室内霉菌污染原因及其控制对策

通过对建筑墙体内湿气迁移过程的研究，详细分析了霉菌污染产生的原因。通过夏、冬两季平均气候条件下沿墙厚度温度、相对湿度分布和湿积累量的具体计算，得出墙内的相对湿度将达到或超过70％，有时甚至处于饱和状态，从而为霉菌的生长提供了有利条件。基于分析结果，提出了对于室内霉菌污染的控制对策。     

套种籽西瓜对杉木幼林生产力和林地质量的影响

8年(1985—1992)的试验研究,证明杉木幼林套种籽西瓜不仅提高了林分的生物生产力,而且增加了林地养分归还量,促进了林地土壤理化性质的改良,有效地防止了林地的水土流失,是一种速生高效和生态协调的山地立体经营模式。     

Competition and group size in Thomas’s langurs (Presbytis thomasi): the folivore paradox revisited

Among primates, group size is highly variable. The standard ecological model assumes that better predation avoidance as group size increases favours living in larger groups, whereas increased travel costs and reduced net food intake due to within-group competition for resources set the upper limit. Folivorous primates, however, tend to defy this generalisation in that some live in small groups despite low costs of feeding competition. To resolve this ’folivore paradox’, it has been suggested that folivore group size is limited by social factors such as male harassment or infanticide, or that females can disperse more easily and thus maintain group size near optimum levels. In this paper, we examine the effects of group size on home range size, day-journey length, activity budget and diet in wild Thomas’s langurs (Presbytis thomasi), which live in one-male multi-female groups with a limited life cycle. We examined only data from the stable middle tenure phase when factors such as the strength of the breeding male or the way in which groups were formed did not influence ranging and activities. During this phase, group size affected day-journey length and home range size, and had a minor effect on diet, but did not influence time spent feeding or resting, allogrooming or birth rates. Hence the upper limit to group size during the middle tenure phase in Thomas’s langurs is not set by feeding competition. The folivore paradox is not due to frequent female dispersal in Thomas’s langurs. The timing of female dispersal is not as expected if it serves to keep group sizes near the ecological optimum, and groups seem to be below this optimum. Instead, female reproductive success is presumably maximised in small to mid-sized groups because larger groups show a clear trend to experience higher risk of take-over, often accompanied by infanticide. Because females can redistribute themselves among nearby groups when groups reorganise each time a new male starts up a new group, females can keep the group small. Thus, a social factor, risk of infanticide, seems to provide the selective advantage to small group size in Thomas’s langurs. Received: 29 July 1999 / Revised: 17 November 1999 / Accepted: 15 October 2000     

The effects of relative humidity on the insecticidal properties of a diatomite‐based dust

Abstract

The feasibility of using diatomaceous earth (diatomite) as an insecticidal dust was investigated under conditions of high (80%) and low (10%) relative humidity, using the adult red flour beetle, Tribolium castaneum. Tested were diatomite and two lots of a commercial formulation of the same diatomite, containing 0.2% pyrethrins and 1.0% piperonyl butoxide. For comparison, talcum and a talcum‐based commercial formulation, containing the same concentrations of pyrethrins and piperonyl butoxide, were included in the tests. The insects were exposed to 0.08 mg/cm² of each material tested, equivalent to the label recommendation of 7 lb/acre for the diatomite‐based commercial insecticide. At 10% RH, higher doses of diatomite were also tested. Mortalities were determined at intervals for up to 84 hours.

Diatomite caused no mortalities at the experimental concentration, regardless of RH. At about four times that rate and 10% RH, it caused less than 5% mortality.

At 80% RH, the diatomite‐based product (P. C. P. Act #14074) was significantly more effective than the talcum‐based one (#13074). At 10% RH, however, the latter acted more quickly than the diatomite‐based formulations, but all produced nearly 100% mortality after 68 hours.

The results are discussed in terms of the physical characteristics of diatomite and in terms of the modes of insecticidal actions of diatomite and pyrethrins. It is concluded that diatomite alone, despite its attractiveness to environmental interests, is not likely to become an effective agent for controlling red flour beetles and other pest insects with similar water‐proofing mechanisms.     

