The aim of this paper is to investigate the effect of nitrite intercalated Mg-Al layered double hydroxides(Mg-Al LDH-NO_(2))on mortar durability under the coexisting environment of Cl−and SO_(4)^(2-).Cl−and SO_(4)^(2-...The aim of this paper is to investigate the effect of nitrite intercalated Mg-Al layered double hydroxides(Mg-Al LDH-NO_(2))on mortar durability under the coexisting environment of Cl−and SO_(4)^(2-).Cl−and SO_(4)^(2-) binding properties of Mg-Al LDH-NO_(2) in simulated concrete pore solutions,Cl−and SO_(4)^(2-) diffusion properties of mortars with Mg-Al LDHNO 2 were examined.The steel corrosion and resistance of mortar against SO_(4)^(2-) attack were also evaluated.The results indicate that Mg-Al LDH-NO_(2) can effectively adsorb the Cl−and SO_(4)^(2-) in simulated concrete pore solution,and inhibit the diffusion of Cl−and SO_(4)^(2-) into cement mortars.The presence of SO_(4)^(2-) can greatly affect the uptake amount of Cl−,and there is a coupled effect of Cl−and SO_(4)^(2-) on their penetration into mortar specimens.In addition,Mg-Al LDH-NO_(2) can greatly upgrade the resistance of mortars against SO_(4)^(2-) attack and well prevent the steel from corrosion.However,Cl−will aggravate the SO_(4)^(2-) attack and SO_(4)^(2-) can initially decrease and then increase the steel corrosion.展开更多
Based on vibration analysis, single-layered graphene sheet （SLGS） with multiple attached nanoparticles is developed as nanoscale mass sensor in thermal environments. Graphene sensors are assumed to be in simplysuppo...Based on vibration analysis, single-layered graphene sheet （SLGS） with multiple attached nanoparticles is developed as nanoscale mass sensor in thermal environments. Graphene sensors are assumed to be in simplysupported configuration. Based on the nonlocal plate the- ory which incorporates size effects into the classical theory, closed-form expressions lot the frequencies and relative fre- quency shills of SLGS-based mass sensor are derived using the Galerkin method. The suggested model is justified by a good agreement between the results given by the present model and available data in literature. The effects of tem- perature difference, nonlocal parameter, the location of the nanoparticle and the number of nanoparticles on the relative frequency shift of the mass sensor are also elucidated. The obtained results show that the sensitivity of the SLGS- based mass sensor increases with increasing temperature difference.展开更多
The 21st century shall be a century of accelerated development of tunnel construction in China. But until now, what have been frequently stated in reports about influence of tunnels on environment are basically negati...The 21st century shall be a century of accelerated development of tunnel construction in China. But until now, what have been frequently stated in reports about influence of tunnels on environment are basically negative. In fact, this is not true. Tunnels, especially those extend across sensitive areas do exert some positive functions on improving environment and preventing local slope hazards. These positive effects, being new phenomena, are found and put forward by the authors after a series of careful observations have been carried out and in-depth analysis performed the first time. Meanwhile, it is a positive evaluation that the authors made upon tunnels. Many important phenomena and data are cited as evidence and their causative factors are analyzed in this paper as well.展开更多
This study attempted to examine the importance of storeenvironment in affecting consumers’store choice deci-sion;the relative importance among the three environ-mental factors;and consumers’expectations on store en-...This study attempted to examine the importance of storeenvironment in affecting consumers’store choice deci-sion;the relative importance among the three environ-mental factors;and consumers’expectations on store en-vironment for the casual-wear chain stores in HongKong.Julie Baker’s Three-category framework onstore environments namely ambient,design and socialfactors was adopted for investigation.The results indi-cated that the store environment was important in affect-ing consumers’selection of store for shopping.It alsorevealed that social factor was perceived relatively im-portant than ambient and design factors.Nine store ex-pectation dimensions were categorised and the resultdemonstrated that most respondents were concerned onthe social aspect in their expectation of having a satisfy-ing store environment.展开更多
