埋地热油管道停输降温过程的研究

介绍了数值求解埋地热油管道停输过程中管内油品、管外保温层和管外土壤温度场3个数学模型确定管道停输降温过程的方法,指出埋地不保温热油管道停输后,管内油品与管外土壤同时降温,管外土壤存在降温影响区,而埋地保温热油管道停输后,管内油品温降速度则明显小于不保温管道.     

解决陕北库坝群泥沙淤积的根本途径

本文在对陕北黄土高原库坝群泥沙淤积治理模式研究的基础上，从该区地貌特征、水土流失成因出发，提出解决库坝群泥沙淤积的途径。     

浅析美国存款保险制度

文章以美国存款保险制度为分析对象,进而总结由这些特征衍生出的美国联邦存款保险公司在金融体系中的特殊地位和功能.根据其特征和功能浅析了存款保险制度对宏观经济的积极影响.     

不同配方快速镍刷镀液沉积速度对比试验研究

通过单因素试验，得到3种配方快速镍刷镀液电压与沉积速度、电极相对速度与沉积速度关系的回归方程和回归曲线，揭示了其中的规律，对机械零件的刷镀修复具有实践意义。     

砾石含量对崩积体坡面细沟横断面形态影响

为研究砾石含量对崩积体坡面细沟侵蚀的影响,采用室内放水冲刷试验,研究了30°坡面下不同冲刷流量(2,4,8,12L/min)对4种土石混合崩积物(0,10%,30%,50%砾石质量比例)冲刷过程中细沟横断面形态特征。结果表明:(1)随冲刷时间的增加,深度增加速度大于宽度增加速度,横断面向窄而深发展。(2)坡顶细沟横断面深度较大,接近“V”形,侵蚀严重;坡底细沟横断面深度较小,侵蚀较弱;细沟横断面形态指标η随坡长增加出现波动变化。(3)横断面深度随砾石含量增加总体呈先减小后增大趋势,10%砾石含量坡面细沟深度最小;10%砾石含量坡面细沟横断面形态指标η变化范围最大;临空面在10~15cm深度开始发育,低砾石含量土壤更有利于临空面发育。     

Impact of spray application methodology on the development of resistance to cypermethrin and spinosad by fall armyworm Spodoptera frugiperda (JE Smith)

The development of resistance to an insecticide under various types of application method has yet to be reported in the literature. Five fall armyworm Spodoptera armigera (JE Smith) colonies were reared in a chamber for ten generations before starting topical application bioassays. From each colony, 200-500 third-fourth-instar larvae were fed for 72 h on corn plants sprayed with cypermethrin or spinosad at minimum application rate (20 g ha(-1)) using a small droplet size nozzle XR8001VS (volume median diameter D(v0.5) = 163 microm) or a large droplet size nozzle XR8008VS (D(v0.5) = 519 microm). Surviving larvae were transferred to untreated corn leaves to complete their life cycle. Next-generation third-instar larvae of each colony were topically dosed with technical cypermethrin or spinosad at 1 microL per larva, and mortality was recorded 24 h post-treatment. The results indicated that cypermethrin demonstrated an insecticidal activity greater than that of spinosad, and the cypermethrin regression lines moved to the right faster than those for spinosad, indicating an increased tolerance of cypermethrin. Generally, larvae from all generations (F1-F7) under the XR8008VS treatments were less susceptible to cypermethrin and developed resistance faster and to higher levels than larvae from the XR8001VS treatments. The confidence limits (95%) of LD(50) for all spinosad treatments indicated that there was no significant difference from the LD(50) value of the susceptible reference strain. The results are a first indication that application technology/insecticide reaction may affect the rapidity of resistance development in certain pest/plant scenarios, but field studies are needed to confirm this conclusion.     

预防性储蓄对吉林省农村居民消费结构影响分析

通过调查研究吉林省农村居民恩格尔系数低于东部发达地区,但其生活水平却较低,消费结构不合理,为探究原因本文采用PanelData模型,以教育、医疗、住房、食品价格变化代表居民的预防性储蓄动机所产生的挤占效应和收入效应综合作用的结果构建消费结构模型,并对模型的参数估计值进行分析,找出影响吉林省农村居民消费结构的原因,为政府部门制定政策提供一定的参考借鉴,为农民合理消费提供一定的导向作用。     

Study on the pathogenesis of foreign body granulomatous inflammation in the livers of sprague-dawley rats

Focal granulomatous inflammation developed in the livers of five 10-week-old male Sprague-Dawley rats. The characteristic features of this lesion were the presence of foreign body multinucleated giant cells engulfing calcium deposits and site-specific development in a fissure formed in a sub-lobation in the left lobe or interlobar fissure of the medial lobe of the liver. To clarify the pathogenesis of this lesion, rat livers showing abnormal sub-lobation or lobar atrophy, rat livers in an acute dermal toxicity study and guinea pig livers in a skin sensitization test were also examined histologically. Consequently, the present lesion was considered to be a reactive change against calcium that was dystrophically deposited in the area of hepatocellular necrosis due to delayed circulatory disturbance caused by external pressure or extension force. Granulomatous lesions like in the present cases should be differentiated from those caused by evident exogenous pathogens such as chemicals or microorganisms.     

神府煤田风沙区采煤塌陷对风蚀的影响

[目的]探究神府煤田风沙区采煤塌陷对风沙活动的影响,为矿区防治风蚀危害和植被恢复提供科学依据。[方法]以塌陷区扰动地表为研究对象,通过野外定位观测,研究塌陷1~2a沙丘典型位置及不同的地表破损率对风蚀/风积量影响。[结果]塌陷1a、塌陷2a和对照(非塌陷)沙丘不同典型位置的风蚀/风积深度分别达到-28.2,-45.6和-2.8cm,其整体的风蚀概率达60%以上,90%以上和10%以下。地表破损率越大,其地表风积过程越显著,且随着地表破损率的减小,风沙运动状态逐渐由风积填缝过程转化为风蚀过程,其风蚀/风积深度(Q)与地表破损率(V)呈多项式函数关系。[结论]采煤塌陷有效地促进了风沙运动,改变了局部的风蚀/风积深度,可能引起固定半固定沙丘重新活化。     

5号柴油低温顺序输送的特殊混油变化

结合低温顺序输送5号柴油的生产实际和低温结蜡溶蜡试验情况,就低温顺序输送5号柴油时的特殊混油变化进行了分析讨论,通过对混油浓度变化、管壁结蜡、溶蜡过程及混油尾拖长的原因分析,指出低温结蜡是造成大量混油的根本原因,在进行高凝点柴油低温顺序输送时,油品的结蜡温度是避免因结蜡而造成混油的关键控制指标。