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451.
叶田  夏福华  臧传花  朱敏  田秀芬 《气象》2001,27(10):46-48
根据当地地理和气候特点建立的人工影响天气作业指挥系统,体现了智能化、积累型的特点,使人工影响天气作业指挥向客观化、自动化迈进了一步,提高了人工影响天气的作业效果。  相似文献   
452.
含钛蒙脱石多孔材料的研究进展   总被引:11,自引:0,他引:11  
含钛蒙脱石多孔材料是近几年来很受国内外矿物学者关注的矿物材料之一,具有很好的吸附性能和光催化性能,在石油催化裂解和污水处理等领域作为吸附剂、催化剂和催化载体材料等有很好的应用前景。本文对近年来国内外此材料的先进制备工艺,表征手段进行归纳总结,并介绍该材料在石油化工和环保领域中的应用。  相似文献   
453.
改性粘土矿物在橡胶中的应用   总被引:7,自引:0,他引:7  
赵丽颖  蒋引珊  王秀平 《世界地质》2001,20(1):95-99,104
改性矿物取代部分炭黑做橡胶填料的研究是目前国内外材料及化工领域为活跃的科研课题,粘土矿物结构独特,有较高的化学反应活性,具有吸附某些离子并把这些离子保护于交换状态的性能,这些性能特点使粘土矿物经表面改性填充于橡胶成为可能,粘土矿物填料的研究主要包括粘土矿物的结构特点,在橡胶中的作用,典型的粘土矿物寺料的性能特点,尤其是针对不同的橡胶体系和性能要求,选取适当的改性剂及改性处理方法及增大填料的填充量等问题,这方面研究的进展对我国矿产资源的开发利用及橡胶工业的发展有着重要意义。  相似文献   
454.
改性蒙脱石吸附Pb^2+、Hg^2+的实验研究   总被引:8,自引:0,他引:8  
对蒙脱石进行化学改性后生成的硫代蒙脱石热稳定性好,并且对金属离子Pb^2 、Hg^2 有很好的吸附性能,是一种处理污水中有害金属离子有效的矿物材料。  相似文献   
455.
The construction of additional facilities at the Florida Power Corporation's Crystal River Energy Complex required an extensive stabilization program to construct foundations for approximately one half mile of cooling towers. This paper presents an overview of the techniques and methods used in the construction of additional facilities at the Crystal River Generating Station. Excavations for intake and discharge structures were to be more than 20 ft below the water table. Cooling tower foundations were constructed on extensively solutioned Florida limerock located on the central Gulf Coast of Florida. Hybrid ground modification techniques were used to stabilize soft or loose soils and solution features in the underlying limerock, allowing mat and spread footing foundations to be used for most of the facility. The ground modification techniques were used to detect, collapse, densify, and fill solution features below the structure foundations. The bearing capacity after ground modification was verified by field load tests. Subsurface investigations indicated that sheet pile excavations with grouted seals were the optimal technique for cofferdam excavations in the limerock formation. Existing collapsed caverns were encountered during construction of the cofferdam for the intake structure and the adjacent discharge structure, requiring a fast-track design change, considerable field coordination, and daily modifications to accommodate the varied conditions encountered. Tied-back soldier pile cofferdam construction was combined with grouting, underwater excavation, and a massive, unreinforced, concrete tremie slab with grouted anchors, and installed off a barge to provide a dewatered excavation. This project involved the use of hybrid soil-rock anchors to anchor one of the largest continuous placement tremie seals installed in Florida. Other excavations used sheeting and grouting of the underlying limerock formation to provide a dewatered excavation. Ground modification techniques were used to treat a filled cavern discovered in the corner of one discharge structure. The entire construction of this facility was confined to a narrow work area by existing wetlands and the generating station discharge canal. Strict environmental restrictions required by the regulatory agencies to prevent impacts to the surrounding area were imposed on this project.  相似文献   
456.
