三峡永久船闸变形监控指标的研究

本文采用变形速率法,对三峡永久船闸变监控指标进行探索。通过比较手施工反馈的结果,证明了加固的效果,说明了三峡永久船闸体整体是稳定的。     

湘西沃溪钨锑金矿床辉锑矿脉矿物学特征及其矿床成因指示

辉锑矿脉为沃溪钨锑金矿床最具工业价值的矿石类型。本文报道了近期对该型矿石的主要矿石矿物如自然金、自然锑、辉锑矿、白钨矿、黑钨矿等的观察研究和电子探针分析结果。分析了矿石矿物微量化学成分特征及其所揭示的矿床成因信息。研究表明，矿床成矿应与区域构造—岩浆作用有成因联系。从而建立了该矿床新的成矿机理模式。     

谱修正迭代结果的协因数矩阵

导出了谱修正迭代结果的协因数矩阵Q_XX,证明了当法方程系数矩阵N满秩且呈良态时,Q_XX就是N的凯利逆N^-1;当N秩亏时,Q_XX就是N的Moore-Penrose逆N⁺。     

"银祥"牌大黄鱼慢沉饲料养殖大黄鱼试验

本文报告了用"银祥"牌大黄鱼慢沉饲料和鲜活饲料进行为期50d的大黄鱼(Pseudosciaenacrocea)养殖对比试验.结果表明，慢沉型颗粒饲料较适合大黄鱼的摄食习性和营养需求，有较低的饵料系数(1.62)，较高的存活率，降低了饲养成本，减轻了对水质的污染，明显地提高了大黄鱼网箱养殖的经济与生态效益.     

等离子体质谱法快速测定地质样品中的痕量铂族元素和金

１￣５ｇ试样于刚玉坩埚经Ｎａ２Ｏ２熔融分解,王水浸取后蒸发脱水除ＳｉＯ２,碲共常常富集铂族元素和金,用同位素稀释－等离子体质谱法测定Ｒｕ、Ｐｄ、Ｉｆ和Ｐｔ,内标法测定Ｒｈ和Ａｕ。按取样５ｇ计算,方法的测定限小于０．３５ｎｇ／ｇ,经ＣＣＲＭＰ６个铂族元素标样分析验证,其结果与标准值基本吻合,５次平行测定的ＲＳＤ在１．５￣６．５％     

区域旅游竞合研究进展

旅游业的激烈竞争态势使区域旅游空间关系研究成为国内外旅游地理学的研究重点,其中竞争与合作是研究旅游区域之间空间关系最重要的两方面。回顾国内外相关文献,从旅游资源、旅游需求、旅游地形象定位与市场营销、旅游者信息查询行为、知识创新、网络联系与旅游地竞争力、特定旅游目的地的竞争力6方面对区域旅游空间竞争进行综述。目前区域旅游合作研究的热点主要集中在利益主体、企业之间的合作、公共与私有部门的合作以及旅游业与其他关联行业之间的合作等方面。多数研究是单纯对空间竞争或空间合作关系的探讨,而实际上旅游区域之间是竞争与合作并存的空间竞合关系。与近年来区域竞争力、产业竞争力和产业集群等研究热点相比较,国内外关于旅游产业竞争力、旅游区域竞争力和旅游企业集群的研究刚刚起步,对旅游区域之间空间竞合的模式、区域旅游竞合的深层机制和区域旅游空间作用过程的研究则更少,亟待深入探索。     

Seasonal changes in the water use strategies of three co‐occurring desert shrubs

Water is a major limiting factor in desert ecosystems. In order to learn how plants cope with changes in water resources over time and space, it is important to understand plant–water relations in desert region. Using the oxygen isotopic tracing method, our study clarified the seasonal changes in the water use strategies of three co‐occurring desert shrubs. During the 2012 growing season, δ¹⁸O values were measured for xylem sap, the soil water in different soil layers between 0 and 300 cm depth and groundwater. Based on the similarities in δ¹⁸O values for the soil water in each layer, three potential water sources were identified: shallow soil water, middle soil water and deep soil water. Then we calculated the percentage utilization of potential water sources by each species in each season using the linear mixing model. The results showed that the δ¹⁸O values of the three species showed a clear seasonal pattern. Reaumuria songarica used shallow soil water when shallow layer was relatively wet in spring, but mostly took up middle soil water in summer and autumn. Nitraria tangutorum mainly utilized shallow and middle soil water in spring, but mostly absorbed deep soil water in summer and autumn. Tamarix ramosissima utilized the three water sources evenly in spring and primarily relied on deep soil water in summer and autumn. R. songarica and N. tangutorum responded quickly to large rainfall pulses during droughts. Differential root systems of the three species resulted in different seasonal water use strategies when the three competed for water. Copyright © 2013 John Wiley & Sons, Ltd.     

Lateral stress caused by horizontal and vertical surcharge strip loads on a cross‐anisotropic backfill

This study derives analytical solutions for estimating the lateral stress caused by horizontal and vertical surcharge strip loads resting on a cross‐anisotropic backfill. The following loading types are employed in this work: point load, line load, uniform strip load, upward linear‐varying strip load, upward nonlinear‐varying strip load, downward linear‐varying strip load and downward nonlinear‐varying strip load. The cross‐anisotropic planes are assumed to be parallel to the horizontal surface of the backfill. The solutions proposed herein have never been mentioned in previous literature, but can be derived by integrating the point load solution in a Cartesian co‐ordinate system for a cross‐anisotropic medium. The calculations by the presented solutions are quick and accurate since they are concise and systematized. Additionally, the proposed calculations demonstrate that the type and degree of material anisotropy and the horizontal/vertical loading types decisively influence the lateral stress. This investigation presents examples of the proposed horizontal and vertical strip loads acting on the surface of the isotropic and cross‐anisotropic backfills to elucidate their effects on the stress. The analytical results reveal that the stress distributions accounting for soil anisotropy and loading types are quite different from those computed from the available isotropic solutions. Restated, the derived solutions, as well as realistically simulating the actual surcharge loading circumstances, provide a good reference for the design of retaining structures for the backfill materials are cross‐anisotropic. Copyright © 2005 John Wiley & Sons, Ltd.     

Minimum principle and related numerical scheme for simulating initial flow and subsequent propagation of liquefied ground

The problem of predicting the evolution of liquefied ground, modelled as a viscoplastic material, is addressed by combining a minimum principle for the velocity field, which characterizes such an evolution, and a time step integration procedure. Two different numerical schemes are then presented for the finite element implementation of this minimum principle, namely, the regularization technique and the decomposition‐co‐ordination method by augmented Lagrangian. The second method, which proves more accurate and efficient than the first, is finally applied to simulate the incipient flow failure and subsequent spreading of a liquefied soil embankment subject to gravity. The strong influence of liquefied soil residual shear strength on reducing the maximum amplitude of the ground displacement is particularly emphasized in such an analysis. Copyright © 2005 John Wiley & Sons, Ltd.     

中国-东盟自由贸易区下中越边境区位优势再造

针对广西与云南两省区对越南贸易比重下滑的现象,提出中越边境区位优势是凸显还是凹陷、递增还是递减的问题;从边境区位优势可再造的角度,用SWOT分析“10＋1”自贸区下中越边境区位的优势、劣势、机遇与挑战,建议通过定期举办“中越边境2＋6省区论坛”、设立跨境工业园区与边境跨国经济合作区、共建区域经贸服务平台、建设区域创新系统、开展中越八角香料及中草药经济带等边境区域合作,扩大合作规模,再造区位优势。