Hydride generation (HG)technique has been widely used for the determination of volatile hydride forming elements by atomic spectroscopy since Holak reported the determination of arsenic with this technique using atomi...Hydride generation (HG)technique has been widely used for the determination of volatile hydride forming elements by atomic spectroscopy since Holak reported the determination of arsenic with this technique using atomic absorption spectrometry in 1969. The most commonly used展开更多
Mining and smelting processes are among the key sources of soil contamination by heavy metals resulting in dramatic disturbances and loss of biodiversity. Native plants growing naturally in hostile mining environments...Mining and smelting processes are among the key sources of soil contamination by heavy metals resulting in dramatic disturbances and loss of biodiversity. Native plants growing naturally in hostile mining environments can be used for management, decontamination and possible rehabilitation of polluted soils. These plants are either excluders or accumulators based on their Bioaccumulation Factors (BAF). This, therefore requires identification of native plants that are able to accumulate heavy metals in their plant tissues at concentrations higher than that in the soil in which they are growing. This study investigated the phytoremediation potential of indigenous plants growing at the tailings dams of Nchanga Mine in Chingola, Zambia. TD4 and a site 50 m away from TD4 were sampled as Sampling Areas One (1) and Two (2), respectively. TD4 was divided into four quadrants and three plots from each quadrant were randomly sampled. Three plots from each of the two quadrants from Sampling Area Two were also sampled. Composite soil samples were collected from the plots and a total of 175 individuals of 16 grass and herbaceous plant species were collected and analysed. Atomic Absorption Spectrophotometry was used to determine the concentrations of Copper (Cu) and Zinc (Zn) in the soils and plant specimens. The findings of the study showed that the concentrations of Cu and Zn in the soil ranged from 891.41 mg/kg to 15,617.47 mg/kg and 20.73 mg/kg to 96.85 mg/kg, respectively. Arthraxonquartinianus had the highest concentration of Cu (1016.8 mg/kg) while Cyperusrotundus had the lowest (29.35 mg/kg). Arthraxonquartinianus had the highest concentration of Zn (192.8 mg/kg) and Crinum had the lowest (28.24 mg/kg). BAF values for Cu were less than 1 in all the plants and BAF values for Zn were highest in Arthraxonquartinianus (10.77) with Crinum having the lowest BAF of 0.01. The Bioaccumulation Factors indicated that all the plant species studied are Cu excluders;and with the exception of Crinum, all were Zn accumulators and Arthraxonquartinianus, a hyperaccumulator of Zn.展开更多
The red alga Gracilaria heteroclada was established by the authors (Zhang Junfu and Xia Bangmei, 1988). The specific name is, however, illegitimatized by the earlier homonym Gracilaria heteroclada (Montagne) (J. et G....The red alga Gracilaria heteroclada was established by the authors (Zhang Junfu and Xia Bangmei, 1988). The specific name is, however, illegitimatized by the earlier homonym Gracilaria heteroclada (Montagne) (J. et G. Feldmann,1943). In 1989, Fredeficq and Hommersand restored the genus Gracilariopsis with its type species, G. lemaneiformis, thus excluding it (Gracilaria heteroclada Zhang et Xia) from the genus Gracilaria. It was transferred to Gracilariopsis展开更多
The method of scoring kidney deficiency symptoms and bone density was used to judge therapeutic efficacy on osteoporosis of traditional kidney-tonifying drugs. It was proved that the drugs not only improved clinical s...The method of scoring kidney deficiency symptoms and bone density was used to judge therapeutic efficacy on osteoporosis of traditional kidney-tonifying drugs. It was proved that the drugs not only improved clinical symptoms but also delayed the developmental pro-cess of this disorder. It also verified the correctness of the traditional theory that the kidney dominates the bone and generates the marrow.展开更多
Uroschesis is manifested by. incompleteness or difficulty in urination or even incapability of urination. Clinically, the symptoms include retention of urine and anuria induced by a variety of causes. In this study, t...Uroschesis is manifested by. incompleteness or difficulty in urination or even incapability of urination. Clinically, the symptoms include retention of urine and anuria induced by a variety of causes. In this study, the patients with anuria or oliguria due to lesions of renal parenchyma or renal failure were excluded. Using acupuncture, the author had treated 36 cases of functional uroshesis with satisfactory results as reported in the following.展开更多
