引线键合机中高加速度高精度定位平台的研究现状与展望

高加速度高精度定位平台是引线键合机的核心部件,决定键合的速度和质量,进而影响芯片的成本与可靠性。随着芯片集成度的不断增大,管脚数量迅速增多,引线间距日益减小,定位平台的性能已经成为引线键合工艺进一步发展的瓶颈。概述了引线键合机中定位平台的发展历程,给出下一代引线键合机对平台性能的要求及相关技术的研究现状,指出由直线电机直接驱动的高推重比气浮定位平台有望满足下一代引线键合机的要求。     

CS5460A应用中的几个关键问题

文章介绍了用CS5460A组成的电测仪表的读/写子程序,以及电压、电流有效值和有功功率的获取、计算和校准的方法。     

模数转换器ICL7135的0—3.9999V显示

ICL7135为4~(1/2)位A/D转换芯片,其模拟输入电压范围为0～±1.9999V。但是在有些情况下,-1.9999～0V不用,只需测量正的电压,此时7135的分辨率只有1/20000。另外,当测量大于2V小于4V的模拟电压时,由于小数点后只能显示三位,分辨率也降低了。     

Research on some superheavy nuclei

Studies on some superheavy nuclei are performed. The α decay energies are calculated by an improved local binding energy formula, and the α decay half-lives are calculated by the Viola-Seaborg formula. Good agreements between theoretical and experimental results are reached.     

基于PLC的加热炉温度曲线控制系统设计

为了补偿环境温湿度对望远镜系统的不利影响,提高大型光电望远镜的成像能力,设计了一种基于CAN总线的温湿度监测系统。系统采用总线式拓扑结构,主要由数字式传感器SHT15、C8051F500单片机、CAN总线以及上位机组成。单片机与传感器之间利用SMBus进行通信,单片机读取传感器数据后,经由CAN总线将数据传送到上位机,上位机实时处理显示温湿度信息。系统设计完成后在实验室中进行了验证实验,成功读取了两个节点的传感器采集到的数据,能够进一步应用于实际工作中。     

通过（p,n）反应实验数据提取对称能(英文)

通过分析（p,n）电荷交换反应的微分散射截面数据,得到了核子光学势实部的同位旋矢量项。（p,n）反应的微分散射截面的大小正比于核子光学势实部的同位旋矢量项v1的平方,利用平面波玻恩近似可以直接提取v1的值。再根据HVH理论,利用v1的值能够得到对称能Esym(ρ0)和它的密度依赖斜率L(ρ0)的值。得到的结果Esym(ρ0)=28.5 MeV, L(ρ0)=76.0 MeV与分析原子核质量和其他核实验数据得到的结果符合较好。The isovector term of the real part of the nucleon optical potential is obtained by analysing differential cross section data of (p,n) charge exchange reaction. The magnitude of the differential cross section of (p,n) experiment is proportional to the square of the isovector term of the real part of the nucleon optical potential v1, so the extraction of the value of v1 is straightforward by using the plane wave Born approximation. Based on the Hugenholtz-Van Hove theorem, the nuclear symmetry energy Esym(ρ0) and its density slope L(ρ0) are estimated by using the extracted value of v1. The calculated results Esym(ρ0)=(28.5±2.0) MeV, L(ρ0)=(67.0±5.0) MeV agree reasonably with those extracted by analysing nuclear masses and other experimental data.     

A Simple Systematical Law of E2＋ Values for Heavy Nuclei in the NpNn Scheme and the Evolution of the Z=64 Shell Gap

A systematics of excitation energy of the first 2^＋ state E2＋ in even-even heavy nuclei （A ≥ 120） is studied in the NpNn scheme. It is found that a simple exponential function describes the dependence of E2＋ values on NpNn values very well. In addition, the Z = 64 shell gap is reexamined by investigating the systematics of the 52 ≤ Z ≤66 region. It is found that the Z = 64 shell gap is largest at N = 82 and becomes smMler with either increasing or decreasing of neutron numbers. The effects of this shell gap become negligible for counting the valence proton numbers when N ≥ 92 or N ≤ 72.     

奇Z超重核的禁戒α衰变(英文)

采用密度依赖的结团模型研究了奇Z 超重核的禁戒α衰变, 粒子与子核之间的微观核势通过双折叠模型对M3Y 核子-核子相互作用势以及 粒子与子核的密度积分给出。 粒子与子核之间的库仑相互作用也通过 粒子与子核的电荷密度积分给出。计算发现,由于非零角动量带来的禁戒效应和小的α粒子预形成几率,奇Z 超重核的α衰变寿命会明显变长。We investigate the α-transition of odd-Z superheavy nuclei by the density-dependent cluster model (DDCM). The microscopic nuclear potential between the -particle and the daughter nucleus is evaluated numerically from the double-folding model with the standard M3Y nucleon-nucleon interaction. The Coulomb potential is also obtained from the double-folding integral of the proton-proton Coulomb interaction with the charge density distributions of α-particle and daughter nucleus. From our calculations, enhanced stability againstα-decays is found for the odd-Z superheavy nuclei due to the hindrance effect of non-zero angular momentum and the small preformation factor of the -particle.     

α–结团模型对超重核α衰变寿命的研究

用α结团模型计算新合成超重元素的半衰期,与已知的实验数据进行对比分析,发现理论和实验数据能够很好地符合,验证了α结团模型对超重核研究的有效性.同时结合标准的形变Har-tree-Fock模型核质量表给出半衰期理论计算结果,可供以后在理论或实验上研究超重核参考,在此基础上进一步分析超重核区域的α衰变能、双中子分离能和双质子分离能,并讨论Z=114和N=184处是否存在壳效应.     

电压／频率转换器与单片机接口的设计

电压/频率(V/F)转换器芯片LM331,具有良好的线性、精度和积分输入特性。在数字化测量仪器中,使用V/F转换器,可以简化设计过程。它与单片机的接口电路简单,抗干扰性能强。下面作一介绍。一、系统硬件构成 (一)LM331工作原理图1是LM331简化的功能框图。正V_(in)加至7端,V_(in)与V_G比较。若V_(in)>V_G,SW接通,电流恒定向C_L充电,V_G逐渐上升。输出管T导通,V_出≈0V。5端内部的晶体管截止,C_t被充电当V_(ct)>2V_(cc)/3时,SW断开,V_出=V_D。C_t通过5端内部的晶体管导通放电。C_L上的电荷通过R_L放掉。使V_G下降。当V_G相似文献