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151.
1引言
在战场上,个体防护装备对士兵有效地发挥战斗力和避免伤亡起到关键的作用。现代科学技术在军事领域的广泛应用,使得防护装备突破了传统模式,新一代的单兵防护装备不仅要抵御武器的袭击,而且要避免自然环境、化学试剂、火焰和其他战场灾难的危害,须成为高度智能化的作战服。 相似文献
152.
Improvements of nano-SiO2 on sludge/fly ash mortar 总被引:1,自引:0,他引:1
Sewage sludge ash has been widely applied to cementitious materials. In this study, in order to determine effects of nano-SiO(2) additives on properties of sludge/fly ash mortar, different amounts of nano-SiO(2) were added to sludge/fly ash mortar specimens to investigate their physical properties and micro-structures. A water-binding ratio of 0.7 was assigned to the mix. Substitution amounts of 0%, 10%, 20%, and 30% of sludge/fly ash (1:1 ratio) were proposed. Moreover, 0%, 1%, 2%, and 3% of nano-SiO(2) was added to the mix. Tests, including SEM and compressive strength, were carried out on mortar specimens cured at 3, 7, and 28 days. Results showed that sludge/fly ash can make the crystals of cement hydration product finer. Moreover, crystals increased after nano-SiO(2) was added. Hence, nano-SiO(2) can improve the effects of sludge/fly ash on the hydration of mortar. Further, due to the low pozzolanic reaction active index of sludge ash, early compressive strengths of sludge/fly ash mortar were decreased. Yet, nano-SiO(2) could help produce hydration crystals, which implies that the addition of nano-SiO(2) to mortar can improve the influence of sludge/fly ash on the development of the early strength of the mortar. 相似文献
153.
An air quality monitoring network (AQMN) usually performs the basic function of assessment of regional air quality and demonstration of compliance with ambient air quality standards in an urban area. Different pollutants, however, may present different characteristic variabilities due to their specific emission patterns, rates of diffusion, and transport and transformation behaviors. But the costs of siting in a pollutant-specific monitoring network would be higher than that for a common network with respect to several pollutants monitored simultaneously. This paper presents a survey of multi-pollutant design principles and optimal searches for siting patterns of an AQMN using both simulation and optimization models as a combined tool. While conservative, quasi-stable, and reactive pollutants are considered in the design principles, cost, coverage effectiveness, and spatial correlation characteristics are included in the multi-criteria decision making process. For illustrative purpose, a series of technical settings and two types of objectives were examined in the case study for the city of Kaohsiung in Taiwan. 相似文献
154.
姜长宁 《防灾减灾工程学报》2001,21(2):1-5
依据江苏数字地震台网的几何布局 ,对区域上设定的不同震级和震源位置的可能事件 ,作了以下两点考虑。 (1)根据不同震级地震的监测范围 ,确定了相应的定位子台组合。 (2 )对同一地震事件 ,考虑到震相分析P震相和S震相测量精度上的差异 ,引入了不同的标准误差σP 和σS。在此基础上 ,通过模拟地震波理论走时和对走时矩阵的奇异值分解方法 ,计算了估计震源参数标准误差的参量空间协方差矩阵值 ,给出了标准误差理论值等值线图 ,用此方法讨论分析了江苏数字地震台网的地震定位能力。 相似文献
155.
Hung-Hui Chen Liang-Cheng Chang Hsin-Yu Shan Jui-Pin Tsai 《Environmental Modeling and Assessment》2009,14(6):715-728
The hysteresis of capillary pressure versus saturation (P–S) relation is an important constitutive relation in multiphase flow, since the P–S relation is widely used to predict P–S relations in the simulation of the non-aqueous phase liquids (NAPLs). This work examined the performance of the scaling rule
on predicting the P–S relationship and then studied the joint impact of the scaling and hysteresis on the multiphase NAPL flow simulation. Various
experimental P–S values of distinct fluid pairs were compared with the scaled P–S curves using the scaling rule. The comparison indicated that the prediction of P–S is more accurate when the water–air P–S curve is used to scale other P–S curves. The joint impact of the scaling and hysteresis on the NAPLs flow simulation was then investigated by numerical simulation
studies. The NAPL simulator was used to simulate the outcome of several scenarios based on a system with water–NAPL–air in
a hypothetical sand tank. For both gasoline and trichloroethylene, the difference of the injected NAPL volume between no hysteretic
and hysteretic simulations over a given time period was the smallest when the water–air P–S curve was used to scale other P–S curves. Simulation results of this study are valuable references for predicting the distribution of NAPLs. 相似文献
156.
The removal of the organic toxic chemicals di-n-butyl phthalate (DBP), di-2-ethyl hexyl phthalate (DEHP), nonylphenol (NP), and bisphenol-A (BPA) by laccase obtained from the spent mushroom compost (SMC) of the white rot fungi, Ganoderma lucidum, was investigated. The optimal conditions for the extraction of laccase from SMC required using sodium acetate buffer (pH 5.0, solid : solution ratio 1 : 5), and extraction over 3 h at 4 °C. The removal of NP was enhanced by adding CuSO(4) (1 mM), MnSO(4) (0.5 mM), tartaric acid (20 mM), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS; 1 mM), and 1-hydroxybenzotriazole (HBT; 20 mg L(-1)), with ABTS yielding a higher NP removal efficiency than the other additives. At a concentration of 2 mg L(-1), DBP, DEHP, NP, and BPA were almost entirely removed by laccase after incubation for 1 day. The removal efficiencies, in descending order of magnitude, were DBP > BPA > NP > DEHP. We believe that these findings could provide useful information for improving the efficiency of the removal of organic toxic chemicals in the environment. 相似文献
157.
