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881.
滇东英武山杜鹃花种质资源的调查 总被引:1,自引:0,他引:1
采用实地调查的方法,以云南省东部曲靖地区师宗县境内英武山为调查研究区域,以分布于该区域的杜鹃花属植物为重点调查对象,记录其区域内杜鹃花属植物种类、杜鹃花资源的垂直分布和水平分布。在对英武山杜鹃花属植物进行系统调查和资料整理的基础上,研究了该属植物在英武山的分布规律,结果表明,英武山杜鹃资源有10种,分布于海拔2 000~2 400 m之间。其水平分布呈现不均匀格局。在此基础上对10种(包括亚种和变种)杜鹃花的的生境类型和主要种类的观赏性状,包括花、叶及其花期以及旅游资源开发现状和利用途径的问题进行了详细观察和探讨。提出了进一步加强对杜鹃花属植物资源保护与开发利用、加强野生杜鹃引种驯化、利用杂交及现代生物学技术培育杜鹃花新品种的建议。 相似文献
882.
云南保存橡胶树部分种质资源干形及分枝变异分析 总被引:2,自引:0,他引:2
对保存于"农业部景洪橡胶树种质资源圃"的1904份橡胶树81’IRRDB种质资源的主干通直度、主干分杈、侧枝分枝轮、侧枝粗细、侧枝分枝角、侧枝伸展等6个表型性状进行调查和分析。结果表明,云南保存橡胶树种质资源具有丰富的遗传多样性(0.2604~1.6731),多样性指数最高的是主干通直度,达1.6731,其次是主干分杈、侧枝粗细、侧枝分枝轮和侧枝分枝角,最低的是侧枝伸展。6个表型性状的相对分布频率最小值为2.92%~8.05%,最大值为41.26%~93.37%。用UPGMA法聚类,当欧式距离为1.05时,1904份样本被聚为5组,其中最大1组包括98.42%的样本,表明同一性状在每份种质资源间具有很大程度的相似性;用Furthest Neighbor法聚类,在欧式距离为1.45时,1904份样本被聚为7组。2种聚类方法都能将每份种质明显区分出来,表明各性状变异极其丰富。 相似文献
883.
Budzanani Tacheba Eagilwe Segosebe Cornelis Vanderpost Reuben Sebego 《African Journal of Ecology》2009,47(S1):71-77
The Okavango wetlands in north western Botswana are the most fire-prone environment in Botswana. Most of these fires are anthropogenic. The fires in this environment are thought to impact the environment negatively and therefore practices that are associated with extensive use of fire have been strongly criticized. Despite this, there has been little work done to understand how these fires impact the wetlands environment and its dynamics, especially the vegetation resources that are used by the local communities in the wetlands. The objective of the study was to identify fire spatial and temporal trends in relation to settlement distribution, through the use of remote sensing, socio-economic and phytosociological surveys. The fire history results show that geographically there has not been any significant change in vegetation structure and that in fact fires may have promoted biodiversity. The results of analysis show an overall variance on vegetation structure of 23% whereas the rest are unaccounted for. There is a strong association between settlements, ethnicities, literacy and fire occurrences. The most fire-prone areas are inhabited by communities that have used fire in the past for various resource use practices. 相似文献
884.
In this article we argue that in order to understand why some governance systems deliver while others do not, we need to assess
contributions and limitations of governability. Here, governability refers to a measure of how governable a particular fisheries
and coastal system is. Such a system is always comprised of two parts: a system-to-be-governed and a governing system. Governability
also depends on the interactions between these two systems. We provide key variables that must be assessed in order to determine
governability related to these systems and their interactions. A governability assessment framework is proposed here to suggest
that governance performance can only be judged from what is in the potential of the governing system, given the limitations
of the governabiltiy of the system-to-be governed, the governing system itself, and their interactions. Such an assessment
helps identify what exactly governing systems can and should do in order to enhance their performance. 相似文献
885.
Hiroyuki Kurota Kazuhiko Hiramatsu Norio Takahashi Hiroshi Shono Tomoyuki Itoh Sachiko Tsuji 《Population Ecology》2010,52(3):359-372
Fisheries management is conducted to achieve sustainable use of fishery resources, mainly through regulation of fishing activities.
For almost a decade, the Commission for the Conservation of Southern Bluefin Tuna (CCSBT) struggled to reach agreement on
a total allowable catch (TAC) for southern bluefin tuna (SBT) because of stock assessment uncertainties. To address this,
in 2002 the CCSBT commenced development of a management procedure (MP), a pre-agreed set of rules to determine how the TAC
will be adjusted as new monitoring data become available. The CCSBT Scientific Committee tested various candidate MPs using
operating models which simulate fish population and fishery dynamics as well as incorporate process, observation, and model
uncertainties. Candidate MPs were evaluated using performance measures related to the following management objectives: maximize
catches, avoid stock collapse, and minimize interannual catch variation. Of the MPs explored, some relied solely on empirical
data [i.e., adjusted TAC based on catch per unit effort (CPUE) trends], whereas others were more complicated, based on population
models. In 2005, the CCSBT adopted a model-based MP that realized a moderate catch with low variability and avoided stock
collapse. This MP struck a compromise between the risk-prone and risk-averse standpoints of the different stakeholders. However,
despite this concerted scientific effort, the MP was not implemented because, shortly after its adoption, it became evident
that historical catches may have been substantially underreported. This complication necessitates returning to near the beginning
of the development process. MP approaches have various advantages and challenges to be explored further. However, it is essential
to lessen human-introduced uncertainty (such as catch misreporting) by enhanced enforcement, and to increase management robustness
to biological uncertainties by implementing MPs. 相似文献
886.
