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91.
Plankton respiration is an important part of the carbon cycle and significantly affects the balance of autotrophic assimilation and heterotrophic production in oceanic ecosystems. In the present study, respiration rates of the euphotic zone plankton community(CR_(eu)), size fractionated chlorophyll a concentration(Chl a), bacterial abundance(BAC), and dissolved oxygen concentration(DO) were investigated during winter and summer in the northern South China Sea(n SCS). The results show that there were obvious spatial and temporal variations in CR_(eu) in the n SCS(ranging from 0.03 to 1.10 μmol/(L·h)), CR_(eu) in winter((0.53±0.27) μmol/(L·h)) was two times higher than that in summer((0.26±0.20) μmol/(L·h)), and decreased gradually from the coastal zone to the open sea. The distribution of CR_(eu) was affected by coupled physical-chemical-biological processes, driven by monsoon events. The results also show that CR_(eu) was positively correlated with Chl a, BAC, and DO, and that BAC contributed the highest CR_(eu) variability. Furthermore, the results of the stepwise multiple linear regression suggest that bacteria and phytoplankton were the dominant factors in determining CR_(eu)(R~2 = 0.82, p0.05) in the n SCS. Based on this relationship, we estimated the integrated water column respiration rate(CRint) within 100 m of the investigated area, and found that the relationship between the biomass of the plankton community and respiration may be nonlinear in the water column.  相似文献   
92.
本研究选取海洋渔业固定资产投资额、海洋渔业劳动力数量、海洋捕捞生产率和海水养殖生产率4个变量,提出影响因素假设;选取我国沿海地区海洋渔业的面板数据,进行模型设定和数据检验。通过确定变截距固定效应的回归模型形式,对模型进行估计和分析,结果表明:海洋渔业固定资产投资额、海洋渔业劳动力数量和海水养殖生产率与海洋渔业经济呈正相关,影响度由大到小依次为劳动力因素、资本因素和生产率因素,而海洋捕捞生产率的影响基本不显著;各地区海洋渔业经济发展程度不一,且差距明显。在此基础上,提出促进我国海洋渔业经济发展的对策建议:加强专业人才集聚;提高资本投入,完善资本市场建设;提高海水养殖生产率,数量和品质兼备;推动区域一体化联动发展。  相似文献   
93.
太湖水体散射特性及其空间分异   总被引:2,自引:0,他引:2  
利用Wetlabs公司研制的AC-S和BB9于2006年10月24目至11月2目对太湖水体的散射系数和后向散射系数进行了测量,在此基础上建立了太湖水体散射系数与后向散射系数之间的关系模型。用2种曲线函数模拟,即在蓝光波段使用S形曲线模型,在绿光和红光波段使用逆函数模型,各模型的MAPE和RMSE变化范围分别为0.027-0.156m^-1、0.005-0.050m^-1,模型整体预测精度都较高。研究发现后向散射系数与散射系数的空间分异现象明显,北部梅梁湾、湖心区、西部及西南部水域散射较强,而东太湖、胥口湾等东部水域的散射相对较弱。  相似文献   
94.
文章主要使用全球简单海洋资料同化分析系统(Simple Ocean Data Assimilation, SODA)产出的海洋再分析数据产品和美国国家环境预报中心(National Centers for Environmental Prediction, NCEP)发布的风场资料, 通过能量学方法分析了2000—2015年夏季至秋季(6—11月)孟加拉湾涡-流相互作用特征在不同印度洋偶极子(Indian Ocean Dipole, IOD)事件发生年的表现。结果表明, 在IOD负位相年更强的西南季风背景下, 涡动能和涡势能的量值均较大, 海洋不稳定过程更多地将平均流场的能量输向涡旋场, IOD正位相年反之。另外, 研究发现孟加拉湾湾口区的涡动能在个别年份会发展出一种与气候态存在显著异常的空间分布, 即在个别年份湾口中央海域异常出现涡动能极大值。通过对出现该异常现象最显著的2010年进行个例分析, 发现当年的孟加拉湾海表风场发展出一个气旋式环流异常, 显著地改变了海洋上层环流形态, 极大地影响了平均流场与涡旋场之间的相互作用。进一步对维持涡动能平衡的各做功项进行诊断后发现, 湾口异常海域涡动能年际变化的主要影响因素为海洋内部的压强做功, 其次是正压不稳定过程和平流的做功, 海表风应力做功项贡献较小。  相似文献   
95.
