南亚热带丘陵土壤水分循环及其有效性的研究──Ⅳ.丘陵土壤贮水量的增减规律

根据三年定位实测资料,阐述0～100cm土层贮水量的动态变化,分析土壤贮水增减与降雨、蒸发的关系．观测结果表明,在气候正常年,雨季土壤贮水为增量,旱季土壤贮水为减量,但在坡地不同坡段和梯地不同梯级,土壤贮水增减有差异。在旱月土壤贮水减至最低,仅相当子田间持水量的55％～80％．因此在土壤水分管理上．应当密切注意土壤贮水减量最大的时期,以采取有效措施减少土壤水分蒸发,提高土壤水分利用率。     

南亚热带丘陵土壤水分循环及其有效性的研究──Ⅷ.丘陵赤红壤水分循环与平衡数学模型

依据田间实测资料,在分析丘陵赤红壤水分性质的基础上,建立了土壤有效含水量与土壤物理粘粒含量之间的数学模型、土壤水分特征曲线数学模型、土壤月均贮水量与月降雨总量之间的数学模型和径流率与土壤表层初始含水量之间的数学模型,研究了土壤水分循环与平衡数学模型及各分量与参数的确定方法.     

The Relationship Between Exposure to Arsenic Concentrations in Drinking Water and the Development of Skin Lesions in Farmers from Inner Mongolia, China

Associations between the concentration of arsenic naturally occurring in drinking water and the development of skin lesions in people have been documented for some years at various locations around the world. Data on the exposure-response relationship between concentrations of arsenic in drinking water and prevalence of skin lesions in farmers from five locations in Inner Mongolia, China have been collected from the original publications and re-analysed together as a meta-study. The calculated data show a positive linear exposure-response relationship without a threshold. The reasons for this linear correlation are discussed and compared with the data from Xinjiang, another arsenism area located in a different geographical area of China. Here a different relationship was recorded that involved a threshold concentration before skin lesions developed. The significance of these two different exposure-response scenarios is discussed.     

Influence of environmental temperature and relative humidity on photocatalytic oxidation of toluene on activated carbon fibers coated TiO2

TiO₂ supported on active carbon fiber (TiO₂/ACF), an absorbable photocatalyst, is a new kind of material applied in air purification. In this paper, the influence of environmental temperature (T) and relative humidity (RH) on the gas-solid adsorption of toluene and the photocatalytic oxidation (PCO) efficiency of adsorbed toluene on TiO₂/ACF were studied, and then, the purification capability of TiO₂/ACF was estimated. PCO results showed that although the PCO efficiency increased under high RH and T levels, the amount of adsorption of toluene decreased. Moreover, quantitative analysis results of intermediates indicated that more environmental risk emerged when PCO of toluene was carried out at higher environmental T and RH levels because more toxic intermediates would be accumulated on the TiO₂/ACF. So, it is significant to control the environmental T and RH conditions in the application of the PCO technique. T = 25°C and RH530% is the optimal condition for purifying toluene in our experimental system.     

青海玉树7.1级地震震害特点分析及启示

根据2010年4月14日玉树7.1级地震震害现场调查资料,对其震害特点进行了全面的分析总结,阐述了震区环境及其地质构造背景,对断层效应及场地效应等也进行了分析,并归纳总结了防震减灾的经验与启示。     

’98重庆市的自然灾害与减灾对策

１９９８ 年夏季, 长江流域发生了特大自然灾害。地处长江上游之尾的重庆市,其灾情以山洪和滑坡、崩塌、泥石流等坡地灾害并发为主, 具有与长江中下游地区不同的特殊性。作者分析了重庆市灾情的严重性, 从自然环境和人类活动两方面分析了灾害成因的特殊性,在此基础上提出了坡地灾害的防治对策     

基于功率法的结构⁃TMD减震控制分析∗

建立了结构-TMD振动方程,推导了无控结构和带TMD受控结构基于功率表达的运动方程,分别解释并给出了各种功率表达参数的物理意义,推导了随机激励下结构耗能功率流均值的随机表达式,对比分析了基于功率法的结构-TMD优化方法与其他优化方法的优化分析结果,并对其减震控制效果进行了对比分析。结果表明,结构-TMD系统的参数可以通过耗能功率流随机分析方法所得均值进行优化,且通过功率法优化后,结构在减震效果上优于其他传统方法得到的结果,从耗能功率均值的随机分析和时程功率分析角度证明了TMD控制的有效性;TMD做功功率为负时对结构有控制效果,起吸收转移能量的作用,且功率幅值越大控制效果越好,做功功率为正时则相反。     

Thermal dependency of burrowing in three species within the bivalve genus <Emphasis Type="Italic">Laternula</Emphasis>: a latitudinal comparison

The upper thermal limits for burrowing and survival were compared with micro-habitat temperature for anomalodesmatan clams: Laternula elliptica (Antarctica, 67°S); Laternula recta, (temperate Australia, 38°S) and Laternula truncata (tropical Singapore, 1°N). Lethal limits (LT₅₀) were higher than burrowing limits (BT₅₀) in L. elliptica (7.5–9.0 and 2.2°C) and L. recta (winter, 32.8–36.8 and 31.1–32.8°C) but the same range for L. truncata (33.0–35.0 and 33.4–34.9°C). L. elliptica and L. truncata had a BT₅₀ 0.4 and 2.4–3.9°C, respectively, above their maximum experienced temperature. L. recta, which experience solar heating during midday low tides, had a BT₅₀ 0.7–2.4°C below and a range for LT₅₀ that spanned their predicted environmental maximum (33.5°C). L. recta showed no seasonal difference in LT₅₀ or BT₅₀. Our single genus comparisons contrast with macrophysiological studies showing that temperate species cope better with elevated temperatures. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Utilization of solidified phosphogypsum as Portland cement retarder

The utilization of the phosphogypsum (PG) as cement retarder is both an economical and an ecological approach to treat this solid waste. Cement using raw PG as retarder has two problems pressing for solution,namely, delaying the setting time and difficulty being fed into the cement mill. The soluble phosphates in PG behave as super-retarder and bring about retarding in the setting process of cement made with PG. Two types of solidified phosphogypsum (SPG) were prepared to solve those two problems. The strength and the water stability of the SPG were good enough to ensure that they may be conveyed easily and fed into the cement mill stably. The cements with SPG had a similar setting time and strength as cement made with natural gypsum (NG). The microstructure of two kinds of SPG were observed with SEM. During factory application of SPG, good techniques and economic benefits were obtained.