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21.
The extent of noise and its impacts continues to grow globally indicating a different approach from regulating individual
noise sources is needed. We pose the argument that soundscapes, or the acoustic environment, should be managed as a common-pool
resource (CPR). Using CPR theory, we argue that soundscapes possess key features of CPRs: (1) multiple soundscape users, (2)
difficulty of exclusion, and (3) subtractability and degradation. Using Ostrom’s Social-Ecological Systems (SES) framework,
we describe the main elements of soundscapes to consider for their sustainable management. In order to assess noise issues
and challenges in managing national park soundscapes, we conducted interviews with U.S. National Park Service managers at
parks identified as having air tour overflight impacts. While most managers indicated that aircraft overflights posed the
most serious impacts to park resources and visitor experiences, the park units also experienced several other types of noise
impacts including traffic on park roads, park maintenance operations, and different types of motorized recreational vehicles.
Addressing single sources of noise is necessary, as is the case with air tour overflights, but we argue that a more comprehensive
approach is needed to protect park soundscapes. From this study several SES framework variables emerged that need to be addressed
for sustainable management, such as the lack of clear soundscape boundaries, availability of acoustic monitoring and data,
and the number and types of soundscape users. Based on CPR theory and using the SES framework, the challenges and a potential
new approach for sustainable management are discussed. 相似文献
22.
Rohny Setiawan Maail Kenji Umemura Hideo Aizawa Shuichi Kawai 《Journal of Wood Science》2011,57(4):302-307
This study examined the effects of supercritical CO2 treatment on the curing and degradation of cementbonded particleboard (CBP). Significant correlations were found between
the supercritical CO2 treatment and mechanical properties during both curing and degradation processes. Internal bond (IB) strength, modulus of
rupture (MOR), and modulus of elasticity (MOE) values of CBP achieved their maximums by supercritical CO2 treatment in 30 min. These conditions indicated that supercritical CO2 treatment accelerates the curing process rapidly and enhances the mechanical properties of the CBP. However, these values
decreased in treatment from 60 min to 10 days and had a negative effect on board performance, indicating that supercritical
CO2 treatment over a longer time span leads to degradation of the CBP. Furthermore, X-ray diffractometry (XRD), thermal gravimetry
(TG-DTG), and scanning electron microscopy (SEM) observation clarified that the mechanisms of degradation are directly affected
by the mineralogical composition of the system, in par ticular, by the calcium carbonate content as caused by carbonation. 相似文献
23.
M. Pupin A. Flissi P. Jacques Valérie Leclère 《European journal of plant pathology / European Foundation for Plant Pathology》2018,152(4):993-1001
As conventional or chemical pesticides have negative impact on environment and health of both farmer and consumers, it becomes relevant to develop alternative solutions to limit their use. In this context, innovative strategies to accelerate the development of biocontrol agents are welcome. For a decade of years, it has been demonstrated that lipopeptides are very efficient weapons against fungi responsible for crop diseases. Lipopeptides are secondary metabolites, produced by many microorganisms including beneficial rhizobacteria. The lipopeptide biosynthetic pathways include nonribosomal peptide synthetases. These modular enzymatic complexes work as assembly lines to build the peptides step by step, leading to the production of original peptide compounds with specific features as the presence of non proteinogenic monomers and cyclic and branched structures. In this paper, Florine and Norine bioinformatics tools, especially dedicated to non-ribosomal synthetases and their products are presented. Their use is mainly focused on the discovery of lipopeptides produced by Bacillus or Pseudomonas because they seem to represent a versatile reservoir of active secondary metabolites with promising activities for applications in phytosanitary area. 相似文献
24.
