Concentrated and gastight sampling technique of deepsea microplankton

A new sampling method of deepsea microplankton with function of in-situ concentrated sampling and gastight sampling was proposed. In-situ concentrated sampling technique was realized as follows: a microplankton membrane was used as filtration membrane, and a deepsea pump was used to pump seawater; the microplankton was captured and the density of microplankton was increased when seawater flow through the filtration membrane. Gastight sampling technique was realized as follows: a precharged accumulator was used as pressure compensator. During the process of lifting the sampler, the accumulator compensated the pressure drop continuously. The laboratory experimental results show that with in-situ concentrated sampling technique, in-situ concentrated sampling can be realized and the maximum concentration ratio reaches up to 500. With pressure compensation technique based on accumulator, gastight sampling can be realized. When sampling at 6 km and the precharge pressure of accumulator is 18 MPa, pressure drop of the sample is less than 2% compared with its original pressure. Deepsea experiment (at 1.9 km) results show that the sampler can realize in-situ concentrated sampling and gastight sampling.     

HR-ICP-MS测定婴幼儿奶粉的有害金属元素

HNO3/H2O2作为消解剂对婴幼儿奶粉样品进行微波消解,然后应用高分辨电感耦合等离子质谱仪(HR-ICP-MS)对其中的铅、砷、镉、铍、铜五种有害元素进行检测,元素的回收率85.2%~110.7%,方法检出限0.3~4.5μg/L,精密度0.9%~4.6%。方法快速简便、准确率高、精密度好。     

旋进旋涡流量计旋涡进动效应的数值模拟研究

使用数值计算的方法建立了旋进旋涡流量计旋涡进动效应数值模拟数学模型，应用FLUENT软件分析了旋涡进动效应流场演变情况，并通过与实验结果的对比分析了数值模拟结果，讨论了仿真误差产生的原因。     

供热系统的可靠性管理

工业企业的供热系统,除了具有系统的集合性、相关性、目的性、环境适应性和整体性外,还有一个最重要的特征:安全可靠性。安全可靠性差,不仅会严重影响正常供热,还可能危及人的生命和国家财产安全。1985～1986年采暖期,我厂所属的七个供热区共发生大的故障72次,停炉时间648小时,虽然未给供热造成太大的影响,但维修费高达12万多元。图1是运行故障排列图。     

利用MAX6675组建测温网络

分析了集成温度传感器的应用局限性以及常用热电偶和热电阻测温系统的缺陷,提出了用高度集成的热电偶信号处理芯片MAX6675组建测温网络（系统）的优越性。介绍了MAX6675的工作原理及特点,并给出了基于MSP430单片机测温网络的硬件实现和软件设计。     

压缩空气动力汽车集成技术

压缩空气动力汽车采用压缩空气发动机做为动力源，可以实现零排放，是真正的环保汽车。压缩空气动力汽车的集成技术，在压缩空气存储、动力系统、辅助设备等方面与普通内燃机动力汽车相比具有一定的特殊性，该文在以上方面进行了研究探讨，并进行了压缩空气动力汽车的初步集成试验，为压缩空气动力汽车集成技术的深入研究提供参考。     

海底热液科学考察中的机电装备技术

在阐述极端海洋环境研究的意义的基础上,介绍了美国科学家在海底热液口考察工作中的机电装备技术,为我国相关领域工作的开展,提供有益的科学资料.并提出了深海资源开发中机电装备技术方面的一些研究方向.     

高洁净度齿轮钢中非金属夹杂物的检测方法

研究了一种方便可靠的夹杂物评估方法:利用合适电化学充氢后的拉伸试样获取夹杂物并与极值统计法相结合估算不同体积钢中非金属夹杂物的最大尺寸并预测疲劳强度。研究选用工业生产的高洁净度20Cr2Ni4A齿轮钢,将淬火+低温回火态的标准拉伸试样进行电化学充氢,使拉伸断口由于氢脆现象存在一些以粗大非金属夹杂物为中心的脆性平台,从而可方便快捷地在扫描电子显微镜下对夹杂物的类型、尺寸和分布进行检测,并利用极值统计法对钢中的最大夹杂物尺寸进行评估。为了验证该方法的准确性,采用传统金相法和旋转弯曲疲劳试验对钢中非金属夹杂物进行了检测,结果表明,使用本文所提出的夹杂物评估方法预测的钢中最大夹杂物尺寸及疲劳强度与疲劳试验结果相吻合。因此,该方法有望成为预测高洁净度高强度钢中最大夹杂物尺寸及其疲劳强度的一种有效方法。      

Improving Suction Performance of Centrifugal Pumps by Using Jetting Device

Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%.