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991.
We assessed short-term ecological and potential human health effects of wastewater treatment plant (WTP) effluent by measuring δ15N‰ and microbial concentrations in oysters and suspended particulate matter (SPM). We also tested male-specific bacteriophage (MSB) as an alternative to fecal coliforms, to assess potential influence of wastewater contamination on shellfish. WTP effluent did not affect oyster growth or survival, but SPM and oysters acquired wastewater-specific δ15N‰. δ15N values were depleted near the WTP, typical of low-level processed wastewater. Fecal coliform and MSB concentrations were higher in samples taken closest to the WTP, and MSB values were significantly correlated with δ15N‰ in oyster tissues. Overall, oysters demonstrated relatively rapid integration and accumulation of wastewater-specific δ15N‰ and indicator microorganisms compared to water samples. These data suggest oysters were superior sentinels compared to water, and MSB was a more reliable indicator of wastewater influence on shellfish than fecal coliforms. 相似文献
992.
Biochemical fingerprinting (BF) databases of 524 enterococci and 571 Escherichia coli isolates and an antibiotic resistance analysis (ARA) database comprising of 380 E. coli isolates from four suspected sources (i.e. dogs, chickens, waterfowls, and human sewage) were developed to predict the sources of faecal pollution in a recreational coastal lake. Twenty water samples representing four sampling episodes were collected from five sites and the enterococci and E. coli population from each site were compared with those of the databases. The degree of similarity between bacterial populations was measured as population similarity (Sp) coefficient. Using the BF-database, bacterial populations of waterfowls showed the highest similarity with the water samples followed by a sewage treatment plant (STP). Higher population similarities were found between samples from STP and water samples especially at two sites (T2 and T3) which were located near the sewerage pipes collecting wastewater from the study area. When using the ARA-database, the highest similarity was found between E. coli populations from STP and water samples at sites T2 and T4. Both faecal indicators and as well as methods predicted human faecal pollution, possibly through leakage from submerged sewerage pipes. The results indicated that the Sp-analysis of faecal indicator bacterial populations from suspected sources and water samples can be used as a simple tool to predict the source(s) of faecal pollution in surface waters. 相似文献
993.
994.
Radio astronomy observations are frequently impacted by radio frequency interference(RFI). We propose a novel method, named 2σCRF, for cleaning RFI in the folded data of pulsar observations, utilizing a Bayesian-based model called conditional random fields(CRFs). This algorithm minimizes the “energy” of every pixel given an initial label. The standard deviations(i.e., rms values) of the folded pulsar data are utilized as pixels for all subintegrations and channels. Non-RFI data without obvious i... 相似文献
995.
A spectral response approach for detecting dominant phytoplankton size class from satellite remote sensing 总被引:1,自引:0,他引:1
Robert J W Brewin Samantha J Lavender Nick J Hardman-Mountfor Takafumi Hirata 《海洋学报(英文版)》2010,29(2):14-32
An important goal in ocean colour remote sensing is to accurately detect different phytoplank- ton groups with the potential uses including the validation of multi-phytoplankton carbon cycle models; synoptically monitoring the health of our oceans, and improving our understanding of the bio-geochemical interactions between phytoplankton and their environment. In this paper a new algorithm is developed for detecting three dominant phytoplankton size classes based on distinct differences in their optical signatures. The technique is validated against an independent cou- pled satellite reflectance and in situ pigment dataset and run on the 10-year NASA Sea viewing Wide Field of view Sensor (SeaWiFS) data series. Results indicate that on average 3.6% of the global oceanic surface layer is dominated by microplankton, 18.0% by nanoplankton and 78.4% by picoplankton. Results, however, are seen to vary depending on season and ocean basin. 相似文献
996.
采用草鱼前肠灌注和3H-Tyr同位素标记方法,进行酪蛋白小肽和氨基酸对草鱼血液循环和组织蛋白质合成的影响研究。结果表明,灌注酶解酪蛋白(CSP)溶液组的草鱼血液循环中总肽量为19430.82μv/μl,灌注游离氨基酸(FAA)溶液组的草鱼血液循环中总肽量为16033.00μv/μl,前者显著高于后者(P0.05),同时前者的大多数肽段肽量也高于后者,2组血浆中某些肽段肽量有显著(P0.05)或极显著差异(P0.01)。CSP与FAA组草鱼肠道、肝脏、背肌组织蛋白质合成率(%/d)分别为96.84和72.25,98.64和81.65,65.38和46.59,CSP组草鱼显著或极显著高于FAA组(P0.05或P0.05)。草鱼血浆中总肽量和某些肽段肽量分别与草鱼肠道、肝胰脏和背肌组织蛋白质合成率有明显的正相关。实验表明,肠道对酪蛋白小肽的迅速吸收和进入血液循环中的某些小肽可能是促进草鱼组织蛋白合成的重要因素。 相似文献
997.
