全文获取类型
收费全文 | 1872篇 |
免费 | 118篇 |
专业分类
各国政治 | 171篇 |
工人农民 | 117篇 |
世界政治 | 224篇 |
外交国际关系 | 136篇 |
法律 | 1003篇 |
中国政治 | 5篇 |
政治理论 | 320篇 |
综合类 | 14篇 |
出版年
2023年 | 26篇 |
2022年 | 16篇 |
2021年 | 35篇 |
2020年 | 60篇 |
2019年 | 86篇 |
2018年 | 111篇 |
2017年 | 129篇 |
2016年 | 125篇 |
2015年 | 81篇 |
2014年 | 116篇 |
2013年 | 330篇 |
2012年 | 99篇 |
2011年 | 83篇 |
2010年 | 56篇 |
2009年 | 39篇 |
2008年 | 71篇 |
2007年 | 84篇 |
2006年 | 58篇 |
2005年 | 40篇 |
2004年 | 59篇 |
2003年 | 41篇 |
2002年 | 30篇 |
2001年 | 30篇 |
2000年 | 31篇 |
1999年 | 17篇 |
1998年 | 17篇 |
1997年 | 8篇 |
1996年 | 6篇 |
1995年 | 13篇 |
1994年 | 7篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1972年 | 4篇 |
1971年 | 2篇 |
1967年 | 3篇 |
1966年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有1990条查询结果,搜索用时 15 毫秒
81.
Peter Michael Rosset Braulio Machín Sosa Adilén María Roque Jaime Dana Rocío Ávila Lozano 《The Journal of peasant studies》2013,40(1):161-191
Agroecology has played a key role in helping Cuba survive the crisis caused by the collapse of the socialist bloc in Europe and the tightening of the US trade embargo. Cuban peasants have been able to boost food production without scarce and expensive imported agricultural chemicals by first substituting more ecological inputs for the no longer available imports, and then by making a transition to more agroecologically integrated and diverse farming systems. This was possible not so much because appropriate alternatives were made available, but rather because of the Campesino-a-Campesino (CAC) social process methodology that the National Association of Small Farmers (ANAP) used to build a grassroots agroecology movement. This paper was produced in a ‘self-study’ process spearheaded by ANAP and La Via Campesina, the international agrarian movement of which ANAP is a member. In it we document and analyze the history of the Campesino-to-Campesino Agroecology Movement (MACAC), and the significantly increased contribution of peasants to national food production in Cuba that was brought about, at least in part, due to this movement. Our key findings are (i) the spread of agroecology was rapid and successful largely due to the social process methodology and social movement dynamics, (ii) farming practices evolved over time and contributed to significantly increased relative and absolute production by the peasant sector, and (iii) those practices resulted in additional benefits including resilience to climate change. 相似文献
82.
Charles Grémont 《Canadian journal of African studies》2014,48(1):29-40
Since the 1980s, the so-called “nomadic” populations in the regions of Northern Mali and Niger have embarked on an extensive process of settlement. Today they mostly live in villages or “settlement sites”. But, at the same time, individuals and small groups among these same populations have considerably enlarged their area of mobility and accelerated the rate and the value of the trade in which they engage. These two phenomena could, at first sight, appear contradictory. But the observation of empirical situations shows, rather, compatibilities, similarities even, between these two concomitant phenomena. Building on innovative debates conducted in geography and sociology, this article puts forward the hypothesis that the building of villages, as well as integration into military bases and barracks, proceeds from (social) rationales of mobility, just as much as transhumance, journeys, migration. Much more than a simple displacement in space, the notion of mobility could describe an “art of doing”, a way of being to others and to the world. 相似文献
83.
Léa Lemaire 《Journal of immigrant & refugee studies》2014,12(2):143-160
Although security has become a common framework for analyzing dispositifs that aim to control irregular migration, island spaces themselves are seldom considered as security dispositifs. The case of Malta, where detention is mandatory upon arrival, epitomizes what could be conceptualized as a “sentinel island” within the European Union. This article demonstrates how the interaction between political discourse, administrative practices, and migrants’ experiences contributes to turning the island into a form of total-institution setting. The empirical data is based on qualitative fieldwork that combines ethnographic observation, migrants’ individual narratives and semi-structured interviews conducted with European and national policy makers. 相似文献
84.
85.
86.
87.
