全文获取类型
收费全文 | 27628篇 |
免费 | 2059篇 |
国内免费 | 4篇 |
出版年
2023年 | 252篇 |
2022年 | 321篇 |
2021年 | 652篇 |
2020年 | 507篇 |
2019年 | 572篇 |
2018年 | 1030篇 |
2017年 | 841篇 |
2016年 | 1055篇 |
2015年 | 1205篇 |
2014年 | 1327篇 |
2013年 | 1832篇 |
2012年 | 2203篇 |
2011年 | 2271篇 |
2010年 | 1354篇 |
2009年 | 1046篇 |
2008年 | 1641篇 |
2007年 | 1555篇 |
2006年 | 1478篇 |
2005年 | 1140篇 |
2004年 | 1119篇 |
2003年 | 1023篇 |
2002年 | 906篇 |
2001年 | 633篇 |
2000年 | 698篇 |
1999年 | 436篇 |
1998年 | 225篇 |
1997年 | 168篇 |
1996年 | 155篇 |
1995年 | 147篇 |
1994年 | 135篇 |
1993年 | 130篇 |
1992年 | 161篇 |
1991年 | 154篇 |
1990年 | 118篇 |
1989年 | 102篇 |
1988年 | 100篇 |
1987年 | 83篇 |
1986年 | 71篇 |
1985年 | 76篇 |
1984年 | 70篇 |
1983年 | 54篇 |
1982年 | 63篇 |
1981年 | 59篇 |
1980年 | 48篇 |
1979年 | 59篇 |
1978年 | 49篇 |
1977年 | 37篇 |
1975年 | 44篇 |
1974年 | 39篇 |
1973年 | 35篇 |
排序方式: 共有10000条查询结果,搜索用时 671 毫秒
991.
992.
Heng Zhang Xabier Judez Alexander Santiago Maria Martinez‐Ibaez Miguel ngel Muoz‐Mrquez Javier Carrasco Chunmei Li Gebrekidan Gebresilassie Eshetu Michel Armand 《Liver Transplantation》2019,9(25)
Amongst post‐Li‐ion battery technologies, lithium–sulfur (Li–S) batteries have captured an immense interest as one of the most appealing devices from both the industrial and academia sectors. The replacement of conventional liquid electrolytes with solid polymer electrolytes (SPEs) enables not only a safer use of Li metal (Li°) anodes but also a flexible design in the shape of Li–S batteries. However, the practical implementation of SPEs‐based all‐solid‐state Li–S batteries (ASSLSBs) is largely hindered by the shuttling effect of the polysulfide intermediates and the formation of dendritic Li° during the battery operation. Herein, a fluorine‐free noble salt anion, tricyanomethanide [C(CN)3?, TCM?], is proposed as a Li‐ion conducting salt for ASSLSBs. Compared to the widely used perfluorinated anions {e.g., bis(trifluoromethanesulfonyl)imide anion, [N(SO2CF3)2)]?, TFSI?}, the LiTCM‐based electrolytes show decent ionic conductivity, good thermal stability, and sufficient anodic stability suiting the cell chemistry of ASSLSBs. In particular, the fluorine‐free solid electrolyte interphase layer originating from the decomposition of LiTCM exhibits a good mechanical integrity and Li‐ion conductivity, which allows the LiTCM‐based Li–S cells to be cycled with good rate capability and Coulombic efficiency. The LiTCM‐based electrolytes are believed to be the most promising candidates for building cost‐effective and high energy density ASSLSBs in the near future. 相似文献
993.
994.
Phillip J. Dugger Pedro G. Blendinger Katrin Bhning‐Gaese Lackson Chama Marta Correia D. Matthias Dehling Carine Emer Nina Farwig Evan C. Fricke Mauro Galetti Daniel García Ingo Grass Ruben Heleno Fbio A. F. Jacomassa Suelen Moraes Catherine Moran Marcia C. Muoz Eike Lena Neuschulz Larissa Nowak Augusto Piratelli Marco A. Pizo Marta Quitin Haldre S. Rogers Romn A. Ruggera Francisco Saavedra Mariano S. Snchez Rocío Snchez Vinicio Santilln Dana G. Schabo Fernanda Ribeiro da Silva Srgio Timteo Anna Traveset Maximilian G. R. Vollstdt Matthias Schleuning 《Global Ecology and Biogeography》2019,28(2):248-261
995.
996.
Esequiel Santos Fábio Ribeiro Pires Fernando Barboza Egreja Filho João Carlos Madalão Robson Bonomo 《International journal of phytoremediation》2019,21(7):652-662
AbstractThis study evaluated remediation of the herbicide sulfentrazone in soils with three different mineralogies (kaolinite, hematite, and gibbsite) and three remediation sulfentrazone treatments (Canavalia ensiformis L., Crotalaria juncea L., and natural attenuation). This study was conducted in a factorial scheme, in triplicate with randomized block design. Sulfentrazone was applied at 0 and 400?g ha?1. We analyzed sulfentrazone residue in the soils by high-performance liquid chromatography and confirmed the results with bioassays of Pennisetum glaucum. Herbicide movement was greater in the kaolinitic soil without plant species. The retention of herbicide in the kaolinitic soil occurred in larger quantities in the 0–12?cm layer, with higher levels found in the treatments with plants. In the hematitic soil with C. juncea, all applied herbicides were concentrated in the 0–12?cm layer. In the other hematitic soil treatments, sulfentrazone was not detected by chemical analysis at any soil depth, although in many treatments, it was detected in the bioassay. Phytoremediation was more efficient with C. ensiformis grown in gibbsitic soil, reducing the sulfentrazone load by approximately 27%. Natural attenuation was more efficient than phytoremediation in oxidic soils due to soil pH and texture soils favored microbial degradation of the compound.
