科创中国

为了优化生物质能供应链,降低成本,在无扰动因素情况,需求不确定且与价格有关的条件下,研究了由能源公司、基地和农户组成的三级生物质供应链中,奖惩与回馈契约对供应链的协调问题,建立了满足渠道协调的条件和供应链内各级参与者实现互赢的数学模型,最后将其用于数值算例中验证.结果证明契约参数的合理选择可以实现供应链各方利益最大.

采用乙二胺水杨醛sch诳碱配体与水合硝酸铜配位生成了一雁形的双核Cu(II)配合物.产物通过了元素分析、红外光谱及单晶x射线衍射分析等手段的证实.结果表明,该配合物晶体属于单斜晶系,P21/c空间群,晶胞参数为:a=0.8559(14),b=2.3276(4),c=1.1057(18)nm,β=91.360(4)°,V=2.2021(6)nm3,Z=2,Do=1.706g/cm3,M=1130.82,RI=0.0.543,wR2=0.1522;结构分析表明,配合物中存在两种截然不同的Cu(II)配位模式,Cu(1)离子采取四方平面构型,Cu(2)离子却为扭曲八面体几何构型.

Layered organic-inorganic hybrids containing bilayer perovsikte (R-NH3)2(CH3NH3)Pb2I7 (where R=C12H25,C6H5C2H4) were synthesized by reactions in solution. The influences of the solvents and the reactant ratio on the structures of the products were investigated. The structures and the properties of the hybrids were characterized using X-ray diffraction (XRD) and ultraviolet and visible (UV) adsorption spectra. For comparing with the bilayer perovskite hybrids in structure and band gap magnitude, the hybrids containing monolayer perovskite (R-NH3)2PbI4 were also synthesized and characterized. The results demonstrate that the thickness of inorganic layer has obvious effect on the tunneling magnitude of the band gap but the organic part can be micro actuator of band gap.

Many attentions for structural synthesis are paid to planar linkages and parallel mechanisms, while design novel pyramid deployable truss structure(PDTS) of satellite SAR mainly depends on experience of designer. To design novel configuration of PDTS, a two-step topology structure synthesis and analysis approach is proposed. Firstly, a conceptual configuration of PDTS is synthesized. Weighted graph and weighted adjacency matrix are established to realize topological description for PDTS. Graph properties are then summarized to distinguish differentia between PDTS and other type structures. According to graph properties, a procedure for synthesis conceptual configuration of PDTS is presented. Secondly, join relationship of components in a PDTS is analyzed. Kinematic chain and corresponding incidence/adjacency matrix are employed to analyze join relationship of PDTS. Properties and simplified rules of kinematic chain are extracted to construct kinematic chain. A procedure for construction kinematic chain of PDTS is then established. Finally, with this two-step approach all 11 rectangular pyramid deployable structures whose folded state is planar are discovered and their kinematic chains are constructed. Based on synthesis results, a novel deployable support structure for satellite SAR is designed. The proposed research can be applied to obtain some novel PDTSs, which is of great importance to design some novel deployable support structures for satellite SAR antenna.

针对轨道车辆铝型材焊接接头缺乏标准化管理、重复建模等问题,设计开发了一个3D铝型材焊接接头库,实现了三维接头模型及其数据信息的有效管理.首先在Pro/E系统中创建了具有参数化功能的样板模型;然后利用MicrosoftAccess创建了数据库,用ADO数据库访问接口技术解决了与Pro/E系统之间的通信;最后在VisualC++编译环境下,调用Pro/Toolkit应用程序提供的相关函数,编制了菜单和用户操作界面.研究结果表明,该铝型材焊接接头库的建立方便了车体建模,还可以允许用户按需求扩展焊接接头库,实现了系列化设计,提高了设计效率.

分析专业图书馆实现知识服务转型的4个主要方面及对图书馆人员结构的需求,包括建设多元化数字资源保障体系、探索面向专业领域的知识服务模式、试验开展集成化知识环境建设、创建柔性灵活的团队与协作机制.结合以国家科技文献中心成员单位为代表的专业图书馆人员队伍结构,分析其人员队伍状况,阐明专业图书馆人员结构与未来发展存在业务布局、专业能力、信息技术水平、组织管理体制等方面的差距.

Current research on the operational reliability of centrifugal pumps has mainly focused on hydrodynamic instability. However, the interaction between the fluid and structure has not been sufficiently considered; this interaction can cause vibration and dynamic stress, which can affect the reliability. In this study, the dynamic stresses in a single-blade centrifugal pump impeller are analysed under different operating conditions; the two-way coupling method is used to calculate the fluid–structure interaction. Three-dimensional unsteady Reynolds-averaged Navier-Stokes equations are solved with the SST k–ω turbulence model for the fluid in the whole flow passage, while transient structure dynamic analysis is used with the finite element method for the structure side. The dynamic stresses in the rotor system are computed according to the fourth strength theory. The stress results show that the highest stress is near the loose bearing and that the equivalent stress increases with the flow rate because the dynamic stresses are closely related to the pressure load. The stress distributions on the blade pressure side, suction side, leading edge, and trailing edge are each analysed for different flow rates; the highest stress distribution is found on the pressure side. On the blade pressure side, a relatively large stress is found near the trailing edge and hub side. Based on these results, a stress distribution prediction method is proposed for centrifugal pumps, which considers the interaction between the fluid and structure. The method can be used to check the dynamic stress at different flow rates when optimising the pump design to increase the pump reliability.

提出了高职院校物流实训基地的课程开发首先要打造基于物流业务核心岗位的实训室群,其次设计合理的实训课程体系,然后开发基于业务流程的实训课程,最后开发单元化的实训项目.

针对电子战中敌方雷达的快速定位,设计了一种基于三基线干涉仪的二维瞬时测向系统,解决了在宽频带范围内保证测向视角和精度的难题.给出了系统的工作原理、电路结构以及软件算法,并重点介绍了信号处理组件的设计等关键技术.试验结果表明,该测向系统在X波段全频带内的测向视角达到了±60°,测角精度优于1°.

本文认为,基层税收征管体系改革,必须以明确征纳双方法律权责、切实提高纳税遵从度和科学可控为目标.在改革原则上,要后移控制措施,前置应需服务;注重分析预警,加强税源管控;强化激励监督,健全内部管理.在整体架构设计上,应划分为宣导办税、税务管理和检查内控3个环节,其工作重点分别为满足需求、预警控制和监督考核.