检索结果-南通市图书馆

Synthesis and Crystal Structure of an Infinite 1D Zigzag Chain Compound (dimbH^+)(ClO_4^-) and Its Comparison with (dimb)2H_2O (dimb = 1,3-Di(imidazol-1-ylmethyl)-5-methylbenzene)

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2003年第4期22卷 439-443页

作者： YAOJing-Cai mayong-Lin HUANGWei GOUShao-Hua DepartmentofChemistry LuoyangTeachersCollegeLuoyang471022China；CoordinationChemistryInstituteStateKeyLaboratoryofCoordinationChemistryNanjingUniversityNanjing210093China CoordinationChemistryInstitute StateKeyLaboratoryofCoordinationChemistryNanjingUniversityNanjing210093China

A new imidazolium compound, C15H17N4ClO4, was prepared from a flexible bidentate ligand of 1,3-di(imidazol-1-ylmethyl)-5-methylbenzene, and characterized by X-ray analysis. It is of orthorhombic, space group Pnma with a = 8.182(2), b = 12.874(3), c = 15.611(4) ? V = 1644.4(7) 3, Dc = 1.425 g/cm3, Z = 4, Mr = 352.78, m(MoKa) = 0.944 mm-1, F(000) = 736, S = 1.036, the final R = 0.0521 and wR = 0.1187 for 1128 observed reflections (I > 2s(I)). An infinite one-dimensional zigzag chain is formed by NH…N hydrogen bonding interactions between the imidazolium salt cations.

关键词： di(imidazol-1-ylmethyl)-5-methylbenzene imidazolium salt hydrogen bonding interactions zigzag chain crystal structure

Non-Noether Conserved Quantity for Relativistic Nonholonomic System with Variable Mass

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第2期43卷 197-200页

作者： QIAOYong-Fen LIRen-Jie mayong-Sheng DepartmentofMechanicalEngineeringandAutomation ZhejiangInstituteofScienceandTechnologyHangzhou312207China／／FacultyofScienceLaiyangAgriculturalCollegeLaiyang265200China FacultyofScience LaiyangAgriculturalCollegeLaiyang265200China EngineeringCollege NortheastAgriculturalUniversityHarbin150030China

Using form invariance under special infinitesimal transformations in which time is not variable, the non-Noether conserved quantity of the relativistic nonholonomic system with variable mass is studied. The differential equations of motion of the system are established. The definition and criterion of the form invariance of the system under infinitesimal transformations are studied. The necessary and sufficient. condition under which the form invariance is a Lie symmetry is given. The condition under which the form invariance can be led to a non-Noether. conserved quantity and the form of the conserved quantity are obtained. Finally, an example is given to illustrate the application of the result.

关键词： analytical mechanics relativity nonholonomic system variable mass non-Noether conserved quantity

Non-Noether Conserved Quantity of Nonholonomic System Having Variable Mass and Unilateral Constraints

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2004年第6X期42卷 801-804页

作者： QIAOYong-Fen LIRen-Jie mayong-Sheng DepartmentofMechanicalEngineeringandAutomation ZhejiangInstituteofScienceandTechnologyHangzhou310027China//PhysicsTeachingDivisionLaiyangAgriculturalCollegeLaiyang265204China// PhysicsTeachingDivision LaiyangAgriculturalCollegeLaiyang265204China EngineeringCollege NortheastAgriculturalUniversityHarbin150030China

Using the Lie Symmetry under infinitesimal transformations in which the time is not variable, the nonNoether conserved quantity of nonholonomic system having variable mass and unilateral constraints is studied. The differential equations of motion of the system are given. The determining equations of Lie symmetrical transformations of the system under infinitesimal transformations are constructed. The Hojman's conservation theorem of the system is established. Finally, we give an example to illustrate the application of the result.

