四川攀枝花小河流域地质灾害发育分布规律浅析

小河流域地处四川省攀枝花仁和区境内,地势南高北低,山脉走向近南北,岭谷相间。总体为中-大起伏中山地貌,较复杂的地形为滑坡、崩塌、泥石流的发生提供了空间,流域内地质灾害的发生一定程度影响了当地经济的发展。本文通过对区内23处地质灾害点的分析,讨论了流域地质灾害的主控因素及发育、分布规律,为科学合理地评价预测地质灾害的发展趋势与可能造成的危害提供参考资料。     

提高线要素匹配率的动态化简方法

矢量线要素匹配是当前空间数据匹配领域的研究焦点之一。本文提出了一种提高已有匹配算法正确率的线要素动态化简方法。首先,对待匹配双方利用开方根规律分别确定各自的化简阈值范围;其次,令化简参数在线要素各自的阈值范围内以一定的步长变化,对每条线要素分别进行化简,每完成一次化简,重新计算待匹配双方的匹配相似度,并与上一次化简后的匹配相似度进行比较,最终得到最高的匹配相似度值;最后,根据获取的最高匹配相似度来判断其是否成功匹配。该算法是一种以动态化简来带动动态匹配的过程。通过化简提取线要素主要形态,降低了局部细节对已有匹配算法的影响,从而提高了匹配正确率。试验验证及对比分析证明了本方法的科学性和普适性。     

新疆城镇化与生态环境耦合关系分析

以典型的干旱地区新疆为例,用熵值法计算1996—2014年城镇化与生态环境综合发展水平及各要素的权重,运用熵增定律对二者的耦合关系进行分析。研究结果表明:新疆城镇化与生态环境的耦合关系呈现出非平稳的波浪形上升过程,耦合模式以磨合、拮抗型为主,显示出城镇化推进是以牺牲生态环境为代价的,且破坏程度在不断加剧,但恶化加剧的幅度却在不断缩小,趋于稳定。从影响城镇化与生态环境耦合关系的"要素流"角度进行剖析,提出适合新疆城镇化生态发展的主要路径。     

我国北极航道开拓的战略选择初探

对于我国,正在发展和形成中的洲际贸易航线——北极航道是当今经济全球化、政治多极化和气候变化大趋势下出现的重大机遇,也是"一带一路"的重要补充,具有较高战略价值。根据北极航道当前发展状况,从开拓北极航道的战略选择角度,针对航运条件、法律和地缘政治等方面对北极东北航道、西北航道和穿极航道三条不同海运路径做了概括性比较,以期为北极航道发展的战略选择做一些前期思考。结果表明:(1)近年来虽然世界贸易和航运业不景气,但北极航运逆势而上,呈现扩大化增长趋势,无强力破冰船引航的商船独立航行时代已初显端倪;(2)三条北极航道处于不同发展阶段:东北航道发展最快,散货船和油气轮方式的资源和过境运输已形成小规模的运营业务;西北航道次之,正在尝试散货船的资源运输;穿极航道过境通行潜力开始受到越来越多关注。三条航道的集装箱过境运输尚处于空白;(3)针对三条北极航道不同发展阶段和趋势,结合战略需求,我国北极航道开拓应采取"用一个、试一个、探一个"的发展思路,即:东北航道做实质性的投入;西北航道做尝试性的投入;穿极航道做探索性的投入。投入重点当为我国有较大需求的中-欧和中-美集装箱船过境运输;(4)科学考察和商业利用是我国北极航道开拓和利用的先导,鉴于北极航道的不同国际法和地缘政治环境,作为"一带一路"北线的实施可采取"对接"和"探索"并行的发展策略。     

胶西北招平断裂带南段金矿勘查模型及找矿方向

招平断裂带是胶西北重要的控矿构造带之一,其南段是下一步重点找矿地区。本文描述了南段已发现的金矿床地质特征,研究了其成矿规律。结果认为,"S"形构造控制矿床产出,不同构造性质决定了矿床类型。根据地层、构造、岩浆岩,各类异常、矿化信息,建立了区域勘查模型和矿床勘查模型,其中构造要素和蚀变矿化标志是重要的成矿要素。进一步指出在萌山-黄同段、张家庄-山旺段应加强勘探工作,已知矿床深部和外围有较大的找矿潜力。     

