To develop suitable grouting materials for water conveyance tunnels in cold regions,firstly,this study investigated the performance evolution of ferrite-rich sulfoaluminate-based composite cement(FSAC grouting materia...To develop suitable grouting materials for water conveyance tunnels in cold regions,firstly,this study investigated the performance evolution of ferrite-rich sulfoaluminate-based composite cement(FSAC grouting material)at 20 and 3℃.The results show that low temperature only delays the strength development of FSAC grouting material within the first 3 d.Then,the effect of four typical early strength synergists on the early properties of FSAC grouting material was evaluated to optimize the early(£1 d)strength at 3℃.The most effective synergist,Ca(HCOO)_(2),which enhances the low-temperature early strength without compromising fluidity was selected based on strength and fluidity tests.Its micro-mechanism was analyzed by XRD,TG,and SEM methods.The results reveal that the most suitable dosage range is 0.3 wt%−0.5 wt%.Proper addition of Ca(HCOO)_(2)changed the crystal morphology of the hydration products,decreased the pore size and formed more compact hydration products by interlocking and overlapping.However,excessive addition of Ca(HCOO)_(2)inhibited the hydration reaction,resulting in a simple and loose structure of the hydration products.The research results have reference value for controlling surrounding rock deformation and preventing water and mud inrushes during the excavation in cold region tunnels.展开更多
The thermodynamics in zinc hydrometallurgical process was studied using a chemical equilibrium modeling code（GEMS） to predict the zinc solubility and construct the species distribution and predominance diagrams for ...The thermodynamics in zinc hydrometallurgical process was studied using a chemical equilibrium modeling code（GEMS） to predict the zinc solubility and construct the species distribution and predominance diagrams for the Zn（Ⅱ）-NH3-H2O and Zn（Ⅱ）-NH3-Cl--H2O system.The zinc solubilities in ammoniacal solutions were also measured with equilibrium experiments,which agree well with the predicted values.The distribution and predominance diagrams show that ammine and hydroxyl ammine complexes are the main aqueous Zn species,Zn（NH3）24-is predominant in weak alkaline solution for both Zn（Ⅱ）-NH3-H2O and Zn（Ⅱ）-NH3-Cl--H2O systems.In Zn（Ⅱ）-NH3-Cl--H2O system,the ternary complexes containing ammonia and chloride increase the zinc solubility in neutral solution.There are three zinc compounds,Zn（OH）2,Zn（OH）1.6Cl0.4 and Zn（NH3）2Cl2,on which the zinc solubility depends,according to the total ammonia,chloride and zinc concentration.These thermodynamic diagrams show the effects of ammonia,chloride and zinc concentration on the zinc solubility,which can provide thermodynamic references for the zinc hydrometallurgy.展开更多
Population estimates of black crested gibbons in Wuliang Nature Reserve,Jingdong,Yunnan,China,with two techniques,average group density total area and average home rang forest coverage,produced quite similar result...Population estimates of black crested gibbons in Wuliang Nature Reserve,Jingdong,Yunnan,China,with two techniques,average group density total area and average home rang forest coverage,produced quite similar results.The population was estimated around 115 groups in the Reserve.The paper also discussed the conservation problems of the Reserve.At present,the main threat to the gibbons is habitat fragmentation and population isolation.Thus,it is urgent to prohibit hunting and protect the habitat and forest corridors or habitat bridges.展开更多
Pinus squamata X. W. Li, a recently-described species of the Pinaceae, is an extremely endangered pine with only 32 individuals in the wild. This species was thought to be intermediate between P. bungeana Zuec. ex End...Pinus squamata X. W. Li, a recently-described species of the Pinaceae, is an extremely endangered pine with only 32 individuals in the wild. This species was thought to be intermediate between P. bungeana Zuec. ex Endl. of subgen. Strobus and P. yunnanensis Franch. of subgen. Pinus by the original author. We made an effort to address the question of the phylogenetic relationship of this peculiar and important species in the context of the major groups of the genus Pinus by using sequences of the rbcL, matK,genes, rpl20-rps18 spacer, trnV intron of the chloroplast genome and the nuclear ribosomal ITS region. The results of the separated analysis and the combined analysis of the four cpDNA sequences and ITS sequence indicated that P. squamata was a stable member of subsect. Gerardianae and P. gerardiana Wall. was the closest species of P. squamata phylogenetically. As a result, the causes of the distribution pattern of subsect. Gerardianae were also discussed.展开更多