关键词：质量变化单边约束不完整系统决策函数解析力学

Effects of Comprehensive Eccentricity of Involute Cam on Gear Profile Deviations

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2011年第3期24卷 392-398页

作者： WANG Liding LING Siying mayong WANG Xiaodong LOU Zhifeng Key Laboratory for Precision ＆ Non-traditional and Micro System Machining of Ministry of Education Dalian University of Technology Dalian 116023 China Key Laboratory for Micro/Nano Technology and System of Liaoning Province Dalian University of Technology Dalian 116023 China

The manufacturing accuracy of ultra-precision master gears signifies the technological capability of the ultra-precision ***,there is little report about the manufacturing technologies of ultra-precision master gears at home and *** order to meet the requirement of grinding ultra precision master gear,the gear grinder with flat-faced wheel Y7125 is chosen as the object machine tool and the geometric model of its precision generating part,the involute cam,is *** to the structure of the involute cam,the effective working section and its adjustable range of the cam are determined,and the mathematical expressions of the effects of comprehensive eccentricity of the involute cam on gear profile deviations are *** to the primary harmonic trends of the deviation curve,it is shown that gear profile form and slope deviations in different work generating sections of the involute cam are different which the latter changes with the cam eccentricity ***,the issues of extreme values and methods of error compensation are studied and the conclusion that large adjustable range is benefit to search the optimal involute-cam section which is responding to the minimum gear profile deviations is obtained.A group of examples are calculated by choosing master gears with d=120 mm and m=2-6 mm and an involute cam with base diameter djcam =117 *** it is found that the maximum gear profile deviation counts for no more than 5% of the cam eccentricity after error compensation.A gear-grinding experiment on the master gear with m=2 mm is conducted by choosing different sections of the involute cam and the differences of gear profile deviations then the existence of the cam eccentricity are *** research discloses the rule of gear profile deviations caused by the comprehensive eccentricity of the involute cam and provides the theoretical guidance and the processing methods for grinding profile of the ultra precision master gear.

关键词： gear grinder with flat-faced wheel involute cam ultra precision master gear gear profile deviations error compensation

Changes of Tempering Microstructure and Properties of Fe-Cr-V-Ni-Mn-C Cast Alloys

在线全文

学校读者我要写书评

暂无评论

材料热处理学报 2004年第5期25卷 631-634页

作者： LIUYan-xia mayong-qing WANGYue-hua ZHANGZhan-ping ZHANGYang InstituteofMaterialsandTechnology DalianMaritimeUniversityDalianChina／DepartmentofPhysicsLiaoningUniversityShenyangChina InstituteofMaterialsandTechnology DalianMaritimeUniversityDalianChina DepartmentofPhysics LiaoningUniversityShenyangChina

The changes of tempering microstructure and properties of Fe-Cr-V-Ni-Mn-C cast alloys with martensite matrix and much retained austenite are studied. The results showed that when tempering at 200 °C the amount of retained austenite in the alloys is so much that is nearly to as-cast, and a lot of retained austenite decomposes when tempering at 350°C and the retained austenite decomposes almost until tempering at 560 °C. When tempering at 600 °C, the retained austenite in the alloys all decomposes. At 560°C the hardness is highest due to secondary hardening. The effect of nickel and manganese on the microstructure and properties of Fe-Cr-V-C cast alloy were also studied. The results show that the Fe-Cr-V-C cast alloy added nickel and manganese can obtain martensite matrix and much retained austenite microstructure, and nickel can also prevent pearlite transformation. With the increasing content of nickel and manganese, the hardness of as-cast alloy will decreases gradually, so one can improve the hardness of alloy by tempering process. When the content of nickel and manganese is 1.3-1.7%, the hardness of secondary hardening is the highest (HRC64). But when the content of nickel and manganese increase continually, the hardness of secondary hardening is low slightly, and the tempering temperature of secondary hardening rises.