Quantitative information of tree biomass is useful for management planning and monitoring of the changes in carbon stock in both forest and agroforestry systems. An estimate of carbon stored in these systems can be useful for developing climate change mitigation strategies. A precise estimate of forest biomass is also important for other issues ranging from industrial forestry practices to scientific purposes. The individual tree-based biomass models serve as fundamental tools for precise estimates of carbon stock of species of interest in forest and agroforestry systems. We developed individual tree aboveground biomass models for Castanopsis indica using thirty-six destructively sampled tree data covering a wide range of tree size, site quality, growth stage, stand density, and topographic characteristics. We used diameter at breast height (DBH) as a main predictor and height-to-DBH ratio (a measure of tree slenderness) and wood density (a measure of stiffness and cohesiveness of wood fibres) as covariate predictors in modelling. We, hereafter, termed the biomass models with former two predictors as first category models (density independent models) and the models with all three predictors as second category models (density dependent models). Among various functions evaluated, a simple power function of the form \(y_{i} = b_{1} x_{i}^{{b_{2} }}\), in each category, showed the best fits to our data. This formulation, in each category, described most of the biomass variations (\(R_{adj}^{2}\) > 0.98 and RMSE < 72.2) with no significant trend in the residuals. Since both density dependent and density independent models exhibit almost similar fit statistics and graphical features, one of them can be applied for desired accuracy, depending on the access of the input information required by the model. Our biomass models are site-specific, and their applications should therefore be limited to the growth stage, stand density, site quality, stand condition, and species distribution similar to those that formed the basis of this study. Further research is recommended to validate and verify our model using a larger dataset with a wider range of values for site quality, climatic and topographic characteristics, stand density, growth stage, and species distribution across Nepal. 相似文献
25.
Sang-Yun Yang Yeonjung Han Yoon-Seong Chang Jun-Ho Park Yonggun Park Hyunwoo Chung Hwanmyeong Yeo 《Journal of Wood Science》2018,64(3):220-225
In this study, hot air heat treatments of larch (Larix kaempferi) wood specimens were conducted at various temperatures (160–220 °C) and times (1–12 h) to classify the degree of hot air heat treatment using near-infrared (NIR) spectroscopy. NIR reflectance spectra were acquired from specimen cross-sections and were then preprocessed using the standard normal variate. Hierarchical clustering analysis (HCA) using the complete linkage and squared Euclidean distance was conducted to classify the three degrees of heat treatment. A principal component score plot of the NIR spectra was well grouped by the HCA grouping result, and the first component reflected the cluster analysis grouping well. A partial least squares discriminant analysis was performed to develop the discriminant regression model of the three heat treatment degrees. The R2 and root mean square error of validation were 0.959 and 0.191, respectively. NIR is considered to be a good candidate to routinely measure the degree of hot air treatment for larch wood. 相似文献
26.
Jarosław Skłodowski Paula Bajor Michał Trynkos 《European Journal of Forest Research》2018,137(5):745-757
The released excess anthropogenic nitrogen and carbon produces habitat enrichment, as exemplified by the modification of one-storied pine stands by introducing deciduous species into the understory or second story. In this study, we discuss the validity of pine stand modification by pitfall-trapping epigeic carabid beetles. Two hypotheses were formulated: (1) proportion of late-successional species is higher in assemblages inhabiting pine stands with understory or a second story than in one-storied pine stands; (2) plant litter composition affects carabid beetle assemblages more than other environmental variables. Additionally, characteristic carabid species of the respective pine stand types were identified. GLMM analysis revealed a higher proportion of late-successional species in pine stands with understory or a second story than in one-storied ones. NMDS separated those pine stand types. RDA analysis indicated that pine litter and humus had the strongest effect on carabid beetle assemblage structure in one-storied stands, being drier and thicker in this stand type than in the others. Indicator value analysis identified two characteristic non-forest species in one-storied stands The study revealed that the introduction of understory and particularly a second story into pine stands increased carabid beetle diversity and the proportion of late-successional species, confirming the validity of pine stand modification. 相似文献
27.
Jianli Liu Baoqi Zuo Xianyi Zeng Philippe Vroman Besoa Rabenasolo Weidong Gao 《Fibers and Polymers》2011,12(7):963-969
Previous work has shown that the uniformity recognition of nonwoven can be considered as a special case of pattern recognition.
In this paper, a generalized frame for uniformity recognition based on computer vision and pattern recognition is introduced
briefly. To validate the proposed generalized frame, a case study id carried out in experiment. In the experiment section,
the uniformity recognition of nonwovens will be solved by unifying wavelet texture analysis, generalized Gaussian density
(GGD) model and learning vector quantization (LVQ) neural network. 625 nonwoven images of 5 different uniformity grades, 125
of each grade, are decomposed at four levels with five different wavelet bases of Symlets family. And wavelet coefficients
in each subband are independently modeled by the GGD model, while the scale and shape parameters of GGD model are extracted
using maximum likelihood (ML) estimator as features to train and test LVQ neural network. For comparison, two energy-based
features are also extracted from wavelet coefficients directly and jointly used as textural features. Experimental results
coming from 625 nonwoven samples indicate the GGD parameters are more expressive and powerful in characterizing textures than
the energy-based ones, especially when the number of decomposition levels is 4. 相似文献
28.
