounding rock, through the statistical analysis of multiple TBM method tunnel engineering data, the functional relationships between disc cutter penetration index and rock mass characteristic index, disc cutter crushing volume wear rate and rock mass characteristic index, TBM equipment utilization and fault width, relative deformation of surrounding rock and strength stress ratio were revealed, and the multi-dimensional TBM adaptability evaluation method was established, which was based on disc cutter excavability and abrasion resistance, the risk of cutter head trapped and shield stuck. The research results provide a quantitative basis for TBM construction method selection, equipment design and solution of construction problems in complex geological tunnels. [ABSTRACT FROM AUTHOR]

Apple pomace was modified by compound enzyme method to increase the content of water-soluble dietary fiber. The optimum process conditions were optimized by response surface test: Solid-liquid ratio 1∶20,compound enzyme (cellulase 20 U/g; pectinase 80 U/g),time 5.5 h, pH 5.1 and temperature 44 ℃.Under this process condition, the soluble dietary fibers content was 16.84%.Scanning electron microscope results showed that the microstructure of modified apple pomace v changed greatly with larger specific surface area and porosity, exposed more hydrophilic and lipophilic groups, making the apple pomace have better physical properties. The water holding capacity, oil holding capacity and expansion capacity of apple pomace have been significantly improved by (p<0.01),114.74%,104.55% and 137.10% respectively. This study provided certain theoretical and data support for the high value-added processing and application of apple pomace. [ABSTRACT FROM AUTHOR]

An intelligent potted plant cultivation platform is designed and produced by simulating the engineering activity chain with the product development as the core. To achieve the functions of watering the potted plants and filling light automatically, the Arduino is used as the controller and the light sensors, soil moisture sensors and water level detection sensor are used to detect the environmental information. The outline structure of the platform is designed to meet the functional requirements, and the 3D printing technology is applied to machine the outline structure. Through the project practice, the scientific research innovation and the practical ability of students are cultivated, and the multidisciplinary consciousness and the sensor of the large-scale engineering of students are established and students can observe and think about problems from multidisciplinary perspective. [ABSTRACT FROM AUTHOR]

Apple pomace cellulose was extracted by alkali method, the effect of sodium hydroxide concentration,solid-liquid ratio,time and temperature on cellulose content was investigated,and the extraction process was optimized by orthogonal test. The results showed that the optimum extraction process of apple pomace cellulose was that the concentration of sodium hydroxide was 14%(w/V) ,the solid-liquid ratio was 1 = 25(g/ml) ,the time was 15 h,the temperature was 45 °C ,at the time,the cellulose content reached its peak value was 73. 61%. The results of SEM and FTIR showed that its had apparent cellulose morphology and characterization peaks of cellulose polysaccharides, which would lay the theoretical foundation for apple pomace cellulose’s wider application. [ABSTRACT FROM AUTHOR]

Facing on the existed problems of the original open-mechanical innovative experimental teaching,the paper systematically studies open experimental teaching model and experimental system. Experimental teaching practice has proved that opening up innovative experimental teaching mode and systems can meet the new requirements of innovative talents. These research and practice are able to play a positive role in regulating open innovation experiment teaching, enhancing open innovation experiment teaching quality and effectiveness, and improving the utilization of open laboratory. [ABSTRACT FROM AUTHOR]

Brief introduction of the extracts of blueberry anthocyanins, pueraria lobata, pueraria lobata flower, and Hovenia dulcis were used as the main raw materials, and wet granulation and table ting were used to prepare compound blueberry anthocyanin orally disintegratingtablets with anti-alcoholic and anti-drunk effects. The formulation screening test was used to initially screen the types of fillers and the ratio of main and auxiliary materials. The formulations were comprehensively evaluated with disintegration time and hardness as comprehensive evaluation indicators. Preliminary optima l formula blueberry anthocyanin 3. 5 %,Pueraria lobata 2. 5 %,Pueraria lobata flower 2. 0 %, Hovenia dulcis 2. 0 %,starch 29. 16 %,maltodextrin 5. 84 %,LHPC 52 . 5 %,others are flavoring agents. The results show that the disintegration time limit of the product is 85 . 5 s, the hardness is 51. 2 N, the sensor y evaluation is good, and the net content tolerance is ( 500. 0 ± 50) m g. The compound blueberry hangover tablet has good drunkenness and anti-drunkenness effects on mice. The results of this study can provide theoretical basis and data support for the development and industrial production of hangover products. [ABSTRACT FROM AUTHOR]

