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981.
With a high population density, immense commercial and industrial activities, Hong Kong produces over two million tonnes of municipal wastewater each day. Until recently, about 50% of the municipal wastewater enters water courses, rivers, and coastal waters without treatment. Untreated organics, heavy metals and refractory synthetic materials accumulate in certain areas, and have led to breakdown of aquatic and marine ecological systems, closure of beaches, red tides and bioaccumulation in seafood. In 1974, a team of consultants was commissioned to study the water pollution problems encountered in Hong Kong. After two decades in the effort to improve the water environment, a flexible framework for environmental planning and management over the following ten years has been designed. This programme comprises (1) establishment of water control zones and pollution control legislation, (2) upgrading of services and facilities for management of municipal sewage and chemical wastes, and (3) construction of the "Strategic Sewage Disposal Scheme". In line with this programme, a priority has been set on implementing a "polluter pays policy" which requires the industries to share the costs of sewage treatment and encourages them to install on-site wastewater pretreatment facilities to reduce wastewater generation and to ensure sustainable development. 相似文献
982.
卫星资料与其它气象信息相结合的有效使用,对当前及未来的短时预报都是一个关键问题。这种与其它气象信息相结合的有效使用,可能涉及到把资料输入到中尺度数值模式或知识库,以及按时间的函数把卫星资料与其它气象资料相结合去解释它们的产品。利用日常可以得到的地球静止气象卫星资料,气象学家能够观察到中尺度机制所导致的中尺度天气的发展。从卫星资料得到的这些见解,正在帮助实现中尺度预报和短时预报。由于日常可以从一系列栩栩如生的卫星云图以及卫星探测资料中得到大量的信息,那么如何更好地从这些资料中提取有用的信息为中尺度预报所用,是气象学家们所面临的最大难点之一。 相似文献
983.
L. Q. ZHANG D. H. ZHAO H. W. SHEN 《国际泥沙研究》2006,21(3):238-247
1 INTRODUCTION The local scour around bridge piers and abutments has always had heightened interest to hydraulic engineers. An accurate and efficient method to estimate the local scour is greatly desired. However, the behavior of flows passing through bri… 相似文献
984.
Radio astronomy observations are frequently impacted by radio frequency interference(RFI). We propose a novel method, named 2σCRF, for cleaning RFI in the folded data of pulsar observations, utilizing a Bayesian-based model called conditional random fields(CRFs). This algorithm minimizes the “energy” of every pixel given an initial label. The standard deviations(i.e., rms values) of the folded pulsar data are utilized as pixels for all subintegrations and channels. Non-RFI data without obvious i... 相似文献
985.
<正>2014年2月《Earthquake Engineering and Engineering Dynamics》出版文章《地震中线性与非线性系统结构碰撞的概率风险分析》,地震引起的结构碰撞对高密度人口城市中的建筑物和其他应用性构筑物,如大跨度桥梁中的相邻桥台,是一种极大的风险。当地震发生时,建筑结构间发生碰撞,导致重大灾害的发生,如1985年墨西哥地震和1995年日本神户地震,造成了巨大损失。 相似文献
986.
采用草鱼前肠灌注和3H-Tyr同位素标记方法,进行酪蛋白小肽和氨基酸对草鱼血液循环和组织蛋白质合成的影响研究。结果表明,灌注酶解酪蛋白(CSP)溶液组的草鱼血液循环中总肽量为19430.82μv/μl,灌注游离氨基酸(FAA)溶液组的草鱼血液循环中总肽量为16033.00μv/μl,前者显著高于后者(P0.05),同时前者的大多数肽段肽量也高于后者,2组血浆中某些肽段肽量有显著(P0.05)或极显著差异(P0.01)。CSP与FAA组草鱼肠道、肝脏、背肌组织蛋白质合成率(%/d)分别为96.84和72.25,98.64和81.65,65.38和46.59,CSP组草鱼显著或极显著高于FAA组(P0.05或P0.05)。草鱼血浆中总肽量和某些肽段肽量分别与草鱼肠道、肝胰脏和背肌组织蛋白质合成率有明显的正相关。实验表明,肠道对酪蛋白小肽的迅速吸收和进入血液循环中的某些小肽可能是促进草鱼组织蛋白合成的重要因素。 相似文献
987.
