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71.
郯庐断裂带自南而北穿越渤海东部,自中生代中期至新生代中期表现裂谷发育特征。裂谷发育经历两个旋回,各旋回的裂谷发育演化、盆地分布格局,沉积相带,沉积补偿速度等均受断裂带的断裂活动的强烈控制。  相似文献   
72.
本文对取自台湾海峡棱鮻 (Lizacarinatus)消化道的弯睾软穴吸虫 (HapalotremaflecterotestisZhukov, 1971)进行重新描述,并对其毛蚴的体外发育进行观察.根据Yamaguti(1971)区分单孔科 (Haploporidae)和叉盘科 (Waretrematidae)的标准,同意李敏敏(1984)将其从单孔科移出并入叉盘科.在与叉盘科已知属比较后,我们发现该吸虫除睾丸形状外,其他主要特征与鲫吸虫属 (CarassotremaPark, 1938)的相似.因此,我们拟将其作为后者的同物异名,并将该吸虫重新命名为弯睾鲫吸虫 [Caras sotremaflecterotestis(Zhukov, 1971)comb. nov. ].实验结果表明:在室温 7~24℃(均值为 15. 3℃)条件下,其虫卵从单个卵细胞到毛蚴孵出共需 12d.  相似文献   
73.
Hydrodynamic modeling can be used to spatially characterize water renewal rates in coastal ecosystems. Using a hydrodynamic model implemented over the semi-enclosed Southwest coral lagoon of New Caledonia, a recent study computed the flushing lag as the minimum time required for a particle coming from outside the lagoon (open ocean) to reach a specific station [Jouon, A., Douillet, P., Ouillon, S., Fraunié, P., 2006. Calculations of hydrodynamic time parameters in a semi-opened coastal zone using a 3D hydrodynamic model. Continental Shelf Research 26, 1395–1415]. Local e-flushing time was calculated as the time requested to reach a local grid mesh concentration of 1/e from the precedent step. Here we present an attempt to connect physical forcing to biogeochemical functioning of this coastal ecosystem. An array of stations, located in the lagoonal channel as well as in several bays under anthropogenic influence, was sampled during three cruises. We then tested the statistical relationships between the distribution of flushing indices and those of biological and chemical variables. Among the variables tested, silicate, chlorophyll a and bacterial biomass production present the highest correlations with flushing indices. Correlations are higher with local e-flushing times than with flushing lags or the sum of these two indices. In the bays, these variables often deviate from the relationships determined in the main lagoon channel. In the three bays receiving significant riverine inputs, silicate is well above the regression line, whereas data from the bay receiving almost insignificant freshwater inputs generally fit the lagoon channel regressions. Moreover, in the three bays receiving important urban and industrial effluents, chlorophyll a and bacterial production of biomass generally display values exceeding the lagoon channel regression trends whereas in the bay under moderate anthropogenic influence values follow the regressions obtained in the lagoon channel. The South West lagoon of New Caledonia can hence be viewed as a coastal mesotrophic ecosystem that is flushed by oligotrophic oceanic waters which subsequently replace the lagoonal waters with water considerably impoverished in resources for microbial growth. This flushing was high enough during the periods of study to influence the distribution of phytoplankton biomass, bacterial production of biomass and silicate concentrations in the lagoon channel as well as in some of the bay areas.  相似文献   
74.
以可持续发展战略为主线,总结和探讨了城市房地产开发建设项目的环境管理问题,指出:环境管理尤其是前置审批把关的重点应当是:(1)突出协调发展的重要性;(2)坚持以人为本,内外兼顾原则;(3)注重资源的合理有效利用;(4)提高技术含量,讲求效益统一;(5)建设期与营运期环境保护并重;(6)突出生态保护的重要性;(7)加强公众参与工作。  相似文献   
75.
