检索结果-南通市图书馆

Science China Chemistry 2017年第3期60卷 358-365页

作者： Cai-ming Liu de-Qing zhang Xiang Hao Dao-Ben Zhu Beijing National Laboratory for Molecular Sciences Center for Molecular Science Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

Two dysprosium(Ⅲ) complexes derived from 2,2'-bipyridine-6,6'-dicarboxylic acid(H_2bpdc),[Dy(bpdc)(Hbpdc)]-3H_2O(1) and[Dy_2(bpdc)_3(H_2O)_3]·2.125H_2O(2),were isolated from the same hydrothermal reaction container as different ***1 is a mononuclear complex with a DyN_4O_4 coordination polyhedron;whereas compound 2 is a dinuclear complex with two types of eight coordinated dy sprosium(Ⅲ) ions,showing DyN_4O_4 and DyN_2O_6 coordination polyhedra,***,a new type of(H_2O)_6 supramolecular aggregate exists in the crystal structure of *** investigations revealed that 1 is a field-induced single-ion magnet with an effective energy barrier of 45.6 K,exhibiting two-step magnetic relaxation;while an intramolecular ferromagnetic interaction exists in 2,which is a field-induced single-molecule magnet,displaying two-step magnetic relaxation too,with effective energy barriers of 53.4 and 92.1 K,respectively.

关键词： single-molecule magnet single-ion magnet dysprosium(Ⅲ) complexes slow magnetic relaxation water aggregations

Flow Patterns in the Sedimentation of a Capsule-Shaped Particle

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第8期29卷 160-163页

作者： NIE de-ming LIN Jian-Zhong zhang Kai Institute of Fluid Mechanics China Jiliang UniversityHangzhou 310018 State Key Laboratory of Fluid Power Transmission and Control Zhejiang UniversityHangzhou 310027

The main objective of this study is to numerically investigate the settling of a capsule-shaped particle in an infinitely long channel by the newly developed LB-DF/FD *** work will focus on the effects of the particle orientation and particle/fluid density ratio on the flow patterns during *** the density ratio is varied,our results show that there are four distinct modes of sedimentation:vertical sedimentation,horizontal sedimentation,periodically oscillating sedimentation and chaotic mode where the particle is released from the center of the domain with an initial inclination ofπ/4 to break the ***,we also numerically investigate the flow patterns where the particle is released with an initial inclination of 0,π/6,π/3 andπ/*** conduct a detailed study on the effects of density ratio on the transition from the vertical sedimentation mode to horizontal sedimentation mode.

关键词： method infinitely oscillating

不同热处理蛋黄脂质对小鼠学习认知能力下降的缓解能力

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

食品工业科技 2025年第1期46卷 367-376页

作者：吴瑶刘铭坤方冰张明合肥工业大学食品与生物工程学院安徽合肥230061 中国农业大学营养与健康系北京100083 北京工商大学食品与健康学院北京100048

为探讨不同温度处理下蛋黄脂质对小鼠学习认知能力下降的缓解能力的差异。本研究利用小鼠认知障碍模型,比较95℃(水浴30 min)和121℃(灭菌锅加热30 min)热处理蛋黄脂质组分改善小鼠学习认知能力的差异。研究结果表明,相较于121℃热处理... 详细信息

为探讨不同温度处理下蛋黄脂质对小鼠学习认知能力下降的缓解能力的差异。本研究利用小鼠认知障碍模型,比较95℃(水浴30 min)和121℃(灭菌锅加热30 min)热处理蛋黄脂质组分改善小鼠学习认知能力的差异。研究结果表明,相较于121℃热处理的蛋黄脂质,95℃热处理的蛋黄脂质更有效地降低了Tau蛋白的磷酸化和Aβ1-40、GSK-3β表达,下调了促炎因子的表达,其提升小鼠的学习记忆能力的效果更好。95℃热处理蛋黄脂质中的多不饱和脂肪酸以及DHA较121℃热处理的蛋黄脂质显著增加(P<0.05)。因此,过度的加热条件,会破坏蛋品中DHA等多不饱和脂肪酸,削弱蛋黄脂质的改善认知的生物活性。本研究为蛋制品的热加工工艺的优化提供参考依据。

关键词：蛋黄脂质热处理学习和记忆

Boundary element method of hydrodynamic characteristics of lubricant in three-leaf dislocated floating-ring bearing

同方期刊数据库

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

航空动力学报 2014年第5期29卷 1211-1215页

作者： HUANG ming-han zhang Wen-zhong TONG de-sheng PENG Hong-mei YANG de-quan CCCC-Key Hydrodynamic Laboratory for Coastal Engineering Tianjin Port Engineering Institute Limited of China Communications Construction Company Limited Tianjin 300222 China School of Civil Engineering Tianjin University Tianjin 300072 China Institute of Physics and Electronic Information Inner Mongolia University for the NationalitiesTongliao Inner Mongolia 028043 China

