To improve the cyclic stability at high temperature and thermal stability, the spherical Al2O3-modified Li(Ni0.5Co0.2Mn0.3)O2 was synthesized by a modified co-precipitation method, and the physical and electrochemic...To improve the cyclic stability at high temperature and thermal stability, the spherical Al2O3-modified Li(Ni0.5Co0.2Mn0.3)O2 was synthesized by a modified co-precipitation method, and the physical and electrochemical properties were studied. The TEM images showed that Li(Ni0.5Co0.2Mn0.3)O2 was modified successfully with nano-Al2O3. The discharge capacity retention of Al2O3-modified Li(Ni0.5Co0.2Mn0.3)O2 maintained about 99% after 200 cycles at high temperature(55 ℃), while that of the bare one was only 86%. Also, unlike bare Li(Ni0.5Co0.2Mn0.3)O2, the Al2O3-modified material cathode exhibited good thermal stability.展开更多
s: A new method for the preparation of an organic-inorganic composite film of the heteropolyanion has been developed by modifying P(Mo2O7)6-7 to the indium tin oxide (ITO) electrode surface. The modified electrode dis...s: A new method for the preparation of an organic-inorganic composite film of the heteropolyanion has been developed by modifying P(Mo2O7)6-7 to the indium tin oxide (ITO) electrode surface. The modified electrode displayed a strong catalytic activity towards the reduction of IO3-. In the range of 1.0?0-6~5?0-4mol/L, the catalytic current was linear proportional to the IO3- concentration.展开更多
[ Objective ] This study aimed to investigate the major contributors to the measurement uncertainty in quantitative analysis of genetically modified ingreclients and improve the quality of quantitative detection of ge...[ Objective ] This study aimed to investigate the major contributors to the measurement uncertainty in quantitative analysis of genetically modified ingreclients and improve the quality of quantitative detection of genetically modified components. [ Method] The content of CaMV35S promoter (parameter) in GTS40- 3-2 soybean powder samples was measured to estimate the measurement uncertainty preliminarily. [ Result] Type A uncertainty (uA) ' type B uncertainty (uB) and combined standard uncertainty (Uc) were 0.0 004, 0.002 and 0.002, respectively. At a confidence level ofp = 95% and freedom degree of Voff = 3 251, coverage factor k = 1.96, expanded uncertainty U = 0.004. The final measurement result was C = 0.028 ± 0. 004, which was dose to the conventional true value (0.03). Thus, the measurement uncertainty was relatively small, indicating a high quality of measurement. In this study, uncertainty evaluation indicated that the deviation of micro liquid transfer made the greatest contribution to the measurement uncertainty. [ Cludusion ] The deviation of micro liquid transfer should be reduced to im- prove the quality of measurement.展开更多
BACKGROUND Radiological detection of small liver metastasis or peritoneal metastasis is still difficult,and some patients with biliary tract cancer(BTC)are unresectable after laparotomy.Staging laparoscopy may help av...BACKGROUND Radiological detection of small liver metastasis or peritoneal metastasis is still difficult,and some patients with biliary tract cancer(BTC)are unresectable after laparotomy.Staging laparoscopy may help avoid unnecessary laparotomy.However,which category of BTC is amenable with staging laparoscopy remains unclear.AIM To clarify the risk factors for occult metastasis in patients with BTC.METHODS Medical records of patients with BTC who underwent surgery at our institution between January 2008 and June 2014 were retrospectively reviewed.The patients were divided into two groups,according to resection or exploratory laparotomy(EL).Preoperative laboratory data,including inflammation-based prognostic scores and tumor markers,were compared between the two groups.Prognostic importance of detected risk factors was also evaluated.RESULTS A total of 236 patients were enrolled in this study.Twenty-six(11%)patients underwent EL.Among the EL patients,there were 16 cases of occult metastasis(7 liver metastases and 9 abdominal disseminations).Serum carcinoembryonic antigen level,carbohydrate antigen 19-9 level,neutrophil-lymphocyte ratio and modified Glasgow prognostic score were significantly higher in the EL group than in the resected group,and these factors were prognostic.Among these factors,carcinoembryonic antigen>7 ng/mL was the most useful to predict occult metastasis in BTC.When patients have more than three of these positive factors,the rate of occult metastasis increases.CONCLUSION Inflammation-based prognostic scores and tumor markers are useful in detecting occult metastasis in BTC;based on these factors,staging laparoscopy may reduce the rate of EL.展开更多