Annual temperatures during the last 2485 years in the mid-eastern Tibetan Plateau inferred from tree rings 总被引:2,自引:0,他引:2
Hans W. LINDERHOLM 《中国科学D辑(英文版)》2009,52(3):348-359
By combining living trees and archaeological wood, the annual mean temperatures were reconstructed based on ring-width indices
of the mid-eastern Tibetan Plateau for the past 2485 years. The climate variations revealed by the reconstruction indicate
that there were four periods to have average temperatures similar to or even higher than that mean of 1970 to 2000 AD. A particularly
notable rapid shift from cold to warm, we call it the “Eastern Jin Event”, occurred from 348 AD to 413 AD. Calculation results
show that the temperature variations over the mid-eastern Tibetan Plateau are not only representative for large parts of north-central
China, but also closely correspond to those of the entire Northern Hemisphere over long time scales. During the last 2485
years, the downfall of most major dynasties in China coincides with intervals of low temperature. Compared with the temperature
records in other regions of China during the last 1000 years, this reconstruction from the Tibetan Plateau shows a significant
warming trend after the 1950s.
Supported by National Natural Science Foundation of China (Grant Nos. 40525004, 40599420, 40890051), National Basic Research
Program of China (Grant Nos. 2007BAC30B00, 2004CB720200, 2006CB400503) and the Swedish International Development Cooperation
Agency (SIDA, Grant to Hans W. Linderholm) 相似文献
998.
Lessons in bridge damage learned from the Wenchuan earthquake 总被引:2,自引:0,他引:2
A strong earthquake occurred in Wenchuan County, Sichuan Province, China, on May 12, 2008. Shortly after the earthquake, the Turner-Fairbank Highway Research Center of the Federal Highway Administration, in partnership with the Research Institute of Highways, the Ministry of Communication of China, led a reconnaissance team to conduct a post-earthquake bridge performance investigation of the transportation system in the earthquake affected areas. The U.S.transportation system reconnaissance team visited the area during July 20-24, 2008. This paper presents the findings and lessons learned by the team. 相似文献
999.
Anti-plane (SH) waves diffraction by cavity: analytical an underground semi-circular solution 总被引:1,自引:1,他引:0
Diffraction of a two-dimensional (2D) semi-circular cavity in a half-space under incident SH-waves is studied using the classic
wave function expansion method with a new de-coupling technique. This so-called “improved cosine halfrange expansion” algorithm
exhibits an excellent performance in reducing displacement residual errors at two rim points of concern. The governing equations
are developed in a manner that minimizes the residues of the boundary conditions. Detailed derivation and analysis procedures
as well as truncation of infinite linear governing equations are presented. The semi-circular cavity model presented in this
paper, due to its simple profile, is expected to be used in seismic wave propagation studies as a benchmark for examining
the accuracies of various analytical or numerical methods for mixed-boundary wave propagation problems. 相似文献
1000.
对米仓山南江-南郑剖面上的13个花岗岩类样品进行了磷灰石(U-Th)/He测年和剥露速率计算,分析过程综合考虑了样品冷却速率、晶体大小等因素对磷灰石(U-Th)/He封闭温度的影响和地形起伏、岩体热传导、热对流及放射性元素生热等因素对地温场的影响.研究表明,米仓山南部沉积变形区自~50 Ma以来发生快速剥露 (剥露速率为~70 m/Ma),新生代以来的剥蚀量超过了3 km;中部光雾山杂岩体记录了~90 Ma时一次快速剥露事件(剥露速率>75 m/Ma);北部汉南隆起区~100 Ma以前以快速剥露为特点,平均剥露速率>40 m/Ma,此后转为缓慢剥露.整个米仓山-汉南隆起区在90~50 Ma基本处于缓慢剥露状态,平均剥露速率仅有10~25 m/Ma. 相似文献