With increasing frequency, relatively small, fragmentary evidence thought to be osseous or dental tissue of human origin is submitted to the forensic laboratory for DNA analysis with the request for positive identification. Prior to performing DNA analysis, however, it is prudent to first perform a presumptive test or "screen" to determine whether the questioned material may be eliminated from further consideration. When material is shown not to be consistent with bone/teeth, DNA testing is not performed. When such determinations cannot be made from gross morphological features, elemental analysis can be indicative. This presumptive test is made possible by applying scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) in conjunction with an X-ray spectral database recently developed by the FBI laboratory. This database includes spectra for many different materials including known examples of bone and tooth from many different contexts and representing the full range of taphonomic conditions. Results of SEM/EDS analysis of evidence can be compared to these standards to determine if they are consistent with bone and/or tooth and, if not, then what the material might represent. Analysis suggests that although the proportions and amounts of calcium and phosphorus are particularly important in differentiating bone and tooth from other materials, other minor differences in spectral profile can also provide significant discrimination. Analysis enables bone and tooth to be successfully distinguished from other materials in most cases. Exceptions appear to be ivory, mineral apatite, and perhaps some types of corals. 相似文献
88.
Torres MC Osuna E Pérez-Cárceles MD Gómez-Zapata M Luna A 《The American journal of forensic medicine and pathology》2002,23(2):155-158
The authors evaluated the usefulness of the postmortem biochemical analysis of ionic ratios in different parts of the heart and their relation to cardiac damage caused by chest trauma, as observed by anatomopathologic study. Fifty-nine 59 cases were studied, selected from routine necropsies, and samples were taken from different sites of cardiac tissue. The cause of death was trauma in 40 cases and nontraumatic causes in 19 cases. The object of this study was to analyze the levels of Na+, K+, Ca+2, Mg+2, and Zn+2 in different zones of the heart, and the relationship between intracellular and extracellular ion ratios and the different causes of death and any anatomopathologic alterations observed. The biochemical tests revealed a possible relation between the ionic values and cause of death. Alterations in cell membrane permeability and corresponding modification of the ionic ratios were produced earlier than histologic alterations, which need longer to establish themselves whether or not they follow a traumatic process. 相似文献
89.
Baptista MJ Monsanto PV Pinho Marques EG Bermejo A Avila S Castanheira AM Margalho C Barroso M Vieira DN 《Forensic science international》2002,128(1-2):66-78
A sensitive analytical method was developed for quantitative analysis of delta(9)-tetrahydrocannabinol (delta(9)-THC), 11-nor-delta(9)-tetrahydrocannabinol-carboxylic acid (delta(9)-THC-COOH), cannabinol (CBN) and cannabidiol (CBD) in human hair. The identification of delta(9)-THC-COOH in hair would document Cannabis use more effectively than the detection of parent drug (delta(9)-THC) which might have come from environmental exposure. Ketamine was added to hair samples as internal standard for CBN and CBD. Ketoprofen was added to hair samples as internal standard for the other compounds. Samples were hydrolyzed with beta-glucuronidase/arylsulfatase for 2h at 40 degrees C. After cooling, samples were extracted with a liquid-liquid extraction procedure (with chloroform/isopropyl alcohol, after alkalinization, and n-hexane/ethyl acetate, after acidification), which was developed in our laboratory. The extracts were analysed before and after derivatization with pentafluoropropionic anhydride (PFPA) and pentafluoropropanol (PFPOH) using a Hewlett Packard gas chromatographer/mass spectrometer detector, in electron impact mode (GC/MS-EI). Derivatized delta(9)-THC-COOH was also analysed using a Hewlett Packard gas chromatographer/mass spectrometer detector, in negative ion chemical ionization mode (GC/MS-NCI) using methane as the reagent gas. Responses were linear ranging from 0.10 to 5.00 ng/mg hair for delta(9)-THC and CBN, 0.10-10.00 ng/mg hair for CBD, 0.01-5.00 ng/mg for delta(9)-THC-COOH (r(2)>0.99). The intra-assay precisions ranged from <0.01 to 12.40%. Extraction recoveries ranged from 80.9 to 104.0% for delta(9)-THC, 85.9-100.0% for delta(9)-THC-COOH, 76.7-95.8% for CBN and 71.0-94.0% for CBD. The analytical method was applied to 87 human hair samples, obtained from individuals who testified in court of having committed drug related crimes. Quantification of delta(9)-THC-COOH using GC/MS-NCI was found to be more convenient than GC/MS-EI. The latter may give rise to false negatives due to the detection limit. 相似文献
90.