The modified QUICK scheme on unstructured grid was used to improve the advection flux approximation, and the depth-averaged κ-ε turbulence model with the scheme based on FVM by SIMPLE series algorithm was establishe...The modified QUICK scheme on unstructured grid was used to improve the advection flux approximation, and the depth-averaged κ-ε turbulence model with the scheme based on FVM by SIMPLE series algorithm was established and applied to spur-dike flow computation. In this model, the over-relaxed approach was adopted to estimate the diffusion flux in view of its advantages in reducing errors and sustaining numerical stability usually encountered in non-orthogonal meshes. Two spur-dike cases with different defection angles (90°and 135°) were analyzed to validate the model. Computed results show that the predicted velocities and recirculation lengths are in good agreement with the observed data. Moreover, the computations on structured and unstructured grids were compared in terms of the approximately equivalent grid numbers. It can be concluded that the precision with unstructured grids is higher than that with structured grids in spite that the CPU time required is slightly more with unstructured grids Thus, it is significant to apply the method to numerical simulation of practical hydraulic engineering.展开更多
To synthesize a series of 3-, 4-, and/or 11-trihydroxy modified bergenin derivatives and evaluated their cytotoxic activity in vitro. The phenolic hydroxyl groups of bergenin were protected by benzyl groups with benzy...To synthesize a series of 3-, 4-, and/or 11-trihydroxy modified bergenin derivatives and evaluated their cytotoxic activity in vitro. The phenolic hydroxyl groups of bergenin were protected by benzyl groups with benzyl bromide. Treatment of dibenzyl bergenin with the corresponding acid in the presence of EDC·HCl and DMAP in CH2Cl2, followed by hydrogenation over Pd/C catalysts, afforded derivatives of bergenin esters. All of the target compounds were identified by IR, MS, and 1H NMR. Twenty-six novel and three known derivatives of bergenin esters were synthesized. Their cytotoxicity values were evaluated by the MTT assay on the inhibition of DU-145 and BGC-823 cells in vitro. Several triply-substituted(3a, 4a, 5a, 6a, 7a) and doublysubstituted(8b, 9b) bergenin derivatives exhibited higher cytotoxic activity than bergenin. The result showed that the size of substituents and the lipophilicity of the bergenin esters displayed an important role on their cytotoxic activity.展开更多
In this paper, a collocation technique with the modified equilibrium on line method (ELM) for imposition of Neumann (natural) boundary conditions is presented for solving the two-dimensional problems of linear ela...In this paper, a collocation technique with the modified equilibrium on line method (ELM) for imposition of Neumann (natural) boundary conditions is presented for solving the two-dimensional problems of linear elastic body vibrations. In the modified ELM, equilibrium over the lines on the natural boundary is satisfied as Neumann boundary condition equations. In other words, the natural boundary conditions are satisfied naturally by using the weak formulation. The performance of the modified version of the ELM is studied for collocation methods based on two different ways to construct meshless shape functions: moving least squares approximation and radial basis point interpolation. Numerical examples of two-dimensional free and forced vibration analyses show that by using the modified ELM, more stable and accurate results would be obtained in comparison with the direct collocation method.展开更多
Electrochemical CO_(2) reduction driven by renewable electricity is one of the promising strategies to store sus-tainable energy as fuels.However,the selectivity of value-added multi-carbon products remains poor for f...Electrochemical CO_(2) reduction driven by renewable electricity is one of the promising strategies to store sus-tainable energy as fuels.However,the selectivity of value-added multi-carbon products remains poor for further application of this process.Here,we regulate CO adsorption by forming a Nafion layer on the copper(Cu)electrode that is repulsive to OH^(-),contributing to enhanced selectivity of CO_(2) reduction to C_(2) products with the suppression of C 1 products.The operando Raman spectroscopy indicates that the local OH^(-)would adsorb on part of active sites and decrease the adsorption of CO.Therefore,the electrode with repulsive to OH^(-)can adjust the concentration of OH^(-),leading to the increased adsorption of CO and enhanced C–C coupling.This work shows that electrode design could be an effective strategy for improving the selectivity of CO_(2) reduction to multi-carbon products.展开更多
