土壤水库和森林植被对水资源的调节作用

以湖南省土地、森林利用状况等有关资料为基础,从土壤和森林对降水形成径流的影响,调节水资源的数量和方式,防洪抗旱减灾方面的作用3个层次,详细地剖析了土壤水库和森林植被对水资源的调节作用。结果指出,土壤水库和森林植被能够调节水资源,其潜力非常大。合理利用土壤水库和森林植被可以蓄水保土减蚀,削减洪峰,减少自然灾害。     

土地资源永续利用的生态经济对策

土地资源是人类赖以生存的最基本的自然资源,土地资源的永续利用是实现社会、经济和生态全面可持续发展的基础。本文在分析土地资源利用特点,土地资源永续利用的内涵、原则与指南的基础上,提出了实现土地资源永续利用的一系列生态经济对策。     

聚苯乙烯基硫代磺酸钾树脂对水中卤代物的选择性结构分析

本文用聚苯乙烯基硫代磺酸钾树脂为选择性试剂与水中卤代物作用,排除水体中其它化合物对结构分析的干扰,采用动态恒温柱法及Ｃ－１８柱富集法作为该反应发生的途径,结果表明：前一种途径的检测结果由样品反应活性决定,而后者检测结果还受到萃取率的影响,两种方法均可达到１０－２０ｍｇ·ｌ＾－１的检测水平。     

Why is competition more intense if food is supplied more slowly?

We investigated competition for food among two groups of six clone amagos (salmonids), Oncorhynchusmasoumacrostomus, in a laboratory experiment with different rates of food input. We examined the effect of temporal clumping of food resources on the inequality of food sharing between competitors. Monopolization of food by dominants was greater at a low input rate (one food item per 10 s) than at a high input rate (1 food item per 1 s). Aggressive behavior by dominants was more frequent at the low input rate than at the high input rate; its purpose was presumably to interfere with the feeding behavior of subordinates. We assessed the relative importance of three foraging factors (the number of approaches to food items, the chance per approach and the gain per chance) in enhancing inequality in food gain between individuals. Dominants had a disproportionately high chance per approach and gain per chance at the low input rate, but not at the high input rate. The chance of obtaining a food item per approach depended on how many competitors approached simultaneously. The gain per chance depended on the competitive ability of the approaching fish. There was an interaction between these components, such that the number of approaches affected the chance per approach and gain per chance. We evaluated the independent effect of the chance per approach, and showed that it was higher for dominants than for subordinates at the low input rate, but not at the high input rate. This implies that subordinates changed their behavior and became more likely to avoid approaching food at the same time as dominants at the low input rate. Received: 13 August 1996 / Accepted after revision: 30 November 1996     

黄红壤上烟草对钾的反应及种烟后土壤钾的变化

黄红壤上烟草对钾的反应及种烟后土壤钾的变化马友华，李道林，陈邦本，方明（安徽农业大学土化系，合肥２３００３６）（南京农业大学资环系）我国南方亚热带的红壤是我国植烟面积较大的土类，适用于种植各种类型的烟草［１］。烟草是喜钾作物，近年来我国南方在烟草种植...     

Renewable Resources and Economic Sustainability: A Dynamic Analysis with Heterogeneous Time Preferences

In recent years there has been increasing interest in the study of economic sustainability and its relationship with natural resources. This paper attempts to shed some light on the issue by taking into account the individual variations in time preferences for consumption and resource amenity. We characterize the long-run steady state, analyze its asymptotic stability, and explore the transational dynamics from any initial state. The welfare implications of the optimal path are also discussed.     

建筑垃圾循环利用实践

建筑垃圾的循环利用是今后建筑垃圾处理的必经之路。在对国内外建筑垃圾循环利用的相关政策、法律法规及回收现状进行比较分析的基础上,对目前建筑垃圾循环利用的案例进行调查整理,总结出建筑垃圾循环利用的一般过程;并在对目前建筑垃圾循环利用的方法进行研究后,介绍了一种先进实用的建筑垃圾循环利用方法;最后对我国建筑垃圾循环利用存在的问题进行剖析并提出解决问题的建议,以期对我国建筑垃圾循环利用的发展有所裨益。     

默克公司COD测试剂的替代品开发

德国默克（MERCK）公司制造的COD测定仪在我国环保行业、科研院所的水质监测工作中应用广泛，但配套测试剂价格昂贵，限制了该仪器的使用。设计了高量程（100～1500mg／L）和低量程（25～100mg／L）下COD测试剂替代品的开发方案。通过实验，确定了两个量程下COD测试剂替代品中K2Cr2O2，H2SO4-Ag2SO4，HgSO4的浓度和加入量以及测试方法。实验结果表明，在高量程和低量程范围内，使用COD测试剂替代品的测试结果与MERCK公司配套测试剂的测试结果比较相符，反应时间也可缩短至0．5h。     

A double‐edged sword: The moderating role of conscientiousness in the relationships between work stressors,psychological strain,and job performance

Although conscientiousness was commonly viewed as a type of personal resource to help individuals reduce strain or mitigate the impacts of stressors, empirical research demonstrated mixed results. Based on the personal resource allocation perspective, we posited that rather than functioning as personal resource per se, conscientiousness may act as a key factor influencing how individuals allocate their personal resources. The current study examined the moderating roles of conscientiousness in the relationships that work stressors (i.e., challenge stressors and hindrance stressors) have with employee psychological strain and job performance by using multi‐source, time‐lagged data collected from 250 employees working at two companies. The results showed that both challenge stressors and hindrance stressors were positively related to psychological strain. Conscientiousness moderated the relationships between both stressors and psychological strain, such that the positive relationships were stronger for individuals with high conscientiousness. Conscientiousness also moderated the relationship between challenge stressors and performance, such that the relationship was positive for individuals with high conscientiousness but negative for those with low conscientiousness. Altogether, the findings suggest that conscientiousness acts as a double‐edged sword that both promotes performance and exacerbates the stress reaction of employees when they are confronted with stressful situations. Copyright © 2014 John Wiley & Sons, Ltd.     

不同萃取剂对花生粕饼中重金属的去除效果

比较了柠檬酸钾、酒石酸钾和盐酸萃取对花生粕饼中重金属的去除效果,并对萃取前后花生粕饼中营养元素和粗蛋白浓度的变化进行了研究。结果表明:随着萃取时间和萃取剂浓度的增加,花生粕饼中Pb、Zn、Cu和Cd的去除率也逐渐增加;采用0.50%和1.00%的盐酸萃取后,粕饼中的Cd浓度为0.42和0.34 mg/kg;3种萃取剂连续萃取3次后,Zn和Cu的去除率均有较大提升,30 mmol/L酒石酸钾第3次萃取和0.25%盐酸第2次萃取后粕饼中Cd浓度为0.36和0.21 mg/kg,均满足GB 13078—2017《饲料卫生标准》的要求;柠檬酸钾和酒石酸钾在去除重金属的同时,营养元素流失较小,低浓度的盐酸萃取使部分营养元素流失量大,对粗蛋白流失的影响小。综合考虑,低浓度的盐酸可作为花生粕饼中重金属的萃取剂。