Fungal-fermentation is a solid-state fermentation process caused by Eurotium cris tatum and the key process for the flavor quality of Fu tea. The flavor characteristics of Fu tea are related to many aroma compounds derived from lipids degradation. However, there were relatively few researches on tea lipids. In this study, the lipid profiles of black tea (T) and Eucommia ulmoides leaves (DZ) before and after fungal-fermentation were analyzed by ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (UHPLC-Q Exactive MS)-based lipidomics, 414 lipid species, spanning 19 lipid categories were tentatively identified, including ceramide (Cer). phosphatidylinositol (PI), phosphatidylcholine (PC). diacylglycerol (DG). monogalactosyldiacylglycerol (MG DG), digalactosyldiacylglycerol (DGDG), triacylglycerol (TG), (0-acyl)-w-hydroxy fatty acids (OAHFA), monogalactosylmonoacylglyceride (MGMG), lysophosphatidylcholine (LPC), lysophosphatidylglycerol (LPG). phosphatidylethanolamine (PE). lysophosphati dylethanolamine (LPE), lysophosphatidylinositol (LPI). phosphatidylserine (PS).phospha tidic acid (PA).lysophosphatidic acid (LPA) phosphatidylglycerol (PG).cardiolipin (CL). Partial least squares discriminant analysis (PLS-DA) showed there were significant differ ences for Fu brick tea samples produced by black tea and Eucommia ulmoides leaves. Univa riate statistical analysis showed that for black tea, the fungal-fermentation process increased the contents of Cer. MGMG. PA.OAHFA. LPC, LPG, PI and short-chain TG. and reduced the contents of DGDG. MGDG.LPE.DG.PG.CL.PS. PE and long chainFor Eucommia ul moides leaves the fungal-fermentation process increased the contents of short-chain TG.CL. LPA.LPI.PL.LPC,DG,PC.PG and Cer, and reduced the contents of long chain TG.MGDG and DGDG. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to explore the genetic trend of apricot of aromatic substances. [Method ]We extracted and separated aromatic substances in new strains'Zl0-1-78' and'Zl0-1-60' apricot fruits, and their parents'Chuanzhihong' and' Fengyuanhong' apricot fruits at commercial stages and ripe stages, by headspace solid-phase microextraction and gas chromatography-mass spectrometry. Then we compared the spectra with NISTll database. The relative content of aromatic substances was determined by area normalization method. [Result] The result showed that 72 aromatic components were detected in the fruits of four apricot varieties (lines), including 20 kinds of alcohols, 18 kinds of esters, 14 kinds of ketones, 5 kinds of acids, 4 kinds of alkanes, enes and aldehydes, 1 kind of benzene, phenols and naphthalene. The number of aromatic substances components was the most in'Zl0-1-78', which contained 37 kinds. The contents of all aromatic components was changed with the fruit maturity, alcohols content was the highest in the male parent' Fengyuanhong' and its offspring'Zl0-1-78','Zl0-1-60' fruit at commercial stages and ripe stages. Ester content was the highest in the female parent' Chuanzhihong' at commercial stages. The most aromatic substances in the offspring'Zl0-1-78' and'Zl0-1-60' fruits inherited from their male parent' Fengyuanhong', 75. 6 % of the aromatic components in the'Zl0-1-78' fruits were consistent with that in the male parent'Fengyuanhong', and 47. 44 % of the aromatic components in the'Zl0-1-60' fruits were consistent with that in the male parent. The characteristics aroma of linalool content was the most in'Zl0-1-78' and'Zl0-1-60' and their male parent' Fengyuanhong', the values was 13 293. 33- 28 986. 67, and acetic ester in' Chuanzhihong' was the most, its value was 6230. 00. Rose scent characteristics of the offspring of the most important fruit fragrance ingredients linalyl alcohol and geraniol inherited from the parent. [Conclusion] The most important aromatic components in offspring was linalyl alcohol and geraniol, inherited from their male parent, and the content of offspring was much more than that of its male patent. Moreover, we evaluated fruit quality and provided the theory for further application demonstration. [ABSTRACT FROM AUTHOR]

