Recent progress in rechargeable nickel/metal hydride and lithium-ion miniature rechargeable batteries

VARTA is searching for alternative battery solutions for memory back-up and bridging applications, and for this, it is developing nickel/metal hydride and lithium-ion button cells. Presented are the results on different sizes and forms of lithium-ion cells (621, 1216 and 2025) containing different electrode materials and shapes. Presently, the most favoured cathode material is lithiated manganese dioxide. The electrodes are made from both solid and porous materials and, together with an organic electrolyte, result in a cell system with a voltage level of approximately three. Included are results, both from these lithium-ion cells, and also from ones using the nickel/metal hydride system.     

A PECVD diamond device for chemical gas sensing applications

This paper presents a new diamond based microelectronic gas sensor for applications that require operation at a higher and wider temperature range and in harsh environments such as process control, exhaust emission and engine monitoring. The CO gas sensing performance and detection mechanism of the new sensor have been studied by using I–V and I–t characteristics as a function of gas concentration over a wide temperature range (50–500 °C). The gas sensitivity of the sensor is high, repeatable and reproducible. The response time is in seconds to a small concentration of CO gas. Gas detection mechanism of the new sensor is attributed to the modification of the oxygen vacancies in the SnO_x layer through the reduction reaction between pre-adsorbed oxygen and CO gases.     

灰色关联分析法在油井套管腐蚀评价中的应用

运用灰色关联分析方法对油田的腐蚀环境数据进行相关处理，分析影响套管腐蚀的主要因素，并确定各主次因素之间的关系。分析结果与现场情况一致，证明该方法的可行性。     

Ozone for Plant Pathological Applications

The effect of ozone on Xanthomonas oryzae pv. oryzae, a bacterium causing leaf blight disease in Paddy (Oryza sativa), was studied in culture. Viability of this pathogen was lost by flushing ozone at a flow rate of 300 ml/min for 3 minutes in culture condition. The inhibitory effect was dependant on cell concentration and time. With a cell concentration of 0.008 OD at 540 nm, the inhibition of the bacterium was total and no growth was observed in nutrient agar plates even after 36 hrs. With higher concentrations of cells (0.08 OD and above) the bacterium survived, though there was a bacteriostatic effect initially. Conductivity of the cell suspension increased after ozone treatment owing to altered cell membrane permeability and subsequent release of cellular contents. As the bacterium is seed borne, washing the paddy seeds with ozonized water would help control the bacterial blight of rice, the most serious disease of rice in Asia.     

An Improved UV/Ozone Oxidation System

Several modifications were made to a commercial UV-ozone stripper/cleaner in an effort to improve UV/ozone technology. Heating of the sample platform was done with radiant heaters instead of a resistance neater. Quartz infrared heat lamps and a metal ribbon radiant heater significantly shortened the heating-cooling cycle relative to a resistance heater; the lamps also heated the sample platform uniformly. With the radiant heaters, samples of different thickness could easily be processed. A cold cathode UV grid lamp provided more uniform illumination of the sample support platform than did the standard hot cathode spiral lamp. The grid lamp also reached steady state power output sooner than the spiral lamp. A polymeric membrane was found to be an effective diffuser for ozone/oxygen mixtures and there was no apparent degradation of the membrane due to exposure to UV/ozone. Furthermore, it is anticipated that the membrane diffuser would prevent any particles larger than 0.2 μm (the average membrane pore size) from entering the UV-1 reaction chamber. The performance characteristics of the modified system are presented.     

气相色谱内标物正构烷烃畸峰的研究

论述了内标法色谱分析中 ,导致内标物正构烷烃峰形畸变的因素 ,指出畸峰是由于正构烷烃超出色谱柱的容量造成的 ,并估算出所述分析条件下的最大柱容量。     

Saft lithium-ion energy and power storage technology

Since they were first introduced in the early 1990s, lithium-ion batteries have enjoyed unprecedented growth and success in the consumer marketplace. Combining excellent performance with affordability, they have become the product of choice for portable computers and cellular phones. Building on the same energy and life cycle attributes which marked their consumer market success, but adding new high power storage capability, lithium-ion technology is now poised to play a similar role in the transportation sector. With major programmes in both high capacity and high power lithium-ion technology, Saft has developed a family of products which can address the power and energy storage needs for vehicles, utilities, aviation, satellites, and other applications where light weight, long life, and excellent energy or power storage capabilities are needed. Although further development and refinements are underway, Saft has made a major commitment to bring this technology to the market with the establishment of a major pilot and research facility in Bordeaux France. This paper discusses the performance of this family of products and their potential applications.     

从实际应用看波纹管补偿器在热力管道中的优势

从实际应用的角度出发，对波纹管补偿器与Ⅱ型补偿器、球形补偿器在热力管道中的应用效果进行了比较，提出了在应用设计和施工中应注意的问题。     

应用前景广阔的纳米材料

介绍纳米材料的发展及在各领域中的应用.     

Identifying students’ mathematical skills from a multiple-choice diagnostic test using an iterative technique to minimise false positives

There is anecdotal evidence that a significant number of students studying computing related courses at degree level have difficulty with sub-GCE mathematics. Testing of students’ skills is often performed using diagnostic tests and a number of computer-based diagnostic tests exist, which work, essentially, by testing one specific diagnostic skill at a time.