Identifying human-induced influence on microbial community: A comparative study in the effluent-receiving areas in Hangzhou Bay

Microbial compositions showed high differences in two study areas. COD was the key anthropogenic indicator in the coastal wastewater disposal area. Distinctive microbes capable of degrading toxic pollutants were screened. Microbial communities in effluent-receiving areas followed “niche theory”. Microbial community structure is affected by both natural processes and human activities. In coastal area, anthropegenetic activity can usually lead to the discharge of the effluent from wastewater treatment plant (WWTP) to sea, and thus the water quality chronically turns worse and marine ecosystem becomes unhealthy. Microorganisms play key roles in pollutants degradation and ecological restoration; however, there are few studies about how the WWTP effluent disposal influences coastal microbial communities. In this study, sediment samples were collected from two WWTP effluent-receiving areas (abbreviated as JX and SY) in Hangzhou Bay. First, based on the high-throughput sequencing of 16S rRNA gene, microbial community structure was analyzed. Secondly, several statistical analyses were conducted to reveal the microbial community characteristics in response to the effluent disposal. Using PCoA, the significant difference of in microbial community structure was determined between JX and SY; using RDA, water COD and temperature, and sediment available phosphate and ammonia nitrogen were identified as the key environmental factors for the community difference; using LDA effect size analysis, the most distinctive microbes were found and their correlations with environmental factors were investigated; and according to detrended beta-nearest-taxon-index, the sediment microbial communities were found to follow “niche theory”. An interesting and important finding was that in SY that received more and toxic COD, many distinctive microbes were related to the groups that were capable of degrading toxic organic pollutants. This study provides a clear illustration of eco-environmental deterioration under the long-term human pressure from the view of microbial ecology.     

Changes in Soil Properties After Establishment of Artemisia halodendron and Caragana microphylla on Shifting Sand Dunes in Semiarid Horqin Sandy Land, Northern China

In the semiarid Horqin sandy land of northern China, establishment of artificial sand-fixing shrubs on desertified sandy lands is an effective measure to control desertification and improve the regional environment. Caragana microphylla Lam. and Artemisia halodendron Turcz. ex Bess. are two of the dominant native shrub species, which are adapted well to windy and sandy environments, and thus, are widely used in revegetation programs to control desertification in Horqin region. To assess the effects of artificially planting these two shrub species on restoration of desertified sandy land, soil properties and plant colonization were measured 6 years after planting shrubs on shifting sand dunes. Soil samples were taken from two depths (0–5 cm and 5–20 cm) under the shrub canopy, in the mid-row location (alley) between shrub belts, and from nonvegetated shifting sand dune (as a control). Soil fine fractions, soil water holding capacity, soil organic C and total N have significantly increased, and pH and bulk density have declined at the 0–5-cm topsoil in both C. microphylla and A. halodendron. At the 5–20 cm subsurface soil, changes in soil properties are not significant, with exception of bulk density and organic C concentration under the canopy of A. halodendron and total N concentration under the canopy of C. microphylla. Soil amelioration processes are initiated under the shrub canopies, as higher C and N concentrations were found under the canopies compared with alleys. At the same time, the establishment of shrubs facilitates the colonization and development of herbaceous species. A. halodendron proved to have better effects in fixing the sand surface, improving soil properties, and restoring plant species in comparison to C. microphylla.     

更新观念转换机制

近两年来．海淀区地震办公室在区政府的领导下，在中国地震局的大力支持和北京市地震局的具体指导下．更新观念．转变理念，开阔视野，借助区域优势．转换机制．在新的形势下重新确定工作思路。调整工作定位．加强管理．积极探索，努力实践，在夯实基础上下功夫．防震撼灾各项工作的局面逐渐打开，呈现良好发展势头：2004年建立了海淀区青少年防灾减灾科普教育基地，     

液化石油气贮配站安全评价的实践

针对液化石油气贮配站火灾爆炸危险性大的特点，采用规范评价和危险度分级相结合的方法，对其进行安全评价，为液化石油气贮配企业进行整改、保障自身安全和社会公共安全，以及政府有关部门对液化石油气贮配企业实施宏观管理，提供科学的依据。     

黄河山东段断流的成因及对策

近年来黄河下游断流时段、断流河段逐年延长, 断流开始日期逐年提前, 下游黄河面临决口改道的险境。同时, 下游的经济发展受到很大损失, 生态平衡受到严重破坏。本文分析产生的原因、指出危害、总结过去认识上的不足、探讨性的提出解决的对策     

水稻壮秧分蘖剂苗期抗冷效果初探

利用人工气候室在苗期施用水稻壮秧分蘖剂对水稻秧苗的形态及生理方面的表现进行了探讨。结果表明：水稻壮秧分蘖剂具有增加秧苗干物重,提高秧苗素质,降低电解质渗出率和提高脯氨酸含量的作用。同时增加了秧苗的分蘖能力和提高水稻产量。     

Engineering properties of asphalt concrete made with recycled glass

Taiwan is an island nation with high population density: 23 million people living in a total land area of 30 000 sq. km. The island has transformed from an agricultural society to an industrial one in the past three decades. Coming with the transformation is a cumulated waste problem. Taiwan produces nearly 5 million tons of waste each year, of which 10% is of glass materials. Bureau of Highway Department funded a research program to investigate ways of recycling the glass waste. This report presents information on the program and laboratory/field test data. Materials used in the test program included 85/100 asphalt, Type II modified asphalt, and treated glass waste. Four glass contents: 0, 5, 10, and 15%, in terms of the total aggregate weight, were used in the mixture designs for casting series of 10 cm diameter by 6.35 cm disk specimens. Tests including Marshall stability value, dry/wet moisture damage, skid resistance, light reflection, water permeability, and compaction were carried out in accordance with the ASTM and AASHTO procedures. The test results reveal that glass waste is a viable material for asphalt concrete that has been widely used in pavement that offers profound engineering and economic advantages.     

人工神经元网络在事故应急对策中的应用

本文简述了人工神经元网络的结构及其特征。介绍了人工神经元网络BP算法在大型炼油厂灾害、事故防治对策中的应用,并以停水、停电为例进行了仿真运算。结果表明,采用人工神经元网络做出的决策符合实际情况和人的思维逻辑,可克服传统专家系统的某些不足,具有一定的实用价值。     

在安全评价中应用优化技术的探讨

在安全评价中，针对企业安全投资有限的条件，综合应用０—１整数规划、层次分析法和有关职业危害分级标准，对企业安全状况的优化途径进行了探讨。     

唐山7.8级地震短临前兆场源特征的研究

为了通过场的动态监视和源的过程追踪以实现地震预报,以唐山7.8级地震为例,研究了震前各种前兆方法观测到的短临异常的场兆和源兆的特征。通过研究得出:场兆数量多、密度小、异常台项比低,源兆数量少、密度大、异常台项比高;台点多的地下水位和流动重力较易区分场兆和源兆的差异性;源兆主要分布在一些断裂构造形成的闭锁区内,场兆主要分布在闭锁区附近一些活动断裂及交汇部位。