浅谈弃档现象的解决方法及对策

由于人事档案的多方管理和方方面面的原因,社会上出现了弃档现象,然后防范和杜绝：只有当人事档案的使用价值得到提升,公民的档案意识得到进一步增强,人事档案才会真正得到人们的认可和重视,弃档方可减少和得到有效的遏制才能从根本上解决弃档现象。     

催化分解方法分析高纯氨中微量水分含量

研究高纯氨中微量水分的测试。采用催化分解氨的方法得到氢气和氮气,测试氢氮混合气中的水分,用氦离子放电气相色谱仪检测得到氨中氧含量,换算可以得到高纯氨中的水含量。     

内蒙古自治区新巴尔虎左旗2011年农业综合开发林业生态示范建设项目可行性报告

项目建成后可以使2000．00亩流动及半固定沙丘地得到治理,营造新灌木林地2000．00亩,并可间接防护草场面积1．00万亩。建成后项目区沙地的再生植被可以得到明显恢复,周边地区生态环境也会得到很大改观,沙化形势得到迅速扼制,实现以林促牧、以林保牧,达到农牧经济腾飞。     

万能角度尺示值误差的不确定度分析

文章依据不确定度传播定律介绍了万能角度尺的测量方法、不确定度来源及测量模型,根据万能角度尺的测量方法和测量程序分析得到影响万能角度尺示值误差结果的因素。再通过对万能角度尺进行10次重复性测量后,利用贝塞尔公式计算得到其单次实验标准差,从而计算得到A类标准不确定度,然后从角度块的资料计算得到万能角度尺的B类标准不确定度,最后经过合成得到万能角度尺的合成标准标不确定度,取置信因子k=2进而得到其扩展不确定度。     

核电站扩建工程爆破开挖振动信号的HHT分析?

通过对田湾核电站二期扩建工程爆破施工的振动监测,得到了大量的试验数据,经由Hilbert-Huang变换(HHT)方法处理,分析论证了此方法运用于爆破地震波处理的科学性和可行性。第一步,用经验模态分解信号,得到了振动信号的固有模态分量,考虑到噪声信号的干扰,又对信号进行了改进算法的滤波处理;之后,对各个分量进行Hilbert变换,得到了信号的时频能量谱;针对时频能量谱分析,得到了信号的时频特性;从得到的瞬时能量谱中得到了3段微差起爆的间隔时间,为检测雷管的质量提供了新方法;而边际谱分析提供了一个频域分析的新角度。     

基于一元对称幂基的等距曲面有理逼近算法

给出了基于一元对称幂基的等距曲面蒙面逼近新算法。利用一元对称幂基逼近张量积Bézier曲面u向曲线的等距曲线,得到一组等距逼近曲线,取固定的v值,得到一组数据点,用反算控制顶点的方法得到过这组数据点的v向曲线。对这两组曲线用蒙面算法得到逼近的有理等距曲面。该算法计算简单,将二元等距曲面有理逼近转化为一元曲线有理逼近,同时方便地解决了整体误差问题,随着对称幂基阶数的升高,可以得到较理想的逼近效果。     

马来酰壳聚糖/纳米SiO2纳米微球的制备及热性能

由甲壳素脱乙酰得到壳聚糖,然后以碳酸钠催化马来酸酐酰化,得到壳聚糖酰化物钠盐。纳米二氧化硅经高分子表面活性剂聚二甲基二烯丙基氯化铵(PDDA)处理,其与聚合物相容性得到提高,然后利用静电作用使其与马来酰壳聚糖钠盐复合。经红外光谱(IR)、扫描电镜、热重分析分析,结果表明得到了分布均一的球形包覆物,粒径处于1 nm~100nm范围内,说明得到了复合物纳米微球,且复合后产物的热性能较马来酰壳聚糖有了显著提高。     

全面加强民生计量工作 促进小康社会建设 蒲长城副局长在全国质检系统民生计量工作表扬暨地方计量处长座谈会上的讲话(摘编)

近年来,计量工作得到了国家质检总局的高度重视,计量工作在全系统、全国范围内得到进一步加强,特别是民生计量、能源计量这两项工作,取得了显著的工作成效。计量工作在经济社会发展各个领域的作用越来越重要,而且得到了越来越多的认可和肯定。     