The Loess Plateau is one of China s developing areas where socio-econ-omy is backward, ecological environment deteriorated and people's life difficult.The purpose of carrying out comprehensive development of the area's agriculture is, in essence, to open up new fields of agro-production, to intensify the utilization of related resources, to raise productivity and to win bigger output. The decision is important, as by so doing, the physical landscape could be tranformed, the local economy could be flourished, and the people's standard of living could be improved, and moreover the national development strategy of "depending on the East and shifting to the West" and building Shanxi Province into an energy and chemical industrial base could be realized.Based on field investigations in recent years, the auther proposed the purpose, target, principles, steps, tactics and strategies for the comprehensive development of the are's agriculture.  相似文献   
76.
Jiyang (济阳) sag is an oil rich basin,consisting of Huimin (惠民),Dongying (东营),Zhanhua (沾化),and Chezhen (车镇) depressions.The elastic rock of Paleogene has undergone early and middle diagenetic stages and now the main clastic reservoir is in the middle diagenetic stage.Primary and secondary pores are developed in Paleogene sandstone,the latter is generated from the dissolution of feldspar and calcite cement in rocks owing to the organic acid from the maturated source rock,but the materials dissolved are different in different depressions.The reservoir secondary pores of Dongying depression are generated from the dissolution of calcite cement,the ones of Zhanhua and Huimin depressions from the dissolution of feldspar,the secondary pores of Chezhen depression from the dissolution of feldspar in upper section,and the dissolution of calcite cement in the lower section of Paleogene,respectively.The secondary pores are developed in two depths and the depth goes down from west to east,from south to north in Jiyang sag.The major controlling factors for secondary pore development are maturity and location of source rock.Lastly,the favorable reservoirs are evaluated according to reservoir buried depth,sedimentation,and diagenesis.The reservoir with high quality is located in the northern and central parts in Dongying depression; there are some good reservoirs in Gndao (孤岛),Gudong (孤东),and Gunan (孤南) areas in Zhanhua depression,and the favorable reservoirs are located in the north steep slope and the south gentle slope of Chezhen depression and central uplift,south gentle slope of Huimin depression.  相似文献   
77.
井中激电地-井方式井旁球体正反演   总被引:2,自引:0,他引:2  
以激发极化法中的地-井方式中的体极化球形体作为研究对象,采用解析法对地下半空间的电位场进行求解,利用提取出的井中二次场异常电位差进行反演,得出极化球体的球心离井的距离和球心的埋深。通过计算机进行正反演模拟,验证了进行正反演计算的解析式的正确性,并从物理意义上对正反演过程中出现的现象进行分析。最后给出该方法的适用条件以及注意事项。研究对激发极化法地下勘探目标的定量分析具有明确意义。  相似文献   
78.
遥感技术在地质找矿中的应用及发展前景   总被引:6,自引:0,他引:6       下载免费PDF全文
遥感技术作为矿产勘查的一种手段应用于找矿,并取得了一定成就.遥感技术的直接应用是蚀变遥感信息的提取,遥感技术的间接应用包括地质构造信息、植被的光谱特征及矿床改造信息等方面.遥感找矿具有很大的发展前景的领域主要有:高光谱数据、数据融合技术、3S的紧密结合、计算机技术的发展.  相似文献   
79.
新疆坎儿井现状及其发展   总被引:2,自引:0,他引:2  
简述了新疆坎儿井的构成、特点、研究意义,分析了坎儿井衰退状况及其原因,列举了已进行的坎儿井保护工作,提出了坎儿井于枯断流的综合治理对策及今后的发展方向。  相似文献   
80.
长白山自然保护区是我国建立较早的和典型的自然保护区之一,其主要功能是进行自然生态环境的保护。但是,为了克服保护资金短缺境况,长白山自然保护区将发展旅游业作为生态环境保护工作资金支持的一条途径,而旅游业曾长期被认为是对生态环境影响微乎其微的产业,但自长白山开始发展旅游业以来,经济效益的实现似乎掩盖了原本的生态环境保护目标。本文在分析了长白山旅游发展对生态环境造成的负面影响之后,提出了一系列在长白山旅游发展过程中生态环境的保护措施,以期兼顾长白山自然保护区发展和保护两大目标的实现。  相似文献   
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