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1.
Michael W. Palmer 《植被学杂志》1995,6(3):447-447
Abstract. This note is to apologize for an error in the computer program used to evaluate the random data used in Fuzzy Set Ordination according to Zhang & Oxley. After correction of this error no artifacts could be detected any longer. However, the basic conclusion of the earlier critical note still stands: if one selects environmental variables after analyzing the results of a multivariate gradient analysis, and then uses these variables as input into a multiple univariate gradient analysis, the results are expected to be comparable. 相似文献
2.
Chronobiologic Evaluation of Drug Efficacy in Hypertension 总被引:1,自引:0,他引:1
Kohji Tamura 《Chronobiology international》1991,8(6):511-525
Time-associated variations of blood pressure became accesible due to the modern development of pressure monitoring technology. The data collection and analysis should be standardized and formulated. Time-associated changes of pressure were evaluated not only by nonparametric and conventional but also by parametric and rhythmometric estimation. The reference data (chronodesms) are essential to define the deviant magnitude of pressure. This chronobiologic approach became feasible to quantitate the efficacy of antihypertensive agents in hypertensives. 相似文献
3.
Quantifying the evidence for ecological synergies 总被引:2,自引:0,他引:2
There is increasing concern that multiple drivers of ecological change will interact synergistically to accelerate biodiversity loss. However, the prevalence and magnitude of these interactions remain one of the largest uncertainties in projections of future ecological change. We address this uncertainty by performing a meta-analysis of 112 published factorial experiments that evaluated the impacts of multiple stressors on animal mortality in freshwater, marine and terrestrial communities. We found that, on average, mortalities from the combined action of two stressors were not synergistic and this result was consistent across studies investigating different stressors, study organisms and life-history stages. Furthermore, only one-third of relevant experiments displayed truly synergistic effects, which does not support the prevailing ecological paradigm that synergies are rampant. However, in more than three-quarters of relevant experiments, the outcome of multiple stressor interactions was non-additive (i.e. synergies or antagonisms), suggesting that ecological surprises may be more common than simple additive effects. 相似文献
4.
Joan Thiesen Torben S. Christensen Thomas G. Kristensen Rikke D. Andersen Brit Brunoe Trine K. Gregersen Mikkel Thrane Bo P. Weidema 《The International Journal of Life Cycle Assessment》2008,13(2):104-114
Goal, Scope and Background Traditionally, comparative life cycle assessments (LCA) have not considered rebound effects, for instance in case of significant
price differences among the compared products. No justifications have been made for this delimitation in scope. This article
shows that price differences and the consequent effects of marginal consumer expenditure may influence the conclusions of
comparative LCA significantly. We also show that considerations about rebound effects of price differences can be included
in LCAs.
Methods The direct rebound effect of a price difference is marginal consumption. Based on statistical data on private consumption
in different income groups (Statistics Denmark 2005a, 2005b), the present article provides an estimate of how an average Danish
household will spend an additional 1 DKK for further consumer goods, when the household has gained money from choosing a cheaper
product alternative. The approach is to use marginal income changes and the following changes in consumption patterns as an
expression for marginal consumption. Secondly, the environmental impact potentials related to this marginal consumption are
estimated by the use of environmental impact intensity data from an IO-LCA database (Weidema et al. 2005). Finally, it is
discussed whether, and in which ways the conclusions of comparative LCAs can be affected by including the price difference
between product alternatives. This is elucidated in a case study of a comparative LCA screening of two different kinds of
Danish cheese products (Fricke et al. 2004).
Results Car purchase and driving, use and maintenance of dwelling, clothing purchase and insurance constitutes the largest percentages
of the marginal consumption. In a case study of two cheeses, the including the impact potentials related to the price difference
results in significant changes in the total impact potentials. Considering the relatively small price difference of the two
products, it is likely also to have a significant influence on the results of comparative LCAs more generally.
Discussion The influence of marginal consumption in comparative LCAs is relevant to consider in situations with large differences in
the price of the product alternatives being compared, and in situations with minor differences in the impact potentials related
to the alternatives. However, different uncertainties are linked to determining the pattern for marginal consumption and the
environmental impact potential related to this. These are first of all related to the method used, but also include inaccurate
data of consumption in households, aggregation and weighting of income groups, aggregation of product groups, estimation and
size of the price difference, and the general applicability of the results.
Conclusion Incorporating marginal consumption in consequential LCAs is possible in practice. In the case study used, including the rebound
effects of the price difference has a significant influence on the result of the comparative LCA, as the result for the impact
categories acidification and nutrient enrichment changes in favour of the expensive product.
Recommendations and Perspectives It is recommended that the rebound effects of price differences should be included more frequently in LCAs. In order to ensure
this, further research in marginal consumption and investment patterns and IO data for different countries or regions is required.
Furthermore, this study does not consider the economic distributional consequences of buying an expensive product instead
of a cheaper product (e.g. related to how the profit is spent by those who provided the product). It should also be noted,
that more expensive products not necessarily result in less consumption, as those who provided the product also will spend
the money they have earned from the sale. Ideally, these consequences should also be further investigated. Likewise, the development
of databases to include marginal consumption in PC-tools is needed. In general, considerations of marginal consumption would
favour expensive product alternatives, depending, however, on the type of consumer.
ESS-Submission Editor: Dr. David Hunkeler (david.hunkeler@aquaplustech.ch) 相似文献
5.
