片状陶瓷材料高低温电性能参数的自动检测

由进口电性能仪配上自制的高温系统，计算机自动采集数据，配置成一套高低温电性参数测定装置，该装置的特点是，升温快，炉体小巧，炉芯可更换盛液氮装置，屏蔽良好，等温区长，温工及参数测量精确可靠。     

助剂对Pd/树脂醚化催化剂催化性能的影响 Ⅰ.铝助剂的影响

研究了不同助剂对Ｐｄ／树脂醚化催化剂在临氢条件下对催化裂化汽油Ｃ５馏份与甲醇和Ｈ２反应的催化性能的影响。结果表明，在Ｐｄ／树脂醚化催化剂中引入Ｚｒ、Ｔｉ、Ｂ、Ｓｎ和Ａｌ等助剂后，都能改善催化剂的醚化、双键异构和二烯烃选择性加氢活性，其中以Ａｌ、Ｓｎ为最好。Ａｌ助剂的体积质量和负载方式对Ｐｄ－Ａｌ／树脂醚化催化剂的活性有影响。ＢＥＴ方法和Ｘ－射线荧光光谱分析（ＸＦＳＡ）表明，Ａｌ助剂对Ｐｄ－Ａｌ／树脂醚化催化剂的表面积、孔结构和Ｐｄ离子交换量影响较小。     

柠檬酸月桂醇酯的合成

介绍了柠檬酸月桂醇酯的合成方法,并经正交实验得出合成的最佳工艺条件:反应温度132℃,反应时间120min,月桂醇/柠檬酸=1:1(mol比),催化剂用量:0.2g。     

Microfabricated liquid chromatography columns based on collocated monolith support structures

There is great interest today in massively parallel analytical strategies as a way to accelerate the rate of discovery in biological research; among them being 'biochips' and 'laboratories-on-a-chip'. The concept in the 'chip' approach is that minaturization will allow large numbers of operations to be performed in parallel in a small space, as in electronics. Proceeding with the semiconductor analogy, this paper demonstrates that in situ micromachining can be used to simultaneously fabricate millions of micrometer size, particle like structures in multiple liquid chromatography columns on a single wafer. Reduction of this widely used bioanalytical tool to the nanoliter volume, parallel processing, chip format is a significant step toward laboratories-on-a-chip.     

Oxygen dependency of retinal adhesion

PURPOSE: Normal retina is firmly attached to the retinal pigment epithelium, but the force of this adhesion drops precipitously within the first 2-3 min after enucleation. The purpose was to study metabolic factors that might be relevant to this postmortem failure of adhesion. METHODS: Dutch rabbit retina was manually peeled from the retinal pigment epithelium on strips of enucleated eyecup within a 37 degrees C bath. Retinal adhesiveness was measured by observing the amount of retinal pigment epithelium that remained adherent to the retina. RESULTS: Autologous whole blood in place of salt solution retarded the decrease in adhesiveness. A solution of hemoglobin alone was similarly effective, whereas methemoglobin solution failed to help the persistence of retinal adhesion. Bubbling oxygen into the salt solution and circulating it to avoid oxygen depletion at the tissue boundary also proved effective at sustaining retinal adhesiveness. Eyes made ischemic in vivo for 5 min or longer, by elevating intraocular pressure, showed virtually no retinal adhesion when enucleated immediately thereafter. However, eyes made ischemic for 10 min, but allowed to regain circulation for 5 min before enucleation, showed a return of retinal adhesiveness to 80% of normal. CONCLUSIONS: Oxidative metabolism is critical to the maintenance of retinal adhesiveness, and the effects of oxygen deprivation on adhesion are reversible within a certain time period.     

Abrasive wear of dental composite resins

Abrasive wear is a major problem in the application of dental composite resins. In this study the friction and wear behaviours of two types of dental composites: one containing relatively coarse filler particles and some microfillers (Estilux) and another containing only microfiller particles (Durafill), have been investigated by using a scratch testing machine. Experimental results show that the coefficients of friction in both composites are essentially constant for applied loads up to 20 N. The wear resistance of Durafill is better than Estilux. Under the same testing conditions, the size, shape and distribution of the filler particles are more important variables than applied load and sliding speed in controlling the wear mechanism. It is shown that for Estilux, plastic ploughing by the diamond indenter is the predominant mechanism. For Durafill, however, the formation and propagation of tensile cracks on the worn surface is the main wear mechanism. The effects of two different indenters, diamond and enamel, on the basic wear mechanisms are also discussed.     

热流法计算高温炉内辐射传热

高温炉内的辐射传热是工业生产中常遇到的问题。过去，人们在应用热流法计算辐射传热时遇到了一定的困难，使计算结果与实际有一定的偏差。本文运用文献［１］中给出的新热流数学模型，开发出由新热流方程与能量方程相耦合的计算机程序，其中的比热流参数由线加热热源情况下计算得到。用该程序计算了实验室用马弗炉内的温度场，并且用热电偶实测了炉内的一些温度值，理论计算与实测值符合很好。     

Cost Effective VLSI Architectures for Full-Search Block-Matching Motion Estimation Algorithm

In this paper, we present efficient VLSI architectures for full-search block-matching motion estimation (BMME) algorithm. Given a search range, we partition it into sub-search arrays called tiles. By fully exploiting data dependency within a tile, efficient VLSI architectures can be obtained. Using the proposed VLSI architectures, all the block-matchings in a tile can be processed in parallel. All the tiles within a search range can be processed serially or concurrently depending on various requirements. With the consideration of processing speed, hardware cost, and I/O bandwidth, the optimal tile size for a specific video application is analyzed. By partitioning a search range into tiles with appropriate size, flexible VLSI designs with different throughput can be obtained. In this way, cost effective VLSI designs for a wide range of video applications, from H.261 to HDTV, can be achieved.