The main extract of pleurotus eryngii-polysaccharide has a variety of physiological activities, In order to extract the polysaccharide of pleurotus eryngii, the polysaccharide was extracted by water extraction and alcohol precipitation method. The effects of extraction temperature, extraction time and ratio of material to liquid on the yield of pleurotus eryngii polysaccharide were studied. Based on the single factor level, the response surface optimization was used to optimize the extraction conditions of pleurotus eryngii polysaccharides. The crude polysaccharide obtained by the extraction was tested for anti-oxidation and hypoglycemic activity in vitro. The results showed that the optimal extraction time was 3 h, the ratio of material to liquid was 1:40(g/mL), and the extraction temperature was 40 °C. The yield of the crude polysaccharide under this condition was 5.9%;The crude polysaccharide of pleurotus eryngii has a good ability to scavenge DPPH and hydroxyl radicals, showing a certain dose effect, and the scavenging ability is enhanced with the increase of concentration; it also has a certain inhibitory effect on α-glucosidase. [ABSTRACT FROM AUTHOR]

A method was developed for the simultaneous determination of pesticide residues by dispersive solid phase extraction-ultra high performance liquid chromatography-quadrupole-orbitrap mass spectrometry.The samples were purified by anhydrous sodium acetate and anhydrous magnesium sulfate dSPE.The samples were qualitatively analyzed by mass spectrometry full scan mode and quantitatively analyzed by matrix matching standard correction method.The results showed that within the linear range,the linear correlation coefficients(r2) of 24 pesticide residues were greater than 0.99,and the determination limits(CCα) and detection capacity(CCβ) were 0.04 ～4.2 μg/kg and 0.07 ～7.27 μg/kg,respectively.The established method has high recovery,accuracy and precision,and can be used for the determination of pesticide residues in dairy products. [ABSTRACT FROM AUTHOR]

In order to realize the target of cultivating industry leading talents of our school, guided by the framework of "Excellent Engineer Project", using the CDIO engineering education concept and the teaching method of school- enterprise double tutorial system, the paper builds a course entitled "Equipment Control and Fault Diagnosis". It describes in detail the course pre construction target, the construction concept and the teaching process. After two years practice, the result shows that this course has a novel curriculum organization, an advanced teaching philosophy, It achieves an outstanding teaching achievement, provides a successful example for the engineering education reform in colleges and universities of our country. [ABSTRACT FROM AUTHOR]

In order to study the differences of the chemical constituents of different kiwifruit cultivars, gas chromatography-mass spectrometry ( GC-MS) technology was used to analyze the primary small molecule compounds in three different varieties of kiwifruits ( Hayward, Yate and Xuxiang) . A total of 76 compounds were identified, including 19 amino acids, 26 sugars, 11 organic acids, 7 fatty acids, 6 TCA cycle intermediates, 2 phenols, and 5 other substances. The supervised multivariable analysis PLS-DA model with UVs caling showed that different kiwifruit varieties had obvious differences. Among them, the Yate samples were clearly separated from the Hayward and Xuxiang samples based on the first principal component. The Hayward and Xuxiang samples were separated along the second PLS principal component. Univariate analysis was applied to screen the differences compounds between any two kiwifruit cultivars. The results showed that the ascorbic acid content was the highest in Yate, while the contents of most organic acids were the lowest ; the contents of monosaccharides were the highest in Hayward, while the contents of some di saccharides were the lowest; the contents of most organic acids and some amino acids in Xuxiang were the highest, and the contents of monosaccharides were the lowest. This study can provide basic data for t he quality evaluation and comprehensive utilization of kiwifruit cultivars. [ABSTRACT FROM AUTHOR]

Lycium barbarum residue polysaccharide was used as a raw material and modified by acetylation to explore a new way of high-value utilization of Lycium barbarum residue polysaccharide. The substitution degree of acetyl was taken as the evaluation index, and the factors such as reaction time, acetic anhydride addition amount and reaction temperature were optimized through single factor and orthogonal experiments. The Lycium barbarum residue polysaccharide before and after modification was characterized. The results showed that when addition amount of Lycium barbarum residue polysaccharide was 0.1g, the optimal preparation process of acetylated polysaccharide was as follows: reaction time of 4 hacetic anhydride addition amount of 15mL and reaction temperature of 60'C. Under these conditions, the acetyl substitution degree was 0.454. Scanning electron microscopy results revealed that the surface of the modified polysaccharide became rough, uneven, and obviously wrinkled. The result of infrared spectroscopy showed that the vibrational absorption peak of C=0 in the ester group appeared after modification, indicating that the polysaccharide was successfully modified by acetylation. [ABSTRACT FROM AUTHOR]