Ecological impact caused by transgene flow from genetically engineered (GE) crops to their wild rela- tives is largely determined by the fitness effect brought by a transgene. To estimate such impact is critical for...Ecological impact caused by transgene flow from genetically engineered (GE) crops to their wild rela- tives is largely determined by the fitness effect brought by a transgene. To estimate such impact is critical for the eco- logical risk assessment prior to the commercialization of GE crops. We produced F1 and F2 hybrid descendants from crosses of two insect-resistant GE rice lines (Bt, Bt/CpT1) and their non-GE rice parent with a wild rice (Oryza ruff- pogon) population to estimate the transgenic fitness. Insect damages and life-cycle fitness of GE and non-GE crop- wild hybrid descendants as well as their wild parent were examined in a common-garden experiment. No significant differences in insect damages were observed between the wild rice parent and GE hybrid descendants under high- insect pressure. The wild parent showed significantly greater relative survival-regeneration ratios than its GE and non-GE hybrid descendants under both high- and low-in- sect pressure. However, more seeds were produced in GE hybrid descendants than their non-GE counterparts under high-insect pressure. Given that the introduction of Bt and Bt/CpT1 transgenes did not provide greater insect resistance to crop-wild hybrid descendants than their wild parent, we predict that transgene flow from GE insect-resistant rice to wild rice populations may not cause considerable ecolog- ical risks.展开更多
In this article, a special type of fractional differential equations(FDEs) named the density-dependent conformable fractional diffusion-reaction(DDCFDR) equation is studied. Aforementioned equation has a significant r...In this article, a special type of fractional differential equations(FDEs) named the density-dependent conformable fractional diffusion-reaction(DDCFDR) equation is studied. Aforementioned equation has a significant role in the modelling of some phenomena arising in the applied science. The well-organized methods, including the exp(-φ(ε))-expansion and modified Kudryashov methods are exerted to generate the exact solutions of this equation such that some of the solutions are new and have been reported for the first time. Results illustrate that both methods have a great performance in handling the DDCFDR equation.展开更多
基金Funded by the National High Technology Research and Development Program of China(863 Program)(No.2015AA034600)Province Science and Technology in Anhui(No.1301021011)
文摘To improve the cyclic stability at high temperature and thermal stability, the spherical Al2O3-modified Li(Ni0.5Co0.2Mn0.3)O2 was synthesized by a modified co-precipitation method, and the physical and electrochemical properties were studied. The TEM images showed that Li(Ni0.5Co0.2Mn0.3)O2 was modified successfully with nano-Al2O3. The discharge capacity retention of Al2O3-modified Li(Ni0.5Co0.2Mn0.3)O2 maintained about 99% after 200 cycles at high temperature(55 ℃), while that of the bare one was only 86%. Also, unlike bare Li(Ni0.5Co0.2Mn0.3)O2, the Al2O3-modified material cathode exhibited good thermal stability.
基金Authors greatly appreciate the supports from the National Natural Science Foundation of China Returnee Foundation of Ministry of Education of China and Analytical Foundation of Nanjing University.
文摘s: A new method for the preparation of an organic-inorganic composite film of the heteropolyanion has been developed by modifying P(Mo2O7)6-7 to the indium tin oxide (ITO) electrode surface. The modified electrode displayed a strong catalytic activity towards the reduction of IO3-. In the range of 1.0?0-6~5?0-4mol/L, the catalytic current was linear proportional to the IO3- concentration.
基金Supported by Project of Standardized Technology System of Sichuan Bureau of Quality and Technical Supervision(ZYBZ2013-39)
文摘[ Objective ] This study aimed to investigate the major contributors to the measurement uncertainty in quantitative analysis of genetically modified ingreclients and improve the quality of quantitative detection of genetically modified components. [ Method] The content of CaMV35S promoter (parameter) in GTS40- 3-2 soybean powder samples was measured to estimate the measurement uncertainty preliminarily. [ Result] Type A uncertainty (uA) ' type B uncertainty (uB) and combined standard uncertainty (Uc) were 0.0 004, 0.002 and 0.002, respectively. At a confidence level ofp = 95% and freedom degree of Voff = 3 251, coverage factor k = 1.96, expanded uncertainty U = 0.004. The final measurement result was C = 0.028 ± 0. 004, which was dose to the conventional true value (0.03). Thus, the measurement uncertainty was relatively small, indicating a high quality of measurement. In this study, uncertainty evaluation indicated that the deviation of micro liquid transfer made the greatest contribution to the measurement uncertainty. [ Cludusion ] The deviation of micro liquid transfer should be reduced to im- prove the quality of measurement.