To provide a theoretical basis for further improvement of Brassica napus yield, additive dominance with additive - by - additive epistatic effects （ ADAA） genetic model and a 6 X 8 partial dial- lel cross des...To provide a theoretical basis for further improvement of Brassica napus yield, additive dominance with additive - by - additive epistatic effects （ ADAA） genetic model and a 6 X 8 partial dial- lel cross design were used to analyze the genetic effects and correlations of five yield related traits of 14 excellent Brassica napus parental lines and their 46 and F2 populations. The results showed that silique density （SD） , siliques per plant （SPP） , seeds per silique （SPS） and thousand - seed weight （TSW） exhibited not only additive and dominant effects, but also significant epistatic effects. The dominant effects of all five yield - related traits were obviously greater than their additive effects and epistatic effects. Yield per plant （YPP） showed significant genetic correlation with SD, SPP and SPS, and the main component of the genetic correlation was the dominance correlation. SPP and SPS both showed a significant negative correlation with TSW. The SD of rapeseed was genetically correlated with all three components of yield to a certain extent, and there were different components of genetic effects positively correlated with the three yield components, indicating that SD is a potential trait to reconcile the conflict between TSW and SPP as well as SPS.展开更多
BACKGROUND:CA19-9 is a carbohydrate tumor-associated antigen which is frequently upregulated in pancreatobiliary neoplasia.However,it may also be elevated in patients with jaundice in the absence of a tumor due to bil...BACKGROUND:CA19-9 is a carbohydrate tumor-associated antigen which is frequently upregulated in pancreatobiliary neoplasia.However,it may also be elevated in patients with jaundice in the absence of a tumor due to biliary obstruction,and in other non-hepato-pancreatico-biliary conditions.This study aimed to evaluate whether CA19-9 levels could accurately differentiate between benign and malignant pancreatobiliary disease.METHODS:All patients referred to a single surgeon for investigation of pancreaticobiliary disease in 2003 in whom a firm diagnosis had been established were included.For malignant disease,a histological diagnosis was required but for benign disease a firm radiological diagnosis was deemed adequate.The patients were divided into 4 categories:pancreatic adenocarcinoma(PCa);cholangiocarcinoma(CCa);chronic pancreatitis(CP)and biliary calculous disease(Calc).Bilirubin and alkaline phosphatase levels corresponding to the point of assessment of CA19-9 were also noted.RESULTS:Final diagnoses were made of pancreatic adenocarcinoma(PCa,n=73),cholangiocarcinoma(CCa,n=19),ampullary carcinoma(Amp,n=7),neuroendocrine carcinoma(Neu,n=4),duodenal carcinoma(Duo,n=3),chronic pancreatitis(CP,n=115),and biliary calculous disease(Calc,n=27).Median CA19-9 levels(U/ml)were:PCa,653;CCa,408;Duo,403;Calc,27;CP,19;Neu,10.5;Amp,8(reference range:0-37).The CA19-9 levels were significantly greater for malignant than for benign disease,could differentiate PCa from CCa/Duo,and were significantly higher in unresectable than in resectable PCa.The sensitivity,specificity,positive predictive value(PPV)and negative predictive value(NPV)for CA19-9 were 84.9%,69.7%,67.7%and 86.1%,respectively.A ROC analysis provided an area under the curve for CA19-9 of 0.871(0.820-0.922),giving an optimal CA19-9 of 70.5 U/ml for differentiating benign from malignant pathology.Using this cut-off,the sensitivity was 82.1%,while specificity,PPV and NPV improved to 85.9%,81.3%and 86.5%,respectively.When standard radiology was included(US/ CT/MRCP)in the decision process,the results improved to 97.2%,88.7%,86.6%,and 97.7%.For benign disease,the CA19-9 correlated directly with the serum bilirubin,but for malignant disease,CA19-9 levels were elevated independent of the bilirubin level.CONCLUSIONS:CA19-9 is useful in the differentiation of pancreatobiliary disease and when using an optimized cut-off and combining with routine radiology,the diagnostic yield is improved significantly,thus stressing the importance of a multi-disciplinary approach to pancreatobiliary disease.展开更多
The main objective of this paper is to evaluate the seismic response of buildings of typical reinforced concrete frames when concrete starts to deteriorate gradually and to make a comparison between the base shear and...The main objective of this paper is to evaluate the seismic response of buildings of typical reinforced concrete frames when concrete starts to deteriorate gradually and to make a comparison between the base shear and the displacement at different stages of earthquake loading. Typical 5, 15, 20 and 30-storey reinforced concrete frames have been designed for seismicity according to the recently adopted seismic code in Abu Dhabi, ACI 318-08/IBC 2009 code. A pushover analysis has been performed to these four buildings by using SAP 2000. Twenty-four models have been created (6 models for each building) by decreasing the concrete strength gradually from 4000 psi (281 kg/cm<sup>2</sup>) to 1500 psi (105 kg/cm<sup>2</sup>). This is to simulate the effect of harsh environment on the strength of concrete in existing buildings.展开更多
