浅论县（市）级土地利用数据库系统建设

随着经济的迅猛发展,各地土地利用情况多种多样,采用手工管理土地资料更新周期长,综合利用率低,各种查询统计要耗费大量的人力物力,而且统计计算的数据结果精度不高。因此仅仅依靠传统的手工管理模式已经远远不能满足土地管理工作的需要,为保质保量按时完成全国土地利用现状更新调查,加强地籍规范化管理,利用成熟的计算机技术辅助进行土地调查已势在必行。     

提高多波束测量有效条幅覆盖宽度的方法研究

随着海洋科技的发展,声学技术在海洋仪器上的应用越来越广泛,多波束测深系统就是声学技术应用的一个范例.多波束测量中有效条幅的覆盖宽度对于调查船只和单位都有重要的意义.在调查中,应尽可能提高有效条幅覆盖宽度.通过多波束系统测深所应用的两大理论(波束形成理论、声纳方程)着手,详细分析了影响多波束测量有效条幅覆盖宽度的船速、海况、发射阵列等因素,提出了提高多波束测量有效条幅覆盖宽度的几点建议.     

西湖凹陷平北地区烃源岩特征及生排烃史

为了综合确定平北地区的主力烃源岩,深化其油气成藏动力学过程研究,在烃源岩分布特征及有机质丰度、类型和成熟度分析的基础上,应用舍油气盆地数值模拟技术,定量恢复了研究区主要烃源岩层系的生排烃历史。研究表明,平北地区主要发育始新统平湖组、渐新统花港组两套烃源岩系,其中平湖组暗色泥岩为主力烃源岩,具较高的有机质丰度、成熟度、生排烃强度与排烃效率;以平湖组为源岩的油气系统应是本区油气勘探的主要目标。     

Using otolith weight to predict the age of <Emphasis Type="Italic">Pennahia macrocephalus</Emphasis> in the mouth of the Beibu Gulf

The relation between otolith weight (OW) and the age of marine fish is studied. A total of 222 individuals of bighead white croaker, Pennahia macrocephalus were sampled seasonally in the mouth of the Beibu Gulf, the South China Sea, in 2007. Since there are no significant differences in sagittal OW between otolith in pairs (P≥0.05), the undamaged left sagittal otolith is used for age determination. The highest correlations among standard length, OW and fish ages are confirmed by linear, exponential and multinomial regression. Results show that sagittal OW overlaps only occasionally among age groups, and to individuals with similar standard length, the older and slower-growing fish has a heavier otolith because of the continued otolith material deposition. There are differences in sagittal OW among different age groups and significant positive linear relationship with age (P<0.05). The age readings can be verified by plotting the sagittal OW versus the standard length for age groups, and the individuals with similar standard length but in different ages can be separated by sagittal OW frequency analysis. Mostly, the predicted ages using the regression between sagittal OW and ages are closed to the observed ages by counting annulus on scale. It indicates that the sagittal OW analysis is a useful technique for validating the accuracy of age determination by annuli counts, especially for individuals of similar size. Furthermore, the technique is applied for Pennahia macrocephalus with discussion in this paper. Supported by the National Natural Science Foundation of China (No. 30771653) and Bureau of Fisheries, Ministry of Agriculture     

Impacts of soil fauna on litter decomposition at different succession stages of wetland in Sanjiang Plain, China

Litter decomposition is the key process in nutrient recycling and energy flow. The present study examined the impacts of soil fauna on decomposition rates and nutrient fluxes at three succession stages of wetland in the Sanjiang Plain, China using different mesh litterbags. The results show that in each succession stage of wetland, soil fauna can obviously increase litter decomposition rates. The average contribution of whole soil fauna to litter mass loss was 35.35%. The more complex the soil fauna group, the more significant the role of soil fauna. The average loss of three types of litter in the 4mm mesh litterbags was 0.3–4.1 times that in 0.058mm ones. The decomposition function of soil fauna to litter mass changed with the wetland succession. The average contribution of soil fauna to litter loss firstly decreased from 34.96% (Carex lasiocapa) to 32.94% (Carex meyeriana), then increased to 38.16% (Calamagrostics angustifolia). The contributions of soil fauna to litter decomposition rates vary according to the litter substrata, soil fauna communities and seasons. Significant effects were respectively found in August and July on C. angustifolia and C. lasiocapa, while in June and August on C. meyeriana. Total carbon (TC), total nitrogen (TN) and total phosphorus (TP) contents and the C/N and C/P ratios of decaying litter can be influenced by soil fauna. At different wetland succession stages, the effects of soil fauna on nutrient elements also differ greatly, which shows the significant difference of influencing element types and degrees. Soil fauna communities strongly influenced the TC and TP concentrations of C. meyeriana litter, and TP content of C. lasiocapa. Our results indicate that soil fauna have important effects on litter decomposition and this influence will vary with the wetland succession and seasonal variation. Foundation item: Under the auspices of State Key Development Program for Basic Research of China (No. 2009CB421103), Key Program of National Natural Science Foundation of China (No. 40830535/D0101), Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-BR-16, KSCX2-YW-N-46-06)     

