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81.
防静电、防过电流和过电压冲击是目前工程师设计电子产品时必须考虑的一个问题,否则这些产品的市场销路一定会大打折扣。本文集中探讨了目前市场上所有的电路保护技术,并展望了未来电路保护器件的发展方向。 相似文献
82.
The fabrication of a dispersion slope equaliser on a silica-based planar lightwave circuit for 16×20 Gbit/s wavelength division multiplexing transmission is reported. This device comprises an array of sixteen equalisers with different compensation values and an arrayed-waveguide grating for wavelength multiplexing 相似文献
83.
Janarthanan Supramaniam Darren Yi Sern Low See Kiat Wong Loh Teng Hern Tan Bey Fen Leo Bey Hing Goh Dazylah Darji Fatimah Rubaizah Mohd Rasdi Kok Gan Chan Learn Han Lee Siah Ying Tang 《International journal of molecular sciences》2021,22(11)
Cellulose nanofibers (CNF) isolated from plant biomass have attracted considerable interests in polymer engineering. The limitations associated with CNF-based nanocomposites are often linked to the time-consuming preparation methods and lack of desired surface functionalities. Herein, we demonstrate the feasibility of preparing a multifunctional CNF-zinc oxide (CNF-ZnO) nanocomposite with dual antibacterial and reinforcing properties via a facile and efficient ultrasound route. We characterized and examined the antibacterial and mechanical reinforcement performances of our ultrasonically induced nanocomposite. Based on our electron microscopy analyses, the ZnO deposited onto the nanofibrous network had a flake-like morphology with particle sizes ranging between 21 to 34 nm. pH levels between 8–10 led to the formation of ultrafine ZnO particles with a uniform size distribution. The resultant CNF-ZnO composite showed improved thermal stability compared to pure CNF. The composite showed potent inhibitory activities against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative Salmonella typhi (S. typhi) bacteria. A CNF-ZnO-reinforced natural rubber (NR/CNF-ZnO) composite film, which was produced via latex mixing and casting methods, exhibited up to 42% improvement in tensile strength compared with the neat NR. The findings of this study suggest that ultrasonically-synthesized palm CNF-ZnO nanocomposites could find potential applications in the biomedical field and in the development of high strength rubber composites. 相似文献
84.
Teo M. Mhaisalkar S.G. Wong E.H. Poi-Siong Teo Wong C.C. Kristine Ong Chin Foo Goh Lay Kuan Teh 《Components and Packaging Technologies, IEEE Transactions on》2005,28(1):157-164
The anisotropic conductive adhesive (ACA) is a promising solder alternative candidate that shows potential for further pitch reduction. Although much work has been published on ACA joint behavior, study on correlation of material properties with reliability performance is still lacking. The main objective in this study was to identify the impact of material properties on reliability, so as to engineer highly reliable microelectronics assemblies. Four representative ACA materials (both film and paste types) with diverse properties were selected. Material properties were characterized as close as possible to "stress test" conditions so as to allow more accurate correlation predictions. Reliability performance was obtained by assembling test chips of 200-/spl mu/m pitch onto BT-substrates, then subjecting them to reliability tests. Correlation analysis was conducted and key material properties that contributed to good reliability performance were identified. Findings indicated that the best properties for high reliability assemblies were: high adhesion strength after subjecting to "stress aging", low coefficient of moisture expansion (CME) and low elastic modulus (E). 相似文献
85.
In this note, a simple computational procedure is given for solving a class of optimization problems, where an objective function is to be minimized subject to conventional inequality constraints as well as to inequality constraints of the functional type. 相似文献
86.
Reviews the book, Enemies of freedom: Understanding right-wing authoritarianism by Bob Altemeyer (see record 1988-98419-000). This book is the second of a projected three volume series by Altemeyer on the right-wing authoritarianism (RWA) construct. In this volume, Altemeyer (1988) reports the results of further research conducted since the first volume using his RWA scale. Specifically, three issues are dealt with: (1) how RWA develops in the individual, (2) why RWA is organized the way it is, and (3) how RWA can be controlled in a democratic society. Altemeyer's underlying assumption in this and the preceding volume is that a considerable potential for RWA exists in countries like Canada and the United States and that it is therefore a potentially serious problem requiring vigilance and perhaps ultimately preventive measures. Are his fears in this regard justified? It depends on how seriously one takes the respondents' self-reports. Altemeyer repeatedly shows that individuals (usually college students) who score high on the RWA scale are reportedly willing to punish others and to endorse actions that would curtail the civil rights of others, especially those with left-wing political leanings, who threaten the established order. However, in most instances, the measures are attitudinal ones dealing with respondents' reactions to hypothetical incidents and situations as to what they might do or would endorse having others do. Thus, Altemeyer's fears of the high RWA scorers and the seriousness of their threat to North American and other societies depend on knowing how willing they would be to act on their personal inclinations. Be that as it may, from a number of angles Altemeyer's current book on RWA deserves close and thoughtful reading by social, personality, and developmental psychologists. Those interested in political psychology, a relatively new area attracting social and personality psychologists and political scientists, will find it especially valuable and insightful. As noted earlier in the review, both of Altemeyer's RWA volumes should be required reading for would-be constructors of personality and attitude scales. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
87.
