三疣梭子蟹全人工工厂化育苗技术

2000年笔者在日照市水产研究所利用1450m^3水进行梭子蟹全人工工厂化育苗生产，共出Ⅱ-Ⅲ期幼蟹512．7万只，创造了出苗量为3500只／m^3，总产值为150多万元的直接经济效益，同时对幼体培育的密度进行了初步试验，结果表明：从Z1至M期幼体培育密度10－15万／m^3为宜，M期以后密度以0．8－1．5万／m^3为宜。     

Uniaxial compression and tension tests of anthracite and loading rate dependence of peak strength

The mechanical characteristics of coal under uniaxial compressive stress and uniaxial tensile stress are key factors in investigations of the stability of galleries and coal faces, and are vital considerations for the efficient design of coalmines, disaster prevention, and environmental preservation. These mechanical characteristics have long been a topic of research, but remain insufficiently understood. In this study we performed uniaxial compression tests and uniaxial tension tests on coal, with particular attention to two concerns. The first was to measure the loading rate dependence of the peak strength of coal. Coal shows high sample-to-sample scatter in strength; test methods that are successful in comparatively homogeneous rock types cannot be used for coal. We therefore used an alternative test method that was recently developed by the authors. Anthracite samples were subjected to alternating slow and fast strain rates. Measured variations in stress during this process were used to estimate the loading rate dependence of peak strength. The second objective was to obtain complete stress–strain curves for coal under uniaxial tensile stress. It is difficult to hold samples secure during a tensile test; consequently, such curves have yet to be obtained. This study presents a successful application of the authors' method to the analysis of coal samples, yielding a complete stress–strain curve under tensile stress. The two methods presented here hold promise for application not only to anthracite but also to a wide variety of coals. It is possible to derive the values of the constants used in constitutive equations from the obtained experimental results. Once these equations are determined, they can be incorporated into finite-element software to investigate various time-dependent behaviors of coal and aid in the efficient design of coalmines and the prevention of subsidence and mine disasters.     

Fluid permeability of sedimentary rocks in a complete stress–strain process

The permeability of sedimentary rocks during triaxial compression tests was investigated to relate it to the complete strain–stress process. It was found that the permeability was not constant, but varied with the stress and strain states in the rocks. Prior to the peak strength, the permeability decreases with increasing load. A dramatic increase in permeability occurs during the strain softening period. In the present study, in situ measurements of fluid flow and pressure in floor strata was carried out in a double longwall mining face in the Yangzhuang colliery. These measurements show that both the strata pressure and the position with respect to the mining face influence the hydrogeologic properties. The permeability increased in the floor strata behind the mining face because those mining induced fractures opened as the strata pressure decreased. To better understand this change in hydraulic behavior around the mining faces, 3-D numerical modeling was carried out. The model provides the general picture of the stress distribution and failure zone both in the floor and roof strata. The field and model results demonstrate the importance of changes in the stress and strain states on the hydrogeology of a site.     

Spatial variation of seismic motion induced by propagation of body waves

Spatial variation of earthquake ground motion is an important phenomenon that cannot be ignored in the design and safety of strategic structures. Several models have been developed to describe this variation using statistical, mathematical or physical approaches. The latter approach is not specific to an event. A recent contribution, which uses such an approach and called complete stochastic deamplification approach (CSDA), was developed [1]. The aim of this paper is to analyze the spatial variation of earthquake motion induced by the propagation of body waves using the CSDA. Coherency functions are evaluated for the cases of SH–SV–P waves propagating through stratified soil. Results obtained show that the variation of the coherency function is not the same for vertical and horizontal components and that the motion is more coherent at depth than at the free surface. In fact, we found that the rate of decrease with frequency and distance is not the same if P–SV waves propagate through stratified soil.     

