The effects of tropical storm Dennis on coastal phytoplankton

The effects of tropical storm Dennis were documented in the coastal waters of South Carolina during August 1981. Phytoplankton photosynthesis vs. irradiance curves showed initial depression of the parameter a followed by three- to five-fold increase of both a and the asymptotic maximum rate of photosynthesis P_m^B. Productivity rates were depressed in most samples immediately after the storm. Surface samples at the inshore stations were around 50 mg C m^?3 h^?1 at saturating light intensities, while the offshore station rates were around 10 mg C m^?3 h^?1. After a 10-day lag these rates had increased to about 200 mg C m^?3 h^?1 inshore and 75 mg C m^?3 h^?1 offshore. These changes are thought to be primarily caused by changes in species composition. Some of the dominant diatom species changed and dinoflagellate species were introduced. No significant changes in nutrient concentrations were observed. Transient depressions of water temperature, salinity and light intensity may have contributed to the observed changes.     

Deoxygenation and remineralization above the sediment-water interface; an in situ experimental study

An in situ chamber of volume 3881 and bottom area 0·64 m² was used to determine the flux of oxygen and inorganic nutrients across an estuarine sediment-water interface over a 65-day period. Over the first 7 days, oxygen uptake was 378 mg m^?2 day^?1 and the rates of ammonium and phosphate release were 2·22 and 0·34 mg at. m^?2 day^?1, respectively. The water became anoxic in 14 days.The rates of flux in a similar chamber containing only detritus recently settled from the water column were 371 mg m^?2 day^?1 (oxygen), 1·66 mg at. m^?2 day^?1 (ammonium) and 0 12 mg at. m^?2 day^?1 (phosphate), demonstrating that detritus contributes substantially to exchange across the sediment-water interface.The evolution of the two chambers was similar over the latter part of the experimental period. A third chamber containing only water exhibited very minor changes.The role of detritus in nutrient recycling at the sediment-water interface is discussed in relation to the productivity of shallow water bodies such as the estuary in which the experiment was conducted, which itself undergoes periodic deoxygenation during prolonged stratification. The measured flux of nitrogen across the interface was found to represent approximately 31% of the mean daily phytoplankton requirement.     

Study on the phytoplankton · in a large reservoir

A comprehensive study on the community structure and function of the phytoplankton in Taipinghu Reservoir, the largest reservoir (9400 ha) in Anhui Province, China, was carried out during 1985–1986. A total of 175 species of algae belonging to 8 phyla and 87 genera was noted. The composition of phytoplankton was dominated by species of Chlorophyta, Cyanophyta and Bacillariophyta. The species number, cell density and biomass of the three groups were respectively 88%, 86.5% and 78.9% of the total phytoplankton. The weighted annual average biomass was 1.52 mg/L and cell density was 1.43×10⁶ ind/L. The growth maximum was observed in summer. Diatoms were abundant in the region adjoining a river. A large number of flagellated algae such asEuglena andChromulina occurred in the artificial fish culture bay. It can be inferred from the algal composition and total nitrogen concentration (1.48 mg/L) that this reservoir is a mesotrophic water body that had undergone slight natural eutrophication. Presented are an equation for the relation between cell density and biomass of algae and a newly developed method based on the energy flow principle in ecology for theoretically estimating algal fishery potential. The algae volumes of 128 species were measured for calculating the biomass.     

广西田林县地质灾害易发程度分区与评价

田林县地质灾害较为发育 ,并主要分布于县内交通沿线。文章打破以往定性评价方法 ,采用定量的易发程度指数法评价田林县地质灾害易发程度 ,收到较好的效果。评价结果可以作为田林县国土资源开发与整治并建立一套完善的地质灾害群测群防网络系统打下基础。     

HUMAN RELATIONS AND PRIMARY HEALTH CARE DELIVERY IN RURAL NEPAL: THE CASE OF DEURALI *

A preliminary analysis of the primary health care delivery component of a small rural development project in Deurali, Nepal, suggests that personal relations between project personnel and their target population (e.g., implementors'sincerity and commitment to service) can overcome many cultural, geographical, and class-related social barriers to achieving project objectives. The Deurali medical staff's ability to combine their technical skills with sincerity, hard work, and commitment has made the Deurali project reasonably successful in meeting villagers'primary health care needs.     

