Clone classification of dually discriminator algebras with finite support

Dually discriminator algebras are considered up to clones generated by the algebra operations. In terms of binary relations, all clones of the operators on a finite set that contain the Pixley dual discriminator are efficiently described. As a consequence, a similar clone classification of quasi-primal algebras with finite support is determined. Translated fromMatematicheskie Zametki, Vol. 61, No. 3, pp. 359–366, March, 1997. Translated by A. I. Shtern     

可调平衡重垂直升船机(湿运)系统研究

采用可调平衡重系统，以机电一体化技术手段，程控调整滑轮两侧钢绳张力差△F值的大小和方向，实现运行全过程的静动态平衡、随遇平衡，进而实现无需配置电力驱动系统，减小悬吊钢丝绳直径，取消尾绳、取消卷扬筒、不设转矩平衡重，简化制动装置等效果。     

可调分束角棱镜的分束角与入射角的关系

本文对可调分束角棱镜的分束角与入射角及棱镜切角的关系进行了理论分析,并进行了实验测量,测量结果与理论计算符合很好。     

Transfer matrix spectrum for the finite-width Ising model with adjustable boundary conditions: Exact solution

Using the spinor approach, we calculate exactly the complete spectrum of the transfer matrix for the finite-width, planar Ising model with adjustable boundary conditions. Specifically, in order to control the boundary conditions, we consider an Ising model wrapped around the cylinder, and introduce along the axis a seam of defect bonds of variable strength. Depending on the boundary conditions used, the mass gap is found to vanish algebraically or exponentially with the size of the system. These results are compared with recent numerical simulations, and with random-walk and capillary-wave arguments.     

万能可调镗刀的创新设计

为适应加工对象的不断变化,采用参数化特征建模技术创新性地设计了万能可调镗刀,节省了各种镗刀的库存量,减少了企业的资金占用,创造了可观的经济效益。     

自然数八度周期律暨丢番图四定理

在发现自然数八度周期律的基础上,明确而系统地制定了丢番图四定理,从而准确、彻底、全面地解决了数论中任意正整数究竟能够分解成几个平方数之和的这一古老问题。     

Tunable bandgaps and flat bands in twisted bilayer biphenylene carbon

Owing to the interaction between the layers, the twisted bilayer two-dimensional(2 D) materials exhibit numerous unique optical and electronic properties different from the monolayer counterpart, and have attracted tremendous interests in current physical research community. By means of first-principles and tight-binding model calculations, the electronic properties of twisted bilayer biphenylene carbon(BPC) are systematically investigated in this paper. The results indicate that the effect of twist will not only leads to a phase transition from semiconductor to metal, but also an adjustable band gap in BPC(0 me V to 120 me V depending on the twist angle). Moreover, unlike the twisted bilayer graphene(TBG), the flat bands in twisted BPC are no longer restricted by "magic angles", i.e., abnormal flat bands could be appeared as well at several specific large angles in addition to the small angles. The charge density of these flat bands possesses different local modes, indicating that they might be derived from different stacked modes and host different properties. The exotic physical properties presented in this work foreshow twisted BPC a promising material for the application of terahertz and infrared photodetectors and the exploration of strong correlation.     

智能型乳化液泵站可调倾角平板车研制

介绍了智能型乳化液泵站可调倾角平板车研制项目的基本情况,探讨了可调倾角平板车的工作原理、性能及特点,阐述了可调倾角平板车的安装与操作。     

磨削加工中砂轮的有级恒线速控制

介绍一种在实际使用中非常有效的有级恒线速控制方法 ,该方法对于只有手动进给修整装置的磨床也能实现砂轮的线速度控制 ,以保证磨削加工的表面质量与加工效率     

一种应用于射频接收机的电流舵电荷泵设计

电荷泵锁相环(charge pump phase-locked loop, CPPLL)作为频率合成器(frequency synthesizer, FS),广泛应用于接收机中来提供低杂散、低噪声、高频谱纯度的本振(local oscillator, LO)信号。电荷泵(charge pump, CP)作为关键模块之一,其存在的非理想效应以及失配会带来更高相位噪声影响锁相环(phase-locked loop, PLL)频率综合器输出本振的频谱纯度。基于台积电(Taiwan semiconductor manufacturing company,TSMC ) 0.18 μm CMOS工艺,采用电流舵电荷泵结构并加入泄漏电流模块设计了一款低电流失配率、低相位噪声的电荷泵电路,较好地克服了传统电荷泵所存在的非理想效应,使整个电荷泵电路的相位噪声保持在较低的水平。利用Cadence Spectre对电荷泵的整体性能进行仿真。仿真结果表明,供电电压为1.8 V时,电荷泵电流为31.71 μA,最大相位噪声为-230 dBc/Hz,在0.4~1.4 V输出电压范围内最大电流失配率仅有0.22%。