柯伐镀金盖板电化学腐蚀的剖析及其防腐措施

对半导体器件封装的气密性失效进行了研究。发现，柯伐镀金盖板遭致电化学腐蚀是导致气密性失效的主要原因。对电解液的形成和电化学腐蚀机理进行了深入的分析。提出了防止腐蚀，提高器件气密可靠性的思路和方法。     

Sorghum seed storage in Purdue Improved Crop Storage (PICS) bags and improvised containers

Seed storage is a major challenge for smallholder farmers in developing nations. Purdue Improved Crop Storage (PICS) bags effectively control the postharvest insect pests of cowpea and other crops. Farmers, encouraged by this success, have begun to expand the use of PICS bags for storing other crops. Little is known about how sorghum seed, one of these important crops, fares when stored under hermetic conditions. Accordingly, we stored sorghum seed for six months in either airtight containers (PICS bags or sealed plastic bottles) or open ones (woven polypropylene bags and open plastic bottles). Overall, sorghum seed stored in PICS bags and in sealed plastic bottles maintained its initial moisture level, germination rate and seed weight. Porous polypropylene bags and open plastic bottles lost moisture over six months. We conclude that sorghum seed can be safely stored in hermetic containers without any loss of quality for extended periods of time.     

Triple bag hermetic technology for controlling a bruchid (Spermophagus sp.) (Coleoptera,Chrysomelidae) in stored Hibiscus sabdariffa grain

We assessed the performance of hermetic triple layer Purdue Improved Crop Storage (PICS) bags for protecting Hibiscus sabdariffa grain against storage insects. The major storage pest in the grain was a bruchid, Spermophagus sp.. When we stored infested H. sabdariffa grain for six months in the woven polypropylene bags typically used by farmers, the Spermophagus population increased 33-fold over that initially present. The mean number of emergence holes per 100 seeds increased from 3.3 holes to 35.4 holes during this time period, while grain held for the same length of time in PICS bags experienced no increase in the numbers of holes. Grain weight loss in the woven control bags was 8.6% while no weight loss was observed in the PICS bags. Seed germination rates of grain held in woven bags for six months dropped significantly while germination of grain held in PICS bags did not change from the initial value. PICS bags can be used to safely store Hibiscus grain after harvest to protect against a major insect pest.     

Adoption of cowpea hermetic storage by women in Nigeria,Niger and Burkina Faso

In this study, 2741 randomly selected rural women were interviewed about their cowpea storage practices in 101 villages in Burkina Faso, Niger and Nigeria in late 2010 and early 2011. The overall objective was to determine their cowpea storage practices and identify the most important factors in choosing Purdue Improved Crop Storage (PICS) triple bag storage. About two thirds of women said they used some type of hermetic storage. The hermetic containers included metal drums, plastic jugs, double bags and triple bags. The weighted percentage of women using PICS triple layer bags is 46%. Quantity of cowpea stored by technology showed similar patterns. Overall the percentage of cowpea in hermetic storage was 64%. The study estimated that women stored 50% of their cowpea in PICS bags. The percentage of cowpea in hermetic storage overall and in PICS bags specifically is higher for women than for men in a parallel 2012 ten-country study of mostly male household heads. In PICS villages, the women cite PICS technicians as the most important source of information. In Non-PICS villages, radio was the most important. Most women say that higher income is the major benefit of PICS. The 2009–2010 three country weighted average of the net cash flow from cowpea storage in PICS bags is $10.81/100 kg bag and $39.27 per respondent. Overall, the women indicated that local unavailability was the primary constraint to use of PICS bags. The LOGIT regression analysis shows that the most important factor influencing use of PICS technology is living in a village where PICS demonstrations occurred. The regression shows that radio and the PICS technicians have key roles as information sources. Being able to attend mixed gender meetings was statistically significant only in Burkina Faso where PICS did not organize many women-only PICS activities.     

Quality change and mass loss of paddy during airtight storage in a ferro-cement bin in Sri Lanka

In Sri Lanka, prices for paddy fluctuate severely showing a minimum price at harvest. To benefit from higher prices, farmers strive to store paddy, but lack of facilities and poor storage management cause quantitative and qualitative losses by rodents, insects and microbial deterioration. To overcome these problems an airtight storage system, based on a ferro-cement bin, has been developed. The objective of this study was to evaluate the storage system in terms of paddy quality and mass loss. Before and after storage, samples were drawn from this bin and a control to analyse moisture content, thousand-grain mass, insect infestation, mould, germination rate and head rice yield. Additional samples were taken from different regions in the bin.Oxygen concentration dropped to 2.7% within 30 days and carbon dioxide rose to 9.1%. The change in gas composition was caused mainly by insect respiration. Ephestia cautella were found on the top layer in the bin and Sitophilus spp. and Rhyzopertha dominica in the bottom layer. The average infestation rate was 4.8 insects/kg. Most of the insects were dead at unloading. After 6 months storage, mass loss was 0.4% in the bin and 2.1% in the control. Head rice yield was 35.8% in the bin and 27.3% in the control. A significant amount of mould was found only in the control (0.85%). Germination rate, however, decreased from 85% to 0% in the airtight bin, whereas it was still 38% in the control. The study has shown that airtight ferro-cement bins provide a safe and convenient method for farmers in the tropics to preserve their harvest for later sale at a higher price. Further work is necessary to develop strategies for avoiding the decrease in germination capacity.     

