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461.
构造动力成矿对独山半坡锑矿床的形成产生巨大的作用。通过深入研究,笔者找到了独山半坡锑矿床构造动力成矿的依据,进一步计算出了成矿的差应力大小和相对成矿能量值。分析了构造动力对矿物的微观影响,提出了构造动力成矿模式。这些将对该矿床的成因研究产生积极的推动作用。 相似文献
462.
463.
Ranked set sampling: an annotated bibliography 总被引:1,自引:1,他引:1
The paper provides an up-to-date annotated bibliography of the literature on ranked set sampling. The bibliography includes all pertinent papers known to the authors, and is intended to cover applications as well as theoretical developments. The annotations are arranged in chronological order and are intended to be sufficiently complete and detailed that a reading from beginning to end would provide a statistically mature reader with a state-of-the-art survey of ranked set sampling, including historical development, current status, and future research directions and applications. A final section of the paper gives a listing of all annotated papers, arranged in alphabetical order by author.This paper was prepared with partial support from the United States Environmental Protection Agency under a Cooperative Agreement Number CR-821531. The contents have not been subject to Agency review and therefore do not necessarily reflect the views or policies of the Agency and no official endorsement should be inferred. 相似文献
464.
陈哲勇 《湖南环境生物职业技术学院学报》2006,12(1):69-72
目前,我国流动人口犯罪率居高不下,严重危及着社会的安定,已成为社会各界关注的热点和解决的难点问题.流动人口犯罪的主要表现特征为主体的复杂性,犯罪的团伙性、流窜性、侵财性等.相对剥夺论是流动人口犯罪一种可行的理论阐释,有助于深化我们对流动人口犯罪的理解.加强和完善政府职能是控制流动人口犯罪行之有效的应对措施. 相似文献
465.
466.
目的 对动车组关键板卡进行失效分析,并提出预防改进措施.方法 通过对动车组运用过程中的环境分析,确定影响板卡性能的主要因素为温度与湿度应力.为缩短试验周期,设计恒温恒湿加速应力试验,快速暴露板卡及其元器件的薄弱环节.试验中受应力影响,板卡与元器件发生了不同程度的失效.通过对失效部件的物理化学性能进行分析,对板卡的使用环境与分析方法提出建议.结果 动车组板卡在高温高湿环境下的失效模式为电性能故障,由于密封不良,电感表面有纤毛和白色附着物,工作时温度过热导致漆包膜破损,从而使电感失效,焊点、PCB基材与三防漆未检测到失效老化.结论 电感、MOS管、电解电容等元器件受温湿度应力影响较大,且板卡的密封与使用环境也影响着板卡的使用寿命,日常使用应注重散热与密封.通过该项目研究为板卡失效预防提供了可行方法. 相似文献
467.
The measurement of roadway PM10 emission rates using atmospheric tracer ratio techniques 总被引:2,自引:0,他引:2
Ravi Kantamaneni Glen Adams Lee Bamesberger Eugene Allwine Hal Westberg Brian Lamb Candis Claiborn 《Atmospheric environment (Oxford, England : 1994)》1996,30(24):4209-4223
In this work, stationary and mobile point source tracer release techniques have been used to determine PM10 emission rates from four-lane commercial/residential paved roads under sanded and unsanded conditions, and from unpaved roads relative to site-specific vehicular and ambient parameters. Measured street (4 + lanes; ? 10,000 vehicles per day) emission factors for unsanded and sanded roads were 40 and 20% lower, respectively, than the EPA approved reference value. The sanded road emission factor was approximately 40% higher than that for the unsanded road. These results indicate a consistent relationship between PM10 and relative humidity under unsanded conditions. There is some evidence to suggest that street sweeping has a measurable effect on PM,, emission reduction during periods of low relative humidity (i.e. ? 30%). Within the constraints imposed by the variable experimental conditions, the emission factors determined for unpaved roads agreed reasonably well with the unpaved road empirical formula. Limited correlations were observed with ambient meteorological parameters. The capability of the “upwind-dowiawind” concentration modeling method to predict accurate emission was tested using a Gaussian dispersion model (SIMFLUX). Predictions agreed well with the experimentally determined emission factors. 相似文献
468.
Kazuhiko Sakamoto Hisae Takada Kazuhiko Sekiguchi 《Atmospheric environment (Oxford, England : 1994)》2004,38(40):6961
To evaluate the influences of O3, relative humidity (RH), and flow rate on the reaction between yellow sand and SO2, the SO2 deposition velocity and the oxidation state of sulfur were investigated by means of exposure experiments in a cylindrical flow reactor. Early in the reaction, the deposition velocity was not influenced by the RH or the presence of O3; as the reaction progressed, however, the deposition velocity increased in the presence of O3 and at high humidity. The oxidation of sulfur from S(IV) to S(VI) was also enhanced under these conditions. The amount of sulfur oxidation was positively correlated with the amount of deposited O3. Furthermore, the SO2 deposition velocity increased with increasing flow rate. However, changes in the flow rate had no noticeable effect on the amount of SO2 oxidation. 相似文献
469.
470.
江苏省相对资源承载力与可持续发展问题研究 总被引:26,自引:1,他引:25
以往资源承载力的研究成果存在众多的缺陷,本文以江苏省为例,采用相对资源承载力的研究思路和计算方法,计算分析了其1978—1995年相对土地资源承载力、相对经济资源承载力和综合承载力及其演化过程。研究表明:①江苏省的经济资源对综合承载力的贡献大于土地资源,是江苏省人口的主要承载资源;②从1982年开始,江苏省的综合承载力超过实际人口数量,进入相对富余状态;③相对资源承载力的地区差异较明显,南部地区处于富余状态,而北部地区处于超载状态;④相对土地资源承载力与相对经济资源承载力的不协调发展是江苏省可持续发展战略中需要重点解决的问题。 相似文献