如何进行库区和水利工程防护工作

我国的经济发展得到了显著的成绩,与此同时,我国的经济的支持产业的发展状况也得到了重视,这其中,水利工程是十分重要的,它不仅可以保障经济的建设而且还可以使得人们的正常生活得到了保障。但是,在现在水利工程的相关设施的防护工作一定要得到人们的重视,只有确保水库的库区和水利工程的安全,才会促进我国经济的更好发展。     

某车车内噪声信号的测试与分析

依据国标规定,对某车车内噪声进行测试。利用傅立叶变换对在不同转速工况下测得的噪声信号进行频谱分析,得到其关键频率。在对急加速工况分析的过程中发现虽然傅立叶变换可以分析出整体的变化规律,但不能得到其细节信息。由此采用小波分析对其进行补充,利用小波变换的“自适应变化”的时频窗结构得到信号的细节,并加以处理得到更多的频率信息。     

基于机器视觉的图像形状特征提取方法研究进展

基于机器视觉的图像形状特征提取应用的常见方法有阈值处理法、基于轮廓的形状特征提取法和基于区域的形状特征提取法3种。阈值处理法是常见的图像分割提取方法,具备操作简单、速度快等优势,但对于需精确提取图像形状和目标图像形状较为复杂的工况不适用;基于轮廓的形状特征提取方法,处理速度较快,但当处理复杂目标图像形状时,容易出现较大的偏差或错误;基于区域的形状特征提取方法,在提取形状特征时更加容易实现,且在处理复杂图像时更加准确,但需要的内部存储空间较大。由此可知,目前形状特征提取方法的应用局限性较大,而发展图像特征提取方法意义重大。     

超微量液体容积双波长参比测量方法研究

为克服静力称重法受蒸发量影响大的不足,同时适应在线测量的需要,基于Lambert-Beer定律,研究了520nm和730nm双波长超微液体容量光度吸收测量法,通过稀溶液浓度与吸光度之间的线性关系可以计算出待测超微量液体容积。设计了双波长参比光度吸收法的测量系统,采用与静力称重测量系统比对试验的方式对这种方法进行了验证,1μL和5μL微量液体试验数据表明:双波长参比光度吸收法和静力称重法测量结果具有良好的一致性,均符合ISO 8655的技术要求。与静力称重法方法相比,双波长参比光度吸收法对测量环境要求低,易于实现在线测量,而且可以有效减少液体蒸发对测量结果的影响。     

Viscoplastic response of multiphase composites using a strain-compatible volume-averaging method

The strain-compatible volume-averaging method, a recently developed micromechanical method for the analysis of multi-phase composites, is extended here to deal with viscoplastic behavior. Specifically, the method is applied to the problem of finding the viscoplastic response of a boron–aluminum unidirectional composite. A unified Bodner–Partom viscoplasticity model is used to model the inelastic behavior of the aluminum matrix of the composite. The inelastic response is obtained for different loading conditions and for several different fiber architectures. The influence of the loading orientation on the viscoplastic response of the composite is investigated using the strain-compatible volume-averaging method and the widely utilized generalized method of cells. It is shown that the response predictions of the strain-compatible volume-averaging method are invariant with respect to coordinate transformations while those of the generalized method of cells are not. This is due to the fact that the new method accurately models shear-coupling, a feature that is absent in the generalized method of cells. The results obtained with the new method are also compared with those of the finite element method. As far as the effective response of the composite is concerned, it is found that the results of the strain-compatible volume-averaging method are in good agreement with those of the other two methods. It is found however, that the computational cost of each of the three methods is proportional to the accuracy of the microstress field as might be expected.     

A boundary density evolutionary topology optimization of continuum structures with smooth boundaries

Based on the variable density method, this article proposes a boundary density evolutionary topology optimization method. The method uses a material interpolation model without penalization. Combined with the density grading filtering method, an optimal topology with only 0/1 cells can be obtained. Compared with the solid isotropic microstructures with penalization method (SIMP), no penalty factor is required in the material interpolation model; compared with the evolutionary structural optimization method (ESO), intermediate-density elements are allowed in the optimization process, but the concept of gradually removing the low-utilization materials near the boundary in the ESO method is retained. After the optimal result is obtained, the structural boundary element is processed by the level set of nodal strain energy, and the optimization result with smooth boundaries similar to the level set method (LSM) can be obtained. The proposed method has the superiority of the variable density method, and it also combines the advantages of the evolutionary method and the level set method, so which is named as boundary density evolution (BDE) method. The four static and one dynamic optimization examples illustrate the stability and efficiency of the proposed method.     

