检索结果-南通市图书馆

Review and prospect of soil compound erosion

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2023年第9期15卷 1007-1022页

作者： yang wenqian ZHANG Gangfeng yang Huimin LIN Degen SHI Peijun State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China Academy of Disaster Reduction and Emergency Management Ministry of Emergency Management and Ministry of EducationBeijing Normal UniversityBeijing 100875China College of Land and Tourism Luoyang Normal UniversityLuoyang 471934China School of Business Wenzhou UniversityWenzhou 325035China Academy of Plateau Science and Sustainability Qinghai Normal UniversityXining 810016China

Soil erosion is one of the most serious environmental issues constraining the sustainable development of human society and *** compound erosion is the result of the alternation or interaction between two or more erosion *** recent years,fluctuations and extreme changes in climatic factors(air temperature,precipitation,wind speed,etc.)have led to an increase in the intensity and extent of compound erosion,which is increasingly considered in soil erosion ***,depending on the involvement of gravity,compound erosion process can be divided into compound erosion with and without *** systematically summarized the research on the mechanisms and processes of alternating or interacting soil erosion forces(wind,water,and freeze-thaw)considering different combinations,combed the characteristics of compound erosion in three typical regions,namely,high-elevation areas,high-latitude areas,and dry and wet transition regions,and reviewed soil compound erosion research methods,such as station observations,simulation experiments,prediction models,and artificial neural *** soil erosion model of wind,water,and freeze-thaw interaction is the most significant method for quantifying and predicting compound ***,it is proposed that there are several issues such as unclear internal mechanisms,lack of comprehensive prediction models,and insufficient scale conversion methods in soil compound erosion *** is also suggested that future soil compound erosion mechanism research should prioritize the coupling of compound erosion forces and climate change.

关键词： soil compound erosion soil erosion gravity erosion wind and water erosion freeze-thaw erosion

UbD理论下小学数学综合与实践教学设计探究——以“节约用水”课程为例

在线全文

学校读者我要写书评

暂无评论

豫章师范学院学报 2024年第3期39卷 96-100页

作者：安吉娜王梅杨文倩黔南民族师范学院教育科学学院贵州都匀558099

UbD(Understanding by Design)逆向教学设计能有效促进学生从接受学习向理解学习转变。在小学数学综合与实践模块中,教师在结合UbD理论对模块内容进行教学设计时,应合理设计评估证据、注重融合多学科学习、注重真实情境的创设与信息技... 详细信息

UbD(Understanding by Design)逆向教学设计能有效促进学生从接受学习向理解学习转变。在小学数学综合与实践模块中,教师在结合UbD理论对模块内容进行教学设计时,应合理设计评估证据、注重融合多学科学习、注重真实情境的创设与信息技术的使用,以此促进学生知识迁移和应用能力的发展。

关键词：小学数学 UbD理论综合与实践教学设计 “节约用水”课程

Development of a method to quantify total and free irinotecan and 7-ethyl-10-hydroxycamptothecin(SN-38) for pharmacokinetic and bio-distribution studies after administration of irinotecan liposomal formulation

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Pharmaceutical Sciences 2019年第6期14卷 687-697页

作者： wenqian yang Zimeng yang Jieru Liu Dan Liu Yongjun Wang Wuya College of Innovation Shenyang Pharmaceutical UniversityShenyang 110016China Key Laboratory of Structure-Based Drugs Design&Discovery of Ministry of Education Shenyang Pharmaceutical UniversityShenyang 110016China

In 2015,liposomal formulation of irinotecan(ONIVYDE)has been approved by FDA and widely applied in the treatment of pancreatic *** is a novel liposome formulation,entrapping CPT-11 in the aqueous core of vesicles using a modified gradient loading *** to toxicity concerns,it is essential to explore a rapid and reliable method to effectively isolate and quantify the non-liposomal,namely,free CPT-11and total CPT-11 in *** study focuses on separation of non-liposomal CPT-11,evaluation of the pharmacokinetics of free CPT-11 and total CPT-11 and bio-distribution after intravenous administration of CPT-11 *** CPT-11 in plasma was separated by solid-phase extraction(SPE).The amount of total CPT-11 and main metabolite 7-ethyl-10-hydroxycamptothecin(SN-38)in plasma was quantified by ultra-performance liquid chromatography–MS/*** calibration curves fitted well and lower limit of quantitation for SN-38,free CPT-11,total CPT-11 and CPT-11 in tissue and were 5 ng/ml,10 ng/ml,4.44 ng/ml and 25 ng/ml *** recoveries,precision and accuracy of the method appear *** this method,the pharmacokinetics and bio-distribution of CPT-11 liposome formulation after an intravenous dose of 2.5 mg/kg were then investigated.