Livelihood strategy change and land use change —Case of Danzam Village in upper Dadu River watershed, Tibetan Plateau of China

Land use change in rural China since the 1980s, induced by institution reforms, urbanization, industrialization and population increase, has received more attention. However, case studies on how institution reforms affect farmers’ livelihood strategies and drive land use change are scarce. By means of cropland plots investigations and interviews with farmers, this study examines livelihood strategy change and land use change in Danzam Village of Jinchuan County in the upper Dadu River watershed, eastern Tibetan Plateau, China. The results show that, during the collective system period, as surplus labor forces could not be transferred to the secondary and tertiary industries, they had to choose agricultural involution as their livelihood strategy, then the farmers had to produce more grains by land reclamation, increasing multiple cropping index, improving input of labor, fertilizer, pesticide and adopting advanced agricultural techniques. During the household responsibility system period, as labors being transferred to the secondary and tertiary industries, farmers chose livelihood diversification strategy. Therefore, labor input to grain planting was greatly reduced, which drove the transformation of grain to horticulture, vegetable or wasteland and decrease of multiple cropping index. This study provides a new insight into understanding linkages among institution reforms, livelihood strategy of smallholders and land use change in rural China. Foundation item: Under the auspices of National Natural Science Foundation of China (No. 40601006, 40471009), National Basic Research Program of China (No. 2005CB422006)     

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PCI9052在PCI接口卡中的应用

结合具体的应用,介绍基于PCI9052接口卡开发过程中一些需要注意的问题。     

EGM96和EGM2008地球重力场模型计算弹道扰动引力的比较

给出了利用地球重力场模型计算扰动引力以及重力场模型截断误差的公式,计算了36阶、360阶、2 160阶地球重力场模型在径向和水平方向的截断误差,并对36阶、360阶的EGM96和EGM2008重力场模型计算的弹道扰动引力矢量进行了分析和比较.结果表明,采用重力场模型计算扰动引力时,模型阶数和弹道点的高度越低,模型截断误差越大;EGM96和EGM2008模型的一致性随着模型阶数的升高而逐渐降低.总体来看,EGM2008模型的精度要好于EGM96模型.     

鞍山地区陈台沟变质表壳岩的年龄

鞍山市东部陈台沟村附近，有一套以斜长角闪岩类、石英岩类和长英质片麻岩类等组成的变质表壳岩（陈台沟表壳岩），它虽被划归为鞍山群但同该地区公认的鞍山群明显不同。它同白家坟花岗岩（３．８Ｇａ）和陈台沟花岗岩（３．３Ｇａ－３．１Ｇａ）为断层接触。采用Ｋｏｂｅｒ提出的单颗粒锆石逐层蒸发－沉积方法，测定了侵入陈台沟表壳岩的两条花岗岩脉（Ａ９２１２－３，Ｃｈ１０）中锆石的年龄，Ａ９２１２－３测定了８粒锆石，年龄为３３５７±４Ｍａ－３３１５±４Ｍａ（误差均为２ｄ，Ｃｈ１０测定了３粒锆石，结果为３３３７±１２Ｍａ，３２２８±３７Ｍａ和１８１３±７Ｍａ。３３５７Ｍａ和３３３７Ｍａ是这两条花岗岩脉侵位时间。１８１３Ｍａ是后期地质作用的时间。陈台沟表壳岩的年龄大于３．３５Ｇａ，建议将陈台沟表壳岩从鞍山群分离出来单独建群。