文摘BACKGROUND Radiological detection of small liver metastasis or peritoneal metastasis is still difficult,and some patients with biliary tract cancer(BTC)are unresectable after laparotomy.Staging laparoscopy may help avoid unnecessary laparotomy.However,which category of BTC is amenable with staging laparoscopy remains unclear.AIM To clarify the risk factors for occult metastasis in patients with BTC.METHODS Medical records of patients with BTC who underwent surgery at our institution between January 2008 and June 2014 were retrospectively reviewed.The patients were divided into two groups,according to resection or exploratory laparotomy(EL).Preoperative laboratory data,including inflammation-based prognostic scores and tumor markers,were compared between the two groups.Prognostic importance of detected risk factors was also evaluated.RESULTS A total of 236 patients were enrolled in this study.Twenty-six(11%)patients underwent EL.Among the EL patients,there were 16 cases of occult metastasis(7 liver metastases and 9 abdominal disseminations).Serum carcinoembryonic antigen level,carbohydrate antigen 19-9 level,neutrophil-lymphocyte ratio and modified Glasgow prognostic score were significantly higher in the EL group than in the resected group,and these factors were prognostic.Among these factors,carcinoembryonic antigen>7 ng/mL was the most useful to predict occult metastasis in BTC.When patients have more than three of these positive factors,the rate of occult metastasis increases.CONCLUSION Inflammation-based prognostic scores and tumor markers are useful in detecting occult metastasis in BTC;based on these factors,staging laparoscopy may reduce the rate of EL.
基金the National Nature Science Foundation of China (Grant Nos. 50679019 and 50009001)the National Basic Research Program of China (973 Program, Grant No. 2008CB418202)the Social Technology Development Foundation of Jiangsu Province (Grant No.BS2006095)
文摘The modified QUICK scheme on unstructured grid was used to improve the advection flux approximation, and the depth-averaged κ-ε turbulence model with the scheme based on FVM by SIMPLE series algorithm was established and applied to spur-dike flow computation. In this model, the over-relaxed approach was adopted to estimate the diffusion flux in view of its advantages in reducing errors and sustaining numerical stability usually encountered in non-orthogonal meshes. Two spur-dike cases with different defection angles (90°and 135°) were analyzed to validate the model. Computed results show that the predicted velocities and recirculation lengths are in good agreement with the observed data. Moreover, the computations on structured and unstructured grids were compared in terms of the approximately equivalent grid numbers. It can be concluded that the precision with unstructured grids is higher than that with structured grids in spite that the CPU time required is slightly more with unstructured grids Thus, it is significant to apply the method to numerical simulation of practical hydraulic engineering.
基金supported by the Natural Science Foundation of China(Nos.81274064 and 81373956)the National Fund for Fostering Talents of Basic Science(NFFTBS)(No.J1030830)the Science and Technology Supporting Project of Xinjiang(No.201291160)
文摘To synthesize a series of 3-, 4-, and/or 11-trihydroxy modified bergenin derivatives and evaluated their cytotoxic activity in vitro. The phenolic hydroxyl groups of bergenin were protected by benzyl groups with benzyl bromide. Treatment of dibenzyl bergenin with the corresponding acid in the presence of EDC·HCl and DMAP in CH2Cl2, followed by hydrogenation over Pd/C catalysts, afforded derivatives of bergenin esters. All of the target compounds were identified by IR, MS, and 1H NMR. Twenty-six novel and three known derivatives of bergenin esters were synthesized. Their cytotoxicity values were evaluated by the MTT assay on the inhibition of DU-145 and BGC-823 cells in vitro. Several triply-substituted(3a, 4a, 5a, 6a, 7a) and doublysubstituted(8b, 9b) bergenin derivatives exhibited higher cytotoxic activity than bergenin. The result showed that the size of substituents and the lipophilicity of the bergenin esters displayed an important role on their cytotoxic activity.
