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1.
桂林是广西石灰岩矿的主要产地之一,开采石灰岩的矿山达250个。桂林地区石灰岩矿山的地质环境问题基本类似,发育的地质灾害主要有崩塌、滑坡、岩溶地面塌陷。该文以广西永福某石灰岩矿山为例,在收集矿山地质资料的基础上,通过详细的野外调查,发现该矿山地质环境问题主要为采场的高陡岩质边坡,基岩裸露,破坏和影响了地貌景观,容易引发岩质崩塌灾害;矿山功能区和废渣、表土的堆放占用和破坏了土地资源,可能引发小型的滑坡;灰岩石料加工等人类工程活动致使粉尘污染和噪音污染较为严重,对附近居民的生活环境造成了影响。针对矿山的地质环境问题划分了恢复治理分区,提出了相应的工程措施,恢复治理工程的实施可从根本上改变矿山采场的地貌景观,恢复破坏和压占的土地资源,消除地质灾害隐患,创造绿色矿山,为桂林地区石灰岩矿山的地质环境问题恢复治理提供参考。  相似文献   

2.
三峡库区崩滑地质灾害变形监测技术研究及应用   总被引:1,自引:1,他引:0  
以三峡库区巫山-万州段为例,介绍了GPS在滑坡变形监测中的应用,并开展了InSAR和声发射技术在滑坡、危岩体变形监测应用的试验性研究。同时,根据实际需要,还研制了基于GPRS的地质灾害无线遥测系统,实践证明,该系统具有工程应用价值。  相似文献   

3.
In recent years, many coal-producing countries have paid great attention to the land subsidence causedby coal cutting. In China, because of the dense population in coalfield areas, the land subsidence hazard is more seri-ous. After a brief analysis on the mechanism of land subsidence, this paper gives a comprehensive and systematical ac-count on all kinds of hazards caused by the land subsidence in China. The study shows that land subsidence has endan-gered land, buildings, traffic and communication lines, dykes and dams. It also causes damage to ecological and socialenvironment. In order to lessen the hazard of land subsidence, preventive measures should be taken to reduce the col-lapse amount, such as extraction with stowing, banded mining system, succession and coordination mining system, orhigh-pressure mudflow between rock strata. Measures of reinforcing or moving certain buildings should also be taken toreduce the destructive degree. In order to harness the subsidence land and bring them under control for fanning, mea-sures should be taken such as filling with spoil or fine breeze, excavating the deeper and covering the shallower land.  相似文献   

4.
After Wenchuan earthquake,Code for verification of Seismic Protection of Building is revised and the seismic verification for the buildings of primary and secondary schools is upgraded from Class C to Class B.With this background,nearly one hundred buildings of primary and secondary schools in Jilin Province have been reevaluated by the earthquake-resistant standards and a set of simplified earthquake-resistant evaluation methods based on relevant technical standards and regulations were summarized and presented here.These methods can serve as an important reference for future earthquake-resistant evaluation for primary and secondary school buildings as well as a convenient guide for the relevant construction and modification works.  相似文献   

5.
河南省自然地质条件复杂 ,生态环境脆弱 ,不仅分布有特殊不良地质环境条件和严重的地质灾害 ,而且存在由人类活动引起的诸多环境地质问题。特殊不良地质环境条件主要有特殊不良岩土体 (湿陷性黄土与胀缩土 )、原生地球化学异常 (高氟水、低碘水、咸水 )和次生地球化学异常(土壤盐渍化 ) ;地质灾害有崩塌、滑坡、泥石流、水土流失、地面塌陷、矿坑突水、瓦斯爆炸等 ;环境地质问题有水资源枯竭、水质污染、固体废弃物堆放等。这些已成为制约我省人民生活水平提高和社会经济发展的重要因素  相似文献   

6.
Significant effects of fishing gear selectivity on fish life history   总被引:1,自引:0,他引:1  
Over the past few decades, extreme changes have occurred in the characters of exploited fish populations. The majority of these changes have affected the growth traits of fish life history, which include a smaller size-at-age, an earlier age-at-maturation and among others. Currently, the causes of these life history traits changes still require systematic analyses and empirical studies. The explanations that have been cited are merely expressed in terms of fish phenotypic adaptation. It has been claimed that the original traits of fish can be recovered once the intensity of exploitation of the fish is controlled. Sustained environmental and fishing pressure will change the life history traits of most fish species, so the fish individual’s traits are still in small size-at-age and at earlier age-at-maturation in exploited fish populations. In this paper, we expressed our view of points that fishing gear has imposed selectiv-ity on fish populations and individuals as various other environmental factors have done and such changes are unrecoverable. Ac-cording to the existing tend of exploited fish individual’s life history traits, we suggested further researches in this field and provided better methods of fishery management and thereby fishery resources protection than those available early.  相似文献   