关键词： Irinotecan Liposome UPLC-MS-MS SPE Pharmacokinetics Bio-distribution

The impacts of China’s economic policies on Sino-African agricultural trade:evidence from the gravity model analysis

在线全文

学校读者我要写书评

暂无评论

China Finance and Economic Review 2015年第1期4卷 101-115页

作者： yang Jun Liu Hongbo yang wenqian University of International Business and Economics BeijingChina College of Business Law&GovernanceJames Cook UniversityAustralia Louis Dreyfus(Beijing)Trading LLC China

The rapid economic growth of China and some African countries provides tremendous opportunity for the agricultural *** China and African countries have made great efforts in achieving win-win cooperation between the two *** paper aims to provide a comprehensive analysis of impacts of various factors on bilateral agricultural trade between China and *** fixed effect Gravity model is adopted in the study to assess the impacts of different factors on Sino-African bilateral agricultural trade,based on the various data sets covering *** economic growth and rising agricultural production are found to be the two key factors to drive Sino-African future bilateral agricultural ***,the focus should be put on the long-run effects of investment in promoting bilateral agricultural ***,the agricultural cooperation should be enhanced to improve the agricultural production and fully use the comparative advantages in both sides.

关键词： Sino-African agricultural trade influencing factor gravity model

知识性和商业性资源对制造企业二次创业影响的差异研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

沈阳工业大学学报（社会科学版） 2024年第2期17卷 140-148页

作者：郭惠玲李惠梅杨雯茜华侨大学工商管理学院福建泉州362021

二次创业是制造企业持续发展的重要方式,已经成为当前学术界和业界的热点,知识性和商业性资源是制造企业二次创业的关键性资源。基于RBV理论、双元创业理论,对223个有效样本企业进行实证分析。结果表明:知识性资源和商业性资源对制造企... 详细信息

二次创业是制造企业持续发展的重要方式,已经成为当前学术界和业界的热点,知识性和商业性资源是制造企业二次创业的关键性资源。基于RBV理论、双元创业理论,对223个有效样本企业进行实证分析。结果表明:知识性资源和商业性资源对制造企业二次创业具有正向影响,其中知识性资源对探索式创业行为的作用更强,商业性资源对利用式创业行为的作用更强;创业导向正向调节知识性资源与两种创业行为的关系,负向调节商业性资源与探索式创业的关系,对商业性资源与利用式创业行为的调节作用不明显。

关键词：知识性资源商业性资源二次创业创业导向探索式创业利用式创业

Study on the geochemical characteristics of arc-volcanic rocks in the Chiang Rai-Lampang belt of northern Thailand

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal Of Geochemistry 2010年第3期29卷 255-260页

作者： SHEN Shangyue FENG Qinglai yang wenqian ZHANG Zhibin Chongpan Chonglakmani State Key Laboratory of Geo-Processes and Mineral Resources Chinese University of Geology Wuhan 430074 China Regional Survey of Yunnan Province Geological Survey Yuxi 653110 China Suranaree University of Technology Muang District Nakhon Ratchasima 30000 Thailand

On the basis of the petrographic characteristics, rock assemblages, petrochemistry, REEs, trace elements and geotectonic settings, the authors described the characteristics of continental marginal arc-volcanic rocks in the Late Permian-Early Triassic (P2-T1) volcanic rocks distributed on the eastern side of the ocean-ridge/oceanic island basalts in the Chiang Mai belt. The volcanic rock assemblage is basaltic andesite-andesite-rhyolite. The volcanic series is dominated by the calc-alkaline series, with the tholeitic series coming next. The chemical composition of the volcanic rocks is characterized by high Al2O3; the REE distribution patterns are of the LREE-enrichment rightward incline type; the large cation elements are highly enriched, and the volcanic rocks are generally enriched in U and Th and depleted in Ti, Cr and P. The petrochemical plot falls within the field of island-arc volcanic rocks, in consistency with the projected points of continental marginal arc-volcanic rocks in the Lancangjiang belt. These continental mar-ginal arc-volcanic rocks, together with ocean-ridge/oceanic island-type volcanic rocks in the Chiang Mai belt, con-stitute the ocean-ridge volcanic rock-arc magmatic rock belts distributed in pairs, indicative of eastward subduction of the oceanic crust in the Chiang Mai belt. This result is of great importance in exploring the evolution of the paleo-Tethys in the Chiang Mai belt.