This work investigates the effects of the excluded volume and especially those of the chain stiffness on the structural and dynamical properties of a model polymer chain. The theoretical framework is the same as in th...This work investigates the effects of the excluded volume and especially those of the chain stiffness on the structural and dynamical properties of a model polymer chain. The theoretical framework is the same as in the recent works by Steinhauser et al., where a Rouse approach is adopted. Our model differs in that our chains have a finite average bending angle. As in the works by Steinhauser et al., Langevin dynamic simulations were performed without hydrodynamic interactions. Whereas this doesn＇t impact the static properties we obtain, it also allows us to compare our results on dynamic properties to those predicted by Rouse theory, where hydrodynamic interactions are also neglected. Our results show that the structural properties are very sensitive to the chain stiffness, whereas the dynamic scaling laws remain the same as those by Rouse theory, with the prefactor depending on the persistence length.展开更多
We report our experience with potential donors for living donor liver transplantation(LDLT), which is the first report from an area where there is no legalized deceased donation program. This is a single center retros...We report our experience with potential donors for living donor liver transplantation(LDLT), which is the first report from an area where there is no legalized deceased donation program. This is a single center retrospective analysis of potential living donors(n = 1004) between May 2004 and December 2012. This report focuses on the analysis of causes, duration, cost, and various implications of donor exclusion(n = 792).Most of the transplant candidates(82.3%) had an experience with more than one excluded donor(median = 3). Some recipients travelled abroad for a deceased donor transplant(n = 12) and some died before finding a suitable donor(n = 14). The evaluation of an excluded donor is a time-consuming process(median = 3 d, range 1 d to 47 d). It is also a costly process with a median cost of approximately 70 USD(range 35 USD to 885 USD). From these results, living donor exclusion has negative implications on the patients and transplant program with ethical dilemmas and an economic impact. Many strategies are adopted by other centers to expand the donor pool; however, they are not all applicable in our locality. We conclude that an active legalized deceased donor transplantation program is necessary to overcome the shortage of available liver grafts in Egypt.展开更多
Understanding the excluded volume of anisotropic particle is of great importance in the evaluation of continuum percolation and random packing behaviors of soft/hard particle systems in heterogeneous disordered media....Understanding the excluded volume of anisotropic particle is of great importance in the evaluation of continuum percolation and random packing behaviors of soft/hard particle systems in heterogeneous disordered media.In this work,we obtain the excluded volumes of several anisotropic convex particles including prolate spheroids,oblate spheroids,spherocylinders,and Platonic particles,using theoretical and numerical approaches.According to the second virial coefficient,we first present a theoretical scheme for determining the excluded volumes of anisotropic particles.Also,the mean tangent diameters of anisotropic convex particles are formulated by the quantitative stereology.Subsequently,Monte Carlo simulations are demonstrated to numerically evaluate the excluded volumes.The theoretical results of the dimensionless excluded volume are thereafter compared with that of the numerical results to verify the validity of the theoretical scheme.We further investigate the dependence of the dimensionless excluded volume on the geometric characteristics of anisotropic particles based on the proposed theoretical and numerical schemes.Results show that the dimensionless excluded volume mainly relies on the shape and surface information of anisotropic particles.The developed theoretical and numerical schemes can provide theoretical insights into the percolation threshold and packing density of soft/hard anisotropic particle systems in heterogeneous materials,physics,and chemistry fields.展开更多