关键词： Fe-Cr-V-Ni-Mn-C合金显微结构调温过程热处理

Simulation of Rolling Billet in Oval Pass by Explicit Dynamics Elastic-Plastic FEM

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2004年第2期11卷 30-33页

作者： LIJian-chao CUIJian-zhong mayong-lin WANGBao-feng NortheasternUniversity Shenyang110004China BaotouUniversityofIronandSteelTechnology Baotou014010China

Considering the strip speed during controlled laminar cooling on Baosteel 1580 hot strip mill in China, the influence of strip speed fluctuation on coiling temperature control for the tail and “neck” of the strip wa... 详细信息

关键词： hot strip laminar cooling speed control coiling temperature

High Carbon Alloy Steels with Multiple Types of Ultra-fine Carbides and Their Characteristics

在线全文

学校读者我要写书评

暂无评论

材料热处理学报 2004年第5期25卷 117-121页

作者： mayong-qing GAOHong-tao QIYu-hong ZHANGZhan-Ping DAIYu-mei LIUYan-xia DalianMaritimeUniversity DalianChina

Under normal forging and annealing conditions, there are different ultra fine carbides (M3C, M23C6, M7Cj, M6C and MC) in high carbon alloy steels when alloy composition design is carried out properly. On the basis of carbides transformation orderliness, the alloy composition design of the high carbon alloy steels is conducted by phase-equilibrium thermodynamic calculation for Fe-Cr-W-Mo-V-C system. The nucleation and growth of new carbides, dissolution of previous partial carbides in these steels during annealing process, all these lead to ultra-fine distribution of carbides. Due to different crystal structures of carbides and different thermodynamics as well dynamics parameters of the carbides dissolution and precipitation, the range of quenching temperature of these steels is widened, and the good temper-resistance is obtained. The characteristics of heat treatment process and microstructure variance, and the carbides transformation for different temperature are explained by the phase-equilibrium component satisfactorily. Their bend and yield strength, flexibility and toughness all are advanced markedly comparing with that of kindred steels. Results of the applications have proved that the microstructure of ultra-fine carbides in these steels played importance roles in the enhancement of edginess and fatigue crack resistance of the die and knives.

关键词：超细硬质合金高碳钢结构设计成分设计

Application of ion chromatography to the determination of water-soluble inorganic and organic ions in atmospheric aerosols

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2004年第5期16卷 813-815页

作者： YUXue-chun HEKe-bin mayong-liang YANGFu-mo DUANFeng-kui ZHENGAi-hua ZHAOCheng-yi DepartmentofEnvironmentalScienceandEngineering TsinghuaUniversityBeijing100084China AnalyticalandTestingCenter BeijingNormalUniversityBeijing100875China

A simple, sensitive and convenient ion chromatography(IC) method was established for the simultaneous determination of twelve water-soluble inorganic anions(F -, Cl -, NO - 2, NO - 3, SO 2- 3, SO 2- 4, PO 3- 4), and fifteen water-soluble organic ions(formate, acetate, MSA, oxalate, malonate, succinate, phthalates, etc.) in atmospheric aerosols. The linear concentrations ranged from 0.005 μg/m 3 to 500 μg/m 3(r = 0.999—0.9999). The relative standard deviation(RSD) were 0.43%—2.00% and the detection limits were from 2.7 ng/m 3 to 88 ng/m 3. The proposed method was successfully applied to the simultaneous determination of those inorganic ions and organic ions in PM 2.5 of Beijing.

关键词： ion chromatography water-soluble ions aerosols Beijing

Experimental Study on Hydrodynamic Characteristics of Vertical-Axis Floating Tidal Current Energy Power Generation Device

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2016年第5期30卷 749-762页

作者： mayong LI Teng-fei ZHANG Liang SHENG Qi-hu ZHANG Xue-wei JIANG Jin College of Shipbuilding Engineering Harbin Engineering University Harbin 150001 China

To study the characteristics of attenuation, hydrostatic towage and wave response of the vertical-axis floating tidal current energy power generation device （VAFTCEPGD）, a prototype is designed and experiment is carried out in the towing tank. Free decay is conducted to obtain attenuation characteristics of the VAFTCEPGD, and characteristics of mooring forces and motion response, floating condition, especially the lateral displacement of the VAFTCEPGD are obtained from the towing in still water. Tension response of the #1 mooring line and vibration characteristics of the VAFTCEPGD in regular waves as well as in level 4 irregular wave sea state with the current velocity of 0.6 m/s. The results can be reference for theoretical study and engineering applications related to VAFTCEPGD.

关键词： tidal current energy power generation device experiment hydrodynamic characteristics attenuation wave response lateral displacement