凹凸棒土吸附剂的制备和脱色性能研究

用以凹凸棒土为主料，配以其呛助剂所制备的凹凸棒土吸附剂，对癸二酸单钠盐 进行了吸附脱色和再生性能的试验，结果表明：该吸附剂具有明显的吸附脱色效果，且其制原料价廉易得，制备工艺简单，成本低，再生容易，是一种较好的脱色吸附型净化剂。     

劈裂拉伸条件下大红山铜矿矿岩变形特性的试验研究

对大红山铜矿的3种岩石的试样进行了劈裂拉伸(巴西法)试验和单轴压缩试验,研究了岩石的变形特性。劈裂试验中在试样中部相互垂直的方向上粘贴了电阻应变计测量试样的变形。结果表明,在劈裂试验条件下,两种岩石均出现垂直于加载轴线方向所获得的拉伸弹模小于平行于加载轴线方向所获得的压缩弹模的现象。与单轴压缩下试样出现破裂、扩容的破坏特征相比,劈裂拉伸下试样的变形特征为接近峰值时变形曲线斜率会逐渐降低,达到峰值应力后则很快出现数值很大的拉伸变形,直至试样破坏。劈裂拉伸循环加卸载试验发现,大多数试样的拉伸卸载变形大于加载变形,致使残余变形的数值为负值,称之为反向残余变形。此现象与连续介质变形行为的预期不符,至今未见类似报道。反向残余变形是否具有普遍性及其影响,应该开展更多研究。     

Understanding the opposition

Current debates about sex selection start from a paradox: on the one hand, the ‘liberal’ argument in favour of sex selection is often thought to be sound; but on the other hand there is widespread public opposition to sex selection. So it is worth spending some time examining the arguments against sex selection. Four different types of argument are identified: (i) religious arguments; (ii) consequentialist arguments, mainly concerning disturbance to the sex ratio; (iii) arguments to the effect that sex selection involves a failure to respect the autonomy of a child; (iv) arguments to the effect that the motivation for sex selection brings with it an instrumental attitude to children not compatible with a child's need for unconditional acceptance and love. In the end the conclusion is reached that none of these arguments provide decisive arguments against the liberal thesis that sex selection ought to be permitted, especially where 'family balancing' is envisaged. In the light of this conclusion the issue of fetal sexing followed by selective feticide as a method of sex selection is discussed. It is argued that sex selection is not in general a good reason for abortion, but that this practice may become unstoppable. Copyright © 2006 John Wiley & Sons, Ltd.     

油罐清洗技术综述

油罐清洗自动化和系统化是石油储运行业发展的必然结果，油罐清洗技术经历了从人工清洗、机械清洗最后到自动清洗的渐进式的发展历程。介绍了油罐清洗技术的进化过程。并重点描述了当今世界上最为成熟的两大自动清洗系统。以及我国在这一领域的进展情况。     

Color choices by bumble bees (Bombus terrestris): innate preferences and generalization after learning

It is usually assumed that the choice behavior of bees for floral colors is influenced by innate preferences only for the first flower visits prior to any experience. After visits to rewarding flowers bees learn to associate their colors with a reward. This learning process leads to an acquired preference for the trained colors that has been believed to dominate over previous experiences and over innate preferences. This work investigates how bumble bees (Bombus terrestris) chose among artificial flowers of different colors after they had been extensively trained to other colors. The bees chose novel colors according to their similarity to the trained color if the trained color was similar to some of the test colors. This was true also if trained colors and test colors were well distinguished, so their color choice reflected generalization between colors. If the test colors were so different from the trained color that no generalization took place, choice behavior was not affected by the trained color and reflected innate preferences. The differences in choice frequencies could not be explained by physical properties of the test colors other than the dominant wavelength, a parameter taken to reflect hue perception. Preferred dominant wavelengths correspond to those observed in naive bumble bees and honeybees. Thus bumble bees show innate preferences for certain colors not only prior to color learning but also after intensive learning when choosing among very different novel colors. Color choice among similar colors, however, is controlled by generalization from the learned color. Received: 9 November 1999 / Received in revised form: 19 March 2000 / Accepted: 31 March 2000     

