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201.
采用间歇振荡法,研究了钢渣吸附模式、选择性以及等温吸附方程。结果表明,钢渣对阳离子的吸附容量远远大于对阴离子的吸附容量,其吸附模式属于离子交换;其对重金属离子具有一定的吸附选择性,其选择性能与离子的电性、电价、离子半径和水化热等因素有关;钢渣吸附Pb2+是单层吸附,符合Langmuir等温吸附方程。 相似文献
202.
湖南省雷电特征及闪电数据分析 总被引:1,自引:0,他引:1
湖南是雷暴多发区,雷暴分布是南多北少,西多东少。近35年地面雷暴观测数据显示,全省年平均雷暴数呈下降趋势。湖南闪电以负地闪为主,占总地闪的94.59%,平均闪电强度随着海拔高度的增加而加大,长沙、韶山为闪电强度低值中心。一天中13~20时是闪电高发期,正地闪的平均能量要大于负地闪。 相似文献
203.
Yuanhang Zhang Yanhui Liu Jiayin Li Yufang M Ming Zhou Zhaofeng Tan Limin Zeng Keding Lu 《环境科学学报(英文版)》2023,123(1):522-534
The atmospheric chemical mechanism is an essential component of airshed models used for investigating the chemical behaviors and impacts of species. Since the first tropospheric chemical mechanism was proposed in the 1960s, various mechanisms including Master Chemical Mechanism (MCM), Carbon Bond Mechanism (CBM), Statewide Air Pollution Research Center (SAPRC) and Regional Atmospheric Chemistry Mechanism (RACM) have been developed for different research purposes. This work summarizes the development and applications of these mechanisms, introduces their compositions and lumping methods, and compares the ways the mechanisms treat radicals with box model simulations. CBM can reproduce urban pollution events with relatively low cost compared to SAPRC and RACM, whereas the chemical behaviors of radicals and the photochemical production of ozone are described in detail in RACM. The photolysis rates of some oxygenated compounds are low in SAPRC07, which may result in underestimation of radical levels. As an explicit chemical mechanism, MCM describes the chemical processes of primary pollutants and their oxidation products in detail. MCM can be used to investigate certain chemical processes; however, due to its large size, it is rarely used in regional model simulations. A box model case study showed that the chemical behavior of OH and HO2 radicals and the production of ozone were well described by all mechanisms. CBM and SAPRC underestimated the radical levels for different chemical treatments, leading to low ozone production values in both cases. MCM and RACM are widely used in box model studies, while CBM and SAPRC are often selected in regional simulations. 相似文献
204.
Ma Xiaoling Tan Hongbin Su Xuemei Hou Xiong Dong Faqin Yang Feihua 《Journal of Material Cycles and Waste Management》2022,24(4):1542-1550
Journal of Material Cycles and Waste Management - Red gypsum comes from TiO2 production industry by sulfate method, which comes from the low acidic liquid stream treatment using lime or limestone.... 相似文献
205.
Tan Yan-Ling Chen Jen-Eem Yiew Thian-Hee Habibullah Muzafar Shah 《Environmental science and pollution research international》2022,29(42):63260-63276
Environmental Science and Pollution Research - South and Southeast Asia is by far the most populous region in Asia, with the greatest number of threatened species. Changes in habitat are a major... 相似文献
206.
Simon Anthony Morley Koh Siang Tan Robert W. Day Stephanie M. Martin Hans-O. Pörtner Lloyd S. Peck 《Marine Biology》2009,156(10):1977-1984
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. 相似文献
207.
不同种植制度土壤氧化还原酶活性和动力学特征 总被引:1,自引:0,他引:1
土壤质量与土壤的生物学性质密切相关,种植制度对土壤生物学特性的影响研究对土壤质量管理具有重要的意义.以黑龙江853农场不同种植制度土壤为研究对象,探讨种植制度对土壤理化性质,过氧化氢酶、脱氢酶活性和动力学特征的影响.主要研究结果:农作物轮作有利于提高土壤全碳含量,而大豆连作和玉米-大豆轮作使土壤有效氮和全氮含量提高,大豆连作土壤pH显著低于其它作物连作及轮作处理,全磷含量显著高于其它处理;2种轮作体系均提高土壤过氧化氢酶活性和催化能力,且催化能力的提高源于酶的Km降低(即酶-底物亲合力提高);玉米-小麦-大豆轮作提高土壤脱氢酶活性及催化能力,其催化能力的提高由2个动力学参数的变化共同决定,禾本科作物连作土壤动力学参数与豆科作物种植(大豆连作及与禾本科轮作)具有显著差异.本文的研究表明,合理的轮作方式是提高土壤生物学活性的有效手段. 相似文献
208.
Since the early 1970s, Singapore has enacted a number of measures to tackle traffic congestion, including measures to restrain vehicle ownership. Although Singapore's per capita GDP is comparable to that of OECD countries, the present car-ownership level in Singapore (10 cars per 100 people) is only a fraction of levels in the OECD countries. Traffic flow in this city-State is relatively smooth, even during peak hours. Although the measures taken were aimed primarily at tackling traffic congestion, they have had other positive impacts, such as reducing energy consumption, air pollution and CO2 emissions. This article presents an overview of the transportation measures and initiatives in Singapore, and analyses two of the transport demand management measures in detail: the vehicle restraint measure, in particular the unique vehicle quota system introduced in 1990; and the two road pricing systems, i.e. the area licensing scheme (ALS) that operated from 1974 to 1998, and the electronic road pricing system (ERP) that went into operation in 1998. Energy and environmental impacts are then discussed, and finally factors contributing to the success of these schemes. Although certain conditions are unique to Singapore, the experience shows that substantial energy and environmental benefits can be achieved through managing urban transportation system in an integrated and innovative way. 相似文献
209.
210.
Ting Guo Zhipeng Bai Can Wu Tan Zhu 《Frontiers of Environmental Science & Engineering》2008,2(2):224-229
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. 相似文献