基于BP神经网络的近震中地震波和干扰波的识别

在ＢＰ神经网络的基础上,利用传统的ＳＴＡ／ＬＴＡ阈值分类法建立了一个用于区分地震波和干扰波的神经网络分类器,并做了检验。结果表明,具有良好的分类效果。     

稳健协同克立格因子分析及其在化探中的应用

稳健协同克立格因子分析集稳健统计、协同克立格和因子分析的优点于一体,可同时研究多个变量不同方向的结构差异及变化性,用该方法研究次生晕指示的结构特征可在一定程度反映原生晕的特征,揭示其深层次信息．对团结沟金矿区次生晕分析表明：在矿产预测中矿床原生晕组合标志并不适用于次生晕及分散流的研究,本方法对大（中）比例尺次生晕、分散流与原生晕的信息转换和关联有独到之处．     

Zonation in primary halos and geochemical prospecting pattern for the Guilaizhuang gold deposit, eastern China

The Guilaizhuang gold deposit, with an average grade of 8.10 g/t Au and reserves of over 30 mt, is a subvolcanic epithermal deposit. The deposit is hosted in Paleozoic carbonate rocks in the western Shandong metallogenic terrane of the littorine Pacific metallogenic domain, eastern China, and is associated spatially with an early Mesozoic subvolcanic alkalic intrusive complex (188–190 Ma). The orebody was discovered at the end of the 1980s based on anomalies of Au in stream sediment samples at a map scale of 1∶200,000. The ore is rich in Au, Ag, Te, V, F, As, Sb, Tl, W, and Mo but poor in Cu, Pb, and Zn. The ore is similar in its trace elements to Carlin-type Au deposits. The transverse element association zonation of the deposit is as follows: (on the hanging wall) F⟸ W−Mo−As−Tl⟸Se−Sb−Bi⟸Au−Ag−Te (orebody) ⟹ Se−Sb−Bi (on the foot wall). The axial zonation is as follows: Au⟹Ag⟹Sb⟹V⟹Zn ⟹W⟹F⟹Mo⟹Tl⟹As. Indexes such as (Au+Sb) _d / (As+Tl) _d and (Au+ Ag) _d /(As+Tl) _d decrease with depth but dramatically increase at the level where the orebody pinches out, which indicates another orebody might exist at depth. Multivariate statistical analysis suggests that the ore (halo)-forming process can be divided into two stages: alteration and mineralization. The former includes: potash feldsparization, albitization, silicification, and fluoritization. The latter includes the following substages: arsenopyritization and scheelitization; pyritization, chalcopyritization, and sphaleritization; and native gold, electrum, and calaveritization. The last substage is considered to be the main ore-forming stage in the formation of the deposit.     

应用GIS技术进行油气资源评价的探讨

简要介绍了地理信息系统（ＧＩＳ）概况,同时讨论了利用ＧＩＳ进行油气评价的可能性及优越性,并利用此法辽河外围盆地进行凹陷评价,建立了辽河外围盆地地质信息系统,最后应用自组织神经网络对这些凹陷优选排队。     

差异扩散速度与晶体形态标型

本文依据矿物晶体结晶时不同结晶离子对晶体结晶的作用不同,提出了差异扩散速度控制晶体形态的观点。文中论述了差异扩散速度的产生及影响因素,指出外部因素（温度、压力、粘度、酸碱度等）是通过离子的扩散速度变化来主导占位选择和形成优势面网,最终形成反映差异扩散速度的晶体形态。用差异扩散速度来解释矿物的晶体形态标型,比较全面地考虑各种外部因素的共同作用,从而避免了文中列举的片面性。此外,文中还探讨了晶体的生长方式、优势面网的产生和产生的必要条件以及相对衍射强度与优势面网的关系。