COSTS AND BENEFITS OF POLLUTION CONTROL IN PENNSYLVANIA,NEW YORK,AND NEW JERSEY, 1840–1906

ABSTRACT. Judges in Pennsylvania saw the costs and benefits of protecting people from industrial pollution quite differently from judges in New York and New Jersey between 1840 and 1906. Not only did they invoke balancing doctrine more than did judges in New York and New Jersey; but when costs and benefits were considered, Pennsylvania judges almost always concluded that the price of pollution abatement was too high to justify enjoining polluting industries. New York and New Jersey judges commonly did the reverse, acknowledging great social value and little cost to making businesses alleviate pollution. Judicial interpretation of the notions of cost and benefit mirrored the political, economic, and social conditions in each state, conditions that differed across time and place.     

A study of rupture length vs. moment for synthetic earthquakes

From the events synthesized from the one-dimensional dynamical mass-spring model proposed byBurridge andKnopoff (1967), the relation between rupture length and earthquake momentM is studied for various model parameters. The earthquake moment is defined to be the total displacement of a connected set of mass elements which slide during an event. A parameter stiffness ratios is defined as the ratio of the spring constant between the two mass elements to that between one mass element and the moving plate. The velocity-dependent friction law (including weakening and hardening processes) is taken to control the sliding of a mass element. The distribution of the breaking strengths over the system is considered to be a fractal function. The cases for severals values and different velocity-dependent friction laws with different decreasing ratesr _w of the frictional force with sliding velocity are studied numerically. The weakening process of the frictional force from the static one to the dynamic one obviously affects theM– relation. Meanwhile, a rapid weakening process rather than a slow weakening process can result in aM– relation, which is comparable to the observed one. Although an increase in thes value can yield an increase in the upper bound of the value and the number of events with largeM and values, the scaling of theM– relation is not affected by the change of thes value. For the cases in this study, the theoretical –M relations for small events withM<1 are almost in the form: M ^1/2, while those for large events withM>1 have a scaling exponent less than but close to 1. In addition, the fractal dimension, the friction drop ratio and the roughness of the distribution of the breaking strengths over the fault surface are the minor parameters influencing the –M relation. A comparison between the theoreticalM– relation and the observed one for strike-slip earthquakes shows that for large events the theoreticalM– relation is quite consistent with the observed one, while for small events there is a one-order difference in the two relations. For the one-dimensional model, the decreasing rate of the dynamic frictional force with velocity is the main factor in affecting the characteristic value of the earthquake moment, at which the scaling of theM– relation changes.     

地震工作中的国家计量法规

在综述现行有效的国家计量法规和计量技术法规的同时,重点介绍了１９９４年７月１月开始施行的最新版《量和单位》国家标准的特点,以及从事地震工作的科技人员和管理人员正确认识与使用这一强制性国家标准的重要性。     

双相岩石流变学研究评述

从自相容理论,Ｖｏｉｇｔ－Ｒｅｕｓｓ极限理论及显微构造分析方法３个方面说述了当前双相岩石流变学的研究现状和发展方向;介绍了双相岩石流谱学实验的一些研究进展和存在问题;流动律合成的方法目前只有两种：Ｔｕｌｌｉｓ的经验公式和Ｊｉ的迭代公式。     

地下水中砷元素的形成及其控制因素

研究了长江中下游地区和吉林省地区地下水中砷元素形成和主要控制因素及其分布规律。结果表明,地下水中砷主要以H_3ASO_3、H_2AsO_4~-、HA_3O_4~(2-)等形式存在。它的形成和分布与含水介质及其上覆土层的砷含量、地下水的酸碱度、地下水的迳流条件、氧化还原环境、有机物质及铁锰等有密切的关系。