The problem of hydrodynamics of the three-leaf dislocated floating-ring bearing was studied by means of boundary element *** law including the distribution of pressure on boundary surface(axial,bearing and floating-ring)and its friction loss in different eccentricities was *** results show that the inner friction of three-leaf dislocated bearing increases from 390.875to 1 091.65,and the inner friction of three-leaf dislocated floating-ring bearing increases from 94.2523to 114.5069with eccentricity varying from 0to 0.075in *** changing the pressure and flow field of bearing by adding floating-ring is more stability and less wasted work of friction than three-leaf dislocated bearing.

关键词：三叶错位浮环轴承流体力学边界元法稳定性内摩擦

Comparison of Pb,Cd Adsorption to Surface Coatings developed in Natural Waters with that in Plant Effluents

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2003年第4期19卷 417-421页

作者： DONG de-ming LI Yu HUA Xiu-yi zhang Jing-jing College of Environment and Resources Jilin UniversityChangchun 130023P.R.China

The comparative studies of Pb and Cd adsorption to the surface coatings(Fe, Mn, Al oxides, organic materials, and associated minerals), which were developed on glass slides in five natural and two technical waters(plant effluents), were carried out under controlled laboratory conditions(mineral salts solution with defined speciation, ionic strength 0 05 mol/L, 25 ℃ and pH 6 0). The classical Langmuir adsorption isotherm was applied to estimating the equilibrium coefficients of Pb and Cd adsorption to the surface coatings. The results show that the maximum adsorption of Pb and Cd to the surface coatings mentioned above varied widely. There was a systemic increase in the maximum adsorption of Pb and Cd to the surface coatings with increasing the contents of Mn and Fe oxides in the surface coatings in significant correlation, respectively, not only highlighting the relative importance of the metal oxide fraction for Pb and Cd adsorption to the surface coatings developed in natural and technical water samples, but also implying the same adsorption mechanisms of Pb and Cd to the surface coatings developed both in natural and technical water samples.

关键词： Natural waters Plant effluents Surface coatings Pb Cd

Buckling Properties of Water-Drop-Shaped Pressure Hulls with Various Shape Indices Under Hydrostatic External Pressure

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第1期38卷 1-17页

作者： DING Xiao-de zhang Jian WANG Fang JIAO Hui-feng WANG ming-lu School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Shanghai Engineering Research Center of Marine Renewable Energy College of Engineering Science and Technol-ogyShanghai Ocean UniversityShanghai 201306China China Ship Scientific Research Center Wuxi 214082China

The water-drop-shaped pressure hull has a good streamline,which has good application prospect in the underwater ***,this study conducted analytical,experimental and numerical investigation of the buckling properties of water-drop-shaped pressure hulls under hydrostatic pressure.A water-drop experiment was conducted to design water-drop-shaped pressure hulls with various shape *** critical loads for the water-drop-shaped pressure hulls were resolved by using Mushtari’s *** numerical simulations including linear buckling analysis and nonlinear buckling analysis including eigenmode imperfections were *** results indicated that the critical loads resolved by Mushtari's formula were in good agreement with the linear buckling loads from the numerical *** formula can be extended to estimate the buckling capacity of water-drop-shaped pressure *** addition,three groups of pressure hulls were fabricated by using stereolithography,a rapid prototyping ***,three groups of the pressure hulls were subjected to ultrasonic measurements,optical scanning,hydrostatic testing and numerical *** experimental results were consistent with the numerical *** results indicate that the sharp end of the water-drop-shaped pressure hulls exhibited instability compared with the blunt *** paper provides a new solution to the limitations of experimental studies on the water-drop-shaped pressure hulls as well as a new configuration and evaluation method for underwater observatories.

关键词： buckling pressure hull water drop underwater observatory

Achievements and problems of geotechnical engineering investigation in China

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第2期12卷 87-102页

作者： Zai-ming zhang Beijing Geotechnical Institute (BGI) Engineering Consultants Ltd. Beijing 100038 China College of Architecture and Civil Engineering Beijing University of Technology Beijing 100124 China

As an industry and a discipline,geotechnical investigation in China differs from that in the USA and European countries in its course of emergence and evolution. For over half a century,Chinese geotechnical investigation professionals witnessed continuous technical advances as they undertook independently almost all of China's large-scale construction projects. Based on projects that won the "National Outstanding Engineering Investigation" Gold Medal Awards since the year 2000,this paper discusses the achievements of geotechnical investigation in the context of comprehensive technical ability,project evaluation and analysis,hi-tech applications and engineering monitoring,and analyzes several factors that have hindered the industry's further development and alignment with international practice. Finally,some suggestions are given for future improvement.

