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931.
为查明黄沙坪-廖家湾矿集区深部地球物理异常与成矿的关系,以及地下精细结构,本文采用人工地震、AMT、高精度磁测、综合物性研究等探测技术,结合该区的地质资料和前人的物性成果,通过磁、电、震联合反演,探讨了廖家湾成矿地球物理异常的深部地质成因;采用深、浅不同深度的地震反演速度剖面所提供的相对精细、精确的地下介质几何结构与速度变化特征,约束磁性与电性异常的解释,获得了较好的磁-震、电-震的一致性.研究表明:高磁性的矽卡岩与地面和航空磁异常密切相关,成矿地球物理异常与区内多金属矿(化)关系密切,是由深部隐伏钨锡矿(化)矽卡岩体引起. 相似文献
932.
Relationships between persistent organic pollutants and carbonaceous materials in aquatic sediments of Taiwan 总被引:4,自引:0,他引:4
Chin-Chang Hung Gwo-Ching Gong Hung-Yu Chen Jian-Ming Wu Fan-Hua Nan Peter H. Santschi 《Marine pollution bulletin》2010,60(7):1010-1017
Recent studies have shown that many persistent organic pollutants (POPs, e.g., polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and various pesticides), are strongly associated with carbonaceous materials (including organic carbon (OC) and black carbon (BC)). We hypothesize that carbonaceous materials can be used as a first-order pollution index, to indicate areas where POP pollution may require further investigation. We tested our hypothesis and found that strong, positive correlations between BC and OC contents versus the concentrations of PCBs (and PAHs) existed in estuarine sediments of the Danshui River in 2005 and 2008. Thus, our preliminary results demonstrate that POC and BC are potential indicators of the POP pollution potential in fluvial sediments of the Danshui River in Taiwan. This innovative approach can provide a simple, relatively inexpensive and expedient means to monitor concentrations of POPs in polluted aquatic sediments of Taiwan, and/or those having a legacy of POP inputs. 相似文献
933.
Lymphocystis disease, caused by the lymphocystis disease virus (LCDV), is a significant worldwide problem in fish industry
causing substantial economic losses. In this study, we aimed to develop the DNA vaccine against LCDV, using DNA vaccination
technology. We evaluated plasmid pEGFP-N2-LCDV1.3 kb as a DNA vaccine candidate. The plasmid DNA was transiently expressed
after liposome transfection into the eukaryotic COS 7 cell line. The distribution and expression of the DNA vaccine (pEGFP-N2-LCDV1.3kb)
were also analyzed in tissues of the vaccinated Japanese flounder by PCR, RT-PCR and fluorescent microscopy. Results from
PCR analysis indicated that the vaccine-containing plasmids were distributed in injected muscle, the muscle opposite the injection
site, the hind intestine, gill, spleen, head, kidney and liver, 6 and 25 days after vaccination. The vaccine plasmids disappeared
100 d post-vaccination. Fluorescent microscopy revealed green fluorescence in the injected muscle, the muscle opposite the
injection site, the hind intestine, gill, spleen, head, kidney and liver of fish 48 h post-vaccination, green fluorescence
did not appear in the control treated tissue. Green fluorescence became weak at 60 days post-vaccination. RT-PCR analysis
indicated that the mcp gene was expressed in all tested tissues of vaccinated fish 6–50 days post-vaccination. These results demonstrate that the
antigen encoded by the DNA vaccine is distributed and expressed in all of the tissues analyzed in the vaccinated fish. The
antigen would therefore potentially initiate a specific immune response. the plasmid DNA was injected into Japanese flounder
(Paralichthys olivaceus) intramuscularly and antibodies against LCDV were evaluated. The results indicate that the plasmid encoded DNA vaccine could
induce an immune response to LCDV and would therefore offer immune protection against LCD. Further studies are required for
the development and application of this promising DNA vaccine. 相似文献
934.