The vulnerability analysis method has been widely used in many environmental fields. In recent years, the tool has succeeded in comprehensive assessment of environmental problems. This study applied the vulnerability and resilience analysis method on watershed conservation and grasped the environmental change capacity that watershed could bear. The Fei-tsui reservoir watershed in Northern Taiwan provided the setting for the case study reported herein. This study considered both internal and external effect factors, including watershed vulnerability, rainfall energy and the distances between the outlet and subbasins, and developed a new index, WP, for the priority restraints strategies on the land-use activities. The land-use restraint index can be a significant criterion for watershed protection and management strategies. 相似文献
158.
This article reports on soil samples collected from Hsiang-Shan wetland, Taiwan. Canonical discriminant analysis (CDA) was applied to identify an existing habitat type's scheme by identifying the physico-chemical properties of sediment in Hsiang-Shan wetland. The three constructed discriminant functions (CDFs) showed a marked contribution by most of the discriminant variables, and the recognition capacities in these three CDFs were 49.5, 32.8 and 17.7%. Our study revealed that the most important latent factors in Hsiang-Shan wetland are soil texture-caused factor, ocean current-caused factor, nutrient-caused factor, and the redox reaction-caused factor. And the most sensitivity parameters in this habitat followed the descending order: OBD, EC, Eh, sand, TN, porosity, STP, silt, VCP and pH. And the inhabited sediment properties for U. formosensis in terms of soil texture are sand, silt, and clay (34.05, 29.72, and 32.35%, respectively): that is clay loam soil. We also found that U. formosensis preferred to inhabit the upper intertidal zone, spending 8.41% of the time submerged. Vegetation coverage on the ground was less than 2.20%, showing that it preferred to live in a bare intertidal habitat. Concerning nest choosing, excavating burrows is more difficult when a high soil penetration force is required, and in this study the soil penetration force for 20 cm was found to be is 45.98 N/cm(2). The results will be helpful in developing a methodology for use by the government in refining its management programs. 相似文献
159.
The objective of this study is to assess the risk of insufficient water supply posed by high-turbidity water. Several phenomena
can pose risks to the sufficiency of a water supply; this study concerns risks to water treatment plants from particular properties
of rainfall and raw water turbidity. High-turbidity water can impede water treatment plant operations; rainfall properties
can influence the degree of soil erosion. Thus, water turbidity relates to rainfall characteristics. Exceedance probabilities
are presented for different rainfall intensities and turbidities of water. When the turbidity of raw water is higher than
5,000 NTU, it can cause operational problems for a water treatment plant. Calculations show that the turbidity of raw water
at the Ban-Sin water treatment plant will be higher than 5,000 NTU if the rainfall intensity is larger than 165 mm/day. The
exceedance probability of high turbidity (turbidity >5,000 NTU) in the Ban-Sin water treatment plant is larger than 10%. When
any water treatment plant cannot work regularly, its ability to supply water to its customers is at risk. 相似文献
160.
Haozhi Long Yilin Wang Sijing Chang Guangxiu Liu Tuo Chen Guanghua Huo Wei Zhang Xiukun Wu Xisheng Tai Likun Sun Baogui Zhang 《Environmental monitoring and assessment》2017,189(3):116
The aim of this study was to survey the response of the microbial community to crude oil and the diversity of alkane hydroxylase (alkB) genes in soil samples from the Qinghai-Tibet Plateau (QTP). The enrichment cultures and clone libraries were used. Finally, 53 isolates and 94 alkB sequences were obtained from 10 pristine soil samples after enrichment at 10 °C with crude oil as sole carbon source. The isolates fell into the phyla Proteobacteria, Actinobacteria, and Bacteroidetes, with the dominance of Pseudomonas and Acinetobacter. The composition of degraders was different from polar habitats where Acinetobacter sp. is not a predominant responder of alkane degradative microbial communities. Phylogenetic analysis showed that the alkB genes from isolates and enrichment communities formed eight clusters and mainly related with alkB genes of Pseudomonas, Rhodococcus, and Acinetobacter. The alkB gene diversity in the QTP was lower than marine environments and polar soil samples. In particular, a total of 10 isolates exhibiting vigorous growth with crude oil could detect no crude oil degradation-related gene sequences, such as alkB, P450, almA, ndoB, and xylE genes. The Shannon-Wiener index of the alkB clone libraries from the QTP ranged from 1.00 to 2.24 which is similar with polar pristine soil samples but lower than that of contaminated soils. These results indicated that the Pseudomonas, Acinetobacter, and Rhodococcus genera are the candidate for in situ bioremediation, and the environment of QTP may be still relatively uncontaminated by crude oil. 相似文献