The reaction of dimedone with various aromatic aldehydes produces 2,2＇-arylmethylene bis （3-hydroxy-5,5-dimethyl-2- cyclohexene-l-one） in excellent yields. The reactions occur in water as solvent at room temperatur...The reaction of dimedone with various aromatic aldehydes produces 2,2＇-arylmethylene bis （3-hydroxy-5,5-dimethyl-2- cyclohexene-l-one） in excellent yields. The reactions occur in water as solvent at room temperature and avoiding the addition of any catalyst. The workup procedure is very simple and the products do not required further purification.展开更多
A new convenient and environmentally benign procedure for synthesis of azines from hydrazme sulfate with several aromatic aldehydes coupled with grinding is studied. This reaction is carried out under solvent-free con...A new convenient and environmentally benign procedure for synthesis of azines from hydrazme sulfate with several aromatic aldehydes coupled with grinding is studied. This reaction is carried out under solvent-free conditions and in absence of catalyst to afford high yields of relevant azines.展开更多
基金Project(51478164)supported by the National Natural Science Foundation of ChinaProject(BK20181306)supported by Natural Science Foundation of Jiangsu Province,China。
文摘The aim of this paper is to investigate the effect of nitrite intercalated Mg-Al layered double hydroxides(Mg-Al LDH-NO_(2))on mortar durability under the coexisting environment of Cl−and SO_(4)^(2-).Cl−and SO_(4)^(2-) binding properties of Mg-Al LDH-NO_(2) in simulated concrete pore solutions,Cl−and SO_(4)^(2-) diffusion properties of mortars with Mg-Al LDHNO 2 were examined.The steel corrosion and resistance of mortar against SO_(4)^(2-) attack were also evaluated.The results indicate that Mg-Al LDH-NO_(2) can effectively adsorb the Cl−and SO_(4)^(2-) in simulated concrete pore solution,and inhibit the diffusion of Cl−and SO_(4)^(2-) into cement mortars.The presence of SO_(4)^(2-) can greatly affect the uptake amount of Cl−,and there is a coupled effect of Cl−and SO_(4)^(2-) on their penetration into mortar specimens.In addition,Mg-Al LDH-NO_(2) can greatly upgrade the resistance of mortars against SO_(4)^(2-) attack and well prevent the steel from corrosion.However,Cl−will aggravate the SO_(4)^(2-) attack and SO_(4)^(2-) can initially decrease and then increase the steel corrosion.
文摘Based on vibration analysis, single-layered graphene sheet （SLGS） with multiple attached nanoparticles is developed as nanoscale mass sensor in thermal environments. Graphene sensors are assumed to be in simplysupported configuration. Based on the nonlocal plate the- ory which incorporates size effects into the classical theory, closed-form expressions lot the frequencies and relative fre- quency shills of SLGS-based mass sensor are derived using the Galerkin method. The suggested model is justified by a good agreement between the results given by the present model and available data in literature. The effects of tem- perature difference, nonlocal parameter, the location of the nanoparticle and the number of nanoparticles on the relative frequency shift of the mass sensor are also elucidated. The obtained results show that the sensitivity of the SLGS- based mass sensor increases with increasing temperature difference.
文摘The 21st century shall be a century of accelerated development of tunnel construction in China. But until now, what have been frequently stated in reports about influence of tunnels on environment are basically negative. In fact, this is not true. Tunnels, especially those extend across sensitive areas do exert some positive functions on improving environment and preventing local slope hazards. These positive effects, being new phenomena, are found and put forward by the authors after a series of careful observations have been carried out and in-depth analysis performed the first time. Meanwhile, it is a positive evaluation that the authors made upon tunnels. Many important phenomena and data are cited as evidence and their causative factors are analyzed in this paper as well.
文摘This study attempted to examine the importance of storeenvironment in affecting consumers’store choice deci-sion;the relative importance among the three environ-mental factors;and consumers’expectations on store en-vironment for the casual-wear chain stores in HongKong.Julie Baker’s Three-category framework onstore environments namely ambient,design and socialfactors was adopted for investigation.The results indi-cated that the store environment was important in affect-ing consumers’selection of store for shopping.It alsorevealed that social factor was perceived relatively im-portant than ambient and design factors.Nine store ex-pectation dimensions were categorised and the resultdemonstrated that most respondents were concerned onthe social aspect in their expectation of having a satisfy-ing store environment.
基金This research was supported by the National Basic Research Program of China （ 973 Program, 2011CB109302）；the National High - Tech R＆D Pro-gram of China （863 Program, 2011AA10A104, 2012AA101107） ； Natural Science Foundation of Hu-bei Province （2015CFA103） ； Hubei Agricultural Science and Technology Innovation Center.
