透镜单片加工高效生产的研究

本文以建立百花相机第一镜片的单片加工高效生产流水线为依据,阐述了以“铣磨-高速金刚石丸片精磨-固着磨料抛光”为主体工序的高效生产的基本原理和加工全过程。着重介绍生产中的主要工艺参数,分析高效生产中影响产品质量的可能因素。     

高效线各工序的匹配

光学零件高效加工生产线建成后，工艺人员应解决的关键问题就是生产线内部各道工序之间的匹配。本文较系统地讨论了从铣磨、精磨到抛光各道工序之间在光圈、光学粗糙度、加工余量诸方面的匹配关系。这三个方面既互相独立、又互相影响。每道工序都要同时满足这三方面的要求，才能保证高效线的稳定、高产     

SH型轻质高效装饰隔声门通过鉴定

1995年6月26日由上海市二轻局主持，国家环保局、上海市经委、市环保局有关领导和北京上海声学专家参加，对上海申华声学装备有限公司（上海红旗机筛厂）试制生产的SH型轻质高效装饰隔声门通过了生产鉴定．近年来，为满足电台、电视台、剧场、影院、宾馆会议室等厅堂音质工程的需要和高隔声量噪声控制工程的需要，国内试制了一些不同类型的隔声门，也从国外进口了一些隔声门．上海申华声学装备有限公司在有关专家教授的指导下，新开发了一种轻质高效装饰隔声门．总厚度为60mm，面质量为48kgm2，隔声指数大了42dB，与单位厚度单位面质量相…     

国产光学设备棱镜高效制造技术的工艺参数

介绍的棱镜高效制造技术工艺参数 ,是在使用国产光学加工设备的条件下依靠工装夹具的精度来保证棱镜的角精度 ,采用工装夹具上刚性盘和靠体翻转加工的方法来实现高效生产 ,由此确定的技术参数。并对高效加工的前期准备条件和要求 ,及为适应工艺要求而对机床进行的局部改进也进行了介绍     

新的氢燃料来源

美国与希腊的科学家发明了一种从酒精中生产氢气的反应器.Menisoda大学的LannySchmidt及Patras大学的XenephonVerykipos等表示,他们的反应器高效而经济,代表着向着实际的“氢经济”迈进了重要的一步.这种反应器可用于小型燃料电池,产生35 0W·h的电能(DelugaGetal.Sci ence,2 0     

浅谈如何构建初中物理高效课堂

随着新课改的深入发展,创建物理高效课堂成为了初中物理教学的一个重要任务。本文主要从构建初中物理高效课堂的角度进行分析,探讨怎样围绕新课程理念上好初中物理课。     

自聚焦透镜高效批量加工的双面研磨抛光法研究

依据双面研磨抛光原理,提出了加工自聚焦透镜平面和斜面辅助工装设计.从工艺技术特点和生产实际过程等方面对设计的工装使用情况进行分析验证.多次大批量加工实践证明,该辅助工装的设计完全满足了自聚焦透镜高效批量加工技术要求,简化整个生产线工艺,减少工艺流程时间,降低材辅料的消耗成本,从而验证了双面研磨抛光法是一种实用的加工自聚焦透镜的新方法.     

高效液相色谱法测定喷昔洛韦钠原料药含量

高效液相色谱法测定了喷昔洛韦钠原料药的含量,并与常量非水滴定法的测定结果进行了比较,该法简便、快速、结果准确。为喷昔洛韦钠药物在生产过程中的质量控制提供了可靠依据。     

高效液相色谱紫外检测法测定小麦幼苗中的内源激素

本文从小麦幼苗中提取出三种植物内源激素,并用反相高效液相色谱紫外检测法测定了激素的含量。选择最佳色谱条件及仪器参数,建立了内源激素的高效液相色谱紫外检测法,该法简便,快速,准确度高,重现性好。     

物理教师怎样尽快适应高效课堂

结合教学实践,从五个方面说明物理教师如何进行高效教学.     

高速流场下凸台周围的气动光学效应

针对高速流场下凸台周围的气动光学效应,对不同马赫数下的三种凸台形状周围的流场进行仿真计算,计算得到流场的密度变化,计算了光线经流场传输后的光程差。仿真结果表明:随马赫数增大,光程差逐步增大;同等条件下,不同出射角度对应的光程差不同,凸台存在强烈的尾流区域,从而导致较大的光程差;在马赫数达到跨音速时,凸台顶端也会产生较大的光程差;曲率较小的凸台结构对周围流场的影响较小。     

Classroom demonstrations of acoustic beamforming

A tabletop apparatus permitting demonstrations and hands-on student exercises in the acoustic beamforming of linear arrays is described. The apparatus can be used to demonstrate how interference effects from two or more linearly arranged sources produce patterns of maxima and minima as described by theory. A transmitting array is attached to the top of a rotating table and a receiving transducer provides voltages to a signal processor. Students measure the angular speed of the rotating table and the voltages produced by the receiving transducer as a function of time. These data can be analyzed in a spreadsheet program and compared to theory. The angles at which signal maxima occur correspond well to theory and useful teaching discussions result from comparisons of signal maxima magnitudes. The spreadsheet analysis can also provide the students a graphical demonstration of l'H?pital's rule.     