Combined interior‐point method and semismooth Newton method for frictionless contact problems

In the present paper, a solution scheme is proposed for frictionless contact problems of linear elastic bodies, which are discretized using the finite element method with lower order elements. An approach combining the interior‐point method and the semismooth Newton method is proposed. In this method, an initial active set for the semismooth Newton method is obtained from the approximate optimal solution by the interior‐point method. The simplest node‐to‐node contact model is considered in the present paper, that is, pairs of matching nodes exist on the contact surfaces. However, the discussions can be easily extended to a node‐to‐segment or segment‐to‐segment contact model. In order to evaluate the proposed method, a number of illustrative examples of the frictionless contact problem are shown. The proposed combined method is compared with the interior‐point method and the semismooth Newton method. Two numerical examples that are difficult to solve using the semismooth Newton method are solved effectively using the proposed combined method. It is shown that the proposed method converges within far fewer iterations than the semismooth Newton methods or the interior‐point method. Copyright © 2009 John Wiley & Sons, Ltd.     

结构损伤识别中灵敏度法的改进

针对原有灵敏度法对复杂结构损伤识别中存在的不足（误判损伤位置和高估损伤程度），本文对其进行了改进。改进后的方法仅利用结构损伤前后的前两阶模态参数即可确定结构损伤的位置并评估结构损伤的程度。为验证改进后方法的有效性，利用二维钢架结构有限元模型数值模拟了五种典型的损伤工况，用原有灵敏度法和改进后的方法进行了识别。结果表明，与原有灵敏度法相比改进后的方法提高了结构损伤识别的精度，并且该方法简便，有望应用于实际结构中。     

非线性最优化问题的一种混合解法

把BFGS方法与混沌优化方法相结合,基于混沌变量提出一种求解具有变量边界约束非线性最优化问题的混合优化方法。混合算法兼顾了混沌优化全局搜索能力强和BFGS方法收敛速度快的优点,成为一种求解非凸优化问题全局最优的有效方法。算例表明,当混沌搜索的次数达到一定数量时,混合优化方法可以保证算法收敛到全局最优解,且计算效率比混沌优化方法有很大提高。     

The reduction of computational time of the Monte Carlo method,applied to radiative heat transfer with variable properties,by using a fixed properties loop

The Monte Carlo method has the excellent feature of easy adaptation to problemens such as radiative heat transfer with variable properties, and problems of system of heat transfer including radiation, with complex geometries. However, this method has a deficiency that it requires a large computational time when the energy equation is non-linear. In this paper, a modified Monte Carlo method, named the DPEF method, is suggested to overcome this deficiency, by adding an iterative loop of fixed properties to the conventional method, without sacrificing the advantageous of the Monte Carlo method. An analytical example of this new method, as applied to a model of radiative heat transfer in a furnace with variable properties, is given. It is found that the computational time is reduced by half of that of the conventional Monte Carlo method, and moreover, the stability in iteration process is found to be improved.     

干摩擦阻尼系统动力响应分析的迭代方法

本文提出了一种求解干摩擦阻尼系统稳态动力响应的迭代方法.此方法基于一次谐波平衡,同时保证计算状态下与原始模型下干摩擦阻尼器所消耗的能量相等,从而保证了迭代过程收敛,计算精度与等效粘性阻尼法相当.方法可用来分析带任意多个干摩擦阻尼器的系统,并可方便地与有限元分析程序包相连接.算例表明,计算结果与直接积分法所得结果吻合.     

基于平衡原理的液滴接触角估计方法

基于液滴表面力的平衡原理推导了一种新的液滴表面曲线方程,通过提取图像上的样本点,以牛顿-拉夫逊法拟合曲线方程为基础来获取接触角的估计值,从而得到了一种基于平衡原理的液滴接触角估计方法。通过JGW-360A接触角测定仪采集实测图像,针对水滴与不同材料的接触场景进行了实验,采用Canny法获取液滴边缘曲线并提取采样点,计算出液滴表面接触角。将该算法与传统的影像分析法进行了比较,在大角度下与传统影像类方法相比估计值差别约为0.2°~0.3°,实验结果验证了算法的有效性。