屏障隔振系统失效机理的探讨

屏障隔振是一种用来阻碍或改变外围振波向受保护区(屏蔽区)传播的工程方法，由于其机理的探讨尚不深入，工程实践中常出现隔振系统失效的现象．本假设屏障是埋入土介质的中厚弹性板，采用薄层法分析了该弹性板在振波作用下的振动响应和屏蔽区内位移变化规律；研究了影响屏障隔振效果的主要参量；发现了使屏障隔振效率降低甚至失效的入射波全透射现象．结果表明柔性屏障易发生波的全透射，并指出了避免屏障失效的措施．     

Seismic attenuation estimation using a complete ensemble empirical mode decomposition-based method

The frequency attenuation gradient method can provide important information for hydrocarbon detection. In this paper, a method using Complete Ensemble Empirical Mode Decomposition (CEEMD), Hilbert transform and the least-squares curve-fitting is proposed for seismic attenuation estimation as an effective frequency attenuation gradient estimation approach. We first use CEEMD to obtain the different Intrinsic Mode Functions (IMFs), which have a narrow band and can enhance the physical meaning of instantaneous attributes trace by trace. The time-frequency spectrum, which is computed using a Hilbert transform of each IMF, is represented as a spectrum with a single-peak that has narrow side lobes, which is conducive to frequency attenuation gradient estimation. Second, for each time sample, the frequency-amplitude spectrum of each IMF trace is extracted from the time-frequency spectrum to conduct the attenuation gradient computation. Then, the logarithm operation is performed for each IMF trace. Due to the very narrow bands of some IMFs in some seismic traces, a variable frequency window is adopted along the IMF trace according to the local data characteristics. Finally, the attenuation gradient for each IMF in a seismic trace can be computed using least-squares fitting. A different IMF reflects a seismic trace with a different spatiotemporal scale and can highlight different geologic and stratigraphic information. The correlation weighted average operation is used to highlight some useful details in seismic trace and obtains the attenuation gradient for each seismic trace. Field data examples demonstrate our method and its effectiveness. The proposed method can stably estimate the frequency attenuation gradient.     

完整资料的地震危险性参数估计及敏感性分析

应用考虑震级不确定笥和资料完整性估计地震危险性参数的极大似然法，分别采用１９４０年和１０７０年至１９９３年完整的地震资料，计算了汾渭地震带及陕南地区的地震危险性参数。结果表明：利用近几十年来的完整地震资料结合研究区历史上发生的最大地震，可以得到较为可靠的地震危险性参数；参数敏感性分析表明，完整震级不确定性对β的影响较小；随震级不确定性的增大地震年发生率减小；在资料完整的前提下，震级下限在一定范围内     

MAXIMUM INFORMATION ENTROPY THEORY OF EFFLUENT BAND IN OPEN CHANNEL UNIFORM FLOW

ＭＡＸＩＭＵＭＩＮＦＯＲＭＡＴＩＯＮＥＮＴＲＯＰＹＴＨＥＯＲＹＯＦＥＦＦＬＵＥＮＴＢＡＮＤＩＮＯＰＥＮＣＨＡＮＮＥＬＵＮＩＦＯＲＭＦＬＯＷＫｅＺｈｏｎｇＨＵＡＮＧ１ａｎｄＴａｏＪＩＡＮＧ２ＡＢＳＴＲＡＣＴＴｈｅｐｒｉｎｃｉｐｌｅｏｆｍａｘｉｍｕｍ...     

高围压高水压渗流条件下岩石的力学性质试验研究

对锦屏二级水电站引水隧洞大理岩、砂岩和板岩进行了高水压高围压渗流条件下的全应力应变过程三轴压缩实验,分析了高围压高水压对岩石强度及变形的影响,探讨了岩石强度与围压及孔隙水压力之间的关系。     

三种红层岩石常规三轴压缩下的强度与变形特性研究

利用MTS815Teststar程控伺服岩石力学试验系统研究了川东地区一红层边坡中的砂岩、粉砂岩和泥岩围压为03MPa的应力-应变全过程曲线,建立了峰值强度、峰值强度前弹性模量以及峰值强度后的弹性模量和围压的关系。将低围压下红层的全应力-应变曲线概化成5个阶段,分别为压密段、弹性段、屈服段、应变软化段和塑性流动阶段。试验结果得出,红层弹性模量随围压的增加而提高且变化明显,砂岩和粉砂岩在此围压内为脆性破坏,泥岩为塑性破坏的规律。