文摘To provide a theoretical basis for further improvement of Brassica napus yield, additive dominance with additive - by - additive epistatic effects （ ADAA） genetic model and a 6 X 8 partial dial- lel cross design were used to analyze the genetic effects and correlations of five yield related traits of 14 excellent Brassica napus parental lines and their 46 and F2 populations. The results showed that silique density （SD） , siliques per plant （SPP） , seeds per silique （SPS） and thousand - seed weight （TSW） exhibited not only additive and dominant effects, but also significant epistatic effects. The dominant effects of all five yield - related traits were obviously greater than their additive effects and epistatic effects. Yield per plant （YPP） showed significant genetic correlation with SD, SPP and SPS, and the main component of the genetic correlation was the dominance correlation. SPP and SPS both showed a significant negative correlation with TSW. The SD of rapeseed was genetically correlated with all three components of yield to a certain extent, and there were different components of genetic effects positively correlated with the three yield components, indicating that SD is a potential trait to reconcile the conflict between TSW and SPP as well as SPS.
文摘BACKGROUND:CA19-9 is a carbohydrate tumor-associated antigen which is frequently upregulated in pancreatobiliary neoplasia.However,it may also be elevated in patients with jaundice in the absence of a tumor due to biliary obstruction,and in other non-hepato-pancreatico-biliary conditions.This study aimed to evaluate whether CA19-9 levels could accurately differentiate between benign and malignant pancreatobiliary disease.METHODS:All patients referred to a single surgeon for investigation of pancreaticobiliary disease in 2003 in whom a firm diagnosis had been established were included.For malignant disease,a histological diagnosis was required but for benign disease a firm radiological diagnosis was deemed adequate.The patients were divided into 4 categories:pancreatic adenocarcinoma(PCa);cholangiocarcinoma(CCa);chronic pancreatitis(CP)and biliary calculous disease(Calc).Bilirubin and alkaline phosphatase levels corresponding to the point of assessment of CA19-9 were also noted.RESULTS:Final diagnoses were made of pancreatic adenocarcinoma(PCa,n=73),cholangiocarcinoma(CCa,n=19),ampullary carcinoma(Amp,n=7),neuroendocrine carcinoma(Neu,n=4),duodenal carcinoma(Duo,n=3),chronic pancreatitis(CP,n=115),and biliary calculous disease(Calc,n=27).Median CA19-9 levels(U/ml)were:PCa,653;CCa,408;Duo,403;Calc,27;CP,19;Neu,10.5;Amp,8(reference range:0-37).The CA19-9 levels were significantly greater for malignant than for benign disease,could differentiate PCa from CCa/Duo,and were significantly higher in unresectable than in resectable PCa.The sensitivity,specificity,positive predictive value(PPV)and negative predictive value(NPV)for CA19-9 were 84.9%,69.7%,67.7%and 86.1%,respectively.A ROC analysis provided an area under the curve for CA19-9 of 0.871(0.820-0.922),giving an optimal CA19-9 of 70.5 U/ml for differentiating benign from malignant pathology.Using this cut-off,the sensitivity was 82.1%,while specificity,PPV and NPV improved to 85.9%,81.3%and 86.5%,respectively.When standard radiology was included(US/ CT/MRCP)in the decision process,the results improved to 97.2%,88.7%,86.6%,and 97.7%.For benign disease,the CA19-9 correlated directly with the serum bilirubin,but for malignant disease,CA19-9 levels were elevated independent of the bilirubin level.CONCLUSIONS:CA19-9 is useful in the differentiation of pancreatobiliary disease and when using an optimized cut-off and combining with routine radiology,the diagnostic yield is improved significantly,thus stressing the importance of a multi-disciplinary approach to pancreatobiliary disease.
文摘The main objective of this paper is to evaluate the seismic response of buildings of typical reinforced concrete frames when concrete starts to deteriorate gradually and to make a comparison between the base shear and the displacement at different stages of earthquake loading. Typical 5, 15, 20 and 30-storey reinforced concrete frames have been designed for seismicity according to the recently adopted seismic code in Abu Dhabi, ACI 318-08/IBC 2009 code. A pushover analysis has been performed to these four buildings by using SAP 2000. Twenty-four models have been created (6 models for each building) by decreasing the concrete strength gradually from 4000 psi (281 kg/cm<sup>2</sup>) to 1500 psi (105 kg/cm<sup>2</sup>). This is to simulate the effect of harsh environment on the strength of concrete in existing buildings.
文摘The reaction of dimedone with various aromatic aldehydes produces 2,2＇-arylmethylene bis （3-hydroxy-5,5-dimethyl-2- cyclohexene-l-one） in excellent yields. The reactions occur in water as solvent at room temperature and avoiding the addition of any catalyst. The workup procedure is very simple and the products do not required further purification.
文摘A new convenient and environmentally benign procedure for synthesis of azines from hydrazme sulfate with several aromatic aldehydes coupled with grinding is studied. This reaction is carried out under solvent-free conditions and in absence of catalyst to afford high yields of relevant azines.