Minor constituents of palm oil 总被引:5,自引:5,他引:0
Crude palm oil contains about 1% of minor components including carotenoids, tocopherols, sterols, triterpene alcohols, phospholipids,
glycolipids and terpenic and paraffinic hydrocarbons. The nutritionally important components such as carotenes and tocopherols
also improve stability of the oil. Although a highly valued product, carotene unfortunately is bleached or destroyed in refining
because suitable recovery technology is not available. Thermal degradation of carotene, previously suspected of giving rise
to undesirable chemicals, now is known to furnish mainly harmless hydrocarbons, most of which are removed by the deodorization
step in refining. Tocopherols, being natural antioxidants, need to be carefully preserved during milling, refining, fractionation
and modification of palm oils. The accumulation of tocopherols in the palm fatty acid distillate promises to provide a new
source for the recovery of this valuable substance. The role played by phospholipids is frequently misunderstood because they
can act in two ways, i.e. as an antioxidant synergist and a surface active agent to disperse impurities in oil. In crude palm
oil the phospholipid content is small, because most of it is removed during milling; the phosphorus content is due mainly
to inorganic phosphorus. Among the sterols, cholesterol constitutes too small a percentage to be of much concern. Sterols,
triterpenoids and terpenoid hydrocarbons are also potentially useful side products should recovery technology become available.
Other newly characterized minor and trace components also are discussed. 相似文献
88.
Chun Hooi Bu Sai Hin Lai Xiang Ting Goh Wen Tong Chong Ren Jie Chin 《Water and Environment Journal》2021,35(1):181-189
Biofilters are promising technologies that widely applied in the treatment of urban stormwater. However, the microbial removal capacity performance depends greatly on the design of biofilters. Hence, this laboratory study attempts to investigate the influence of filter media depths (i.e. 150, 250, 350 and 450 mm) and the variation of native plants, that is, Cow Grass (Axonopus compressus) and Pearl Grass (Axonopus compressus, dwarf) in removing stormwater microorganism particularly Faecal Coliform (FC). Findings showed that a minimum media depth of 300 mm was required to achieve >1 log FC removal. The mean removal of FC at 450 mm depth filter exceeded 2 log for both Cow and Pearl grass biofilter columns. Results showed that there was no statistically significant difference in vegetation type on the performance of FC removal, however, Cow grass biofilter column revealed higher FC mean log removal compared to Pearl grass biofilter column. 相似文献
89.
Oni Yuliarti Lara Matia‐Merino Kelvin T. Goh John Mawson Charles Brennan 《International Journal of Food Science & Technology》2012,47(3):633-639
Pectin was extracted from gold kiwifruit by four commercial enzyme preparations (Celluclast 1.5 L, Cytolase CL, Cellulyve TR 400 and NS33048). The chosen enzymes were used either in single or in combination, with and without protease addition. The recovered pectin was characterised and compared for the yield, total nonstarch polysaccharide and neutral sugar composition, protein and ash, pectin, molecular weight distribution and the viscosity. Results indicated that enzyme‐extracted gold kiwifruit pectin was rich in galacturonic acid. Purified pectin yield, and their physicochemical composition and rheological property (viscosity), was significantly affected by the type of enzyme used. The pectin extracted by Celluclast 1.5 L demonstrated to be the most viscous and recorded the highest in molecular weight (Mw) (1.65 × 106 g mol–1) compared with the other extracts. The extract Mw and their distribution were discussed and related to their viscosity behaviour. 相似文献
90.
Abbass Allan; Arthey Stephen; Elliott Jason; Fedak Tim; Nowoweiski Dion; Markovski Jasmina; Nowoweiski Sarah 《Canadian Metallurgical Quarterly》2011,48(2):109
The advent of readily accessible, inexpensive Web-conferencing applications has opened the door for distance psychotherapy supervision, using video recordings of treated clients. Although relatively new, this method of supervision is advantageous given the ease of use and low cost of various Internet applications. This method allows periodic supervision from point to point around the world, with no travel costs and no long gaps between direct training contacts. Web-conferencing permits face-to-face training so that the learner and supervisor can read each other's emotional responses while reviewing case material. It allows group learning from direct supervision to complement local peer-to-peer learning methods. In this article, we describe the relevant literature on this type of learning method, the practical points in its utilization, its limitations, and its benefits. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献