目的评价Rapid Chek SELECT方法对食品中沙门菌的检测效果并验证。方法用添加并回收沙门菌标准菌株方法验证Rapid Chek SELECT的检测限,添加非沙门菌标准菌株方法测定其特异性,以国标法为参比,通过检测实际样品,对Rapid Chek SELECT方...目的评价Rapid Chek SELECT方法对食品中沙门菌的检测效果并验证。方法用添加并回收沙门菌标准菌株方法验证Rapid Chek SELECT的检测限,添加非沙门菌标准菌株方法测定其特异性,以国标法为参比,通过检测实际样品,对Rapid Chek SELECT方法进行验证。结果 1Rapid Chek SELECT沙门菌检测试纸条的检测限为1 cfu/25 g(或1 cfu/ml);2与10种非沙门菌无交叉反应特异性;3直接检测食品中沙门菌的最低浓度为106cfu/ml;4对实际样品中沙门菌的检测结果显示,Rapid Chek SELECT方法和国标方法阳性率分别为87.5%(35/40)和85%(34/40),两种方法最终检测结果的符合率为97.5%(39/40),Rapid Chek SELECT方法等同于国标方法。结论与国标方法相比,Rapid Chek SELECT沙门菌检测试剂盒灵敏度高、特异性强、操作简便,有效减少非沙门菌的干扰、省时,适用于食品中沙门菌的快速检测。展开更多
Moose （Alces alces cameloides） is typically representative of the fauna of the frigid temperate zone and has been put on the Chinese second priority list of protected animals. The moose of northeast China is on the ...Moose （Alces alces cameloides） is typically representative of the fauna of the frigid temperate zone and has been put on the Chinese second priority list of protected animals. The moose of northeast China is on the southern most edge of its distribution in Asia. To study resource selection characteristics of moose and their response to human distur- bances and forest resource variables, the field work was conducted in Heilongiiang Provincial Shengshan Forestry Farm, which is located in the northwestern slope of Lesser Khingan Mountains, northeastern China, from January to March in both 2006 and 2007. A total of 428 plots were examined within the study area. Signs of moose use were found in 19 plots. Based on the analysis of resource selection function, we found that moose selected areas with higher densities of mixed deciduous broadleaf patch and mixed coniferous and broad leaf patch, and a higher NDVI value. Moose avoided settlement 6 km away and remained low probability of occurrence within 3 km from roads,展开更多
Pollution caused by toxic nitrobenzene has been a widespread environmental concern. Selective reduction of nitrobenzene to aniline is beneficial to further efficient and cost-effective biologic treatment. Electro- che...Pollution caused by toxic nitrobenzene has been a widespread environmental concern. Selective reduction of nitrobenzene to aniline is beneficial to further efficient and cost-effective biologic treatment. Electro- chemical reduction is a promising method and Cu-based catalysts have been found to be an efficient cathode material for this purpose. In this work, Cu catalysts with different morphologies were fabricated on Ti plate using a facile electrodepositon method via tuning the applied voltage. The dendritic nano-structured Cu catalysts obtained at high applied voltages exhibited an excellent efficiency and selectivity toward the reduction of nitro- benzene to aniline. Effects of the working potential and initial nitrobenzene concentration on the selective reduction of nitrobenzene to aniline using the Cu/Ti electrode were investigated. A high rate constant of 0.0251 mini and 97.1% aniline selectivity were achieved. The fabri- cated nano-structured Cu catalysts also exhibited good stability. This work provides a facile way to prepare highly efficient, cost-effective, and stable nano-sWuctured electro- catalysts for pollutant reduction.展开更多
The copolymerization of ethylene and styrene can be efficiently carried out by using Cp＊TiCl2（N=CtBu2）/ MAO （Cp＊=η5-C5Me5） system, yielding the poly（ethylene-co-styrene）s with isolated styrene units. In order...The copolymerization of ethylene and styrene can be efficiently carried out by using Cp＊TiCl2（N=CtBu2）/ MAO （Cp＊=η5-C5Me5） system, yielding the poly（ethylene-co-styrene）s with isolated styrene units. In order to in- vestigate the reasons for formation of the structure, the mechanism of copolymerization, especially the selective in- sertion of ethylene and styrene, is studied in detail by density functional theory （DFT） method. At the initiation stage, insertion of ethylene is kinetically more favorable than insertion of styrene, and insertion of styrene kinet- ically and thermodynamically prefers 2,1-insertion. That is different from the conventional half-titanocene system, in which the 1,2-insertion is favorable. At chain propagation stage, the computational results suggest that the con- tinuous insertion of styrene is hard to occur at room temperature due to the high free energy barriers （28.90 and 35.04 kcal/mol for 1,2-insertion, and 29.15 and 34.00 kcal/mol for 2,1-insertion） and thermodynamically unfavora- ble factors in two different conditions. That is mainly attributed to the steric hindrance between the coming styrene and chain-end styrene or ketimide ligand. The computational results are in good agreement with the experimental data.展开更多