关键词： Geotechnical engineering Engineering investigation Technical advance

Sectorization Model of Terminal Airspace with Arrival and departure Separation

在线全文

学校读者我要写书评

暂无评论

Transactions of Nanjing University of Aeronautics and Astronautics 2016年第4期33卷 442-450页

作者： zhang ming Yu Hui zhang ming College of Civil Aviation Nanjing University of Aeronautics and Astronautics

Terminal airspace(TMA)is the airspace centering several military and civil aviation airports with complex route structure,limited airspace resources,traffic flow,difficult management and considerable airspace complexity.A scientific and rational sectorization of TMA can optimize airspace resources,and sufficiently utilize the control of human resources to ensure the safety of *** functional sectorization model was established based on the route structure of arriving and departing aircraft as well as controlling *** on principles of sectorization and topological relations within a network,the arrival and departure sectorization model was established,using tree based ant colony algorithm(ACO)*** TMA was taken as an example to be sectorizaed,and the result showed that this model was superior to traditional ones when arrival and departure routes were separated at dense airport terminal airspace.

关键词： air traffic management arrival and departure sectorization model controller′s workload route structure of arriving and departing aircraft Ant colony algorithm

Lead and Cadmium Adsorption onto Iron Oxides and Manganese Oxides in the Natural Surface Coatings Collected on Natural Substances in the Songhua River of China

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2007年第6期23卷 659-664页

作者： DONG de-ming ZHAO Xing-min HUA Xiu-yi zhang Jing-jing WU Shi-ming College of Environment and Resources Jilin University Changchun 130012 P. R. China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 P. R. China Jilin Environmental Protection Monitoring Station Jilin 132001 P. R. China

Natural surface coatings collected from natural substances （NSCsNS） were employed to study the roles of the main chemical components （iron oxides, manganese oxides, and other components） in controlling the adsorption of lead（Pb） and cadmium（Cd） in aquatic environments. The selective chemical extraction followed by the adsorption of Pb and Cd experiments and statistical analysis, were used to investigate the adsorption property of each component. Hydroxylamine hydrochloride was used to remove manganese oxides selectively, and sodium dithionite was used to extract iron oxides and manganese oxides. The result indicated that iron oxides and manganese oxides played an important role in the adsorption of Pb and Cd on NSCsNS, and the relative contribution was about two-thirds. The contribution of manganese oxides was the greatest, with a lesser role indicated for other components. The adsorption ability of manganese oxides for Pb and Cd was greater than that of iron oxides or other components for Pb and Cd. The Pb adsorption observed in each component was greater than Cd adsorption.

关键词： Surface coating Iron oxide and manganese oxide Extraction Lead and cadmium adsorption

Structural Analysis of Water-soluble Polysaccharide PIP_1 Extracted from the Cultured Mycelium of Phellinus igniarius

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2006年第6期22卷 708-711页

作者： WU ming-jiang JIANG de-zhi LIU Tie-mei zhang Li-ping School of Life Science Northeast Normal University Changchun 130024 P. R. China School of Life and Environment Science Wenzhou University Wenzhou 325035 P.R. China

Water-soluble crude polyseccharide（PIP） was extracted from cultured mycelium of the fungus Phellinus igniarius. After ethanol precipitation and sepharose CL-6B gel filtration, the fraction of PIP1 was obtained, which was shown to be a homogeneous polysaccharide by means of high-performance liquid chromatography. The structure of PIPt was determined by using several methods. C.,C analysis indicates that PIP1 is composed of the monosaccharides of glucose, galactose, and mannose. Their malar ratio is 3. 70： 4. 06： 1.00. The molar weight was estimated to be 17 kd via HPLC. IR, GC, partial hydrolysis with acid, pefiedate oxidation, Smith degradation, methylation, and GC-MS analysis were used for the structural analyses of PIP1. The results show that PIP1 has a small quantity of branch structure, The main glycosidic linkage of PIP1 has a β-configurafion. The main chain is made up of a large mass of glucose （ 1→3 ） and few mannose （ 1→4 ） ; the side chain is composed of glucose （ 1 →3 ） and galactose （ 1→6 ） ; the nonreduced end is composed of galactose and glucose. The side chains are branched at 6-0 of glucose（ 1→3,6） and mannose（1→4,6）. On an average, there are three branches among 20 residues. It is presumable that the existence of 1,3-linked Glc in the main and side chains is the main reason for its higher antitumor activity.

关键词： Phellinus igniarus Cultured mycelium Polysaccharide Structural analysis