Chain architecture effect on static and dynamic properties of unentangled polymers is explored by molecular dynamics simulation and Rouse mode analysis based on graph theory.For open chains,although they generally obe...Chain architecture effect on static and dynamic properties of unentangled polymers is explored by molecular dynamics simulation and Rouse mode analysis based on graph theory.For open chains,although they generally obey ideal scaling in chain dimensions,local structure exhibits nonideal behavior due to the incomplete excluded volume(EV)screening,the reduced mean square internal distance(MSID)can be well described by Wittmer'theory for linear chains and the resulting chain swelling is architecture dependent,i.e.,the more branches a bit stronger swelling.For rings,unlike open chains they are compact in term of global sizes.Due to EV effect and nonconcatenated constraints their local structure exhibits a quite different non-Gaussian behavior from open chains,i.e.,reduced MSID curves do not collapse to a single master curve and fail to converge to a chain-length-independent constant,which makes the direct application of Wittmer's theory to rings quite questionable.Deviation from ideality is further evidenced by limited applicability of Rouse prediction to mode amplitude and relaxation time at high modes as well as the non-constant and mode-dependent scaled Rouse mode amplitudes,while the latter is architecture-dependent and even molecular weight dependent for rings.The chain relaxation time is architecture-dependent,but the same scaling dependence on chain dimensions does hold for all studied architectures.Despite mode orthogonality at static state,the role of cross-correlation in orientation relaxation increases with time and the time-dependent coupling parameter rises faster for rings than open chains even at short time scales it is lower for rings.展开更多
This paper provides a review on China＇s meat trade for the 2000–2012 period and discusses its future development, with reference to China＇s grain trade. With marginal decreases in meat exports and slight increases ...This paper provides a review on China＇s meat trade for the 2000–2012 period and discusses its future development, with reference to China＇s grain trade. With marginal decreases in meat exports and slight increases in their imports, China＇s net imports of major meat products（including pork, beef, mutton and poultry but excluding meat offal） were just below 1 million tons in 2012, dwarfed by China＇s net imports of grains which reached 66.7 million tons in the same year. This slow growth in meat trade seems to contradict earlier expectations on increasing meat demand and imports, based upon projected shifts in consumption patterns driven by rapid per capita income growth. Several plausible explanations of this paradoxical trade pattern are offered, including mass imports of feed grains, persistent（but shrinking） gaps between Chinese and international meat prices, tariff barriers, and non-tariff measures. In the near future China may not be able to maintain such a lower profile on the world meat markets, as per capita income is projected to continue to rise and domestic production cost advantages erode due to rising labor costs. A model-based projection exercise indicates that under plausible assumptions China＇s meat imports may rise sharply by 2030.展开更多
The viscosity behavior of polyvinylpyrrolidone(PVP)has been determined at 25℃ in mixed solvents comprising water/dimethylformamide(DMF)and water/methanol(MeOH).Analysis of the data has considered the PVP as being bot...The viscosity behavior of polyvinylpyrrolidone(PVP)has been determined at 25℃ in mixed solvents comprising water/dimethylformamide(DMF)and water/methanol(MeOH).Analysis of the data has considered the PVP as being both host and vip polymer in solution.The intrinsic viscosity of PVP in DMF is higher than in water and in MeOH,but also increases in a mixed solvent with high water content because of the effect of polymer-solvent interactions.It was also found that the intrinsic viscosity of PVP at finite concentration,[η_(pvp)]_c decreases with an increase in the concentration of PVP in solution.The viscosity behavior of PVP in a mixed solvent is affected by the concentration-dependent intermolecular excluded volume effect,which can be quantitatively expressed by the parameter,b_Y,which reflects the shrinkage of PVP chain coils,resulting in a decrease of[η_(pvp)]_c.The effect of temperature on the viscosity behavior of PVP in MeOH shows that the interaction parameter increases up to a maximum value,and then decreases after a certain temperature.展开更多