7.
柴达木盆地东北缘地质灾害及防治   总被引:1,自引:0,他引:1  
青海省柴达木盆地东北缘地貌类型复杂,新构造运动强烈,由各种内外应力造成的地质灾害具有类多、发生频繁等现象,集中反映在土地荒漠化、水土流失、草场退化、湖泊萎缩、地震、泥石流及滑坡等面,人类生存环境日趋恶劣。通过对该区各类地质灾害及生态环境现状进行评述,提出了治理建议。  相似文献   

8.
Decreasing fish resources in estuaries is a subject of anthropogenic activities.Studies of the spatiotemporal distribution of fish eggs and larvae can help identify the status and processes underlying recruitment in a fishery.As the fifth largest river estuary in the world,the Huanghe(Yellow)River estuary(HRE)is a typical estuary that has been seriously affected by human activities.Annual surveys on ichthyoplankton and environmental factors were conducted in the months of May of 2005 and 2009-2016 in the HRE to investigate the spatiotemporal distribution of fish eggs and larvae and the associated influencing factors.A total of 23 and 20 species of eggs and larvae,respectively,were collected.The dominant orders were Perciformes(51.2%)and Clupeiformes(25.6%).The average number of fish species eggs and larvae were 6.0 and 4.1 in average abundance of 0.91 and 0.13 ind./m~3,respectively.The dominant species were mainly low-commercial-value small-sized fishes,such as Clupanodon punctatus,Hare,ngula zutnasi,and Acanthogobius,whereas certain traditional commercial fishes,such as Trichiurus lepturus,and Clupea pallasii,were not seen.Analysis of the fish egg and larval community revealed four temporal assemblages and two spatial assemblages.Salinity was the main factor on the spatial distribution of ichthyoplankton communities,the species number and Shannon-Weiner diversity index(H')of the fish egg and larval community near the river mouth with lower salinity were significantly lower than the community far away from the river mouth with higher salinity.In addition,increases of water temperature promoted the number and abundance of fish species eggs,and the areas of abundant prey tended to have a more diversified and abundant of ichthyoplankton species.In overall,overfishing,dam construction,and other human activities were the main drivers that led to the substantial decline in fishery resources in the HRE.  相似文献   

9.
地籍信息服务政策是国家用于引导地籍信息服务业的发展和信息活动的行为规范及准则。文章对我国地籍信息服务政策体系进行了研究和分析,这些政策包括保密法规、信息发布、地籍管理、信息化标准、服务管理和服务收费等方面,涵盖了实施地籍信息服务涉及的主要行为。在此基础上,提出了地籍信息服务标准,加快构建地籍信息数据共享制度等问题的思考。  相似文献   

10.
根据枣庄市峄城区矿山开采对地质环境造成的破坏及对矿业可持续发展调研分析,认为开采不仅对山体、植被等造成了直接破坏,还导致诸如地表塌陷、山体滑坡等安全隐患,矿山环境治理要从思想上、经费上、法律法规上、技术上入手解决,对已关停矿山地质环境治理,除加大宣传力度外,重点落实对矿山地质环境治理工作的责任、治理规划的编制实施,不断完善、探索治理方法和治理技术攻关及对策预案工作。  相似文献   

11.
This study was carried out to investigate the biogenic amines(BAs), physicochemical property and microorganisms in dry salted fish, a traditional aquatic food consumed in China. Forty three samples of dry salted fish were gathered from retail and wholesale markets and manufacturers, which had been produced in various regions in China. Cadaverine(CAD) and putrescine(PUT) were quantitatively the most common biogenic amines. About 14% of the samples exceeded the histamine content standards established by the FDA and/or EU. The highest histamine content was found in Silver pomfret(Pampus argenteus)(347.79 mg kg-1). Five of forty three samples exceeded the acceptable content of TYR(100 mg kg-1), and 23.26% of dried-salted fish contained high contents of biogenic amines(above 600 mg kg-1). In addition, species, regions, pickling processes and drying methods made the physicochemical property, microorganisms and biogenic amines in dry salted fish to be different to some extents. The total plate count(TPC) was much higher than that of total halophilic bacteria in all samples. The biogenic amines, physicochemical property and microbiological counts exhibited large variations among samples. Furthermore, no significant correlation between biogenic amines and physicochemical property and TPC was observed. This study indicated that dry salted fish may still present healthy risk for BAs, depending on the processing methods, storage conditions among others.  相似文献   

