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1.
Current levels of suppression of waterhyacinth in Florida USA by classical biological control agents
Waterhyacinth, Eichhornia crassipes (Mart.) Solms (Pontederiaceae), has been a global target for classical biological control efforts for decades. In Florida, herbicidal application is the primary control method employed, usually without regard for the activities of the three biological control agents introduced intentionally during the 1970s, namely Neochetina eichhorniae Warner, Neochetina bruchi, Hustache (Coleoptera: Curculionidae), and Niphograpta albiguttalis Warren (Lepidoptera: Crambidae). A series of field experiments from 2008 to 2010 was conducted at four Florida sites using an insecticide-check approach to quantify the current levels of suppression provided by these agents. In the field N. albiguttalis was rarely found while more than 99% of all Neochetina sp. adults were N. eichhorniae. Although it was not possible to disentangle the relative impacts of Neochetina sp. adults from larvae on individual plant variables, the larvae played a major role in reducing plant biomass and the number of inflorescences. Plots exposed to unrestricted herbivory contained 58.2% less biomass and produced 97.3% fewer inflorescences at the end of the experiments. Despite these large reductions, herbivory decreased waterhyacinth coverage by only 16.8% and most of this was attributed to a low-nutrient site where coverage was reduced disproportionately. Overall, coverage trended upwards during the course of the experiments and was always close to 100% when the plots were harvested. Although coverage is a somewhat arbitrary metric, especially for floating plants subject to compression and dispersion, it influences the perception of biological control efficacy which, in turn, directly influences herbicide management decisions in Florida. Despite waterhyacinth populations that now produce less than half as much biomass and up to 98% fewer seeds than before the deployment of biological control agents, the overall approach used to achieve maintenance control of the plant in Florida will probably not change unless new biological control agents, such as Megamelus scutellaris Berg (Hemiptera: Delphacidae), can reduce coverage significantly. 相似文献
2.
There is a need for large-scale demonstrations to address the challenges and possibilities for upscaling of ecosystem restoration, and for learning and sharing knowledge across professions and habitats. Large-scale and complex restoration projects need new perspectives on goal formulation, indicators for success, and evaluation to encompass both scientific approaches and the tacit knowledge held by practitioners. The objective of this paper is to use the restoration of a 165 km2 former military training area in alpine central Norway into National Park to demonstrate the challenges of upscaling and integration. Main tasks were to remove roads and technical infrastructure, prepare for natural recovery and remove undetonated ordnance. In total, 19 indicators were used to evaluate the restoration outcome, related to four overall restoration goals formulated by the Norwegian Parliament: nature protection, considerable nature benefit, safe civilian use, and restoration back to natural state. Despite an overall linear project cycle, a dynamic and adaptive process of planning, implementation and evaluation was performed at the individual site scale. A dynamic dialogue between all involved professions allowed for exchanging scientific and tacit knowledge, and continuous improvement of solutions. The study demonstrated the relevance of qualitative assessments combined with quantitative indicators – i.e., use of expert opinions and the continuous evaluation to feed back into planning and improving the implementation of restoration measures. A “Green training” procedure was developed, linking top-down formally defined settings of the project with bottom-up hand-on solutions. This procedure can be directly transferred to other large-scale mitigation and restoration projects. Demonstration sites like the one described here, are valuable to develop an expanded vision of restoration to meet the UN Sustainable Goals. 相似文献
3.
分析了传统手术室的现状与存在问题,提出将手术室设备与医院信息整合,组建一体化功能手术室是医院发展方向。建议对手术室一体化设制制定专门标准。 相似文献
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5.
Banana streak virus (BSV) is a plant dsDNA pararetrovirus (family Caulimoviridae, genus badnavirus). Although integration is not an essential step in the BSV replication cycle, the nuclear genome of banana (Musa sp.) contains BSV endogenous pararetrovirus sequences (BSV EPRVs). Some BSV EPRVs are infectious by reconstituting a functional
viral genome. Recent studies revealed a large molecular diversity of episomal BSV viruses (i.e., nonintegrated) while others
focused on BSV EPRV sequences only. In this study, the evolutionary history of badnavirus integration in banana was inferred from phylogenetic relationships between BSV and BSV EPRVs. The relative evolution rates
and selective pressures (dN/dS ratio) were also compared between endogenous and episomal viral sequences. At least 27 recent independent integration events
occurred after the divergence of three banana species, indicating that viral integration is a recent and frequent phenomenon.
