This paper presents the results of our experiments to assess average labor quality and labor force utilization in different regions of China using slack-based inefficiency measurement (SBI). We found that there is a...This paper presents the results of our experiments to assess average labor quality and labor force utilization in different regions of China using slack-based inefficiency measurement (SBI). We found that there is a discrepancy between different regions' labor resources and their stages' of economic development. In central and western regions, the average quality of labor is significantly higher than in eastern regions, but labor force utilization is less efficient. Slow in economic growth and laggard in industrial upgrading, central and western regions have failed to provide their high-quality labor forces with adequate and suitable job opportunities, leading to the discrepancy between labor resource quality and economic development. Resolving this discrepancy might help coordinate economic development across different regions in China.展开更多
Due to the relatively late start of organic rice(Oryza sativa L.) research in China,there is a still lack of systematic research on rice varieties,organic fertilizer management practices,and especially the mechanisms ...Due to the relatively late start of organic rice(Oryza sativa L.) research in China,there is a still lack of systematic research on rice varieties,organic fertilizer management practices,and especially the mechanisms of nitrogen(N) uptake and utilization.Three rice varieties,Nanjing 5055,Nanjing 9108,and Nanjing 46,were grown under organic farming(OF) at three organic fertilizer levels(103.2,160.8,and 218.4 kg N ha^(-1)) and conventional farming(CF) with regular chemical fertilizers.Rice grain yields,yield components,and quality,dry matter accumulation,and plant N were measured at different growth stages during the 2012 and 2013 growing seasons.Compared with CF,OF had a significantly reduced yield.Nanjing 9108 showed significant reductions in number of panicles per unit area and percentage of filled grains,and had the lowest yield.The effects of fertilizer type and application rate on dry matter accumulation during the main growth periods were significant for all varieties.The N content and uptake in organically grown rice were lower compared with those of rice under CF.The N recovery efficiency and N agronomic efficiency were significantly lower,whereas N physiological efficiency and N partial factor productivity were greater under OF than under CF.Under OF,the processing quality showed a slight but insignificant decline,protein content and gel consistency increased,and amylose content decreased compared with those under CF.Correlation analysis showed that under OF,grain yield was significantly correlated with N uptake.The medium organic fertilizer level(160.8 kg N ha^(-1)) was found to be the optimum fertilizer treatment,and Nanjing 46 appeared to be the best variety for organic rice cultivation.To increase rice grain yields and reduce the potential risk of non-point source pollution in organic agriculture,further research is needed to improve the N use efficiency in organic rice cultivation.展开更多
In this study, we investigate the fabrication of periodically poled lithium niobate(PPLN) microdisk cavities on a chip. These resonators are fabricated from a PPLN film with a 16 μm poling period on insulator using c...In this study, we investigate the fabrication of periodically poled lithium niobate(PPLN) microdisk cavities on a chip. These resonators are fabricated from a PPLN film with a 16 μm poling period on insulator using conventional microfabrication techniques.The quality factor of the PPLN microdisk resonators with a 40-μm radius and a 700-nm thickness is 6.7×10~5. Second harmonic generation(SHG) with an efficiency of 2.2×10^(-6) mW(-1) is demonstrated in the fabricated PPLN microdisks. The nonlinear conversion efficiency could be considerably enhanced by optimizing the period and pattern of the poled structure and by improving the cavity quality factors.展开更多
A simple HPLC method was established for the determination of entrapment efficiency of a new 5-FPE liposome formulation. Chromatographic separation was performed on a Kromasil 100 A C18 column (350 mm×4.6 mm, 5 ...A simple HPLC method was established for the determination of entrapment efficiency of a new 5-FPE liposome formulation. Chromatographic separation was performed on a Kromasil 100 A C18 column (350 mm×4.6 mm, 5 μm). The mobile phase was consisted of methanol-water (58:42, v/v). The flow rate of mobile phase was set at 0.8 mL/min. The UV detection wavelength was 271 nm, and the column temperature was 30 ℃. The linear range of 5-FPE was from 0.8-12.8 μg/mL, r = 0.9999. The RSD of intm-day and inter-day precision were less than 2.97%. The average recovery was from 96.8%-104.6% with RSD less than 2.24%. The method was simple, rapid, accurate, and sensitive. It is suitable for the determination of entrapment efficiency of the 5-FPE liposome formulation.展开更多