环境质量评价模糊集理论与模式研究

探讨了模糊集理论方法对环境质量评价的可行性，以大气环境质量评价为例，叙述了这种方法的研究程序及计算步骤。研究表明，采用模糊集理论方法对大气环境质量进行评价，结果结果合理，方法可行，有一定的参考价值。     

提高测量悬浮物的准确性

通过一系列实验数据的对比，提出影响悬浮物测量准确性的两个因素——空气相对湿度和称量时间控制，从而提出较为可行的测量方法与步骤．     

巷道围岩温度分布及调热圈半径的影响因素分析

分析了巷道壁面水分蒸发情况下通风时间、岩石的热物理性质、巷道几何尺寸、巷道风流与围岩壁面的对流换热系数、壁面湿度系数与风流相对湿度的变化对围岩温度分布及调热圈半径的影响。随着通风时间的延长 ,围岩冷却范围逐渐向围岩内部推移 ,推移速度逐渐降低 ;巷道壁面水分蒸发和风流相对湿度对靠近壁面处围岩温度分布影响很大 ,但对深部围岩温度分布的影响逐渐变小 ,所以对调热圈半径的影响很小 ;岩石导温系数对调热圈半径及其内部的温度分布影响较大。巷道壁面风流与围岩的换热系数和巷道的几何尺寸对巷道围岩的冷却范围影响非常小。     

生产力标准是检验档案工作的根本标准

运用生产力标准这一马克思主义的基本观点来衡量和检验档案工作,是做好新时期档案工作的需要,也是使档案工作更好地服从和服务于经济建设的需要。     

The Long Beach/Fort Lauderdale relative risk study

Problem

The role of alcohol as a major factor in traffic crash causation has been firmly established. However, controversy remains as to the precise shape of the relative risk function and the BAC at which crash risk begins to increase.

Methods

This study used a case-control design in two locations: Long Beach, California, and Fort Lauderdale, Florida. Data were collected on 2,871 crashes of all severities and a matched control group of drivers selected from the same time, location, and direction of travel as the crash drivers. Of the 14,985 sample drivers, 81.3% of the crash drivers and 97.9% of the controls provided a valid BAC specimen.

Results

When adjusted for covariates and nonparticipation bias, increases in relative risk were observed at BACs of .04-.05, and the elevations in risk became very pronounced when BACs exceeded .10.

Discussion

The results provide strong support for .08 per se laws and for state policies that increase sanctions for BACs in excess of .15.

Impact on Industry

This study provides further precision on the deleterious effects of alcohol on driving and, by implication, on other complex tasks.     

Food utilization and growth of cutworm Spodoptera litura Fabricius larvae exposed to nickel,and its effect on reproductive potential

Food utilization and growth of the 5th and 6th instar Spodoptera litura Fabricius larvae, and its effect on reproduction potential was evaluated by feeding larvae diets with different doses of Ni for 3 generations. Dose-dependent relationships between Ni levels and food consumption and growth were variable with different larval developmental period and Ni exposure duration. RCR, AD and RGR of the 6th instar larvae were much more affected by Ni exposure than those of 5th instar larvae, and the effects were strongest in the 3rd generation. It was found that RCR was significantly stimulated after 1 and 20 mg kg⁻¹ Ni exposure, while AD was significantly inhibited after 1, 5, 10 and 40 mg kg⁻¹ Ni exposure. However, lower levels of Ni (?5 mg kg⁻¹) significantly increased and higher levels of Ni (?10 mg kg⁻¹) significantly decreased RGR. In 3 successive generations, 10 mg kg⁻¹ Ni significantly increased the ECI and ECD of the 5th instar larvae, and 5 mg kg⁻¹ Ni significantly increased the ECD of the 6th instar larvae. However, ECD were all significantly inhibited with 20 mg kg⁻¹ Ni exposure. Results also revealed that durations of larvae were shortened at low levels of Ni, but extended at high levels of Ni. Fecundity was inhibited by the highest Ni doses in each generation, while improved by low Ni doses in the 3rd generation. Hatching rates in all treatments were significantly decreased in a Ni dose-dependent manner. Study indicated that effects of Ni on these parameters were predominant with the increasing Ni exposure period.