赤潮的监测和防治简介

近海水域有机物污染,引起海水富营养化,是形成赤潮的主要原因。赤潮不仅给渔业生产、海水养殖业带来重大损失,而且破坏了海洋环境,危及人民的健康。近年来,我国沿海赤潮时有发生,应加强对有发生赤潮潜在危险海区的经常性观测和监测;切实控制沿海工业和生活污水的任意排放;科学、合理地开发利用海洋资源;推广科学养殖技术,防止海水养殖自身污染;大力开展有关赤潮科学的研究,特别是赤潮的防治方法和技术研究,避免或减少赤潮造成的危害     

对虾暴发性流行病及其预防研究

１９９３～１９９４年我国沿海养殖对虾发生了特大的暴发性流行病，损失惨重。本文报道该病的特点、症状及危害，并在患病的中国对虾、日本对虾、长毛对虾的中肠、肝胰腺的上皮细胞核和细胞质及腹肌纤维间质中发现大量具有囊膜的杆状病毒。通过病毒引起宿主靶组织细胞的病理变化、无包涵体等特性分析，认为该病毒属于有囊膜杆状病毒科Ｃ亚群，不同于已知的对虾所有杆状病毒，为对虾的一类新致病病毒。文中还分析了主要致病原因，通过调查和试验提出８条有针对性的预防措施。     

Biochemical Mechanism of the Eutrophication and Its Prevention—the Deep Treatment of Waste Water and Its Denitrification and Dephosphorization

Biochemical mechanism of forming the red tide is discussed in this paper.The existence of a large number of nitrates and phosphates in the eutrophic water is the prerequisite of explosive increase of algae and the forming of red tide.Reduction of eutrophication is an important approach to preventing the red tide.The method of deep treatment of the waste water and its denitrification and dephosphorization are introduced,and a new opinion on the red tide formation and fundamental prevention is put forward.     

湖南煤炭坝矿区岩溶水害特征及防治对策

煤炭坝矿区是全国闻名的大水矿区,矿区最大涌水量已超过12000m^3／h,年排水费用达1．2亿元,吨煤成本达150元,并呈上升趋势,严重影响了煤矿的安全生产。本文在详细论述煤炭坝矿区水文地质特征的基础上提出了切实可行的治理思路,治理方法,并进行了效益预测。对矿区防治水患具有指导性作用。     

焦作-郑州天然气输气管道工程地质灾害防治措施及防治建议

焦作-郑州天然气输气管道是较重要建设项目,输气管道起自焦作市博爱县磨头镇,南止郑州市惠济区古荥镇,该输气管道沿线地质环境条件复杂程度为简单-中等。地质灾害类型主要为崩塌、地裂缝、地面不均匀沉陷,黄土湿陷和沙土液化等地质灾害。工程建设有引发和加剧崩塌灾害的可能性,有遭受地质灾害的危险性。工程建设过程中应针对不同的灾害类型采取适当的预防或治理措施。     

首都减灾圈的思考与建议

首都减灾圈,系首都减轻自然灾害预测防治圈。1991年12月20—21日在北京召开了《首都圈自然灾害及其减灾对策研讨会》。本文根据这次会议所提供的材料,在从整体上实现减灾的思想指导下,就首都减灾圈的“成灾背景”、“首都减灾圈的组成”、“首都减灾圈的灾害预测与防治状况”、“首都减灾圈的灾害关联性分析”、“首都减灾圈的减灾实效预估”和“首都减灾圈的减灾对策与实施”等六个带有共同性的问题,进行了讨论。供制定首都圈减灾方案时参考。     

Displacement-length scaling relations for faults on the terrestrial planets

Displacement-length (D/L)scaling relations for normal and thrust faults from Mars, and thrust faults from Mercury, for which sufficiently accurate measurements are available, are consistently smaller than terrestrial D/L ratios by a factor of about 5, regardless of fault type (i.e. normal or thrust). We demonstrate that D/L ratios for faults scale, to first order, with planetary gravity. In particular, confining pressure modulates: (1) the magnitude of shear driving stress on the fault; (2) the shear yield strength of near-tip rock; and (3) the Young's (or shear) modulus of crustal rock. In general, all three factors decrease with gravity for the same rock type and pore-pressure state (e.g. wet conditions). Faults on planets with lower surface gravities, such as Mars and Mercury, demonstrate systematically smaller D/L ratios than faults on larger planets, such as Earth. Smaller D/L ratios of faults on Venus and the Moon are predicted by this approach, and we infer still smaller values of D/L ratio for faults on icy satellites in the outer solar system. Collection of additional displacement-length and down-dip height data from terrestrial normal, strike-slip, and thrust faults, located within fold-and-thrust belts, plate margins, and continental interiors, is required to evaluate the influence of fault shape and progressive deformation on the scaling relations for faults from Earth and elsewhere.     

Correlations in aftershock and seismicity patterns

Correlations in space and time play a fundamental role in earthquake processes. One direct manifestation of the effects of correlations is the occurrence of aftershocks due to the stress transfer in the vicinity of a main shock. Less obvious and more speculative changes in correlations may occur in the background seismicity before large earthquakes. Using statistical physics it is possible to introduce a measure of spatial correlations through a correlation length. This quantity characterizes how local fluctuations can influence the occurrence of earthquakes over distances comparable with the correlation length. In this work, the physical basis of spatial correlations of earthquakes is discussed in the context of critical phenomena and the percolation problem. The method of two-point correlation function is applied to the seismicity of California. Well defined variations in time of the correlation length are found for aftershock sequences and background seismicity. The scaling properties of our obtained distributions are analyzed with respect to changes in several scaling parameters such as lower magnitude cutoff of earthquakes, the maximum time interval between earthquakes, and the spatial size of the area considered. This scaling behavior can be described in a unified manner by utilizing the multifractal fit. Utilizing the percolation approach the time evolution of clusters of earthquakes is studied with the correlation length defined in terms of the radius of gyration of clusters. This method is applied to the seismicity of California.     

江西省宜春城区地面塌陷特征及防治建议

宜春城区属岗阜低丘地形,分布石炭系-二叠系覆盖型及裸露型碳酸盐岩,占城区面积近70%。浅部岩溶发育,覆盖层厚度一般小于20m,土洞较多,基岩面起伏大,第四系岩性结构复杂,地下水埋藏浅。由于抽采地下水及建筑施工振动等人为因素影响,诱发地面塌陷12处,造成重大经济损失。在城市规划功能布局时应充分考虑地面塌陷的易发程度及场地建设适宜性;应限制诱发塌陷因素的强度,在易发区须严格控制地下水开采,严禁新建开采井;塌陷治理的主要方法有填堵、跨越、灌注、深基础控制抽排水强度、及其它综合治理或避让方法,同时做好灾害的监测预报工作。