Aims Plant litter decomposition is a key ecosystem process that determines carbon and nutrient cycling in terrestrial ecosystems.As a main component of litter,cellulose is a vital energy source for the microbes associ...Aims Plant litter decomposition is a key ecosystem process that determines carbon and nutrient cycling in terrestrial ecosystems.As a main component of litter,cellulose is a vital energy source for the microbes associated with litter decomposition.The important role of cellulolytic enzymes in litter cellulose degradation is well understood,but seasonal patterns of cellulose degradation and whether cumulative enzyme activities and litter quality forecast cellulose degradation in an alpine meadow remain elusive,which limits our understanding of cellulose degradation in herbaceous plant litter.Methods A two-year field litterbag experiment involving three dominant species(Ajuga ovalifolia,Festuca wallichanica,and Pedicularis roylei)was conducted in an alpine meadow of the eastern Tibetan Plateau to explore the seasonal patterns of cellulose degradation and how cumulative cellulolytic enzyme activities and initial litter quality impact cellulose degradation.Important findings Our study demonstrates that cellulose degraded rapidly and exceeded 50%during the first year,which mainly occurred in the first growing season(31.9%–43.3%).At two years of decomposition,cellulose degradation was driven by cumulative endoglucanase(R^(2)=0.70),cumulative cellobiohydrolase(R^(2)=0.59)and cumulative 1,4-β-glucosidase(R^(2)=0.57).In addition,the concentrations of cellulose,dissolved organic carbon,total phenol,lignin and lignin/N accounted for 52%–78%of the variation in cellulose degradation during the two years of decomposition.The best model for predicting cellulose degradation was the initial cellulose concentration(R^(2)=0.78).The enzymatic efficiencies and the allocation of cellulolytic enzyme activities were different among species.The cellulolytic enzyme efficiencies were higher in the litter of F.wallichanica with relatively lower quality.For the complete cellulose degradation of the leaf litter,A.ovalifolia and F.wallichanica required 4-fold and 6.7-fold more endoglucanase activity,3-fold and 4.5-fold more cellobiohydrolase activity and 1.2-fold and 1.4-fold more 1,4-β-glucosidase activity,respectively,than those required by P.roylei.Our results demonstrated that although microbial activity and litter quality both have significant impacts on cellulose degradation in an alpine meadow,using cellulose concentration to predict cellulose degradation is a good way to simplify the model of cellulose degradation and C cycling during litter decomposition.展开更多
文摘This paper presents the results of our experiments to assess average labor quality and labor force utilization in different regions of China using slack-based inefficiency measurement (SBI). We found that there is a discrepancy between different regions' labor resources and their stages' of economic development. In central and western regions, the average quality of labor is significantly higher than in eastern regions, but labor force utilization is less efficient. Slow in economic growth and laggard in industrial upgrading, central and western regions have failed to provide their high-quality labor forces with adequate and suitable job opportunities, leading to the discrepancy between labor resource quality and economic development. Resolving this discrepancy might help coordinate economic development across different regions in China.
基金supported by the National Natural Science Foundation of China (Nos. 31201154 and 31571596)the Open Project Program of Jiangsu Province Key Laboratory of Crop Physiology,China (No. K12008)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Due to the relatively late start of organic rice(Oryza sativa L.) research in China,there is a still lack of systematic research on rice varieties,organic fertilizer management practices,and especially the mechanisms of nitrogen(N) uptake and utilization.Three rice varieties,Nanjing 5055,Nanjing 9108,and Nanjing 46,were grown under organic farming(OF) at three organic fertilizer levels(103.2,160.8,and 218.4 kg N ha^(-1)) and conventional farming(CF) with regular chemical fertilizers.Rice grain yields,yield components,and quality,dry matter accumulation,and plant N were measured at different growth stages during the 2012 and 2013 growing seasons.Compared with CF,OF had a significantly reduced yield.Nanjing 9108 showed significant reductions in number of panicles per unit area and percentage of filled grains,and had the lowest yield.The effects of fertilizer type and application rate on dry matter accumulation during the main growth periods were significant for all varieties.The N content and uptake in organically grown rice were lower compared with those of rice under CF.The N recovery efficiency and N agronomic efficiency were significantly lower,whereas N physiological efficiency and N partial factor productivity were greater under OF than under CF.Under OF,the processing quality showed a slight but insignificant decline,protein content and gel consistency increased,and amylose content decreased compared with those under CF.Correlation analysis showed that under OF,grain yield was significantly correlated with N uptake.The medium organic fertilizer level(160.8 kg N ha^(-1)) was found to be the optimum fertilizer treatment,and Nanjing 46 appeared to be the best variety for organic rice cultivation.To increase rice grain yields and reduce the potential risk of non-point source pollution in organic agriculture,further research is needed to improve the N use efficiency in organic rice cultivation.