Using the tools of distinct excluded blocks, computational search and symbolic dynamics, the classification problem of all 256 elementary cellular automata is discussed from the point of view of time series generated ...Using the tools of distinct excluded blocks, computational search and symbolic dynamics, the classification problem of all 256 elementary cellular automata is discussed from the point of view of time series generated by them,and examples in each class are provided to explain the methods used.展开更多
The Yangtze delta＇s response to accelerating river damming and irrigation is a topic of global concern. This research analyzed the general erosion-accretion of the submerged delta front, the spatio-temporal changing ...The Yangtze delta＇s response to accelerating river damming and irrigation is a topic of global concern. This research analyzed the general erosion-accretion of the submerged delta front, the spatio-temporal changing pattern in different sub-regions, the geomorphological changes in typical cross-sections, and the geomorphological causes of the four main sub-regions（the eastern tidal wetland of Chongming–CM, the Hengsha shoal–HS, the Jiuduansha wetland–JDS, and the eastern tidal wetland of Nanhui–NH）. Data sources include topographic data measured at high-resolution, sediment load at Datong Station, and the corresponding estuary construction information. Major findings are：（1） in general, the study area had slightly eroded（the erosion area ratio was 51.83% and the accretion area ratio was 48.17%） from 1982 to 2010, and it had experienced a shift of “erosion-accretion- erosion”. The spatio-temporal change of geomorphology was also significant in the eight sub-regions, excluding constant erosion in the North Channel;（2） evolution in eastern and northern CM and HS, northern JDS, and the region within the 5 m isobath of NH was dominated by vertical deposition, which was the opposite of that in southern CM and HS, and the region within the 5 m isobath of eastern and southern JDS;（3） on the whole, the encompassed surface areas（ESAs） of the 2 m and 5 m isobaths kept increasing, and the annual growth rates reached 10.42 km^2/yr and 7.99 km^2/yr respectively during 1982–2010（however, four sub-regions exhibited disagreements）, and in the whole region and all sub-regions, the ESA of the 10 m isobath decreased, while the ESA of the 15 m isobath changed slightly during the period and remained stable;（4） being less influenced by the estuarine engineering, CM was the only sub-region where the ESA of the isobath decreased in accordance with the decline of the sediment load. Major conclusions are that estuarine engineering projects play an increasingly important role in affecting the submerged delta against the macro-background of the reduction of sediment load, the change of ESA and the distribution of isobaths. Along with the accelerating construction of the Shanghai International Shipping Centre and reclamation project, the geomorphological evolution of the submerged delta will become more complex and thus deserves frequent monitoring in the future.展开更多
AIM: To hypothesize that the product of calculated Model for End-Stage Liver Disease score excluding exception points and donor age(D-MELD) risk capping ± Rule 14 could improve post liver transplant and overall s...AIM: To hypothesize that the product of calculated Model for End-Stage Liver Disease score excluding exception points and donor age(D-MELD) risk capping ± Rule 14 could improve post liver transplant and overall survival after listing.METHODS: Probabilities derived from the United Network for Organ Sharing database between 2002 and 2004 were used to simulate potential outcomes for all patients listed for transplantation. The Markov simula-tion was then modified by screening matches using a 1200 or 1600 D-MELD risk cap ± allowing transplants for Model for End-Stage Liver Disease(MELD) ≤ 14(Rule 14). The differential impact of the rule changes was assessed.RESULTS: The Markov simulation accurately reproduced overall and post transplant survival. A 1200 D-MELD risk cap improved post-transplant survival. Both the 1200 and 1600 risk caps improved overall survival for waitlisted patients. The addition of Rule 14 further improved post transplant and overall survival by redistribution of donor livers to recipients in higher MELD subgroups. The mechanism for improved overall and post-transplant survival after listing was due to shifting a larger percentage of transplants to the moderate MELD score subgroup(MELD 15-29) while also ensuring that high MELD recipients have livers of high quality to achieve excellent post transplant survival.CONCLUSION: A 1200 D-MELD risk cap + Rule 14 provided the greatest overall benefit primarily by focusing liver transplantation towards the moderate MELD recipient.展开更多