12.
The genomic and cDNA sequences of the CD3γ/δ and CD3ε homologues in the mandarin fish, Siniperca chuatsi, were determined. As in other vertebrate CD3 molecules, the deduced amino acid sequences of mandarin fish CD3γ/δ and CD3ε contained conserved residues and motifs, such as cysteine residues and CXXC and immunoreceptor tyrosine-based activation motifs. However, mandarin fish CD3γ/δ and CD3ε showed some differences to their mammalian counterparts, specifically the absence of a negatively charged residue in the transmembrane region of CD3γ/δ. Additionally, while an N-glycosylation site was present in CD3ε, the site was not observed in CD3γ/δ. The CD3γ/δ and CD3ε subunit sequences contain six and five exons, respectively, consistent with homologues from Atlantic salmon, Salmo salar. Phylogenetic analysis also revealed that CD3γ/δ and CD3ε in mandarin fish are closely related to their counterparts in Acanthopterygian fish. Real-time PCR showed CD3γ/δ and CD3ε were expressed mainly in the thymus and spleen in normal healthy fish and, to a lesser extent, in mucosal-associated lymphoid tissues, such as the intestine and gills. When lymphocytes isolated from head kidney were treated with the mitogens phytohemagglutinin, concanavalin, and polyriboinosinic polyribocytidylic acid, mRNA expression levels of CD3γ/δ and CD3ε were significantly elevated within 12 h of treatment. This indicated the presence of T lymphocytes in the head kidney of teleost fish, and also the recognition of mitogens by the lymphocytes. Mandarin fish infected with the bacterial pathogen Flavobacterium columnare also showed an increase in the expression of CD3γ/δ and CD3ε mRNA, indicating that CD3γ/δ and CD3ε lymphocytes are involved in the immune response of this species.  相似文献   

13.
A considerable part of the world's population is currently experiencing a severe scarcity of freshwater and nutrition. Inland aquaculture has the fastest growth in fresh waters, and this contributes to the eutrophication of freshwater bodies. The increase in freshwater aquaculture impacts on the increasing demand for fresh water. A way to overcome this is to develop aquaculture in saline lakes. This article discusses how saline and hypersaline lakes may contribute to overcome this problem and gives a list of fish and shrimp species that can be cultivated in saline lakes. Successful development of aquaculture depends on a healthy cultured stock of commercial fish and shrimps. A sustainable healthy stock of fish and shrimps can be only maintained using live food for the cultured fish larvae, fry and fingerlings. As well as Artemia spp. there are many other crustacean species with the potential for growing in hypersaline waters. At least 26 copepod species around the world can live at a salinity above 100 g/L with 12 species at a salinity higher than 200 g/L, and these all have excellent nutritional value. There is a high potential to use eukaryotic organisms of diff erent taxa in saline/hypersaline aquaculture for food, agri-aquaculture, diff erent industries and as food supplements.  相似文献   

14.
根据最新一轮地质灾害排查结果,烟台市共发育471处地质灾害隐患点,主要类型包括崩塌、滑坡、泥石流、采空塌陷和岩溶塌陷。该文以烟台市地质环境背景和岩土体类型特征为基础,通过对471处地质灾害隐患点进行统计,首先从地质灾害发育数量和发育密度2个方面分析了烟台市地质灾害在各类岩土体类型中的分布特征,然后重点分析了崩塌、滑坡、泥石流、采空塌陷和岩溶塌陷地质灾害与岩土体类型的关系,分析结果表明,崩塌、滑坡、泥石流主要分布在层状变质岩组中,采空塌陷主要分布在侵入岩岩组中,岩溶塌陷发育区土体结构主要为上部第四系松散土体、下部灰岩或大理岩的二元结构。依据地质灾害与岩土体类型相关性分析,可以有针对性地开展地质灾害易发性分区和监测预警工作。  相似文献   

15.
1INTRODUCTIONPolycyclicaromatichydrocarbons (PAHs)depo sit edinmarineenvironmentsfromavarietyofsourcessuchaswastewater,industrialanddomesticdischarges,andoilspills.Themajorityofthesesourcesfrompetrogenicoriginischaracterizedbyadominanceoflowmolecularweightaromaticcompounds,especiallynaphthaleneandalkylatedPAHs(Sportoletal.,1 983 ) .Crudeoilanditsrefinedproductssuchasgasoline,keroseneandotherfu eloilshaveahighcontentofalkylatedPAHsduetotheirslowformationattemperatureslowerthanthatofcomb…  相似文献   