Listening and speaking is of great importance in language communication, which is being paid close attention to in TEFL in China. However, as most of ethnic minorities are living far away from developed districts, the...Listening and speaking is of great importance in language communication, which is being paid close attention to in TEFL in China. However, as most of ethnic minorities are living far away from developed districts, they lack necessary sources in English listening teaching, which makes the local learners＇ listening ability not so satisfactory. This paper, based on the questionnaire, analyzes the problems existing in current English listening teaching in ethnic minority districts, and puts forward some suggestive solutions.展开更多
X-ray microanalysis was used to study the elemental composition of the shell of the freshwater testate amoeba Difflugia tuberspinifera Hu et al.,1997 collected from Mulan Lake,Hubei province,China in July 2003.The res...X-ray microanalysis was used to study the elemental composition of the shell of the freshwater testate amoeba Difflugia tuberspinifera Hu et al.,1997 collected from Mulan Lake,Hubei province,China in July 2003.The results show that the shell is composed of ten elements:Si in greater quantity;then Ca and Al;and traces of K,Na,Cl,Fe,Mg,S and P.The analysis of results suggests that D.tuberspinifera in elemental composition appears to occupy a middle position between marine and soil testate amoebae.展开更多
[ Objective ] The aim of this study was to investigate the epidemic status of porcine pleuropneumonia in western Shandong and establish the PCR method of actinobacillus pleuropneumoniae （APP）. [ Method] The epidemic...[ Objective ] The aim of this study was to investigate the epidemic status of porcine pleuropneumonia in western Shandong and establish the PCR method of actinobacillus pleuropneumoniae （APP）. [ Method] The epidemic status of APP in lesion tissues of 186 death pigs and 545 health pigs without clinical symptoms was analyzed by PCR method. [ Result] APP positive rate in 186 samples accounted for 43.0% （80/186）, while that in 545 porcine serums accounted for 9.4% （51/545）. [ Conclusion] This PCR method can be used as one of the important means for APP clinical diagnosis.展开更多
The mathematical topological rule was proposed to plot the predominance area diagram.Based on the phase rules,the components of In-S-O system were analyzed and the coexisting points of three condensed phases were dete...The mathematical topological rule was proposed to plot the predominance area diagram.Based on the phase rules,the components of In-S-O system were analyzed and the coexisting points of three condensed phases were determined.Combined with the topological rules and thermody namic calculation,four relation diagrams between the coexisting points of three condensed phases,which were denoted as α,β stable plane-topological diagram and unstable plane-topological diagram,were plotted for the In-S-O system.The results show that α stable plane topological diagram is in accordance with the predominance area diagram of In-S-O system plotted by traditional methods,which indicates that the new method is feasible to plot the predominance area diagram of In-S-O system.Meanwhile,β unstable plane-topological diagram can be used to elucidate the indium production with the bath smelting process.展开更多
基金Projcet(52279119)supported by the National Natural Science Foundation of ChinaProject(XZ202201ZY0021G)supported by the Science and Technology Planning Project of Xizang Autonomous Region,China+1 种基金Project(2019QZKK0904)supported by the Second Xizang Plateau Scientific Expedition and Research Program of ChinaProject(51922104)supported by the National Natural Science Foundation for Distinguished Young Scholars of China。
文摘To develop suitable grouting materials for water conveyance tunnels in cold regions,firstly,this study investigated the performance evolution of ferrite-rich sulfoaluminate-based composite cement(FSAC grouting material)at 20 and 3℃.The results show that low temperature only delays the strength development of FSAC grouting material within the first 3 d.Then,the effect of four typical early strength synergists on the early properties of FSAC grouting material was evaluated to optimize the early(£1 d)strength at 3℃.The most effective synergist,Ca(HCOO)_(2),which enhances the low-temperature early strength without compromising fluidity was selected based on strength and fluidity tests.Its micro-mechanism was analyzed by XRD,TG,and SEM methods.The results reveal that the most suitable dosage range is 0.3 wt%−0.5 wt%.Proper addition of Ca(HCOO)_(2)changed the crystal morphology of the hydration products,decreased the pore size and formed more compact hydration products by interlocking and overlapping.However,excessive addition of Ca(HCOO)_(2)inhibited the hydration reaction,resulting in a simple and loose structure of the hydration products.The research results have reference value for controlling surrounding rock deformation and preventing water and mud inrushes during the excavation in cold region tunnels.