The 2013 Monitoring Report of Health Literacy Level of Chinese Residents announced by National Health and Family Planning Commission（NHFPC）on February 17,2015 shows that health literacy level of Chinese residents ha...The 2013 Monitoring Report of Health Literacy Level of Chinese Residents announced by National Health and Family Planning Commission（NHFPC）on February 17,2015 shows that health literacy level of Chinese residents had increased to 9.48%,a rise of 0.68percentage point over 8.80% in 2012 and an increase of 3 percentage points over 6.48% in 2008.展开更多
文摘Hydride generation (HG)technique has been widely used for the determination of volatile hydride forming elements by atomic spectroscopy since Holak reported the determination of arsenic with this technique using atomic absorption spectrometry in 1969. The most commonly used
文摘Mining and smelting processes are among the key sources of soil contamination by heavy metals resulting in dramatic disturbances and loss of biodiversity. Native plants growing naturally in hostile mining environments can be used for management, decontamination and possible rehabilitation of polluted soils. These plants are either excluders or accumulators based on their Bioaccumulation Factors (BAF). This, therefore requires identification of native plants that are able to accumulate heavy metals in their plant tissues at concentrations higher than that in the soil in which they are growing. This study investigated the phytoremediation potential of indigenous plants growing at the tailings dams of Nchanga Mine in Chingola, Zambia. TD4 and a site 50 m away from TD4 were sampled as Sampling Areas One (1) and Two (2), respectively. TD4 was divided into four quadrants and three plots from each quadrant were randomly sampled. Three plots from each of the two quadrants from Sampling Area Two were also sampled. Composite soil samples were collected from the plots and a total of 175 individuals of 16 grass and herbaceous plant species were collected and analysed. Atomic Absorption Spectrophotometry was used to determine the concentrations of Copper (Cu) and Zinc (Zn) in the soils and plant specimens. The findings of the study showed that the concentrations of Cu and Zn in the soil ranged from 891.41 mg/kg to 15,617.47 mg/kg and 20.73 mg/kg to 96.85 mg/kg, respectively. Arthraxonquartinianus had the highest concentration of Cu (1016.8 mg/kg) while Cyperusrotundus had the lowest (29.35 mg/kg). Arthraxonquartinianus had the highest concentration of Zn (192.8 mg/kg) and Crinum had the lowest (28.24 mg/kg). BAF values for Cu were less than 1 in all the plants and BAF values for Zn were highest in Arthraxonquartinianus (10.77) with Crinum having the lowest BAF of 0.01. The Bioaccumulation Factors indicated that all the plant species studied are Cu excluders;and with the exception of Crinum, all were Zn accumulators and Arthraxonquartinianus, a hyperaccumulator of Zn.
文摘The red alga Gracilaria heteroclada was established by the authors (Zhang Junfu and Xia Bangmei, 1988). The specific name is, however, illegitimatized by the earlier homonym Gracilaria heteroclada (Montagne) (J. et G. Feldmann,1943). In 1989, Fredeficq and Hommersand restored the genus Gracilariopsis with its type species, G. lemaneiformis, thus excluding it (Gracilaria heteroclada Zhang et Xia) from the genus Gracilaria. It was transferred to Gracilariopsis
文摘The method of scoring kidney deficiency symptoms and bone density was used to judge therapeutic efficacy on osteoporosis of traditional kidney-tonifying drugs. It was proved that the drugs not only improved clinical symptoms but also delayed the developmental pro-cess of this disorder. It also verified the correctness of the traditional theory that the kidney dominates the bone and generates the marrow.
文摘Uroschesis is manifested by. incompleteness or difficulty in urination or even incapability of urination. Clinically, the symptoms include retention of urine and anuria induced by a variety of causes. In this study, the patients with anuria or oliguria due to lesions of renal parenchyma or renal failure were excluded. Using acupuncture, the author had treated 36 cases of functional uroshesis with satisfactory results as reported in the following.