Storage of mung bean (Vigna radiata [L.] Wilczek) and pigeonpea grains (Cajanus cajan [L.] Millsp) in hermetic triple-layer bags stops losses caused by Callosobruchus maculatus (F.) (Coleoptera: Bruchidae)

Dry mung bean and pigeonpea grains that had sustained some insect damage but fumigated before the start of the experiment were stored in triple-layer hermetic bags (Purdue Improved Crop Storage (PICS™ bags) or woven polypropylene (PP) bags for 6 months. Some of the bags were artificially infested with cowpea bruchid Callosobruchus maculatus (F.) (PICS1, PP1) while others were not (PICS0, PP0). In an additional trial, PP bags containing the grains were treated with Actellic Super^® dust before being artificially infested (PP1Ac). Moisture content, live adult C. maculatus count, grain damage, weight loss, and seed germination were determined on a monthly basis. At six months, moisture contents of grain stored in PICS and PP bags remained below 12%. Storage in PICS bags halted multiplication of C. maculatus, and the initial damage level and weight of grains did not change. Conversely, in the PP bags, C. maculatus populations increased massively and seed damage reached 71.8 ± 1.9%, 76.9 ± 0.4%, and 60.3 ± 0.6% corresponding to weight losses of 14.5 ± 0.1%, 16.5 ± 0.2% and 12.5 ± 0.1% in PP0, PP1 and PP1Ac, respectively, in mung beans. With the pigeonpeas, seed damage reached 55.1 ± 0.6%, 95.7 ± 0.4% and 75.8 ± 0.9%, corresponding to weight losses of 13.0% ± 0.3%, 26.2 ± 0.2% and 13.5 ± 0.1%, in PP0, PP1 and PP1Ac, respectively. PICS bags are an effective tool for preserving mung beans and pigeonpeas against C. maculatus attack, and their performance is superior to that of Actellic Super^® dust.     

光纤涂碳工艺和特性研究

介绍了利用国产拉丝设备、原材料制造碳密封涂覆光纤的工艺和产品特性。涂碳工艺稳定可靠，光纤静态疲劳参数n＞100，平均断裂应力＞60N，能够满足苛刻环境对光纤长期可靠性的要求。     

密闭式油品酸值自动测定仪研制

根据油品酸值测定的特点,设计并定制了一种密闭式油品酸值自动测定仪,测量采用电位滴定法,由主机、样品交换器及控制软件构成。自主研制与消化吸收相结合,主机包含精密小体积加液与计量,负责数据传递与处理;样品交换器可同时盛放12个样品杯,按要求自动去盖加盖;滴定过程由软件控制,按照GB/T 7304方法规范执行程序,测定全过程密闭运行,测定结果相对偏差不大于2.8%,该方法与GB/T 7304方法手工结果具有较好的一致性。     

混合微电路内部水汽含量控制技术

根据气密性封装混合微电路内腔残余气体数据的测试结果,对水汽含量超标的样品进行了深入分析。提出了一种阻断分离法,可用于分析混合微电路水汽失效的原因。采用该方法,对可能引起水汽失效的外壳密封性问题、粘结胶放气问题,以及内部元器件及组装材料放气问题分别进行了试验验证与组合分析,找到了与水汽失效相关的各种原因及控制办法。根据试验分析结果,系统地提出了控制混合微电路内部水汽及其他杂质含量的有效方法。     

Detailed thermodynamic characterization of hermetic reciprocating compressors

The aim of this paper is the detailed analysis of different well-known thermodynamic efficiencies usually used to characterize hermetic compressors. Attention is focussed on the volumetric efficiency, the isentropic efficiency, and the combined mechanical–electrical efficiency. A procedure is presented to detach these efficiencies into their main components (physical sub-processes) to get deeper insight on the overall behavior.The volumetric efficiency is split into partial efficiencies related to pressure drop and heat transfer effects, supercharging effects, superdischarging effects, leakages, etc. The isentropic efficiency is detached using two different points of view: the work associated to the individual sub-processes (compression, discharge, expansion, suction), and the work associated to the underpressures, overpressures, and between the inlet and outlet mean compressor pressures. Finally, the combined mechanical–electrical efficiency is related to the heat transfer losses/gains, and to the exergy transfers and exergy destroyed.Even though some of the concepts introduced in the paper can be applied to different kinds of compressors, the discussion is specially focussed on hermetic reciprocating compressors. An advanced simulation model developed by the authors has been used to generate data to illustrate the possibilities of the detailed thermodynamic characterization proposed. The criteria developed are useful tools for comparison purposes, to characterize compressors, and to assist designers during the optimization process.