Acrylic and metal based Y-branch plastic optical fiber splitter with optical NOA63 polymer waveguide taper region

We proposed a simple low-cost acrylic and metal-based Y-branch plastic optical fiber (POF) splitter which utilizes a low cost optical polymer glue NOA63 as the main waveguiding medium at the waveguide taper region. The device is composed of three sections: an input POF waveguide, a middle waveguide taper region and output POF waveguides. A desktop high speed CNC engraver is utilized to produce the mold inserts used for the optical devices. Short POF fibers are inserted into the engraved slots at the input and output ports. UV curable optical polymer glue NOA63 is injected into the waveguide taper region and cured. The assembling is completed when the top plate is positioned to enclose the device structure and connecting screws are secured. Both POF splitters have an average insertion loss of 7.8 dB, coupling ratio of 55: 45 and 57: 43 for the acrylic and metal-based splitters respectively. The devices have excess loss of 4.82 and 4.73 dB for the acrylic and metal-based splitters respectively.     

Fabrication of 1×2 asymmetric plastic optical fiber coupler for portable optical access-card system

We proposed a simple low-cost acrylic and metal-based Y-branch plastic optical fiber (POF) splitter which utilizes a low cost optical polymer glue NOA63 as the main waveguiding medium at the waveguide taper region. The device is composed of three sections: an input POF waveguide, a middle waveguide taper region and output POF waveguides. A desktop high speed CNC engraver is utilized to produce the mold inserts used for the optical devices. Short POF fibers are inserted into the engraved slots at the input and output ports. UV curable optical polymer glue NOA63 is injected into the waveguide taper region and cured. The assembling is completed when the top plate is positioned to enclose the device structure and connecting screws are secured. Both POF splitters have an average insertion loss of 7.8 dB, coupling ratio of 55: 45 and 57: 43 for the acrylic and metal-based splitters respectively. The devices have excess loss of 4.82 and 4.73 dB for the acrylic and metal-based splitters respectively.     

Heavy Charged Gauge Bosons with General CP Violating Couplings

Heavy gauge bosons such as W＇ are expected to exist in many extensions of the Standard Model. In this paper, the most general Lagrangian for the interaction of W＇ with top and bottom quarks is considered. This Lagrangian consists of V- A and V ＋ A structure with in general complex couplings. Such interactions produce an Electric Dipole Moment （EDM） for the top quark at one loop level. We predict the allowed ranges for the mass and couplings of W＇ by using the upper limit on the top quark EDM.     

Rectangular plate with velocity feedback loops using triangularly shaped piezoceramic actuators: experimental control performance

This paper presents experimental results on the implementation of decentralized velocity feedback control on a new smart panel in order to produce active damping. The panel is equipped with 16 triangularly shaped piezoceramic patch actuators along its border and accelerometer sensors located at the top vertex of the triangular actuators. The primary objective of this paper is to demonstrate the vibration and sound radiation control using the new smart panel. Narrow frequency band experimental results highlight that the 16 control units can produce reductions up to 15 dB at resonance frequencies between 100 and 700 Hz in terms of both structural vibration and sound power radiation.     

Baryogenesis at the weak phase transition

The weak phase transition of the hot big bang can produce quarks, leptons and weak bosons which are out of thermal equilibrium. In a simple extension of the standard model it is shown that the reactions following top quark decays can generate the cosmological baryon asymmetry. The top quark mass must be close to 80 GeV and the Higgs boson must be lighter than 1 GeV. This baryogenesis mechanism can be directly tested at e⁺e⁻ and hadron collider by searching for spectacular events containing six or more bottom quarks and a violation of baryon number at the decay vertex of a long lived neutral particle.     

The EAS-TOP detector at Gran Sasso

Summary EAS-TOP is a detector of the extensive air showers that very high-energy cosmic rays (E ₀≥10¹⁴eV) produce in the atmosphere. The array is located on top of the underground Gran Sasso Laboratory in central Italy; a subarray (11 modules of the e.m. detector) has been operating since the end of 1987. From such data the stability of the detector, and the accuracies in the determination of the arrival directions and in the reconstruction of the electron lateral distribution and of the shower size are derived. The results obtained on VHE-UHE γ-ray sources in the first months of operation are presented. To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee.     

两种不同尺度的颗粒在水平振动容器内分离规律的模拟

用分子动力学方法模拟二维颗粒系统在水平振动下的分离现象.通过数值模拟发现,在固定的振幅下,存在使得分离效率最佳的振动频率,在固定的振动频率下,也存在一个使得分离效率最佳的振幅.根据模拟结果,给出了最佳振幅对振动频率的经验公式.同时,还指出了存在两种不同的分离机制,当振动的加速度过大时,处于垂直边界附近的大粒子会通过容器的边界直接被抛到最顶部.     

硅中的过渡元素杂质能级

本文提出了半导体中过渡元素杂质的一个简单模型,用格林函数方法计算了硅中替代和间隙原子产生的杂质能级和波函数。发现两者的性质有很大的差别。替代原子只有当d原子能级V_d低于价带顶时才能产生杂质能级。它的波函数主要是悬键态,当能级靠近导带边时变成正键态。间隙原子只有当V_d高于价带顶时才能产生杂质能级。它的波函数主要是中心原子d态,当能级靠近导带边时变成弱反键态。最后定性地说明了过渡元素杂质能级的化学趋势和一些实验事实。 关键词：