工作面混合照明对书面阅读工效的影响

目的寻找最优的工作面混合照明,使得书面阅读工效最高。方法以12名在校大学生为被试,采用4(环境照度:0 lx、100 lx、150 lx、300 lx)×4(局部照度:200 lx、300 lx、500 lx、750 lx)双因素设计,研究不同环境照度和局部照度组合对书面阅读工效的影响,并对被试进行混合照度的主观评价。结果局部照度对阅读工效有显著性影响,环境照度对阅读工效无显著性影响。结论当环境照度相对较低,局部照度相对较高时,视觉感受、主观感受等方面均较好;当环境照度为150 lx,局部照度为300 lx时,书面阅读工效最佳。     

硝酸铵的相对吸湿速度

要确定硝酸铵在某种空气状态下是否吸湿,可以容易地从该空气状态下相对湿度与硝酸铵的吸湿点的对比来判断。然而,要比较硝酸铵在不同状态的空气中的吸湿速度,只考虑上述一点就不够了,必须考虑到与气温有关的吸收水分的速度系数。以韶关地区六五年四月及七月份的气候为例:四月份的平均温度为19.9℃,相对湿度为85％;七月份的平均气温为28.8℃,相对湿度为75％。这两月究竟是那一个月硝酸铵的吸湿速度快呢?如果从相对湿度与吸湿点的对比,     

曝光后低照度下视觉适应性的实验研究

为了研究装甲车辆内局部环境照明的视觉工效问题，受试者接受三种强度曝光，而后在低照度水平下判别视标方向，记录正确判别反应时。结果表明：在三种曝光强度下，随着视标照度水平的提高，受试者判别反应时曲线都呈先急后缓的下降趋势，并在视标照度为50lx时出现一有效拐点。据此，建议在无特殊视觉要求的情况下，装甲车辆局部环境照度应不低于50lx，或适当扩展装甲车辆观察窗口的大小和数量。     

特种车辆舱室照度测量方法及效果评价

目的根据特种车辆在试验过程中的实际需求,建立特种车辆舱室内照度测量方法,进行效果评价。方法根据被测部位信息的重要性、面积大小等分别采用五点中心布点法或一点中心布点法,利用照度计进行测试并分别读取数据,按相关要求进行计算。结果利用该方法测试各点的平均照度分别为179.2 lx、313.0 lx、211.8 lx和158.2 lx,照度均匀度分别为1.68、2.23、2.14和2.45,满足GJBz20527的相关要求。结论该测试方法能够满足特种车辆的舱内照度测试需求。     

住宅内固定设施低频噪声特征及评价方法探讨

通过对室内噪声的成因分析、室外声经地面传递至室内的各频段声级衰减特征以及典型固定设施噪声在房间内的噪声传递特征分析,认为对于上海市的住宅室内固定设施噪声的研究定义频段应在20～250 Hz以内,以低频噪声为主;为客观反映室内人的主观感受,参照国内外文献,结合对本市不同区域的实测室内声环境“dB(C)～dB(A)”差值对比,建议在制定上海市住宅室内固定设施噪声排放限值标准时采用"dB(C)～dB(A)的差值超过15 dB"指标预判是否存在低频噪声影响,进而再对20～250 Hz间的频谱进行限值控制。通过对低频为主的固定设备噪声特征分析,为本市住宅建筑内固定设施的噪声制定提出限值建议,为住宅室内环境治理及监管提供科学依据。     

高频语抗噪声通讯系统的研究

详细叙述了高频语抗噪声通讯系统工作原理和研制思想。实验结果证明，该语音系统具有较强的抗噪声功能。高频语声级85、90、95dB(A)，分别对应环境噪声95、100、105dB(A)，语音可懂度达90％以上；高频语声级90dB(A)，舰船主机噪声105dB(A)的现场试验，结果也达到90％。实验显示，噪声环境下使用高频语通讯，佩戴耳塞的效果优于裸耳。该系统在语音信号、环境噪声比为-10至-15dB时语音可懂度达90％以上，突破了传统的语言传递遵循部位机理的信号环境噪声比必须为 5dB的论点。     

烟草实验室恒温恒湿机送回风气流方式的改进

环境温湿度的波动性对烟草实验室检测设备及测试结果的准确性有重要影响。本文对某烟草实验室温湿度波动度、空气流速、噪声等参数无法达标的原因进行分析,对实验室恒温恒湿机的送回风气流方式进行改进:由散流器送风改为孔板送风,并设计制作静压室,降低风速和噪声。改进后,实验室温度短时波动度由原来的2.5℃降为0.9℃,相对湿度短时波动度由原来的5.6%降为2.2%,空气流速由原来的0.8 m/s降为0.2 m/s,噪声由原来的65 dB(A)降为54 dB(A),达到标准要求。     

公路隧道噪声降噪案例研究

隧道型公共设施的声环境,可以使用大量具有高吸声系数的吸声构造,铺设于隧道拱壁及轨道铺面,以降低混响时间及噪声。文中以在湖南省常张高速公路关口哑隧道吸声安装工程为例,在铺设吸声构造后,其混响时间在装吸声构造后在各1／3倍频带约减少64％～84％,预估降噪量则为4．7～8．5dB之间,在200Hz～800Hz之间,降噪量则有7．1dB～8．5dB之间,降噪效果显著。如以实际公路噪声特性预估,降噪量约有6．3dB（A）,SIL（speech interference level）则有6．6dB改善效果。     

卷烟工艺环境温湿度变送器的在线比对

卷烟厂环境温湿度对制丝、卷包、卷烟原材料的质量有重要影响,如《卷烟工艺规范》要求贮叶房空气相对湿度设定值为72．0％RH,允差为±5．0％RH,温度设定值为35．0℃～40．0℃．允差为±2．0℃;卷包车间空气相对湿度设定值为60．0％RH,允差为±5．0％RH,温度设定值为22．0℃～27．0℃．允差为±2．00（2。为保证其测控的准确性．卷烟厂大量使用了国外先进的数字式温湿度传感器．并采用网络监控手段进行测控管理。     

彩色扩印机的安装与调试

１　扩印机安装空间要求　机器四周最好留有５００～７００ｍｍ的空间，以方便机器的维护保养及自身散热的需要。房间高度应在２ｍ以上。面积１２ｍ２以上。温／湿度控制　室温应在１５～３０℃温度范围内，相对湿度要求小于８０％（在３０～７０％之间），室内应保持整洁、干净，并需有防尘措施。照明要求　扩印台面应避免光线直射，此处的照度小于３００ｌｘ，而观片处的照度要求在５００ｌｘ以上，且光源以自然光为佳，也可用２支４０Ｗ的日光灯布置在高１ｍ的高度照明来满足这一要求。排气通风与排液　为保证良好的工作环境，机房需要较…     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.