用穿透法测量声速时初始点的选择问题

用穿透方法测量岩心或固体的声速时，从测量波形中确定纵波（或横波）的到达时刻（或称初始点）比较困难，当声波的频率比较低时，其误差对测量结果影响比较大。本文用相位分析的方法研究了初始点的选择问题。首先，用各向同性较强、均匀的汉白玉制作标准件，测量其不同传播距离的波形，再用相位补偿的方法得到其传播速度；其次，利用传播速度，可从不同距离的测量波形中确定初始点及其对应的测量系统的时间延迟常数；最后，确定波形的其他位置为初始点时对应的时间延迟常数，因此，我们可以根据实际测量波形的特点选择最佳的初始点，利用其对应的时间延迟常数得到比较精确的声速。模型测量结果表明，初始点位置不同，其对应的测量系统的时间延迟常数也不同，也即测量系统的时间延迟常数是与初始点的选择相对应的。     

Siblings' differential experiences of marital conflict and differences in psychological adjustment.

The present study examined whether siblings experience marital conflict differently and whether such differences, if present, were associated with differences in their adjustment. Self-report data about marital conflict, children's depressed mood, behavioral conduct, and externalizing problems were obtained from 122 sibling pairs (mean ages = 10 and 12 years) and their parents. Results indicated that siblings were significantly different in exposure to and appraisals of marital conflict. Differences in siblings' exposure to marital conflict were significantly correlated with differences in their depressed mood, behavioral conduct, and externalizing problems. Differences in siblings' feelings of self-blame for marital conflict were significantly correlated with differences in their depressed mood and behavioral conduct. Children who experienced more marital conflict than their siblings had more adjustment problems than their siblings. These results highlight the importance of studying siblings' unique experiences of marital conflict to better understand its impact on children's adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

综合线损分析系统研究

描述了综合线损分析系统应该具有的主要功能和分析内容，介绍了系统实现中应该注意的几个问题、系统内容和实现方法。     

海洋钻井液有机物添加剂生物降解性评价

随着海洋石油的勘探开发，钻井液有机添加剂不可避免地进入海洋．因此在海洋勘探开发过程中应选择环保性能好，即生物降解性能好的有机物添加剂。用累计耗氧量法测定了海洋钻井液有机添加剂的生物降解性，研究评价了有机添加剂的生物降解规律和机理，探讨了有机物生物降解性同其化学结构的内在联系，为海洋勘探开发过程中选择环保性能好的有机物添加剂提供理论依据。总结实验结果发现：淀粉类(如DFD-140和FI-E1等)最容易生物降解；其次是纤维素类(如MV-CMC等)和烯类单体聚合物(如PAM和PHP)；而沥青类、两性离子类则难以生物降解，有的甚至对生物降解起抑制作用。     

一种微粉碎新设备——离心碎磨一体机

介绍一种离心碎磨一体机的工作原理、构造和特点 ,分析了碎磨机理及应用前景     

Enzymic and in sacco methods to estimate rumen degradation of food protein in cattle

BACKGROUND: Two factorial studies compared enzymic and in sacco methods to estimate degradation of ruminant foods. Enzyme degradation (in vitro = enzyme) was determined from the release of leucine‐equivalent amino acid (LA) crude protein (CP) from sunflower meal (SF), maize gluten meal (MG), distillers' dark grain (DG) and field beans (FB) after their separate incubations with Streptomyces griseus enzyme for 0–24 h. In sacco crude protein (CP) degradation of these foods was estimated during washing (0 h) and rumen incubations in fistulated cows for 2–24 h. The LA data were expressed as g LA per either kg of CP (LACP) or acid‐hydrolysable LA (HLA) of each food and compared with in sacco data. RESULTS: These methods showed comparable degradation with time (P < 0.01). The in sacco and HLA were greater than LACP for all foods except MG where in sacco value was either lower or equal to LACP depending upon the incubation time (P > 0.05 or P < 0.05). Conversely, HLA was significantly (P < 0.01) greater than LACP from 2 h onwards. At 0 h, in sacco values were significantly greater than those of enzyme for SF, DG and FB (P < 0.05) but not for MG. The foods differed significantly for degradation constants (a, b, c) in each method (P < 0.05). CONCLUSIONS: Despite variations between in sacco and enzyme estimates for different foods, the relationships between these estimates suggest that the HLA enzyme method has the potential to estimate food degradation. Copyright © 2007 Society of Chemical Industry     

浅谈建筑工程项目投标施工组织设计编制

工程项目投标施工组织设计是工程投标中的主要工作之一,也是工程项目投标文件的主要组成部分.本文总结投标施工组织设计编制经验,为施工企业在投标过程中提高投标文件质量,提出了自己的一些见解和建议.     

新区采油速度与稳产时间、递减率变化关系研究

针对新区稳产时间以及递减期递减余率大小难以确定等问题,通过对中原油田61个独立小区块进行分析对比,得出采油速度与稳产时间,不同采油速度下无因次采油速度与时间关系曲线,对于新区开发预测稳产时间以及预测递减期产量变化有着重要意义.     

Factors Affecting the Squareness of Hysteresis Loops of Sintered NdFeB Magnets

Investigation into the magnets with different squareness of hysteresis loop (SHL) reveals that the microstructure of sintered NdFeB magnets has great effects on the SHL of the magnets. The abnormal grain growth deteriorates the SHL seriously. The shape of the grain and the grain boundary affect the intensity of demagnetization field, and consequently on the SHL. The added elements have effects on the phase structures and distributions in the magnets, which influences the uniform of demagnetization field.     

小议变动成本法的合理性

企业对盈亏临界点的计算通常是以变动成本法为基础，但也有以制造成本法为计算基础的，对于这两种成本方法计算的几种盈亏临界点的情况，本文结合案例，通过比较分析认为：盈亏临界点的计算应当以变动成本法为基础更为合理。