四阶矩准正态分布和三阶矩剪切近似的验证   总被引:1,自引:0,他引:1  
张强  胡隐樵 《大气科学》1994,18(4):396-404
本文利用近地面层大气湍流量的观测资料对四阶矩的准正态分布假定和三阶矩的剪切近似进行了实验验证。结果表明,四阶矩能够较好地符合准正态分布假定;三阶矩不仅完全满足剪切近似,甚至还可以对剪切程度进一步加强,并且得到了一系列剪切近似的加强修正系数。  相似文献   
457.
A novel sensor for ocean electric field testing has been fabricated by polyacrylonitrile-based on carbon fibers with electro-chemical oxidation.The surface profile characteristics of the carbon fibers were characterized by scanning electron microscope,Fourier transform infrared spectra and contact angle.Cyclic voltammetry and Tafel curves have been used to study its electro-chemical performances.Two identical electrodes in sea water as the electric field sensor will swiftly respond to applied electric field which causes positive and negative ions to move in opposite direction,resulting in a electric potential difference(ΔE).Test result indicates that the offset potential is typically below 1 m V with a drift of 60-170μVd^-1.Typical self noise level is 1.07 nV√Hz1/2@1 Hz.The electric field response indicates that the modified electrode pair shows better response to AC sine signal of amplitude and frequency(5 mV and 1 mHz)respectively than its blank.The electric field response model of the modified electrodes is creatively presented according to its electric double layer capacitance and Faraday pseudo-capacitance.Many advantages of the carbon fiber electric field electrode will make it have potential application prospect.  相似文献   
458.
胡奇  解德 《海洋工程》2014,32(6):24-30
FPSO在海洋环境中频繁地进行装载与卸载操作,使FPSO船体结构产生较大的应力幅值,尤其是承受货油压力的内底纵骨。由于局部的应力集中,应力幅值超过材料的屈服强度,其装卸载次数小于104时,结构将产生低周疲劳。研究一种新的计算方法,根据Neuber假设进行塑性修正,通过应变范围得到伪热点应力范围,并确定热点应力与伪热点应力之间的关系。推导出一种新的S-N曲线作为低周疲劳的设计曲线,以伪热点应力作为计算量来预测低周疲劳寿命,降低了船体结构低周疲劳寿命计算的难度。  相似文献   
459.
本文基于日本KiK-Net,K-Net台网及汶川地震中6 000余条浅壳与上地幔地震竖向加速度记录,分场地类型建立了包含阻尼比和谱周期两个参数的阻尼修正系数模型,用以调整无震级和震源距信息的设计谱。基于固定效应模型对阻尼修正系数对数值及阻尼比对数值的三次多项式进行线性回归得到模型表达式,基于随机效应模型对阻尼修正系数模型的残差及残差的标准差进行分离,分析震源、路径以及场地效应对模型误差的影响。研究结果表明:高阻尼长周期震源效应引起的残差大于其他效应引起的残差;场地效应引起的残差小于其他效应引起的残差。对模型残差的标准差及阻尼比对数值进行线性回归,回归方程易于计算模型残差的标准差。  相似文献   
460.
With proposals that micro-miniaturised Raman spectrometers could soon be part of a suite of analytical instrumentation on the surface of Mars, it is critically important to examine the spectral information that could be forthcoming from attempts to determine key molecular biosignatures under the hostile conditions of extra-terrestrial planetary exploration. Current approaches include the analysis of genuine martian geological material in the form of the SNC class meteorites, the formulation of simulated martian regoliths and the examination of putative martian terrestrial analogues; the latter provide the basis of this paper in the form of Antarctic extremophile habitats. In particular, specimens of epilithic, chasmolithic and endolithic lichen and cyanobacterial colonies sampled along a progressively worsening transect towards a “limits of life” situation, beyond which survival of organisms becomes impossible, provide what is arguably the best terrestrial proving-ground for prototype Raman spectrometers for martian exploration. Here, we report the results of experiments on these extant Antarctic extremophile colonies using a range of Raman excitation wavelengths and experimental conditions and also include a compilation of molecular spectral biosignatures, which may be considered as a suitable database for recognition of bioorganic modification of geological strata.  相似文献   
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