A spectral response approach for detecting dominant phytoplankton size class from satellite remote sensing 总被引:1,自引:0,他引:1
Robert J W Brewin Samantha J Lavender Nick J Hardman-Mountfor Takafumi Hirata 《海洋学报(英文版)》2010,29(2):14-32
An important goal in ocean colour remote sensing is to accurately detect different phytoplank- ton groups with the potential uses including the validation of multi-phytoplankton carbon cycle models; synoptically monitoring the health of our oceans, and improving our understanding of the bio-geochemical interactions between phytoplankton and their environment. In this paper a new algorithm is developed for detecting three dominant phytoplankton size classes based on distinct differences in their optical signatures. The technique is validated against an independent cou- pled satellite reflectance and in situ pigment dataset and run on the 10-year NASA Sea viewing Wide Field of view Sensor (SeaWiFS) data series. Results indicate that on average 3.6% of the global oceanic surface layer is dominated by microplankton, 18.0% by nanoplankton and 78.4% by picoplankton. Results, however, are seen to vary depending on season and ocean basin. 相似文献
988.
1引言
船上现场对164航次991A、995A和996E孔获取的沉积物进行含水量和孔隙率的测量时,是使用105℃恒温进行烘干的。本项研究主要是为了确认105℃的恒温烘干过程是否造成了测量值的偏高。向干燥的烧杯中加入适量沉积物样品,置于105℃对流恒温烘箱中烘干24小时至36小时(Paull,Matsumoto,Wallace,等,1996),在船上使用此方法烘干沉积物然后测量含水量,利用此含水量数据,再结合干样的质量和体积值,就可以求算出孔隙率(孔隙的体积/样品的总体积)值,许多其它项目的研究都应用了这些数据。 相似文献
989.
Cyanobacterial blooms are a global problem, with their occurrence tightly tied to nutrient loading. We cultured Microcystis aeruginosa FACHB-905 in growth medium with either inorganic(orthophosphate) or organic(β-glycerophosphate or polyphosphate) phosphorus and at different N:P ratios with 50:1, 30:1, 16:1, 4:1 and 1:4, serving as the phosphorus source. Fluorescence parameters were measured to determine the response of cellular responses to nutrient stress. Scanning electron microscopy(SEM) and estimates of antioxidant activity were employed to examine potential mechanisms of physical change. The results demonstrate that inorganic phosphorus was more bioavailable to M. aeruginosa relative to organic phosphorus in culture. The highest cell concentration(2.21×10~6 cells/mL), chlorophyll-a(0.39 pg/cell) and phycocyanin(1.57 pg/cell) quotas and high levels of chlorophyll fluorescence parameters( rETR, E_k, α, φ_(PSⅡ) and F_v/F_m) were obtained when phosphorus was supplied as K_2 HPO_4 at a N:P ratio of 16–30. Organic sources of phosphorus(β-glycerophosphate and polyphosphate) were bioavailable to M. aeruginosa. In addition, too concentrated orthophosphate(N:P=1:4) resulted in the oxidative stress and lipid peroxidation of cell membrane(identified by the antioxidant system activity), and the photosynthetic activity declined consequently. This study has demonstrated the effects of different phosphorus chemistries and N:P ratios on the cyanobacterial growth, photosynthetic activity and cell physiology, which could be an effective tool for predicting cyanobacterial dominance or N-deficiency in natural lakes(due to the superior ability of cyanobacteria for dissolved N and fix atmospheric N in some cases). 相似文献
990.
大厂锡矿床成因综合分析及成矿模式 总被引:3,自引:0,他引:3
本文通过对大厂锡多金属矿床区域成矿地质环境、矿体形态特征、原生金属-矿物分带、矿床地球化学的综合分析与研究,论述了该矿床在许多方面具有喷气沉积成因的特点。为此,我们把大厂锡多金属矿床与块状硫化物矿床、绿岩带金矿床及某些层控锡矿床进行了对比,从而明确了大厂锡矿属于含锡块状硫化物型层控锡矿床。本文还从发展、演化的角度,对大厂层控锡矿形成后的变形-变质作用进行了系统研究,阐明了同生与后生地质现象同时存在的原因,解决了对该矿床所提出彼此矛盾成因假说的难题。最后,建立了大厂锡矿的成因模式,并探讨了该超大型锡矿形成的特殊地质环境。 相似文献