Relaxation of selective pressure on badnaviral sequences that experienced neutral evolution after integration in the plant
genome was recorded. Additionally, a significant decrease (35%) in the EPRV evolution rate was observed compared to BSV, reflecting
the difference in the evolution rate between episomal dsDNA viruses and plant genome. The comparison of our results with the
evolution rate of the Musa genome and other reverse-transcribing viruses suggests that EPRVs play an active role in episomal BSV diversity and evolution. 相似文献
6.
The integration of heifers into free stall dairy herds is a frequent management procedure, but little systematic research has been conducted on its effect on cow behavior. Previous studies mainly focused on aggressive interactions, but it is also of interest how integration affects the spatial distribution of both the cows in the herd and the integrated heifers. In the present study we integrated a single and a pair of heifers on each of six Swiss working farms in a balanced order. Using an automatic tracking system, we recorded the positions of all the cows and of the integrated heifers at 1 min intervals for six continuous 24 h periods. From these data we calculated the proportion of time the animals spent in the activity area, at the feed rack and in the lying cubicles, their average path length and the area of the barn that they used. We then compared the behavior of the integrated heifers with that of the cows in the introductory weeks. We also compared the behavior of the cows recorded in the control weeks directly preceding the integration and in the introductory weeks. For evaluation we used linear mixed-effects models. Singly integrated heifers spent a higher proportion of time in the activity area (0.29 vs. 0.14; P < 0.001) and a lower proportion of time in the lying area (0.40 vs. 0.53; interaction with day, P = 0.011) than the cows, whereas the heifers of the pairs mainly spent a lower proportion of time in the feeding area than the cows (0.23 vs. 0.32; interaction with day, P = 0.044). Average path length was longer for the integrated heifers soon after introduction but approached the values of the cows later on (interaction with day, P = 0.012). The total barn area used by a given animal was largest in the cows and was reduced in heifers integrated singly or in pairs (cows: 341/373 m2, pairs: 306 m2, single heifer: 333 m2; P = 0.055). Cows were little influenced in their space use by the integration of a single or pair of heifers. In summary, the behavior of the singly integrated heifers differed more markedly from that of the cows than the behavior of the heifers introduced in pairs during the introductory week. We would therefore recommend integrating pairs rather than single heifers into herds of dehorned dairy cows to ease their integration. 相似文献
7.
8.
Jian-qi Zhang Wen-juan Li Ling Tian Jin-zhong Chen William Jia 《Biochemical and biophysical research communications》2009,387(2):256-3283
TTRAP is a PML-NB protein that is involved in the NF-κB signaling pathway. TTRAP was recently identified by yeast two-hybrid analysis as a HIV-1 integrase (HIV-1 IN) interacting protein. This interaction was verified by co-immunoprecipitation, GST pull-down, and intracellular imaging, and deletion assays suggested that the N-terminal 180 residues of TTRAP are responsible for the interaction. In stable TTRAP knock-down cell lines, the integration of viral vectors decreased significantly compared with non-silenced cell lines. Conversely, overexpression of TTRAP by transient transfection increased the percentage of integration events. This is the first time that TTRAP has been shown to interact with HIV-1 IN and facilitate lentiviral vector integration. These findings reveal a new function of TTRAP and expand our understanding of the cellular response to HIV infection. The interaction between TTRAP and HIV-1 IN may be useful in designing new anti-viral strategies as well as for improving the efficiency of lentiviral-vector-mediated gene delivery. 相似文献
9.
Alexander E. Vinogradov 《Journal of molecular evolution》2009,68(2):192-196
It is shown here that in the yeast protein interaction network the global centrality measure (betweenness) depends on the
protein evolutionary age (i.e., on historic contingency) more weakly than the local centrality measure (degree). This phenomenon
is not observed in mutational duplication-and-divergence models. The network domains responsible for this difference deal
with DNA/RNA information processing, regulation, and cell cycle. A selection vector can operate in these domains, which integrates
the network activity and thus compensates for the process of mutational divergence.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
10.
施玉燕 《现代生物医学进展》2006,6(12):158-158
生物医学信息资源的大量涌现,带来了一些问题。为了节约读者检索时问,提高查全率、查准率。我们有必要利用现有的技术条件对大量有用的生物医学数据库进行收集、整合、加工,形成具有实用性、系统性的新的有机整体。针对各类数据库建立生物医学信息的导航系统。两者的结合可以有效、系统地满足医务人员和科研人员对信息的需求。 相似文献