16.
Methods and techniques for the identification, monitoring and management of natural hazards in high mountain areas are enumerated and described. A case study from the western Himalayan Kullu District in Himachal Pradesh, India is used to illustrate some of the methods. Research on the general topic has been conducted over three decades and that in the Kullu District has been carried out since 1994. Early methods of hazards identification in high mountain areas involved intensive and lengthy fieldwork and mapping with primary reliance on interpretation of landforms, sediments and vegetation thought to be indicative of slope fail ures, rock falls, debris flows, floods and accelerated soil surface erosion. Augmented by the use of airphotos and ad hoc observations of specific events over time, these methods resulted in the gradual accumulation of information on hazardous sites and the beginnings of a chronology of occurrences in an area. The use of historical methods applied to written and photographic material, often held in archives and libraries, further improved the resolution of hazards information. In the past two decades, both the need for, and the ability to, accurately identify potential hazards have increased. The need for accurate information and monitoring comes about as a result of rapid growth in population, settlements, transportation infrastructure and intensified land uses and, therefore, risk and vulnerability in mountain areas. Ability has improved as the traditional methods of gathering and manipulating data have been supplemented by the use of remotesensing, automated terrain modeling, global positioning systems and geographical information systems. This paper focuses on the development and application of the latter methods and techniques to characterize and monitor hazards in high mountain areas.  相似文献   

17.
辽宁省矿产资源丰富 ,开发历史悠久 ,规模大、强度高 ,因而诱发了诸多的矿山环境地质问题。按其灾变的时间特征 ,可将其划分为突变型地质灾害和缓变型环境地质问题两大类。崩塌、滑坡、地面塌陷 ,矿坑突水、瓦斯爆炸等地质灾害属于前者 ;水土流失、地下水污染、煤矸石自燃等环境地质问题属于后者。笔者概述了各灾种的发育特征和危害现状 ,分析探讨了其形成的自然因素和人为因素 ,并提出了相应的防灾减灾对策及建议。  相似文献   

18.
Approach to Mountain Hazards in Tibet, China   总被引:1,自引:1,他引:0  
Tibet is located at the southwest boundary of China. It is the main body of the Qinghai-Tibet Plateau, the highest and the youngest plateau in the world. Owing to complicated geology, Neo-tectonic movements, geomorphology, climate and plateau environment, various mountain hazards, such as debris flow, flash flood, landslide, collapse, snow avalanche and snow drifts, are widely distributed along the Jinsha River (the upper reaches of the Yangtze River), the Nu River and the Lancang River in the east, and the Yarlungzangbo River, the Pumqu River and the Poiqu River in the south and southeast of Tibet. The distribution area of mountain hazards in Tibet is about 589,000 km^2, 49.3% of its total territory. In comparison to other mountain regions in China, mountain hazards in Tibet break out unexpectedly with tremendously large scale and endanger the traffic lines, cities and towns, farmland, grassland, mountain environment, and make more dangers to the neighboring countries, such as Nepal, India, Myanmar and Bhutan. To mitigate mountain hazards, some suggestions are proposed in this paper, such as strengthening scientific research, enhancing joint studies, hazards mitigation planning, hazards warning and forecasting, controlling the most disastrous hazards and forbidding unreasonable human exploring activities in mountain areas.  相似文献   

19.
Evaluation of the damage in fish spermatozoa cryopreservation   总被引:4,自引:0,他引:4  
Cryodamages occur during sperm cryopreservation. Cryopreservation of fish sperm usually results in marked decrease in sperm quality, such as swelling or disruption of the plasma membrane, mitochondrial dysfunction, diminished sperm motility, impaired velocity, shorter motility period, denaturation, and release of some enzymes from spermatozoa. In this paper, damages in morphology, physiology, biochemistry and metabolism, and genetic integrity of fish semen after cryopreservation are discussed. New approaches in assessment of fish thawed sperm quality such as computer assisted sperm analysis, flow cytometic analysis combined with fluorescent probes and single cell gel electrophoresis are also briefly reviewed.  相似文献   

20.
德州市地质灾害与环境地质问题主要有地下水降落漏斗、地面沉降、地面塌陷、地下水污染和地方病等 ,其发育除受地质、水文地质条件制约外 ,还与人为因素有关。本文对地质灾害的分布、危害程度和致灾因素做了分析 ,并提出了相应的防治对策。  相似文献   

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