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1.
壳聚糖高效吸附处理含铬废水的研究   总被引:12,自引:0,他引:12  
壳聚糖是一种吸附剂,对重金属离子有很强的去除能力,且对环境友好.首先进行了壳聚糖对铬吸附的动力学实验,绘制了吸附动力学曲线和吸附等温线,考查了pH值对吸附的影响.结果表明,在强酸性条件下,壳聚糖对C r(Ⅵ)的吸附速度较快,对C r(Ⅲ)的吸附速度较慢;而在弱酸性条件下壳聚糖对C r(Ⅲ)的吸附有利.通过调节pH值组合,可以连续处理含铬废水.对工业实际水样的吸附实验结果表明,按本研究方法,通过控制pH值进行分段吸附,出水中铬含量低于国家排放标准.  相似文献
2.
新型外包钢-砼组合梁滑移及变形性能的试验   总被引:2,自引:0,他引:2  
为研究新型外包钢-砼组合梁的钢-砼交界面相对滑移及变形性能,设计4根不同剪力连接系数足尺简支梁,其中1根为完全剪力连接组合梁,其余为部分剪力连接组合梁。通过对4根简支梁的试验研究,得到组合梁的荷载-滑移、荷载-挠度关系曲线。根据试验结果分析新型外包钢-砼组合梁交界面相对滑移发展的过程和分布规律。利用有限元分析软件ANSYS,对组合梁的交界面相对滑移性能进行了非线性有限元分析,提出剪力连接系数的合理范围。在基于现行规范的基础上提出了组合梁跨中挠度的建议计算公式。把有限元模型和建议公式的计算结果与试验结果进行比较,三者吻合良好。  相似文献
3.
As the traditional particle filter has problems of particle degeneracy and particle diversity loss and filter accuracy depends heavily on the particle number, a gravity optimized particle filter algorithm is proposed.The particle swarm is optimized by the gravity algorithm in the particle filter to improve the filtering accuracy. Each particle is regarded as a mass point and the mass is proportional to the particle weight.The gravity attracts particles moving toward the high likelihood region which optimizes the particle swarm.Then elite particle strategy is introduced to accelerate the particle convergence rate and avoid the local optimum in the gravity algorithm. The perceptual model is used to prevent particles from crowding or overlapping due to excessive convergence. Simulation results show that the proposed algorithm has a better filtering accuracy and speed in the case of few particles compared with the classical particle filter algorithm and particle swarm optimization particle filter algorithm.  相似文献
4.
Aimed at coupling calculation for radar waves and aperture cavity complex TL, a calculation method is proposed based on the MoM, the dyadic Green's function (GF) and mixing of the Π model and Agrawal model. First, the incident electromagnetic field at the aperture of the radar antenna can be obtained by the MoM. Then the MoM-GF hybrid algorithm is used to obtain the equivalent magnetic current in the aperture and the electromagnetic field inside the cavity. Finally, the TL load current response can be calculated with the result of electromagnetic fields and the hybrid TL model of the equivalent Π circuit and Agrawal. Throuth TL simulation results by the BLT equation this method can be validated effectively.  相似文献
5.
针对动圈式磁悬浮永磁平面电机定子磁场谐波含量较大的问题,提出了一种根据实际气隙磁密与期望气隙磁密的平均相对均方差对磁钢参数进行优化设计的方法。通过磁钢阵列的磁密谐波模型分析了定子磁场的3维磁密分布,获取不同水平高度上的平均基波幅值,从而构建了磁钢阵列的期望基波模型;基于谐波模型和期望基波模型,计算了磁钢阵列的实际气隙磁密与期望气隙磁密的平均相对均方差;在此基础上,根据"平均基波幅值应尽可能大、平均相对均方差应尽可能小"的原则设计了磁钢参数。有限元仿真和试验样机实测结果表明,该设计方法对于降低动圈式磁悬浮永磁平面电机定子磁场的高次谐波含量,特别是降低2次谐波具有明显效果。  相似文献
6.