The consecutive reaction of bis [2,2,2-trifluoroethyl ] phosphite and its application to the one-pot synthesis of 3-cyano-β,γ-un-saturated nitriles with exclusive or predominant E-selectivity (E:Z = 100-85:0-15) and...The consecutive reaction of bis [2,2,2-trifluoroethyl ] phosphite and its application to the one-pot synthesis of 3-cyano-β,γ-un-saturated nitriles with exclusive or predominant E-selectivity (E:Z = 100-85:0-15) and excellent yields (94%-99%) are described.展开更多
Tumor diagnosis by analyzing gene expression profiles becomes an interesting topic in bioinformatics and the main problem is to identify the genes related to a tumor. This paper proposes a rank sum method to identify ...Tumor diagnosis by analyzing gene expression profiles becomes an interesting topic in bioinformatics and the main problem is to identify the genes related to a tumor. This paper proposes a rank sum method to identify the re- lated genes based on the rank sum test theory in statistics. The tumor diagnosis system is constructed by the support vector machine (SVM) trained on the set of the related gene expression profiles. The experiments demonstrate that the constructed tumor diagnosis system with the rank sum method and SVM can reach an accuracy level of 96.2% on the colon data and 100% on the leukemia data.展开更多
文章分析了地理信息系统(geographic information system, GIS)的含义和作用,论述了电力辅助基建选址辅助决策的重要性,接着从框架构建、系统设计、功能实现等方面着手,研究基于GIS引导的电力辅助基建选址辅助决策系统的设计及实现要点...文章分析了地理信息系统(geographic information system, GIS)的含义和作用,论述了电力辅助基建选址辅助决策的重要性,接着从框架构建、系统设计、功能实现等方面着手,研究基于GIS引导的电力辅助基建选址辅助决策系统的设计及实现要点,以期为GIS在电力辅助基建选址辅助决策中的应用提供参考。展开更多
基于美国NCEP(National Centers for Environmental Prediction)的CFSR(Climate Forecast System Reanalysis)近20a(1991-2010)10m风场再分析数据(0.3°×0.3°,1h/次,简称CFSR风场),对我国近海风能资源分布特征进行了统计...基于美国NCEP(National Centers for Environmental Prediction)的CFSR(Climate Forecast System Reanalysis)近20a(1991-2010)10m风场再分析数据(0.3°×0.3°,1h/次,简称CFSR风场),对我国近海风能资源分布特征进行了统计分析与评估。利用天津渤海A平台观测站(118°25′E,38°27′N)逐时观测风速数据对CFSR风速数据进行了检验,发现均方根误差和平均偏差仅为均较小(分别为2.28m/s与0.16m/s)。基于此CFSR风场,本文章进一步统计并给出了我国陆地年平均风功率密度分布,结果与第三次风能普查(1971-2000年)及相关文献结果 (1991-2010年)相当一致。依据国家风电场风能资源评估方法,由CFSR风场推算了我国近海20a平均的70m高度风能资源分布。结果显示,年平均风功率密度均达到了200 W/m2以上,大于6m/s的风速累积小时数为4 000h以上;其中台湾海峡和东海南部海区风能最为丰富,黄海中部、渤海中部和辽东湾海区风能次之。参照海上风场选址要求,28°N以北的近岸海域由于水深较浅,30m/s以上风速发生频次极低,比较适合建立海上风电场。展开更多
文摘目的评价Rapid Chek SELECT方法对食品中沙门菌的检测效果并验证。方法用添加并回收沙门菌标准菌株方法验证Rapid Chek SELECT的检测限,添加非沙门菌标准菌株方法测定其特异性,以国标法为参比,通过检测实际样品,对Rapid Chek SELECT方法进行验证。结果 1Rapid Chek SELECT沙门菌检测试纸条的检测限为1 cfu/25 g(或1 cfu/ml);2与10种非沙门菌无交叉反应特异性;3直接检测食品中沙门菌的最低浓度为106cfu/ml;4对实际样品中沙门菌的检测结果显示,Rapid Chek SELECT方法和国标方法阳性率分别为87.5%(35/40)和85%(34/40),两种方法最终检测结果的符合率为97.5%(39/40),Rapid Chek SELECT方法等同于国标方法。结论与国标方法相比,Rapid Chek SELECT沙门菌检测试剂盒灵敏度高、特异性强、操作简便,有效减少非沙门菌的干扰、省时,适用于食品中沙门菌的快速检测。
基金financially supported by National Excellent Doctoral Dissertation of PR China-FANEDD(No.201069)""Program for New Century Excellent Talents in University–NCET(No.10-0310)""the Fundamental Research Funds for the Central Universities(No.DL12DA01)
文摘Moose （Alces alces cameloides） is typically representative of the fauna of the frigid temperate zone and has been put on the Chinese second priority list of protected animals. The moose of northeast China is on the southern most edge of its distribution in Asia. To study resource selection characteristics of moose and their response to human distur- bances and forest resource variables, the field work was conducted in Heilongiiang Provincial Shengshan Forestry Farm, which is located in the northwestern slope of Lesser Khingan Mountains, northeastern China, from January to March in both 2006 and 2007. A total of 428 plots were examined within the study area. Signs of moose use were found in 19 plots. Based on the analysis of resource selection function, we found that moose selected areas with higher densities of mixed deciduous broadleaf patch and mixed coniferous and broad leaf patch, and a higher NDVI value. Moose avoided settlement 6 km away and remained low probability of occurrence within 3 km from roads,
