论汽车电路搭铁不良的故障及检修技巧

现代汽车采用蓄电池负极与车身的金属部分相连接的导线称为搭铁线,搭铁线在汽车电路中起着重要的作用.介绍了汽车电路搭铁线的作用、常见故障的特征、故障分析与检测技巧.     

Migration of kawakawa Euthynnus affinis in the waters near Taiwan

ABSTRACT:   Kawakawa Euthynnus affinis is the most abundant species among the small tuna in the coastal waters of Taiwan. The migration pattern of kawakawa to Taiwan was determined in the present study based on the species' feeding habits and reproductive biology and on temporal variation of catch for kawakawa and its prey fishes. Schools of this species successively migrate to Taiwan from September to May, and then move away in June. They travel to the waters off Taiwan with the warm Kuroshio current, migrate toward coastal waters for feeding and move away for spawning. It is suggested in the present study that the kawakawa spawning ground is in the waters of the northern Philippines. The migration of kawakawa exhibits size-segregating behavior. Schools of immature young fish first arrive in the coastal waters around Taiwan, followed by the adults.     

浅谈坡面覆盖材料

介绍了国内外坡面覆盖材料的发展情况,对常见材料进行分类和介绍,定义了一些专业名词,并展望我国边坡覆盖材料的发展前景。     

Identification of Acceleration Pulses of Near-Fault Earthquake Ground Motion by Wavelet

Acceleration pulses have been found in near-fault earthquake ground motions long ago and attracted lots of researchers, since such pulses, especially low frequency pulses have great impact on engineering structures. Many people previously focused on velocity pulses which result from acceleration pulses, however, recently a few researchers began to directly study acceleration pulses, such as to get high frequency pulses and low frequency pulses with empirical mode decomposition. Wavelet transform was utilized to decompose acceleration records. Subsequently high frequency and low frequency components of the records were obtained and acceleration pulses were identified. By comparisons in response spectra and structural nonlinear responses, it is proved that the decomposition of acceleration records with wavelet is reliable and the identification of acceleration pulses is correct.     

Management of Grazing Intensity in the Semi‐Arid Rangelands of Southern Australia: Effects on Soil and Biodiversity

Overgrazing contributes to rangeland degradation altering plant community composition, erosion and biodiversity. Little unanimity in the literature exists on the effects of livestock grazing on soil carbon and biodiversity, in part, due to uncontrolled grazing pressure from native and feral animals. Paired paddock contrasts at three, long‐term (>8 years) study locations in the southern Australian rangelands were used to examine the effects of managing grazing intensity through the use of exclusion fencing and rotational grazing on soil organic carbon (SOC), soil nitrogen (TN), ground cover and biodiversity (flora and invertebrates). Grazing management had no effect on SOC or TN on grey soils (Vertisols), but for red soils (Lixisols), significantly higher levels of SOC were found for both the 0 to 5 and 5 to 10‐cm soil depths (0·3% and 0·27% respectively) and associated with increased TN. We found strong and consistent relationships among SOC and higher perennial (p < 0·001), higher litter (p < 0·05) cover and close proximity to trees (p < 0·05). Managing grazing intensity resulted in significantly higher perennial ground cover (p < 0·001) on Vertisols (8·9 to 11%) and Lixisols (12·5 to 15%) and higher plant diversity (both native and exotic) but negatively impacted invertebrate diversity, indicating trade‐offs between production and resources. We provide evidence that the effects of grazing management on SOC are mediated by ground cover and increased organic matter supply and/or reduced soil carbon redistribution (erosion), which indicates that the management of grazing intensity may provide a tool to avoid soil carbon loss in rangelands. Copyright © 2016 John Wiley & Sons, Ltd.     

SiF基态分子（X^2Ⅱr）的解析势能函数

利用群论及原子分子反应静力学的有关原理，推导了SiF分子基态的电子态和合理的离解极限，并利用Gaussian 03程序包，采用QCISD（T）和B3P86方法结合D95（3df，3pd），CC-PVTZ，6-311g＊＊和6-311＋＋g（3df，3pd）基组，对SiF分子的基态X^2Ⅱr平衡结构和谐振频率进行了优化计算。通过比较计算结果，发现B3P86方法为最优方法、D95（3df，3pd）为最佳基组。使用该方法和基组对SiF分子的基态进行了单点势能扫描计算，并采用正规方程组拟合Murrell-Sorbie函数，得到了SiF分子基态完整的解析势能函数，计算出了SiF分子的光谱常数ωe、ωeXe、Be和αe的值。     

辽宁省地下水盈亏现状

辽宁省水资源贫乏(年人均885米~3)。由于人口的迅速增长和工农业的迅速发展,国民经济各部门对水的需求量越来越大,对地下水的需求量一直在不断增长,以致引起局部地区地下水超采,并在沈阳、辽阳、鞍山和大连等地出现地下水位下降、永久性地下水漏斗形成、含水层部分疏干以及海水内侵等一系列生态环境问题。     

Evaluation of coastal sandy soils and their saline ground waters for afforestation: A case study from India

A study was conducted in coastal Andhra Pradesh to evaluate current practices and suitability of coastal sandy soils for raising tree plantations. Poor soil moisture retention characteristics of these soils make irrigation an essential, but costly silvicultural practice for obtaining desirable establishment and growth. Saline ground water is the only available source of irrigation. Its use seems safe and successful in such soils. The farmers have adopted a specialized manual splashing technique (Doruvu) of seepage pits for irrigating tree plantations in their establishment phase. This technique was observed to be well suited to the sandy soils. Casuarina equisetifolia and Eucalyptus tereticornis were the two most popular species being afforested. E. camaldulensis is also in an introduction phase. Comparison of growth performance and biomass accumulation by C. equisetifolia and E. tereticornis plantations at different growth stages showed the former to be significantly better than the latter. Build up of the soil organic carbon was also found to be markedly more in comparable C. equisetifolia plantations than those of E. tereticornis. Similarly, the blanketing influence of C. equisetifolia plantations was observed to modify soil temperature extremes considerably more than in the case of E. tereticornis. The findings, indicated a vast scope for utilization of coastal sandy soils for afforestation with the successful use of saline ground waters.     

Diversity and abundance of carabid beetles in short-rotation plantings of sweetgum, maize and switchgrass in Alabama

This study compares assemblages of carabid beetles, potentially important regulators of herbivorous insect pests, in short-rotation plantings of sweetgum (Liquidambar styraciflua L.) with and without grass cover crops, maize (Zea mays L.) and switchgrass (Panicum virgatum L.). A total of 38 species were trapped during the summers of 1996 and 1997. The dominant carabid encountered was Harpalus pensylvanicus Latreille, a widespread omnivorous species; H. pensylvanicus was particularly prevalent in maize plots. Several other commonly encountered species were primarily associated with one plot type. Overall carabid activity was found to be similar in maize and switchgrass plots and much greater than that in sweetgum plots of both cover types. This may be related to the presence of more consistently available dense ground cover in these plots compared to sweetgum plots, a situation favored by most carabids, although both abundance and diversity were similar in sweetgum plots with and without cover. Diversity, as indicated by species richness and dominance levels, was greater in switchgrass than in maize or sweetgum plots, which were similar. This revised version was published online in June 2006 with corrections to the Cover Date.