冲床高速送料数控系统的研制

介绍了一种冲床高速送料数控系统的硬件和软件结构，数控系统硬件采取ＣＰＵ主从式结构，驱动单元采用高，低压供电，恒流斩波控制，并根据步进电机的特性，将升、降速时间控制在最小范围内，保证送料的高速性。数控系统的软件采用模块化结构，根据冲床加工特点，参考ＩＳＯ标准，设置了用户指令，用户指令少，功能强，可大大减少用户程序的编程量。     

Bose–Einstein Condensation of Collective Electron Pairs

Among quantum phenomena in solids at low temperatures, the superconductivity and Bose–Einstein condensation (BEC) are representatives of arising from coherent macroscopic quantum states. In this article, we discuss possible correlations between these two phenomena. It is well known that the Cooper pairs are not true bosons and then, we introduce the concept of collective electron pairs (CEP) through a unitary transformation of electron pairs. The CEP accomplish bosonic commutation relations at the dilute limit, being able to accumulate many of them at a single quantum state, in contrast to the standard Cooper pairs. An exact solution of all single CEP eigenstates is found by means of the Richardson’s equation within a multishell model. The obtained energy spectrum is used to determine the BEC temperature of CEP. In addition, we present an alternative approach to calculate the superconducting critical temperature by using the BEC formalism for a system composed by ground-state CEP, excited pairs and unpaired electrons.     

淮河左岸北淝河洼地防洪减灾对策

防洪标准与保护对象的重要性、地区社会经济发展状况和灾后影响严重程度相协调。沿淮洼地防洪减灾与蓄滞洪区的合理使用,保障人居安全。     

两维高速送排料装置数控系统硬件结构

本文介绍了一种两维分布式数控系统控制单元和驱动单元的硬件结构，这种数控系统可以自动地对在冲床上加工的铁板送排料，控制单元的硬件结构可以使系统在运行用户程序时采用并行工作方式，能根据两个伺服电机的特性分别作升降速处理，将升降速时间控制在最小范围内，保证送排料的高速性；还可以保证数据真正的并行处理，使数据预处理完全不占用伺服单元运行时间．本文还介绍了调频调压运行和低压锁定相结合的步进电机驱动电路，既达到高速送排料的目的，也可降低功耗，提高系统可靠性．     

高速送排料装置NC系统管理软件

本文介绍了送排料装置ＮＣ系统管理软件．该软件采用了模块化结构，各功能块具有相当的独立性，便于增添新的功能．本软件设置了按用户程序段循环加工、循环嵌套加工、跳转的功能．对于冲制板料的加工，其用户程序量减少了８０％以上．本软件建立了以加工类型、加工数据为线索的用户程序诊断方法．对用户程序的格式变化有很大的容忍性．     

Branching Strategy Selection Approach Based on Vivification Ratio

The two most effective branching strategies LRB and VSIDS perform differently on different types of instances. Generally, LRB is more effective on crafted instances, while VSIDS is more effective on application ones. However, distinguishing the types of instances is difficult. To overcome this drawback, we propose a branching strategy selection approach based on the vivification ratio. This approach uses the LRB branching strategy more to solve the instances with a very low vivification ratio. We tested the instances from the main track of SAT competitions in recent years. The results show that the proposed approach is robust and it significantly increases the number of solved instances. It is worth mentioning that, with the help of our approach, the solver Maple_CM can solve additional 16 instances for the benchmark from the 2020 SAT competition.     

石墨负载TiO2薄膜电极光电催化降解甲基橙研究

采用溶胶-凝胶法制备石墨负载TiO2薄膜电极，以125W高压汞灯为光源，以负载TiO2薄膜的石墨片为工作电极，铂电极为对电极，饱和甘汞电极为参比电极，建立三电极的光电催化体系，以甲基橙为降解对象．考察了初始浓度、涂敷层数、外加电压、通入空气对甲基橙降解速率的影响。研究表明，石墨是光催化剂良好的载体．外加电压可以促进光催化降解的效率，外加电压2V、涂敷3层、通入空气时对目标物质的降解效果最好。     

IP音频编解码器在电台传输系统中的应用

通过IP音频编解码的实际应用,我们解决当前广播电台在实时传输节目上的技术问题;阐述IP音频编解码的基本原理,介绍IP音频编解码设备的安装、调试、测试结果;总结如何使用公众网络(互联网)进行节目传输,并符合广播传输通路技术指标,保障安全播出.     

Investigation of optical and electronic properties in Al–Sn co-doped ZnO thin films

Al-Sn co-doped ZnO thin films were deposited onto quartz substrates by sol-gel processing. The surface morphology and electrical and optical properties were investigated at different annealing temperatures. The surface morphology showed a closely packed arrangement of crystallites in all the doped films. As prepared co-doped films show a preferred orientation along an (0 0 2) plane. This preferred orientation was enhanced by increasing the annealing temperature to between 400 °C and 500 °C, but there was a shift to the (1 0 1) plane when the annealing temperature rose above 500 °C. These samples show, on average, 91.2% optical transmittance in the visible range. In this study, the optical band gap of all the doped films was broadened compared with pure ZnO, regardless of the different annealing temperature. The carrier concentration and carrier mobility of the thin films were also investigated.     

皂化法合成硬脂酸钙,锌新工艺

介绍一种在水介质中由梗脂酸与新生成的氢氧化钙、锌进行皂化合成硬脂酸钙、锌的新工艺。与传统的复分解法工上比新工在大提高了生产效率、降低了能耗和水解．