文摘In this paper, a collocation technique with the modified equilibrium on line method (ELM) for imposition of Neumann (natural) boundary conditions is presented for solving the two-dimensional problems of linear elastic body vibrations. In the modified ELM, equilibrium over the lines on the natural boundary is satisfied as Neumann boundary condition equations. In other words, the natural boundary conditions are satisfied naturally by using the weak formulation. The performance of the modified version of the ELM is studied for collocation methods based on two different ways to construct meshless shape functions: moving least squares approximation and radial basis point interpolation. Numerical examples of two-dimensional free and forced vibration analyses show that by using the modified ELM, more stable and accurate results would be obtained in comparison with the direct collocation method.
基金This work was supported by the following projects:INTERNATIONAL COOPERATION Projects of the Ministry of Science and Technology(2014DFE60170)the Strategic Japanese-Swiss Science and Technology Program from the Swiss National Science Foundation(project No.IZJSZ2_180176)+4 种基金the Sino-Swiss Science and Technology Cooperation(SSSTC)2016 project from the Swiss National Science Foundation(project No.IZLCZ2_170294)the National Natural Science Foundation of China(Grant No.61674084)the Overseas Expertise Introduction Project for DisciplineInnovation of Higher Education of China(Grant No.B16027)Tianjin Science and Technology Project(Grant No.18ZXJMTG00220)the Fundamental Research Fund for the Central Universities of China.
文摘Electrochemical CO_(2) reduction driven by renewable electricity is one of the promising strategies to store sus-tainable energy as fuels.However,the selectivity of value-added multi-carbon products remains poor for further application of this process.Here,we regulate CO adsorption by forming a Nafion layer on the copper(Cu)electrode that is repulsive to OH^(-),contributing to enhanced selectivity of CO_(2) reduction to C_(2) products with the suppression of C 1 products.The operando Raman spectroscopy indicates that the local OH^(-)would adsorb on part of active sites and decrease the adsorption of CO.Therefore,the electrode with repulsive to OH^(-)can adjust the concentration of OH^(-),leading to the increased adsorption of CO and enhanced C–C coupling.This work shows that electrode design could be an effective strategy for improving the selectivity of CO_(2) reduction to multi-carbon products.
基金supported by the National Natural Science Foundation of China (31330014)the National Program of Development of Transgenic New Species of China (2016ZX08011006)
文摘Ecological impact caused by transgene flow from genetically engineered (GE) crops to their wild rela- tives is largely determined by the fitness effect brought by a transgene. To estimate such impact is critical for the eco- logical risk assessment prior to the commercialization of GE crops. We produced F1 and F2 hybrid descendants from crosses of two insect-resistant GE rice lines (Bt, Bt/CpT1) and their non-GE rice parent with a wild rice (Oryza ruff- pogon) population to estimate the transgenic fitness. Insect damages and life-cycle fitness of GE and non-GE crop- wild hybrid descendants as well as their wild parent were examined in a common-garden experiment. No significant differences in insect damages were observed between the wild rice parent and GE hybrid descendants under high- insect pressure. The wild parent showed significantly greater relative survival-regeneration ratios than its GE and non-GE hybrid descendants under both high- and low-in- sect pressure. However, more seeds were produced in GE hybrid descendants than their non-GE counterparts under high-insect pressure. Given that the introduction of Bt and Bt/CpT1 transgenes did not provide greater insect resistance to crop-wild hybrid descendants than their wild parent, we predict that transgene flow from GE insect-resistant rice to wild rice populations may not cause considerable ecolog- ical risks.
文摘In this article, a special type of fractional differential equations(FDEs) named the density-dependent conformable fractional diffusion-reaction(DDCFDR) equation is studied. Aforementioned equation has a significant role in the modelling of some phenomena arising in the applied science. The well-organized methods, including the exp(-φ(ε))-expansion and modified Kudryashov methods are exerted to generate the exact solutions of this equation such that some of the solutions are new and have been reported for the first time. Results illustrate that both methods have a great performance in handling the DDCFDR equation.