关键词：岛弧火山岩地球化学特征岩石化学成分轻稀土元素玄武安山岩泰国岩石组合大陆边缘

一种用于低成本两维相控阵的鳍线功分移相辐射单元设计

在线全文

学校读者我要写书评

暂无评论

火控雷达技术 2024年第2期53卷 101-106页

作者：邓龙波王彬彬张炫杨文倩白冰西安电子工程研究所西安710100

本文设计了一种新颖的用于两维相控阵的鳍线功分移相辐射单元,该单元中的功分器、数控PIN二极管移相器、天线均采用鳍线传输线,可以将多个通道的微波部分集成在一块鳍线电路板上。采用的鳍线数控PIN二极管移相器具有尺寸小、插入损耗低... 详细信息

本文设计了一种新颖的用于两维相控阵的鳍线功分移相辐射单元,该单元中的功分器、数控PIN二极管移相器、天线均采用鳍线传输线,可以将多个通道的微波部分集成在一块鳍线电路板上。采用的鳍线数控PIN二极管移相器具有尺寸小、插入损耗低、元器件数量少、天线法向波束状态无功耗的特点。采用ANSYS HFSS软件对辐射单元的性能进行了仿真优化,测试结果表明,该辐射单元在X波段可用现有成熟工艺实现良好的性能,为低成本两维相控阵技术提供了一种新的思路。

关键词：鳍线数控二极管移相器鳍线功分器鳍线辐射单元两维相控阵

Ultrafine PdRu Nanoparticles Immobilized in Metal-Organic Frameworks for Efficient Fluorophenol Hydrodefluorination under Mild Aqueous Conditions

在线全文

学校读者我要写书评

暂无评论

CCS Chemistry 2022年第7期4卷 2276-2285页

作者： wenqian yang Qinglin Liu Jun yang Jiahui Xian Yinle Li Guangqin Li Cheng-Yong Su State Key Laboratory of Optoelectronic Materials and Technologies MOE Laboratory of Bioinorganic and Synthetic ChemistryLehn Institute of Functional MaterialsSchool of Chemistry Sun Yat-Sen UniversityGuangzhou 510006

Fluorinated organic compounds are of great importance to modern industries,while their release to the environment is inevitable,causing extreme environmental pollution and the subsequent hazardous effect on *** is because the degradation of fluorinated compounds under mild conditions remains a challenging task due to the strong C-F bond *** this study,we report preparation of PdRu@MIL-101 through immobilizing ultrafine PdRu alloy nanoparticles with a mean diameter of∼2 nminto the metal-organic framework(MOF),MIL-101(Cr),which was highly active and stable in the hydrodefluorination of 4-fluorophenol(4-FP)under mild aqueous *** optimized catalyst Pd0.5Ru0.5@MIL-101 achieved impressive hydrogenation performance with a 98.5% conversion of 4-FP and a 97.7% selectivity of cyclohexanol,much better than the single metal-doped Pd@MIL-101 and Ru@MIL-101 *** excellent catalytic behavior contributed to the synergistic effect of combining the PdRu alloying effect and the MOF nanospace confinement effect,providing a promising strategy to develop highly efficient hydrodefluorination catalysts to assist environmental restoration and green ecology.

关键词： PdRu ultrafine nanoparticles PdRu alloy metal-organic frameworks hydrodefluorination synergistic effect

An extended numerical model of the first exothermic peak for three dimensional printed cement-based materials

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第1期18卷 80-88页

作者： Wei JIANG wenqian LI Xi CHEN School of Materials Science and Engineering Tongji UniversityShanghai 200092China School of Civil Engineering Tongji UniversityShanghai 200092China

The first exothermic peak of cement-based material occurs a few minutes after mixing,and the properties of three dimensional(3D)printed concrete,such as setting time,are very sensitive to *** this background,based on the classical Park cement exothermic model of hydration,we propose and construct a numerical model of the first exothermic peak,taking into account the proportions of C_(3)S,C_(3)A and quicklime in *** calculated parameters are calibrated by means of relevant published exothermic test *** is found that this developed model offers a good simulation of the first exothermic peak of hydration for C_(3)S and C_(3)A proportions from 0 to 100% of cement clinker and reflects the effect of quicklime content at 8%-10%.The unique value of this research is provision of an important computational tool for applications that are sensitive to the first exothermic peak of hydration,such as 3D printing.

关键词： 3D printed cement-based materials cement hydration the first exothermic peak liquid quick-setting agent numerical model