基金supported by the National Natural Science Foundation of China(Grant Nos.11734009,11674181,11774182,and 11674184)the 111 Project(Grant No.B07013)+1 种基金PCSIRT(Grant No.IRT 13R29)CAS Interdisciplinary Innovation Team
文摘In this study, we investigate the fabrication of periodically poled lithium niobate(PPLN) microdisk cavities on a chip. These resonators are fabricated from a PPLN film with a 16 μm poling period on insulator using conventional microfabrication techniques.The quality factor of the PPLN microdisk resonators with a 40-μm radius and a 700-nm thickness is 6.7×10~5. Second harmonic generation(SHG) with an efficiency of 2.2×10^(-6) mW(-1) is demonstrated in the fabricated PPLN microdisks. The nonlinear conversion efficiency could be considerably enhanced by optimizing the period and pattern of the poled structure and by improving the cavity quality factors.
基金Natural Science Foundation of Gansu Provence (Grant No. 0803RJZA079)Foundation of Herb Medicin Research of Gansu Provence (Grant No. GZK-2009-1)
文摘A simple HPLC method was established for the determination of entrapment efficiency of a new 5-FPE liposome formulation. Chromatographic separation was performed on a Kromasil 100 A C18 column (350 mm×4.6 mm, 5 μm). The mobile phase was consisted of methanol-water (58:42, v/v). The flow rate of mobile phase was set at 0.8 mL/min. The UV detection wavelength was 271 nm, and the column temperature was 30 ℃. The linear range of 5-FPE was from 0.8-12.8 μg/mL, r = 0.9999. The RSD of intm-day and inter-day precision were less than 2.97%. The average recovery was from 96.8%-104.6% with RSD less than 2.24%. The method was simple, rapid, accurate, and sensitive. It is suitable for the determination of entrapment efficiency of the 5-FPE liposome formulation.
基金National Natural Science Foundation of China[31200345,31570605 and 31370628]China Scholarship Council(201706910039) to Y.C.(joint Ph.D.programme grant).
文摘Aims Plant litter decomposition is a key ecosystem process that determines carbon and nutrient cycling in terrestrial ecosystems.As a main component of litter,cellulose is a vital energy source for the microbes associated with litter decomposition.The important role of cellulolytic enzymes in litter cellulose degradation is well understood,but seasonal patterns of cellulose degradation and whether cumulative enzyme activities and litter quality forecast cellulose degradation in an alpine meadow remain elusive,which limits our understanding of cellulose degradation in herbaceous plant litter.Methods A two-year field litterbag experiment involving three dominant species(Ajuga ovalifolia,Festuca wallichanica,and Pedicularis roylei)was conducted in an alpine meadow of the eastern Tibetan Plateau to explore the seasonal patterns of cellulose degradation and how cumulative cellulolytic enzyme activities and initial litter quality impact cellulose degradation.Important findings Our study demonstrates that cellulose degraded rapidly and exceeded 50%during the first year,which mainly occurred in the first growing season(31.9%–43.3%).At two years of decomposition,cellulose degradation was driven by cumulative endoglucanase(R^(2)=0.70),cumulative cellobiohydrolase(R^(2)=0.59)and cumulative 1,4-β-glucosidase(R^(2)=0.57).In addition,the concentrations of cellulose,dissolved organic carbon,total phenol,lignin and lignin/N accounted for 52%–78%of the variation in cellulose degradation during the two years of decomposition.The best model for predicting cellulose degradation was the initial cellulose concentration(R^(2)=0.78).The enzymatic efficiencies and the allocation of cellulolytic enzyme activities were different among species.The cellulolytic enzyme efficiencies were higher in the litter of F.wallichanica with relatively lower quality.For the complete cellulose degradation of the leaf litter,A.ovalifolia and F.wallichanica required 4-fold and 6.7-fold more endoglucanase activity,3-fold and 4.5-fold more cellobiohydrolase activity and 1.2-fold and 1.4-fold more 1,4-β-glucosidase activity,respectively,than those required by P.roylei.Our results demonstrated that although microbial activity and litter quality both have significant impacts on cellulose degradation in an alpine meadow,using cellulose concentration to predict cellulose degradation is a good way to simplify the model of cellulose degradation and C cycling during litter decomposition.