An algorithm for extrapolating the transient field in two-dimensional half-space for the finite-difference time-domain(FDTD) method is firstly presented. In this algorithm, the far-zone scattered field consists of three parts. The first two parts of the field are generated by the equivalent electromagnetic currents at the extrapolation bound in upper space, propagating along the paths of directed and reflected waves, respectively. And the third part is resulted by that currents at that bound in lower space, its propagation following the path of the transmitted wave. To caculate the latter two parts, the reflection and transmission points should be determined with the knowledge of Snell's law and then projected on to the observation time bins, moreover the proper time of the wave propagating from the equivalent source to those points should also be worked out and used to delay those bins, with the reflection or transmission coefficients used as the contribution factor to the far field. Then the proposed algorithm is validated by the applying far-zone scattered fields to two examples.  相似文献
7.
臭氧可以用于工业循环冷却水的处理.为了更好地指导生产应用实际,建立了臭氧在冷却水中分解的数学模型.研究首先从理论上推导出其分解的数学模型,再通过配制不同浓缩倍数的试验用水,用N aHCO3调节碱度,通入不同浓度的臭氧,测定臭氧的分解速率,得到不同pH和CODC r时的相关数据,进而推出臭氧在实验条件下分解的动力学方程.数学模型的分析表明,影响臭氧分解的因素除了与水中的[OH-]有关外,还与其中的CODC r有关,即与系统中所含微生物、有机物、还原性无机物等有关.在实际应用中,应对运行过程中水质实行连续或间歇监测,根据pH和CODC r的变化调整臭氧的投加量,同时控制系统的CODC r以保证处理效果.  相似文献
8.
实际地基处理中,电渗与堆载预压常常联合使用。然而目前综合考虑堆载和电渗作用的成层地基固结解答较为鲜见。针对现有理论的不足,基于Zhao提出的双层地基中水力渗透系数与电渗渗透系数的关系假定,建立考虑堆载和电渗联合作用的双层地基一维固结方程。利用特征函数法获得瞬时堆载和线性堆载下双层地基一维电渗固结解析解。通过与现有解析解和电渗固结试验结果对比,验证了本文解答的可靠性。基于该解答,详细讨论了土层参数及荷载参数对双层地基固结特性的影响。结果表明:当下层土的渗透性高于上层土的渗透性时,由于电渗作用导致地基中间土层在固结初期流入的水量大于流出的水量,造成超静孔隙水压力在固结初期上升及有效应力在固结初期下降的现象;降低下层土的压缩性能够提高双层地基的沉降速率和超静孔隙水压力消散速率;与单纯电渗固结相比,电渗联合堆载作用不仅能提高地基沉降速率,还能提高固结后的地基强度,更有利于减小工后沉降和加快地基处理速率。  相似文献
9.
In order to improve the ability of the non-volatile memory storage device system to concurrently execute access requests, aiming at the diverse nature between read and write access requests and the different properties of file data and metadata in the storage device, we have designed a file-based parallel write-based file data concurrent write strategy, RCU based file data read and write concurrency strategy and a minimum spin lock-based metadata synchronization strategy to improve the degree of concurrency of requests execution. And then we have implemented a prototype of the asymmetric lock-based high concurrent non-volatile memory storage system, which has been tested and analyzed by common test tools and methods, the result shows that compared with the PMFS, the prototype system can increase the throughput by 40%~162% and input/output operations per second by 61%~159%.  相似文献
10.
实际地基处理中,电渗与堆载预压常常联合使用。为了解决目前综合考虑堆载和电渗作用的成层地基固结解答理论的不足,假定土体中的渗透流速可由水力坡降引起的渗透流速与电势差引起渗透流速的进行叠加,建立考虑堆载和电渗联合作用的双层地基1维固结方程;利用特征函数法获得瞬时堆载和线性堆载下双层地基1维电渗固结解析解;通过与现有解析解和电渗固结试验结果对比,验证了本文解答的可靠性。基于该解答,详细讨论了土层参数及荷载参数对双层地基固结特性的影响。结果表明:当下层土的渗透性高于上层土的渗透性时,由于电渗作用导致地基中间土层在固结初期流入的水量大于流出的水量,造成超静孔隙水压力在固结初期上升及有效应力在固结初期下降的现象;降低下层土的压缩性能够提高双层地基的沉降速率和超静孔隙水压力消散速率;与单纯电渗固结相比,电渗联合堆载作用不仅能提高地基沉降速率,还能提高固结后的地基强度,更有利于减小工后沉降和加快地基处理速率。  相似文献
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