Charles R. Brown 《Potato Research》2011,54(4):287-300
Conventional potato breeding refers to development of new cultivars from sexual crosses followed by clonal propagation and
selection. Nearly all new varieties of potato still emerge from this process free from modern technologies of gene insertion.
Conventional breeding remains the most important force for introduction of new phenotypes underlain by new genes. However,
these come from already selected potato breeding lines or named varieties or from wild potatoes or more distant solanaceous
relatives that are amenable to somatic hybridization. Potato breeders are constantly searching for new germplasm, in part
because the potato as a crop still remains highly vulnerable to biotic and abiotic stresses. In addition, the widening of
the genetic base is seen as a means of increasing heterozygosity. Despite a highly conscious import of genetic variability,
commercial varieties often emerge from a relatively restricted genetic pool. This is due to the long list of traits that must
fall within narrow boundaries of performance. The potato must be able to navigate the conditions of modern agriculture, withstand
unusual weather events, and arrive at harvest with skin and flesh appealing to the market for which it is intended. A storage
period must also be endured during which appearance and suitability for processing or the consumer’s kitchen must be maintained.
A lapse in any of these phases usually signals that a new variety will exit commercial use as fast as it entered. The inconvenient
accompaniment of introducing exotic genetic variation is that the breeding products are often outside of the targeted market
niche. It is not surprising that many new varieties stem from crosses from older named varieties. Efforts to diversify are
in conflict with conformism leading to relatively high co-ancestry coefficients between advanced breeding lines. Conventional
breeding has advanced through the last hundred years the appearance, sugar status, Verticillium resistance, and yield of larger sized tubers in statistically robust ways. Potato arrived from the new world and very quickly
became the secret solution to famine for the poor by virtue of its productivity and nutrient content. Meanwhile, in modern
times, challenges to the consumption of potato come from a sedentary and carbohydrate over-satiated society. The genetic repository
of potato germplasm is so rich that a new era of potato varieties beneficial to health may be at hand. Conventional breeding
will certainly be a major part of this. 相似文献
29.
The status of the Potato virus Y (PVY) in Swiss seed potato production was investigated in the years 2003 and 2008 by analysing 385 leaf samples of field-grown,
suspicious potato plants collected in four representative seed control fields. Serological investigations by ELISA showed
that in c. 84% of the PVY-positive samples in both years, viruses belonging to the PVYN group were found. All 124 serologically positive PVY samples collected in 2003 and a selection of 81 isolates of 2008 were
further typified by molecular tests and by biological assays on tobacco and potato plants. These tests largely confirmed the
predominance of the PVYN group and, within this group, the prevalence of recombinant PVYNTN, with 81.4% and 70.4% in 2003 and 2008, respectively. The percentage of PVYN-Wilga (PVYN-Wi) increased from c. 6% to 17% between the two years. PVYO was detected only in 10.5% and 4.9% of all molecularly analysed samples in 2003 and 2008, respectively. The persistent predominance
of recombinant PVYNTN in Swiss seed potatoes indicates that this strain group is now widespread, representing a considerable threat to Swiss seed
potato production. 相似文献
30.
Lena Partzsch 《Agriculture and Human Values》2011,28(3):413-425
The biofuel boom is placing enormous demands on existing cropping systems, with the most crucial consequences in the agri-food
sector. The biofuel industry is responding by initiating private governance and certification. The Roundtable on Sustainable
Palm Oil (RSPO) and the Cramer Commission, among others, have formulated criteria on “sustainable” biofuel production and
processing. This article explores the legitimacy of private governance and certification by the biofuel industry, highlighting
opportunities and challenges. It argues that the concept of output based legitimacy is problematic in the case of biofuel
as long as no consensus or commonly agreed “best” solution has been established on what sustainable biofuel production is.
Furthermore, it shows that the private governance initiatives analyzed fail to adequately include actors from developing countries.
Finally, the article argues that we need mechanisms for control and accountability in order to guarantee that the political
output of biofuel certification serves the common welfare. 相似文献