In order to explore the effects of salt stress on physiological and biochemical indexes of Nostoc flagelliforme in liquid culture, BG-11 mediums supplemented with three different salt concentrations (0.0.1,0.3 M) were used to culture Nostoc flagelliforme cells. The microstructure of Nostoc flagelliforme was observed at 0.5 days, 10 days, 15 days, 25 days and 30 days of culture. Meanwhile, chlorophyll a,carotenoid.phycocyanin, plasma membrane permeability and malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in Nostoc flagelliforme were measured, The results showed that some cells could survive in 0.1 M salt treatment, and the SOD activity was significantly increased compared with the cells without salt treatment; 0. 3 M salt treatment had the greatest damage to Nostoc flagel-liforme cells, which could significantly reduce the contents of chlorophyll-a and phycocyanin, improve the plasma membrane permeability and MDA content, and inhibit the SOD activity of Nostoc flagelliforme cells. The content of carotenoids in Nostoc flagelliforme cells added with 0.3 M salt was higher than that in other groups on the 5th day, and then decreased sharply with the increase of time and was lower than that of other groups. This study revealed that the suspension cells of Nostoc flagelliforme had dose effect on response to salt stress. When 0.1 M salt was added, Nostoc flagelliforme cells had certain salt tolerance, and 0.3 M salt treatment caused irreversible damage to Nostoc flagelliforme cells. [ABSTRACT FROM AUTHOR]

In order to identify the differences of antioxidant activities in different kiwifruit varieties, this paper studied the scavenging abilities of three kiwifruit varieties(including XuXiang, YaTe and Hayward) on DPPH· free radical, hydroxyl radical(·OH), ABTS+· free radical and the chelating ability of the cupric. The results showed that three kiwifruit varieties displayed different abilities to scavenge free radicals. The scavenging rate of DPPH· free radical in XuXiang, YaTe and Hayward was 69. 88%, 52. 23% and 24. 88%, respectively;The scavenging rate of hydroxyl radical(·OH) in the three varieties were 81. 47% for XuXiang, 61. 60% for YaTe and 71. 36% for Hayward;The scavenging rate of ABTS+· free radical in in the three varieties was 38. 05%, 22. 45% and 35. 62%, respectively;The chelating ability of copper ions in the three varieties was 77. 33%, 57. 56% and 65. 12%, respectively. The above data indicated that the antioxidant capacities of the three varieties is XuXiang >YaTe > Hayward. [ABSTRACT FROM AUTHOR]

According to the requirement of professional accreditation of engineering education, a real-engineering problem-driven and outcomes-based experimental teaching project is put forward. The switch structure of autoclave door is used as the subject of the experimental project. The experimental project includes theoretical analysis, finite element simulation, experimental testing and so on. Through the experimental teaching project, students establish the systematic thinking mode and ability of analyzing and solving problems. The abilities of solving complex engineering problems, self-learning and teamwork of students are cultivated. The experimental teaching project has great significance to the cultivation of engineering talents. [ABSTRACT FROM AUTHOR]

A ultra performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry method for the determination of antibiotics drug residues in tilapia was developed using dispersed solid phase extraction as sample preparation method. The matrixmatched standard calibration method was used for quantitation. The results showed great reduction of the matrix effect with corrected matrix factor ranging 0.84~1.17 for 9 antibiotics. Within the linear range, the correlation coefficients(R2)of the calibration curves for the compounds were greater than 0.90. The average recoveries in blank tilapia ranged from 78.04%~103.08%, with intra-and inter-day relative standard deviation(RSD)ranged from 1.37%~9.86%and 3.86%~9.92%, respectively. The limit of detection(LOD)and limit of quantification(LOQ)of the method ranged from 0.31~16.37μg/kg and 1.04~54.56μg/kg, respectively. The method developed in the present study had the advantages of simple operation, less matrix interference, high recovery rate and good repeatability. So it could be used for the detection of multi-antibiotics in tilapia and provide some technical support for food safety supervision. [ABSTRACT FROM AUTHOR]