Javier Pérez-González A. Márcia Barbosa Juan Carranza Jerónimo Torres-Porras 《The Journal of wildlife management》2010,74(8):1701-1708
ABSTRACT Supplementary feeding is a widespread game management practice in several red deer (Cervus elaphus) populations, with important potential consequences on the biology of this species. In Mediterranean ecosystems food supplementation occurs in the rutting period, when it may change mating system characteristics. We studied the role of food supplementation relative to natural resources in the spatial distribution, aggregation, and mean harem size of females in Iberian red deer (Cervus elaphus hispanicus) during the rut. We studied 30 red deer populations of southwestern Spain, 63% of which experienced supplementary feeding. Using multivariate spatial analyses we found that food supplementation affected distribution of females in 95% of the populations in which it occurred. Green meadows present during the mating season acted as an important natural resource influencing female distribution. Additionally, the level of female aggregation and mean harem size were significantly higher in those populations in which food supplementation determined female distribution than in populations in which female distribution did not depend on supplementary feeding. Because female aggregation and mean harem size are key elements in sexual selection, supplementary feeding may constitute an important anthropogenic element with potential evolutionary implications for populations of Iberian red deer. 相似文献
887.
Arnthor Gardarsson 《Hydrobiologia》2006,567(1):89-100
Studies of temporal processes at Lake Mývatn, Iceland, on three scales, millennial, centennial and decadal, are reviewed and a summary is presented of the main results of waterfowl population monitoring studies conducted during the past three decades. The characteristics of shallow, subarctic Lake Mývatn and its volcanic environment, are outlined, as well as recent conflicts between development and conservation. Mining of the bottom sediment of Lake Mývatn has been a major agent causing habitat destruction and damage to the food web. Population limitation of waterbirds at Mývatn is discussed, as three research questions and emerging answers: (1) How is reproductive output determined? All species studied showed positive correlations of production of young with levels of aquatic insects, catastrophic weather was rarely important; (2) How is the dispersion of breeding ducks determined? Densities of migratory species are determined mainly by resource levels on the breeding ground in the year before they return to the breeding area; a year-round resident species, Bucephala islandica, adjusts its density to the current availability of insect food in each of two main habitats used; (3) How are flyway populations of ducks determined? For most species, there is not enough information on total numbers and the state of the habitat on a flyway scale. In B. islandica, there are indications that the total population is limited by resources in winter. The Mývatn study area is dominated by a single, shallow and eutrophic lake and for many waterbird species the area seems to form a single functional unit. This leads to significant correlations when comparing demography with environmental conditions, such as food resources. 相似文献
888.
Toby S. Daly-Engel R. Dean Grubbs Kim N. Holland Robert J. Toonen Brian W. Bowen 《Environmental Biology of Fishes》2006,76(2-4):419-424
We tested for presence or absence of multiple paternity in single litters from each of three congeneric shark species in Hawaii: the sandbar shark, Carcharhinus plumbeus, bignose shark, Carcharhinus altimus, and Galapagos shark, Carcharhinus galapagensis. Based on eight polymorphic microsatellite loci, we excluded paternity by a single sire in sandbar and bignose sharks, but could not exclude a single sire for the litter from the Galapagos shark. This study doubles the number of shark species tested for multiple paternity, and is the first demonstration of multiple paternity in sandbar and bignose sharks. 相似文献
889.
890.
单叶蔓荆子化学成分研究初报 总被引:9,自引:0,他引:9
对产于福建(莆田平海)海滨沙地的单叶蔓荆子的一般化学成分进行了分析,为开发利用福建沿海沙滩单叶蔓荆资源提供科学依据.结果表明:福建产单叶蔓荆子的水分、脂肪、粗蛋白及灰分含量分别为10.8%、4.05%、5.9%和3.36%,符合2005年版《中国药典》要求.其重金属元素含量Pb<0.01 μg/g、As<0.1 μg/g、Hg<0.01 μg/g、Cd为0.02 μg/g、Cu为6 μg/ g,达到《药用植物及制剂进出口绿色行业标准》(WM2-2001)中重金属元素限量要求.蔓荆子生药材17种氨基酸总量为3.51%(mg/100 mg),此外还检出微量γ-氨基丁酸(GABA,2.203 mg/100 g).蔓荆子生药材中含有10种脂肪酸,以不饱和脂肪酸(69.6%)为主,主要成分包括棕榈酸(6.6%)、硬脂酸(5.4%)、油酸(22.0%)、亚油酸(46.0)及少量亚麻酸(0.8%). 相似文献