We examined whether spatially explicit information improved models that use LiDAR return signal intensity to discriminate in-pond habitat from terrestrial habitat at 24 amphibian breeding ponds. The addition of Local Indicators of Spatial Association (LISA) to LiDAR return intensity data significantly improved predictive models at all ponds, reduced residual error by as much as 74%, and appeared to improve models by reducing classification errors associated with types of in-pond vegetation. We conclude that LISA statistics can help maximize the information content that can be extracted from time resolved LiDAR return data in models that predict the occurrence of small, seasonal ponds.   相似文献   
96.
概述了我国海水养殖业在快速发展过程中由于出现养殖产业规划滞后和养殖生态环境恶化而带来的若干问题。简要介绍"浙江省重点养殖海湾养殖生态和养殖容量研究"的立项背景和研究目的,鱼类、贝类和大型藻类的养殖容量研究方法以及相关的主要研究成果,展示了近海养殖生态和养殖容量的研究思路,为相关研究的进一步展开提供了一个范例。海水养殖的长远发展必须走可持续发展之路,良好的沿岸生态环境、资源与环境的和谐是支撑海水养殖业健康、持续发展的前提。总结了我国海水养殖业管理取得的进步并指出尚存在的问题。针对海水养殖业保持可持续发展的基本途径,提出了海水养殖业的规划管理和海水养殖技术改进等方面的科学建议。  相似文献   
97.
98.
Schlieren that form above the solidus are potentially diagnostic of the rheology of crystallizing granitic magmas and could provide insights into magma chamber structure. Here we focus on steep schlieren associated with comagmatic enclaves in the Vinalhaven granite. Steep schlieren extend 1–3 m upward from the sides of enclaves and appear to have steep cylindrical shapes in 3D. Analyses of schlieren widths and the sizes of associated enclaves suggest that granitic crystal mush in which they occur had a plastic rheology probably characterized by a yield strength. The enclaves, now enclosed in coarse-grained granite, must have existed at higher levels in a crystal-poor part of a magma chamber and settled downward until reaching material with a yield strength exceeding the buoyancy of the enclaves. In addition to constraining the local rheology of the granite, their relative positions may indicate vertical rheological variations and possibly the chamber floor.  相似文献   
99.
The long-lived halogen radioisotopes 129I and 36Cl provide valuable information regarding the source of fluids in hydrocarbon systems and in localized areas where infiltration of younger meteoric water has occurred. Despite the utility of these two isotopes in providing time-signatures for fluid end-members, considerable uncertainty remains regarding the interpretation of “intermediate-age” waters in hydrologic systems. These waters are likely the result of the combination of two or more halogen sources at some time in the past, each with its own characteristic concentration and isotopic composition. In order to unravel the evolution of these “intermediate-age” waters, the effect that infiltration of meteoric water has on the isotopic composition of older formation waters is modeled. Also evaluated is the effect that the timing of dilution has on 129I and 36Cl signatures observed in the present, specifically, the hypothesis that halogen isotopic signatures imparted by the mixing of brine and meteoric waters early in the development of a sedimentary basin are quantitatively different from those imparted by the mixing of old brines with recent meteoric waters.  相似文献   
100.
An Open Source C++ inversion framework for magnetic interpretation, including UXO applications, has been developed. The point dipole model is used to approximate a small magnetic object. However, alternative object models can be easily accommodated. Input data can be presented in a variety of formats and physical units including, but not limited to, profiles of the total magnetic field, uniform data grids, random data points, magnetic gradients, and finite magnetic difference measurements. Well-established external numerical optimization software modules such as the SLATEC (Common Mathematical Library, Los Alamos National Laboratory) package are used to solve numerical problems. Other software modules can easily be incorporated as they become available. Some practical examples of the application of the framework using total field data and vertical total field gradient data from a UXO test range are presented. We have decided to “open-source” the toolkit. It can be downloaded without charge under GNU Public License via anonymous FTP from ftp://geom.geometrics.com/pub/mag/Software/magtoolkit-1.0.zip.  相似文献   
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