铲刀连接座凹球面的感应淬火装置及操作方法的研究与应用

通过在铲刀连接座凹球面的感应淬火装置中采取屏蔽环措施,有效地避免了凹球面在感应淬火时出现的尖角效应问题;通过在装置中设置可调水平方向间距的回转组件,有效地解决了凹球面在绕其有效感应弧面回转时出现的球面水平感应间距难以控制的问题;通过在装置中设置可调竖直方向间距的旋转驱动组件,不仅解决了凹球面感应淬火时所需的低速回转问题,而且解决了凹球面与淬火感应器有效感应弧面之间存在的竖直感应间距难以控制的问题,继而进一步确保了淬火质量的控制。该淬火装置结构新颖,操作方法简单,省时省力高效,并易于实施,具有很好的使用价值。     

Predicting species occurrence using information-theoretic approaches and significance testing: An example of dormouse distribution in Cumbria, UK

Predicting the occurrence of species is an essential part of conservation biology. The range of techniques used to do this has increased in recent years. This has included wider use of information-theoretic approaches; particularly Akaike’s information criteria (AIC). AIC is often used with regression modelling when predicting species distribution. The traditional method of model selection in regression modelling, stepwise significance testing, is also still widely used. This paper compares the two approaches, using the occurrence of the dormouse (Muscardinus avellanarius) in Cumbria, UK as an example. The dormouse is a protected species whose abundance and range have declined nationally. Knowledge of its occurrence in Cumbria is required in order to increase measures for its conservation in the area. The paper uses the habitat features woodland size, altitude, soil type, tree species present, temperature and rainfall as potential predictors. As only presence data was available for dormice in Cumbria, pseudo-absences were generated to allow logistic regression modelling. The use of pseudo-absences was justified using a false record permutation test. Cross-validation allowed the ability of models to predict the data to be assessed. This was judged using ROC plots. The size of the wood, temperature and whether the soil was wet or dry were the best predictors of dormouse incidence in Cumbria. The two approaches produced different models; those from the information-theoretic approach had a better ability to fit the data. The information-theoretic approach also had the advantage of enabling model averaging and provided greater understanding of the system.     

亳州中药材市场冷背药材经营现状调查

通过对亳州中药材市场销售的冷背药材种类和经营现状进行实地调查,初步弄清了亳州中药材市场冷背药材的种类、经营现状和目前存在的问题,分析了冷背药材经营中产生这些问题的原因,同时提出了解决问题的相应对策,以便为冷背药材销售市场的健康有序发展提供参考。     

EGR对柴油机工作过程影响的一维模拟

根据柴油机的基本结构,利用BOOST软件建立带有EGR系统增压直喷柴油机一维工作模型.将柴油机台架试验获得的最佳EGR率MAP图作为一维模型中EGR控制单元的控制MAP图,建立了模拟形式下EGR系统控制单元,实现了柴油机在使用EGR后.不同工况EGR率在柴油机转速和负荷连续变化形式下,EGR对柴油机工作全过程影响的一维模拟.以柴油机转速1 900 r/min、10%负荷工况点为例,模拟计算结果表明,柴油机在使用EGR后空燃比、缸压、缸内温度和排气温度都有所下降,缸内气体质量有所增加,与柴油机台架试验获得的结论吻合.     

148例犬难产病例分析与助产方法比较

对临诊所见不同品种犬的148例难产进行了分类,对难产与年龄和胎次的关系及三种助产方法做了比较。结果表明胎儿性难产占46郾62%,产道性难产占27郾70%,产力性难产占25郾68%;1～2岁的怀孕犬难产占53郾38%,第一胎难产占59郾46%;产道性难产和胎儿性难产助产的最佳方法是剖腹产术。     

犬的难产诊断与治疗

当犬发生难产时,助产无效后就必须尽早实施剖腹产手术。手术的越早,胎儿成活率就越高,母体恢复也越快。     

母牛难产的风险病因--基于系列案例研究

[目的]难产是繁殖母牛的常见疾病,危害母牛和犊牛健康,进行难产牛原因分析有助于兽医或者牛场做好接产工作,提高生产力。 [方法]在万方数据服务平台、CNKI中国知网、Elsevier SD数据库和“SCI-科学引文索引”上,用关键词“难产”、“病例”、“牛”精确搜索我国相关的案例,统计筛除后的病例数,对牛难产原因进行统计和分析。 [结果]检索获得母牛难产的病例总数为753例,难产原因占比最大的是胎儿性难产有525例,占69.72%(95%CI 66.3-73.0);其次是产道异常（骨折造成骨盆畸形,子宫颈、阴道、阴门狭窄造成的产道异常）造成的难产89例,占11.82%(95%CI 9.6-14.3);阵缩及努责无力造成的难产41例,占5.44%(95%CI 3.9-7.3);子宫扭转造成的难产38例,占5.05%(95%CI 3.6-6.9);子宫颈开张不全造成的难产26例,占3.46%(95%CI 2.3-5.0);营养不良造成的难产18例,占2.39%(95%CI 1.4-3.8);双胎难产9例,占1.20%(95%CI 0.5-2.3);人为因素和其他因素造成的难产有7例,占0.93%（95%CI 0.4-1.9）。 [结论]引起母牛难产的最主要的因素是胎儿性难产、产道异常。兽医在实际临床中,应快速、准确确定母牛难产的病因,采取对应接产措施,减少经济损失。     

Optimization of a multiple reservoir system using a simulated annealing--A case study in the Mae Klong system, Thailand

A heuristic-based simulated annealing has been developed to optimize the operation of a multiple reservoir system. Simulated annealing is a probabilistic search algorithm, motivated by an analogy of physical annealing in solids. It has been increasingly applied to a broad spectrum of fields for which little prior knowledge is required. The developed model is illustrated by a test application to a benchmark problem of a 10-reservoir problem that had been solved previously in the literature. For this problem, simulated annealing shows its ability to provide better result than those obtained from other techniques. The model is then applied to the real multiple reservoir system in Thailand to derive optimal operating policies. The objective function is formulated to minimize the irrigation deficits during 3 years. The performance of the simulated annealing is compared with that of the genetic algorithm developed for the same problem. The results show that the simulated annealing is more efficient than the genetic algorithm. Simulated annealing produces higher quality solutions while spending lesser computation time compared with the genetic algorithm. The results obtained from these applications have proved that the simulated annealing is capable of addressing a large and complex problem. Simulated annealing is quite a new promising search algorithm for reservoir optimization problems. It is worthy of further investigation for other applications in this area of research.     

渤海对虾流网作业网列和网高最佳尺度研究

依据对虾流网捕捞原理，设计了与捕捞作业同步的试验和调查方法，就取得的资料归纳出与各级流网船相匹配的最佳网列长度和网片高度分别为：５９ｋＷ以上渔船网列长６０００ｍ，高９ｍ；２９ｋＷ渔船网列长４０００ｍ，高８ｍ；１５ｋＷ渔船网列长３０００ｍ，高７ｍ；９ｋＷ渔船网列长２０００ｍ，高７ｍ。这项研究成果为制定渤海对虾流网渔业管理细则提供了科学依据。