Ulvacean green seaweeds are common worldwide; they formed massive green tides in the Yellow Sea in recent years, which caused
marine ecological problems as well as a social issue. We investigated two major genera of the Ulvaceae, Ulva and Enteromorpha, and collected the plastid rbcL and nuclear ITS sequences of specimens of the genera in two sides of the Yellow Sea and analyzed them. Phylogenetic trees
of rbcL data show the occurrence of five species of Enteromorpha (E. compressa, E. flexuosa, E. intestinalis, E. linza and E. prolifera) and three species of Ulva (U. pertusa, U. rigida and U. ohnoi). However, we found U. ohnoi, which is known as a subtropical to tropical species, at two sites on Jeju Island, Korea. Four ribotypes in partial sequences
of 5.8S rDNA and ITS2 from E. compressa were also found. Ribotype network analysis revealed that the common ribotype, occurring in China, Korea and Europe, is connected
with ribotypes from Europe and China/Japan. Although samples of the same species were collected from both sides of the Yellow
Sea, intraspecific genetic polymorphism of each species was low among samples collected worldwide. 相似文献
935.
基于水稻特征波段的决策树分类研究 总被引:1,自引:0,他引:1
针对种植结构复杂、地形复杂的水稻种植面积遥感提取精度不高现象,结合多时相遥感影像中反映水稻物候规律的特征波段,以南京江宁丘陵山区为例,选择典型水稻物候期时相的TM数据,基于多特征波段构建决策树分类提取水稻种植面积。结果表明:纹理、植被指数、湿度因子、坡度因子等多特征参与决策树分类能够提高总体精度;在具有两期物候数据时提取精度和效率较好,而加入了地形特征的水稻抽穗期数据比水稻灌浆期数据获取效果略好。因此,利用合理的作物物候期数据和该遥感影像的特征波段可有效提高分类精度,为地块破碎区作物种植面积提取提供有效手段。 相似文献
936.
大众旅游者与生态旅游者旅游动机比较研究——以云台山世界地质公园为例 总被引:3,自引:0,他引:3
生态旅游者与大众旅游者最大的区别在于生态旅游者具有一定的生态意识.生态旅游者作为生态旅游活动的主体,其旅游动机显得尤为重要.本文以云台山世界地质公园的大众旅游者与生态旅游者为调查对象,通过问卷调查对其生态旅游的动机进行了比较分析.通过因子分析法萃取出生态旅游动机为7项(休息及回避、活动、归属、挑战、成就与地位、自我实现、追求自然美).通过t检验发现:除"自我实现"因子外,大众旅游者与生态旅游者在其他旅游动机因子上均有显著性的差异. 相似文献
937.
利用Matlab及Arcgis软件,将天津市地震应急综合评估系统自2007年底以来人工触发的地震灾害评估结果进行了统计分析。从技术底层梳理了整套评估系统涉及的有关数据库、企业服务总线、灾害评估系统、辅助决策系统、Web服务等各功能模块所处的位置及作用,并使用流程图展示了综合评估系统涉及的技术细节。通过统计分析,得出近两年来触发的地震震级大小、震中、死亡人数、计算耗时等分布特征以及震害损失的分布特点,指出以后工作中需要增添哪些分布特点的人工触发地震事件。进一步分析震害结果得出建议:造价比矩阵值需适当上调,人员伤亡比系数下调,经济损失应增加按建筑用途和因经济活动中断而出现链式损失效应的灾损因素。 相似文献
938.
随着地震观测技术的发展,数字化技术引入地震前兆观测仪器中,由于各种干扰及数字化仪器的自身因素,数字化观测数据有时会出现突升、突降的现象,给数据分析带来不便。本研究引进肖维纳(Chauvenet)准则,从理论上对气体流量干扰数据进行剔除,以便于数据分析。 相似文献
939.
冻结法广泛用于盾构隧道的旁通道施工,但设计上对于冻结引起的作用在隧道上的冻胀力还没有明确取值方法,其主要原因之一是缺乏现场测量数据。以上海长江隧道的旁通道施工为背景工程,采用新型土压力计监测。首先介绍了PAD式土压力计的基本特征和安装方法,然后介绍了自动数据采集和测点设置原则,接着通过实例重点说明电缆保护的重要性和保护措施。上述监测工作保证了全部5个土压力计的正常工作,并获得了有效的实测数据。数据显示,冻结工法造成的最大荷载增量远小于预期值,这主要是由于施工上设置了泄压孔,从而减少了作用在管片上的冻胀力 相似文献
940.