文摘Pollution caused by toxic nitrobenzene has been a widespread environmental concern. Selective reduction of nitrobenzene to aniline is beneficial to further efficient and cost-effective biologic treatment. Electro- chemical reduction is a promising method and Cu-based catalysts have been found to be an efficient cathode material for this purpose. In this work, Cu catalysts with different morphologies were fabricated on Ti plate using a facile electrodepositon method via tuning the applied voltage. The dendritic nano-structured Cu catalysts obtained at high applied voltages exhibited an excellent efficiency and selectivity toward the reduction of nitro- benzene to aniline. Effects of the working potential and initial nitrobenzene concentration on the selective reduction of nitrobenzene to aniline using the Cu/Ti electrode were investigated. A high rate constant of 0.0251 mini and 97.1% aniline selectivity were achieved. The fabri- cated nano-structured Cu catalysts also exhibited good stability. This work provides a facile way to prepare highly efficient, cost-effective, and stable nano-sWuctured electro- catalysts for pollutant reduction.
基金This work was supported by the National Natural Science Foundation of China （Nos. 21404018, 21503030） and the Fundamental Research Funds for the Central Universities （No. DUT16RC（4）79）. Gaohong He gratefully acknowledges Education Department of the Liaoning Province of China （No. LT2015007）, the Fundamental Research Funds for the Central Universi- ties （No. DUT16TD19） and the Chang Jiang Scholar Program （No. T2012049）.
文摘The copolymerization of ethylene and styrene can be efficiently carried out by using Cp＊TiCl2（N=CtBu2）/ MAO （Cp＊=η5-C5Me5） system, yielding the poly（ethylene-co-styrene）s with isolated styrene units. In order to in- vestigate the reasons for formation of the structure, the mechanism of copolymerization, especially the selective in- sertion of ethylene and styrene, is studied in detail by density functional theory （DFT） method. At the initiation stage, insertion of ethylene is kinetically more favorable than insertion of styrene, and insertion of styrene kinet- ically and thermodynamically prefers 2,1-insertion. That is different from the conventional half-titanocene system, in which the 1,2-insertion is favorable. At chain propagation stage, the computational results suggest that the con- tinuous insertion of styrene is hard to occur at room temperature due to the high free energy barriers （28.90 and 35.04 kcal/mol for 1,2-insertion, and 29.15 and 34.00 kcal/mol for 2,1-insertion） and thermodynamically unfavora- ble factors in two different conditions. That is mainly attributed to the steric hindrance between the coming styrene and chain-end styrene or ketimide ligand. The computational results are in good agreement with the experimental data.
基金Project supported by the National Natural Science Foundation of China(No.29972046)and Chinese Academy of Sciences.
文摘The consecutive reaction of bis [2,2,2-trifluoroethyl ] phosphite and its application to the one-pot synthesis of 3-cyano-β,γ-un-saturated nitriles with exclusive or predominant E-selectivity (E:Z = 100-85:0-15) and excellent yields (94%-99%) are described.
文摘Tumor diagnosis by analyzing gene expression profiles becomes an interesting topic in bioinformatics and the main problem is to identify the genes related to a tumor. This paper proposes a rank sum method to identify the re- lated genes based on the rank sum test theory in statistics. The tumor diagnosis system is constructed by the support vector machine (SVM) trained on the set of the related gene expression profiles. The experiments demonstrate that the constructed tumor diagnosis system with the rank sum method and SVM can reach an accuracy level of 96.2% on the colon data and 100% on the leukemia data.
文摘文章分析了地理信息系统(geographic information system, GIS)的含义和作用,论述了电力辅助基建选址辅助决策的重要性,接着从框架构建、系统设计、功能实现等方面着手,研究基于GIS引导的电力辅助基建选址辅助决策系统的设计及实现要点,以期为GIS在电力辅助基建选址辅助决策中的应用提供参考。