Rhamnolipids, produced by Pseudomonas aeruginosa, represent an important group of biosurfactants having various industrial, environmental, and medical applications. Current
methods for rhamnolipid quantification involve the use of strong hazardous acids/chemicals, indirect measurement of the concentration
of sugar moiety, or require the availability of expensive equipment (HPLC-MS). A safer, easier method that measures the whole
rhamnolipid molecules would significantly enhance strain selection, metabolic engineering, and process development for economical
rhamnolipid production. A semi-quantitative method was reported earlier to differentiate between the rhamnolipid-producing
and non-producing strains using agar plates containing methylene blue and cetyl trimethylammonium bromide (CTAB). In this
study, a rapid and simple method for rhamnolipid analysis was developed by systematically investigating the complexation of
rhamnolipids and methylene blue, with and without the presence of CTAB. The method relies on measuring the absorbance (at
638 nm) of the rhamnolipid−methylene blue complex that partitions into the chloroform phase. With P. aeruginosa fermentation samples, the applicability of this method was verified by comparison of the analysis results with those obtained
from the commonly used anthrone reaction technique. 相似文献
6.
F. Heinmets 《Cell biochemistry and biophysics》1989,14(3):283-323
A model-system is established to analyze purine and pyrimidine metabolism leading to DNA synthesis. The principal aim is to
explore the flow and regulation of terminal deoxynucleoside triophosphates (dNTPs) in various input and parametric conditions.
A series of flow equations are established, which are subsequently converted to differential equations. These are programmed
(Fortran) and analyzed on a Cray X-MP/48 supercomputer. The pool concentrations are presented as a function of time in conditions
in which various pertinent parameters of the system are modified. The system is formulated by 100 differential equations. 相似文献
7.
Sophie Calderari Massimiliano Ria Christelle Gérard Tatiane C. Nogueira Olatz Villate Stephan C. Collins Helen Neil Nicolas Gervasi Christophe Hue Nicolas Suarez-Zamorano Cécilia Prado Miriam Cnop Marie-Thérèse Bihoreau Pamela J. Kaisaki Jean-Baptiste Cazier Cécile Julier Mark Lathrop Michel Werner Dominique Gauguier 《Genomics》2018,110(2):98-111
The GLIS family zinc finger 3 isoform (GLIS3) is a risk gene for Type 1 and Type 2 diabetes, glaucoma and Alzheimer's disease endophenotype. We identified GLIS3 binding sites in insulin secreting cells (INS1) (FDR q < 0.05; enrichment range 1.40–9.11 fold) sharing the motif wrGTTCCCArTAGs, which were enriched in genes involved in neuronal function and autophagy and in risk genes for metabolic and neuro-behavioural diseases. We confirmed experimentally Glis3-mediated regulation of the expression of genes involved in autophagy and neuron function in INS1 and neuronal PC12 cells. Naturally-occurring coding polymorphisms in Glis3 in the Goto-Kakizaki rat model of type 2 diabetes were associated with increased insulin production in vitro and in vivo, suggestive alteration of autophagy in PC12 and INS1 and abnormal neurogenesis in hippocampus neurons. Our results support biological pleiotropy of GLIS3 in pathologies affecting β-cells and neurons and underline the existence of trans?nosology pathways in diabetes and its co-morbidities. 相似文献
8.
9.
Tree island ecosystems are important and distinct features of Florida Everglades wetlands. We described the inter-relationships
among abiotic factors describing seasonally flooded tree islands and characterized plant–soil relationships in tree islands
occurring in a relatively unimpacted area of the Everglades. We used Principal Components Analysis (PCA) to reduce our multi-factor
dataset, quantified forest structure and vegetation nutrient dynamics, and related these vegetation parameters to PCA summary
variables using linear regression analyses. We found that, of the 21 abiotic parameters used to characterize the ecosystem
structure of seasonally flooded tree islands, 13 parameters were significantly correlated with four principal components,
and they described 78% of the variance among the study islands. Most variation was described by factors related to soil oxidation
and hydrology, exemplifying the sensitivity of tree island structure to hydrologic conditions. PCA summary variables describing
tree island structure were related to variability in Chrysobalanus icaco (L.) canopy cover, Ilex cassine (L.) and Salix caroliniana (Michx.) canopy cover, Myrica cerifera (L.) plot frequency, litter turnover, % phosphorus resorption of co-dominant species, and nitrogen nutrient-use efficiency.
This study supported findings that vegetation characteristics can be sensitive indicators of variability in tree island ecosystem
structure. This study produced valuable, information which was used to recommend ecological targets (i.e. restoration performance
measures) for seasonally flooded tree islands in more impacted regions of the Everglades landscape. 相似文献
10.
应用排序分析藓类植物分类群分布与气候因素的关系 总被引:13,自引:1,他引:13
以我国21个山地藓类植物区系和气象资料为基础,应用典范对应分析(CCA)和除趋势典范对应分析(DCCA),比较了21个山地中藓类植物61个科,曲尾藓科(Dicranaceae)23个属、曲柄藓属(Campylopus)17种及曲尾藓属(Dicranum)35种分布与年均温度、>10℃积温、1月均温、7月均温、年均相对湿度、年均降雨量、年有雾天数、年有霜天数和年日照时数的关系,通过排序进行了直观的展示;同时还应用典范对应分析直观地反映了包括长白山在内的我国9个山地苔藓植物地理成分组成上的相似性及它们与气候因素间的关系.本文研究表明将DCCA和CCA应用到植物区系地理学研究上是可行的. 相似文献