基金financially supported by the National Natural Science Foundation of China(No.10572056)
文摘This work investigates the effects of the excluded volume and especially those of the chain stiffness on the structural and dynamical properties of a model polymer chain. The theoretical framework is the same as in the recent works by Steinhauser et al., where a Rouse approach is adopted. Our model differs in that our chains have a finite average bending angle. As in the works by Steinhauser et al., Langevin dynamic simulations were performed without hydrodynamic interactions. Whereas this doesn＇t impact the static properties we obtain, it also allows us to compare our results on dynamic properties to those predicted by Rouse theory, where hydrodynamic interactions are also neglected. Our results show that the structural properties are very sensitive to the chain stiffness, whereas the dynamic scaling laws remain the same as those by Rouse theory, with the prefactor depending on the persistence length.
文摘We report our experience with potential donors for living donor liver transplantation(LDLT), which is the first report from an area where there is no legalized deceased donation program. This is a single center retrospective analysis of potential living donors(n = 1004) between May 2004 and December 2012. This report focuses on the analysis of causes, duration, cost, and various implications of donor exclusion(n = 792).Most of the transplant candidates(82.3%) had an experience with more than one excluded donor(median = 3). Some recipients travelled abroad for a deceased donor transplant(n = 12) and some died before finding a suitable donor(n = 14). The evaluation of an excluded donor is a time-consuming process(median = 3 d, range 1 d to 47 d). It is also a costly process with a median cost of approximately 70 USD(range 35 USD to 885 USD). From these results, living donor exclusion has negative implications on the patients and transplant program with ethical dilemmas and an economic impact. Many strategies are adopted by other centers to expand the donor pool; however, they are not all applicable in our locality. We conclude that an active legalized deceased donor transplantation program is necessary to overcome the shortage of available liver grafts in Egypt.
基金The authors acknowledge financial supports from National Natural Science Foundation Project of China(Grant No.11402076)Natural Science Foundation Project for Jiangsu Province(Grant No.BK20130841)+5 种基金China Postdoctoral Science Foundation Funded Project(Grant Nos.2014M560385 and 2015T80493)the Open Research Fund of State Key Laboratory of Structural Analysis for Industrial Equipment(Grant No.GZ1405)the Open Research Fund of State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin(Grant No.IWHR-SKL-201511)the Open Research Fund of Jiangsu Key Laboratory of Construction Materials(Grant No.CM2014-03)Jiangsu Postdoctoral Science Foundation Project(Grant No.1402053C)Research Special of the China Institute of Water Resources and Hydropower Research(Grant No.KY1640).
文摘Understanding the excluded volume of anisotropic particle is of great importance in the evaluation of continuum percolation and random packing behaviors of soft/hard particle systems in heterogeneous disordered media.In this work,we obtain the excluded volumes of several anisotropic convex particles including prolate spheroids,oblate spheroids,spherocylinders,and Platonic particles,using theoretical and numerical approaches.According to the second virial coefficient,we first present a theoretical scheme for determining the excluded volumes of anisotropic particles.Also,the mean tangent diameters of anisotropic convex particles are formulated by the quantitative stereology.Subsequently,Monte Carlo simulations are demonstrated to numerically evaluate the excluded volumes.The theoretical results of the dimensionless excluded volume are thereafter compared with that of the numerical results to verify the validity of the theoretical scheme.We further investigate the dependence of the dimensionless excluded volume on the geometric characteristics of anisotropic particles based on the proposed theoretical and numerical schemes.Results show that the dimensionless excluded volume mainly relies on the shape and surface information of anisotropic particles.The developed theoretical and numerical schemes can provide theoretical insights into the percolation threshold and packing density of soft/hard anisotropic particle systems in heterogeneous materials,physics,and chemistry fields.
基金supported by the National Natural Science Foundation of China(Nos.21790343,21574142,21174154)the National Key Research and Development Program of China(No.2016YFB1100800).
