DDJ-Ⅱ型多功能单片机计时器的改进设计

摘要：介绍应用DDJ-Ⅱ型多功能单片机计时器测刚体转动惯量的原理。通过改变单片机的内置算法，在不改变其硬件的前提下，使测试仪器相对误差由10％以上降低为2％以下。     

智能电话计时器的设计原理

介绍了一种智能电话计时器的设计与实现。该计时器以单片机AT89S51为主控芯片．通过接收电话信号音识别电路CR6230，识别出的各种电话信号音和MT8870的解码信息，以达到对用户每个主叫电话信息记录的目的；并带有人机交互的显示屏和控制键盘，以便用户查询主叫信息。     

基于单片机技术的机械设备计时器的研制

介绍一种基于单片机和振动传感器技术，采用软、硬件结合设计的新型数字式机械设备计时器，分析了原理、硬件结构、技术方法、配套设备和软件功能。     

智能红绿灯在城市中的应用探讨

本文采用一种智能的交通控制系统来控制十字路口交通汽车的流量,使得在车辆数较多的方向上,绿灯开放的时间就会长一些,在车辆数较少的十字路口另一方向上,红灯开放时间长一些,由此自动调节红绿灯的时间长度。利用埋在地下的电磁感应线圈探测经过十字路口的车辆数,结合计时器和计数器传到单片机中,再由单片机来控制交通信号灯的时间。     

基于SPWM的大功率交流恒流源系统研究

针对交流恒流的使用要求,提出了一种不对称规则采样法,利用ATMEGA16单片机的16位计时器生成SP-WM信号,驱动4个IGBT管组成的逆变主电路,通过LC滤波后送到输出端,同时在输出端进行采样,将采样值反馈给单片机。单片机根据采样值通过调整配置寄存器的值输出幅度和频率可变的SPWM信号,从而调整输出电压的幅度或频率,实现电流的恒定输出。实验表明,通过该种系统实现的交流恒流源精度高、可控性好、成本低。     

57428031单片机油料零售系统

５７４２８０３１单片机油料零售系统周迭辉，周光辉湖南大学应用物理系，株洲市电子研究所该系统直接称重，用逐次逼近法来进行测量，开启电磁阀，同时启动计时器计时，当传感器“输出的重量”到达欲称重量ＷＰ的某比例值为９０％时，关闭电磁阀，待稳定后，测出静态油料...     

机械信息

CF-40MR可编程序控制器通过鉴定童工报导:上海起重电器厂会同上海电器技术研究所借鉴进口样品,已完成CF-40MR可编程序控制器的试制任务,日前通过鉴定. 该控制器基本单元的CPU是单片机,有输入24点、输出16点,计时器有16点,计数器有16点.它能按继电器的梯形图或工艺流程来编制程序,并能把程     

萧邦（CHOPARD）Mille Miglia GMT 2005

动力储存46小时，配有测速刻度，可读出60至240公里/小时之间的速度。这款计时表在6时位置有一个12小时计时器，在9时位置有一个小秒计时器，在12时位置有一个30分钟计时器和一个1/4秒计时指针。第二时区时间由镌刻在表圈上的24小时刻度显示。     

关于直读式时间测量的影响因素探讨

本文提出一种用于检测数显计时器走时准确度的方法,通过直接检测被检仪器的显示数字的跳变,来推算出计时器计时误差,对此方法的影响因子进行了分析,并通过试验进行了验证,为一些常用的计时仪器准确度的检测提供了一种方案.     