- Highlights
The influence of soil mineralogy of herbicide sulfentrazone retention was evaluated.
Canavalia ensiformis and Crotalaria juncea were evaluated as phytoremediation plants.
Kaolinite soils presented great movement of sulfentrazone in the soil.
Natural attenuation is more efficient in oxide soils than phytoremediation.
997.
Felipe Couñago Ana Aurora Díaz Gavela Gemma Sancho Irene Ortiz Francisco José Marcos Manuel Recio Julio Fernández Raquel Cano Mar Jiménez Israel J. Thuissard David Sanz-Rosa Juan Castro Nováis Eduardo Pardo Yolanda Molina Hugo Pérez García Elia del Cerro 《Reports of Practical Oncology and Radiotherapy》2019,24(5):472-480
AimTo analyse the efficacy and toxicity of postprostatectomy SRT in patients with a BCR evaluated with mpMRI.BackgroundMultiparametric magnetic resonance imaging (mpMRI) has the ability to detect the site of pelvic recurrence in patients with biochemical recurrence (BCR) after radical prostatectomy (RP). However, we do not know the oncological outcomes of mpMRI-guided savage radiotherapy (SRT).ResultsLocal, lymph node, and pelvic bone recurrence was observed in 13, 4 and 2 patients, respectively. PSA levels were significantly lower in patients with negative mpMRI (0.4 ng/mL [0.4]) vs. positive mpMRI (2.2 ng/mL [4.1], p = 0.003). Median planning target volume doses in patients with visible vs. non-visible recurrences were 76 Gy vs. 70 Gy. Overall, mean follow-up was 41 months (6–81). Biochemical relapse-free survival (bRFS) at 3 years was 82.3% and 82.5%, respectively, for the negative and positive mpMRI groups (p = 0.800). Three-year rates of late grade ≥2 urinary and rectal toxicity were 14.8% and 1.9%, respectively; all but one patient recovered without sequelae.ConclusionSRT to the macroscopic recurrence identified by mpMRI is a feasible and well-tolerated option. In this study, there were no differences in bRFS between MRI-positive and MRI-negative patients, indicating effective targeting of MRI-positive lesions. 相似文献
998.
Santiago José Fernandez Pablo Yorio Javier Ernesto Ciancio 《Marine Biology Research》2019,15(1):84-96
The Magellanic Penguin (Spheniscus magellanicus) is the most abundant and widely distributed seabird breeding on the Patagonian Coast of Argentina. We combined conventional stomach content and stable isotope analysis to assess Magellanic Penguin diet during the chick rearing stage at the two northernmost colonies in an area subject to fisheries. In 2011 and 2013, Thornfish (Bovichtus argentinus) was the main prey by mass at Complejo Islote Lobos (63.0% and 32.3%, respectively) and Argentine Anchovy (Engraulis anchoita) at Estancia San Lorenzo (85.2 and 63.3%, respectively). Magellanic Penguins from both colonies showed low isotopic niche overlap in 2011 (36%) and no overlap in 2013, suggesting a different use of prey species and/or foraging areas. Stable isotope mixing models showed that Argentine Anchovy (52.8%) and Thornfish (65.9%) were the main prey at Complejo Islote Lobos in 2011 and 2013, respectively, while Patagonian Redfish (Sebastes oculatus) (46.4%) and Squat Lobster (Munida gregaria) (50%) were the main prey at Estancia San Lorenzo in 2011 and 2013, respectively. Results show that in addition to Argentine Anchovy, previously recognized as main prey for breeding Magellanic Penguins in northern Patagonia, other juvenile or small sized fish are important diet items. Diet results suggest different scenarios of food conditions for each colony, despite the relative short distance between breeding locations. The low contribution of Argentine Hake (Merluccius hubbsi) and Argentine Shortfin Squid (Illex argentinus) suggests a low trophic overlap with commercial fisheries. The information provided is key to understand changes in the marine ecosystem and potential penguin-fishery interactions. 相似文献
999.
1000.
Nogueira-Ferreira Rita Ferreira Rita Padrão Ana Isabel Oliveira Paula Santos Manuel Kavazis Andreas N. Vitorino Rui Moreira-Gonçalves Daniel 《Journal of physiology and biochemistry》2019,75(4):561-572
Journal of Physiology and Biochemistry - Aerobic exercise training induces a unique cardioprotective phenotype, but it is becoming clear that it does not promote the same structural, functional,... 相似文献