文摘Chain architecture effect on static and dynamic properties of unentangled polymers is explored by molecular dynamics simulation and Rouse mode analysis based on graph theory.For open chains,although they generally obey ideal scaling in chain dimensions,local structure exhibits nonideal behavior due to the incomplete excluded volume(EV)screening,the reduced mean square internal distance(MSID)can be well described by Wittmer'theory for linear chains and the resulting chain swelling is architecture dependent,i.e.,the more branches a bit stronger swelling.For rings,unlike open chains they are compact in term of global sizes.Due to EV effect and nonconcatenated constraints their local structure exhibits a quite different non-Gaussian behavior from open chains,i.e.,reduced MSID curves do not collapse to a single master curve and fail to converge to a chain-length-independent constant,which makes the direct application of Wittmer's theory to rings quite questionable.Deviation from ideality is further evidenced by limited applicability of Rouse prediction to mode amplitude and relaxation time at high modes as well as the non-constant and mode-dependent scaled Rouse mode amplitudes,while the latter is architecture-dependent and even molecular weight dependent for rings.The chain relaxation time is architecture-dependent,but the same scaling dependence on chain dimensions does hold for all studied architectures.Despite mode orthogonality at static state,the role of cross-correlation in orientation relaxation increases with time and the time-dependent coupling parameter rises faster for rings than open chains even at short time scales it is lower for rings.
基金financial support from the National Natural Science Foundation of China(71203096 and 71303112)the Doctoral Program of Higher Education,China(20120097120042 and 20123204120017)
文摘This paper provides a review on China＇s meat trade for the 2000–2012 period and discusses its future development, with reference to China＇s grain trade. With marginal decreases in meat exports and slight increases in their imports, China＇s net imports of major meat products（including pork, beef, mutton and poultry but excluding meat offal） were just below 1 million tons in 2012, dwarfed by China＇s net imports of grains which reached 66.7 million tons in the same year. This slow growth in meat trade seems to contradict earlier expectations on increasing meat demand and imports, based upon projected shifts in consumption patterns driven by rapid per capita income growth. Several plausible explanations of this paradoxical trade pattern are offered, including mass imports of feed grains, persistent（but shrinking） gaps between Chinese and international meat prices, tariff barriers, and non-tariff measures. In the near future China may not be able to maintain such a lower profile on the world meat markets, as per capita income is projected to continue to rise and domestic production cost advantages erode due to rising labor costs. A model-based projection exercise indicates that under plausible assumptions China＇s meat imports may rise sharply by 2030.
文摘The viscosity behavior of polyvinylpyrrolidone(PVP)has been determined at 25℃ in mixed solvents comprising water/dimethylformamide(DMF)and water/methanol(MeOH).Analysis of the data has considered the PVP as being both host and vip polymer in solution.The intrinsic viscosity of PVP in DMF is higher than in water and in MeOH,but also increases in a mixed solvent with high water content because of the effect of polymer-solvent interactions.It was also found that the intrinsic viscosity of PVP at finite concentration,[η_(pvp)]_c decreases with an increase in the concentration of PVP in solution.The viscosity behavior of PVP in a mixed solvent is affected by the concentration-dependent intermolecular excluded volume effect,which can be quantitatively expressed by the parameter,b_Y,which reflects the shrinkage of PVP chain coils,resulting in a decrease of[η_(pvp)]_c.The effect of temperature on the viscosity behavior of PVP in MeOH shows that the interaction parameter increases up to a maximum value,and then decreases after a certain temperature.
文摘Using the tools of distinct excluded blocks, computational search and symbolic dynamics, the classification problem of all 256 elementary cellular automata is discussed from the point of view of time series generated by them,and examples in each class are provided to explain the methods used.
基金National Natural Science Foundation of China, No.71373084 Global Change Scientific Research Program of China, No.2010CB951204 Innovation Program of Shanghai Municipal Education Commission, No. 13ZZ035.Acknowledgements The authors are grateful to Professor Xu Shiyuan of School of Geographic Sciences, East China Normal University, China, and Professor Yu Zhiying of State Key Laboratory of Estuarine and Coastal Research, East China Normal University, China, who gave us great help on this research and constructive advice to the paper.