双电机指针式电波钟

电波钟表是人类计时技术发展历程中继沙漏、日晷、机械表、石英表之后的第五代计时器。电波钟表作为一种标准时间接收器,实现了传统的机械、石英计时器等无法与标准时间建立联系的功能,能够自动使计时器对准北京时间,从而使全部电波钟表达到时间同步,使原子钟的时间精度技术民用化。双电机指针式电波钟是一种计时精度高、走时同步准、自动校时的新一代指针式时钟,它不仅可应用于人们的一般日常生活中,还可广泛应用于金融、交通、通信、计算机系统等领域。     

Effects of polydatin on the proliferation,migration, and invasion of ovarian cancer

To investigate the effects of polydatin on the proliferation, migration, and invasion of ovarian cancer, the change of proliferative ability, migration ability, and invasive ability of human ovarian cancer cell OVCAR-3, A2780, and HO-8910 was detected by using polydatin and up-regulating PI3K. The anticancer activity and mechanism of polydatin in ovarian cancer were analyzed. Polydatin could effectively inhibit the proliferation, migration, and invasion of OVCAR-3, A2780, and HO-8910, and inhibit the expression of PI3K protein. After the expression level of PI3K protein was up-regulated, the inhibitory effect of polydatin on the proliferative ability, migration ability, and invasive ability of OVCAR-3, A2780, and HO-8910 significantly decreased, suggesting that PI3K was the target of polydatin. Therefore, we concluded that polydatin could inhibit the proliferation, migration, and invasion of ovarian cancer cells by inhibiting the expression of PI3K protein, which provides an experimental basis for polydatin in the treatment of ovarian cancer.     

微波消解-电感耦合等离子体质谱法同时测定茶叶中42种元素

建立了电感耦合等离子体质谱法（IcP—Ms）标准模式和优化的碰撞池模式（CCT）结合同时测定茶叶中Li、Be、Mg、Al、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、Ga、As、Se、Sr、Mo、Ag、Cd、Sn、Sb、Cs、Ba、Tl、Pb、Bi和16种稀土元素共42种元素的方法。样品经过微波消解,以Ge、In、Re为内标消除基体干扰,通过碰撞池技术消除多原子质谱干扰测定上述元素。对于所测元素校准曲线的相关系数均大于0．9990,回收率范围为90％-110％,相对标准偏差为0．22％-3．97％,大部分元素检出限均小于0．5μg·kg^-1。该方法简便、省时、准确、灵敏度高,适用于实际样品的检测。     

Two distinct events, section compression and loss of particles ("lost caps"), contribute to z-axis distortion and bias in optical disector counting

Deformation of tissue sections in the z-axis can bias optical disector counting. When samples of particle densities are not representative for the entire tissue section, significant bias of estimated numbers can result. To assess the occurrence, prevalence, extent, sequence of events, and causes of z-axis distortion, the distribution of neuronal nucleoli in thick paraffin and vibratome sections was determined in chicken, rodent, and human brain tissues. When positions of neuronal nucleoli were measured in the z-axis, nucleoli were more frequent at the surfaces (bottom and top) of tissue sections than in the core. This nonlinear z-axis distribution was not lab-, equipment-, or investigator-specific, and was independent of age, fixation quality, coverslipping medium, or paraffin melting temperature, but in paraffin sections, was highly correlated with the tilt of the knife (cutting) angle. Manipulation of subsequent tissue processing steps revealed that two events contribute to z-axis distortion. Initially, a higher density of particles results at surfaces after sectioning, apparently due to section compression. Subsequently, particles can be lost to varying degrees from surfaces during floating or staining and dehydration, resulting in "lost caps." These results may explain different degrees of z-axis distortion between different types of sections and different labs, and reinforce the importance of checking z-axis distributions as a "quality control" prior to selection of guard zones in optical disector counting. Indirect approaches to assess section quality, such as resectioning in a perpendicular plane, yield additional artifacts, and should be replaced by a direct quantitative measurement of z-axis distribution of particles.     