基金Project(74142000023) supported by Postdoctoral Science Foundation of Central South University,ChinaProject(2012M521547) supported by China Postdoctoral Science FoundationProject(721500452) supported by the Fundamental Research Funds for the Central Universities,China
文摘The thermodynamics in zinc hydrometallurgical process was studied using a chemical equilibrium modeling code（GEMS） to predict the zinc solubility and construct the species distribution and predominance diagrams for the Zn（Ⅱ）-NH3-H2O and Zn（Ⅱ）-NH3-Cl--H2O system.The zinc solubilities in ammoniacal solutions were also measured with equilibrium experiments,which agree well with the predicted values.The distribution and predominance diagrams show that ammine and hydroxyl ammine complexes are the main aqueous Zn species,Zn（NH3）24-is predominant in weak alkaline solution for both Zn（Ⅱ）-NH3-H2O and Zn（Ⅱ）-NH3-Cl--H2O systems.In Zn（Ⅱ）-NH3-Cl--H2O system,the ternary complexes containing ammonia and chloride increase the zinc solubility in neutral solution.There are three zinc compounds,Zn（OH）2,Zn（OH）1.6Cl0.4 and Zn（NH3）2Cl2,on which the zinc solubility depends,according to the total ammonia,chloride and zinc concentration.These thermodynamic diagrams show the effects of ammonia,chloride and zinc concentration on the zinc solubility,which can provide thermodynamic references for the zinc hydrometallurgy.
文摘Population estimates of black crested gibbons in Wuliang Nature Reserve,Jingdong,Yunnan,China,with two techniques,average group density total area and average home rang forest coverage,produced quite similar results.The population was estimated around 115 groups in the Reserve.The paper also discussed the conservation problems of the Reserve.At present,the main threat to the gibbons is habitat fragmentation and population isolation.Thus,it is urgent to prohibit hunting and protect the habitat and forest corridors or habitat bridges.
文摘Pinus squamata X. W. Li, a recently-described species of the Pinaceae, is an extremely endangered pine with only 32 individuals in the wild. This species was thought to be intermediate between P. bungeana Zuec. ex Endl. of subgen. Strobus and P. yunnanensis Franch. of subgen. Pinus by the original author. We made an effort to address the question of the phylogenetic relationship of this peculiar and important species in the context of the major groups of the genus Pinus by using sequences of the rbcL, matK,genes, rpl20-rps18 spacer, trnV intron of the chloroplast genome and the nuclear ribosomal ITS region. The results of the separated analysis and the combined analysis of the four cpDNA sequences and ITS sequence indicated that P. squamata was a stable member of subsect. Gerardianae and P. gerardiana Wall. was the closest species of P. squamata phylogenetically. As a result, the causes of the distribution pattern of subsect. Gerardianae were also discussed.
文摘Listening and speaking is of great importance in language communication, which is being paid close attention to in TEFL in China. However, as most of ethnic minorities are living far away from developed districts, they lack necessary sources in English listening teaching, which makes the local learners＇ listening ability not so satisfactory. This paper, based on the questionnaire, analyzes the problems existing in current English listening teaching in ethnic minority districts, and puts forward some suggestive solutions.
文摘X-ray microanalysis was used to study the elemental composition of the shell of the freshwater testate amoeba Difflugia tuberspinifera Hu et al.,1997 collected from Mulan Lake,Hubei province,China in July 2003.The results show that the shell is composed of ten elements:Si in greater quantity;then Ca and Al;and traces of K,Na,Cl,Fe,Mg,S and P.The analysis of results suggests that D.tuberspinifera in elemental composition appears to occupy a middle position between marine and soil testate amoebae.
基金Supported by Visiting Scholar Fund for Outstanding Young Teachersin colleges and Universities of Shandong~~
文摘[ Objective ] The aim of this study was to investigate the epidemic status of porcine pleuropneumonia in western Shandong and establish the PCR method of actinobacillus pleuropneumoniae （APP）. [ Method] The epidemic status of APP in lesion tissues of 186 death pigs and 545 health pigs without clinical symptoms was analyzed by PCR method. [ Result] APP positive rate in 186 samples accounted for 43.0% （80/186）, while that in 545 porcine serums accounted for 9.4% （51/545）. [ Conclusion] This PCR method can be used as one of the important means for APP clinical diagnosis.
基金Project(2011AA061003)supported by the High-tech Research and Development Program of China
文摘The mathematical topological rule was proposed to plot the predominance area diagram.Based on the phase rules,the components of In-S-O system were analyzed and the coexisting points of three condensed phases were determined.Combined with the topological rules and thermody namic calculation,four relation diagrams between the coexisting points of three condensed phases,which were denoted as α,β stable plane-topological diagram and unstable plane-topological diagram,were plotted for the In-S-O system.The results show that α stable plane topological diagram is in accordance with the predominance area diagram of In-S-O system plotted by traditional methods,which indicates that the new method is feasible to plot the predominance area diagram of In-S-O system.Meanwhile,β unstable plane-topological diagram can be used to elucidate the indium production with the bath smelting process.