文摘The Yangtze delta＇s response to accelerating river damming and irrigation is a topic of global concern. This research analyzed the general erosion-accretion of the submerged delta front, the spatio-temporal changing pattern in different sub-regions, the geomorphological changes in typical cross-sections, and the geomorphological causes of the four main sub-regions（the eastern tidal wetland of Chongming–CM, the Hengsha shoal–HS, the Jiuduansha wetland–JDS, and the eastern tidal wetland of Nanhui–NH）. Data sources include topographic data measured at high-resolution, sediment load at Datong Station, and the corresponding estuary construction information. Major findings are：（1） in general, the study area had slightly eroded（the erosion area ratio was 51.83% and the accretion area ratio was 48.17%） from 1982 to 2010, and it had experienced a shift of “erosion-accretion- erosion”. The spatio-temporal change of geomorphology was also significant in the eight sub-regions, excluding constant erosion in the North Channel;（2） evolution in eastern and northern CM and HS, northern JDS, and the region within the 5 m isobath of NH was dominated by vertical deposition, which was the opposite of that in southern CM and HS, and the region within the 5 m isobath of eastern and southern JDS;（3） on the whole, the encompassed surface areas（ESAs） of the 2 m and 5 m isobaths kept increasing, and the annual growth rates reached 10.42 km^2/yr and 7.99 km^2/yr respectively during 1982–2010（however, four sub-regions exhibited disagreements）, and in the whole region and all sub-regions, the ESA of the 10 m isobath decreased, while the ESA of the 15 m isobath changed slightly during the period and remained stable;（4） being less influenced by the estuarine engineering, CM was the only sub-region where the ESA of the isobath decreased in accordance with the decline of the sediment load. Major conclusions are that estuarine engineering projects play an increasingly important role in affecting the submerged delta against the macro-background of the reduction of sediment load, the change of ESA and the distribution of isobaths. Along with the accelerating construction of the Shanghai International Shipping Centre and reclamation project, the geomorphological evolution of the submerged delta will become more complex and thus deserves frequent monitoring in the future.
文摘AIM: To hypothesize that the product of calculated Model for End-Stage Liver Disease score excluding exception points and donor age(D-MELD) risk capping ± Rule 14 could improve post liver transplant and overall survival after listing.METHODS: Probabilities derived from the United Network for Organ Sharing database between 2002 and 2004 were used to simulate potential outcomes for all patients listed for transplantation. The Markov simula-tion was then modified by screening matches using a 1200 or 1600 D-MELD risk cap ± allowing transplants for Model for End-Stage Liver Disease(MELD) ≤ 14(Rule 14). The differential impact of the rule changes was assessed.RESULTS: The Markov simulation accurately reproduced overall and post transplant survival. A 1200 D-MELD risk cap improved post-transplant survival. Both the 1200 and 1600 risk caps improved overall survival for waitlisted patients. The addition of Rule 14 further improved post transplant and overall survival by redistribution of donor livers to recipients in higher MELD subgroups. The mechanism for improved overall and post-transplant survival after listing was due to shifting a larger percentage of transplants to the moderate MELD score subgroup(MELD 15-29) while also ensuring that high MELD recipients have livers of high quality to achieve excellent post transplant survival.CONCLUSION: A 1200 D-MELD risk cap + Rule 14 provided the greatest overall benefit primarily by focusing liver transplantation towards the moderate MELD recipient.
文摘The 2013 Monitoring Report of Health Literacy Level of Chinese Residents announced by National Health and Family Planning Commission（NHFPC）on February 17,2015 shows that health literacy level of Chinese residents had increased to 9.48%,a rise of 0.68percentage point over 8.80% in 2012 and an increase of 3 percentage points over 6.48% in 2008.