Histochemical and ultrahistochemical localization of heavy metals in calf organs

Cadmium, zinc, selenium, and copper were administered, singly or in combination, orally or subcutaneously. Experiment I included 32 calves of both sexes; six received Cd (two groups), Zn, Cd, and Zn, and Cd and Se (two groups) and one group was a control. In Experiment II (21 bulls), three were given Cd, Cd, and Cu, and Cd and Zn, respectively, and one group was a control. For light microscopy, in Experiment I the highest amounts of silver granules were present in the samples of liver, small intestine, and vesicular gland of all the exposed groups; in Experiment II the most affected organs were liver, kidney, and small intestine. For electron microscopy, in Experiment I, after administration of Cd and Zn, the highest amounts of granules were seen in the cytoplasm of hepatocytes and cells of the proximal and distal renal tubules and the lowest amounts were found in glandular cells of the pancreas. Administration of Cd and Se resulted in the presence of large numbers of granules in the nuclei and nucleoli of spermatogonies. In Experiment II, ingestion of Cd and Zn in feed led to the appearance of highest amounts of granules in the nucleoli, nuclei, and cytoplasm of cells in testes, kidneys, and pancreas. Following Cd intake, the highest accumulation of granules was observed in the nucleoli of hepatocytes and cells of the proximal and distal renal tubules. Combined Cd and Cu produced the highest number of granules in cells of the proximal and distal renal tubules and in the nucleoli and nuclei of germinal epithelium.     

面向产品变异设计的零件可拓物元模型研究

为满足产品变异设计的要求,提出了零件可拓物元模型结构.通过融合零件及其子结构的几何、结构关联关系、功能和语义等信息,建立了零件变异物元模型.结合可拓理论,研究了零件变异物元模型的可拓性,分析了零件变异物元模型对产品变异设计的支持情况.最后,基于零件变异物元模型,开发了产品变异设计原型系统,并以发动机曲轴零件为例,建立了零件可拓物元模型.实例证明,零件变异物元模型解决了产品变异设计引起的零件结构干涉和拓扑更新问题,为产品变异设计提供了条件.     

Immunohistochemical distribution of enkephalin, substance P, and somatostatin in the brainstem of the leopard frog, Rana pipiens

The brainstems of frogs contain many of the neurochemicals that are found in mammals. However, the clustering of nuclei near the ventricles makes it difficult to distinguish individual cell groups. We addressed this problem by combining immunohistochemistry with tract tracing and an analysis of cell morphology to localize neuropeptides within the brainstem of Rana pipiens. We injected a retrograde tracer, Fluoro-Gold, into the spinal cord, and, in the same frog, processed adjacent sections for immunohistochemical location of antibodies to the neuropeptides enkephalin (ENK), substance P (SP), and somatostatin (SOM). SOM+ cells were more widespread than cells containing immunoreactivity (ir) to the other substances. Most reticular nuclei in frog brainstem contained ir to at least one of these chemicals. Cells with SOM ir were found in nucleus (n.) reticularis pontis oralis, n. reticularis magnocellularis, n. reticularis paragigantocellularis, n. reticularis dorsalis, the optic tectum, n. interpeduncularis, and n. solitarius. ENK-containing cell bodies were found in n. reticularis pontis oralis, n. reticularis dorsalis, the nucleus of the solitary tract, and the tectum. The midbrain contained most of the SP+ cells. Six nonreticular nuclei (griseum centrale rhombencephali, n. isthmi, n. profundus mesencephali, n. interpeduncularis, torus semicircularis laminaris, and the tectum) contained ir to one or more of the substances but did not project to the spinal cord. The descending tract of V, and the rubrospinal, reticulospinal, and solitary tracts contained all three peptides as did the n. profundus mesencephali, n. isthmi, and specific tectal layers. Because the distribution of neurochemicals within the frog brainstem is similar to that of amniotes, our results emphasize the large amount of conservation of structure, biochemistry, and possibly function that has occurred in the brainstem, and especially in the phylogenetically old reticular formation.     