新中国成立至改革开放前我国应对海洋灾害的实践及启示

梳理和总结新中国初期我国应对海洋灾害的实践,有助于我们了解海洋灾害的应对措施并为当今提供借鉴。通过对我国海洋灾害史料的分析和总结,得知从新中国成立至改革开放前这一时期内,"防重于救"是我国应对海洋灾害的的主要指导思想,在海洋灾害预测预警、建设防护性工程、群众自救和政府辅以必要救济等方面发挥了重要作用,并为之后我国应对海洋灾害打下了一定基础。     

Empirical Estimation of Stream Discharge Using Channel Geometry in Low‐Gradient,Sand‐Bed Streams of the Southeastern Plains

Manning's equation is used widely to predict stream discharge (Q) from hydraulic variables when logistics constrain empirical measurements of in‐bank flow events. Uncertainty in Manning's roughness (n_M) is the major source of error in natural channels, and sand‐bed streams pose difficulties because flow resistance is affected by flow‐dependent bed configuration. Our study was designed to develop and validate models for estimating Q from channel geometry easily derived from cross‐sectional surveys and available GIS data. A database was compiled consisting of 484 Q measurements from 75 sand‐bed streams in Alabama, Georgia, South Carolina, North Carolina (Southeastern Plains), and Florida (Southern Coastal Plain), with six New Zealand streams included to develop statistical models to predict Q from hydraulic variables. Model error characteristics were estimated with leave‐one‐site‐out jackknifing. Independent data of 317 Q measurements from 55 Southeastern Plains streams indicated the model (Q = A_cR_H^0.6906S^0.1216; where A_c is the channel area, R_H is the hydraulic radius, and S is the bed slope) best predicted Q, based on Akaike's information criterion and root mean square error. Models also were developed from smaller Q range subsets to explore if subsets increased predictive ability, but error fit statistics suggested that these were not reasonable alternatives to the above equation. Thus, we recommend the above equation for predicting in‐bank Q of unbraided, sandy streams of the Southeastern Plains.     

动态群体安全投入博弈模拟*——以我国煤矿为例

为探究煤矿生产中的群体安全投入博弈特点,针对煤矿生产参与者面临的安全投入囚徒困境（SIPD）博弈,基于NetLogo模拟平台设计博弈模型,获取不同安全投入策略的工人群体变化、死亡情况和安全收益特征,探究不同安全环境对博弈结果的影响。研究结果表明:在低安全水平煤矿中,消极型工人（D-worker）可以利用积极型工人（C-worker）的安全投入,快速增加消极型群体规模,并攫取高达70%的安全收益,而在高安全水平煤矿中,在制裁型工人（T-worker）影响下,D-worker安全收益可被限制到20.4%。D-worker在恶劣安全环境中将成为主流,攫取最大安全收益,产生较高死亡率,并严重损害群体安全,扭转上述局面的短期方法为抑制群体消极心理,长期方法为逐步提高安全管理技术水平。研究结果可为我国煤矿安全水平提升提供安全投入策略参考。     

声学环境影响评价——大剧院设计声学案例分析

大剧院观众厅是音乐家最后的乐器,音乐效果是由观众厅声学反应出来的。前面演奏者要把声音传播给观众席,再从观众席后排反声回给演奏者,这样的互动是最完美的剧院设计。     

炼油污水三泥脱水装置调试运行

炼油污水处理装置的三泥脱水实验表明,剩余污泥的脱水性能最好。根据实验结果,将浮渣与剩余污泥按比例混合进行脱水,连续少量掺入油泥,调整转速与混凝剂用量后取得较好的脱水效果。在离心机处理量13～15m3/h,离转速3000r/min,差转速5～7r/min,混凝剂量5kg/h的工况下,离心机所产泥饼含水率<85%、滤液ρ(COD)<800mg/L。脱水处理直接成本19.6元/m3。