GC/MS法同时分析液体制剂及口服液型保健品中31种防腐剂和抗氧化剂

为满足药品监管需要,建立了气相色谱-质谱（GC/MS）联用方法测定以水、醇等液体为基质的药品及保健品中的防腐剂和抗氧化剂。采用选择离子监测（SIM）技术,同时检测滴眼液、注射液、滴剂、涂剂、口服液型保健品中的三氯叔丁胺、苯酚、苯甲醇、山梨酸、苯甲酸、2-甲基异噻唑啉酮、脱氢乙酸、乙氧基喹啉、己基间苯二酚、对羟基苯甲酸酯等28种防腐剂及TBHQ、BHA、BHT等3种抗氧化剂。结果显示,31种物质在0.005~1 mg/L范围内具有较好的线性关系,线性相关系数为0.998 5~0.999 9;在0.02～0.30 mg/L加标范围内,回收率为73.6%～109.9%,相对标准偏差（RSDs）为1.2%～13.6%;检出限（LODs,S/N ≥3）为0.001～0.008 mg/L,定量下限（LOQs,S/N ≥10）为0.003～0.020 mg/L。应用该方法进行了多个批次的实际样品分析,结果表明,此方法灵敏、准确、稳定、可靠,且应用范围广泛。     

The structure and function of auditory chordotonal organs in insects

Insects are capable of detecting a broad range of acoustic signals transmitted through air, water, or solids. Auditory sensory organs are morphologically diverse with respect to their body location, accessory structures, and number of sensilla, but remarkably uniform in that most are innervated by chordotonal organs. Chordotonal organs are structurally complex Type I mechanoreceptors that are distributed throughout the insect body and function to detect a wide range of mechanical stimuli, from gross motor movements to air-borne sounds. At present, little is known about how chordotonal organs in general function to convert mechanical stimuli to nerve impulses, and our limited understanding of this process represents one of the major challenges to the study of insect auditory systems today. This report reviews the literature on chordotonal organs innervating insect ears, with the broad intention of uncovering some common structural specializations of peripheral auditory systems, and identifying new avenues for research. A general overview of chordotonal organ ultrastructure is presented, followed by a summary of the current theories on mechanical coupling and transduction in monodynal, mononematic, Type 1 scolopidia, which characteristically innervate insect ears. Auditory organs of different insect taxa are reviewed, focusing primarily on tympanal organs, and with some consideration to Johnston's and subgenual organs. It is widely accepted that insect hearing organs evolved from pre-existing proprioceptive chordotonal organs. In addition to certain non-neural adaptations for hearing, such as tracheal expansion and cuticular thinning, the chordotonal organs themselves may have intrinsic specializations for sound reception and transduction, and these are discussed. In the future, an integrated approach, using traditional anatomical and physiological techniques in combination with new methodologies in immunohistochemistry, genetics, and biophysics, will assist in refining hypotheses on how chordotonal organs function, and, ultimately, lead to new insights into the peripheral mechanisms underlying hearing in insects.     

铁碳合金相图的绘制

在分析铁碳合金相图特征的基础上,及说明相图中的特征点、线的含义的前提下,介绍了铁碳合金相图的画法,填写各区域的组织,从而完成整个铁碳合金相图的绘制.通过这种方式,能够较快地掌握铁碳合金相图的画法,理解相图中特征点、线及各区域组织的含义,对钢铁材料的选用和加工工艺的制订具有重要的理论和实践意义.     

Future directions of fundamental research in additive tribochemistry

This paper reviews briefly the present state of fundamental research, in tribochemistry of load-carrying additives, including oiliness agents, organolsulphur, organochlorine, organophosphorus, organic borates and organometallic compounds. The emphasis is on the weak areas of investigation. It is revealed that the least understood mechanisms, such as the effect of additives on fretting wear, additive-material compatibility, the efficacy of antifatigue additives and the action of water-based fluid additives in metalworking, are the concern of overlapping spheres of learning. A cooperative effort by chemists, metallurgists and mechanical engineers would help overcome the difficulties posed by problems in areas beyond individual expertises. Some research projects for the future are also suggested.