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31.
Huber Bernhart M. postner Rudolf Mayer H. Mayer und Ernst 《Forstwissenschaftliches Centralblatt》1959,78(3-4):122-128
Ohne Zusammenfassung 相似文献
32.
Mägdefrau Attenberger E. Rohmeder H. Mayer Rohmeder und Rössler 《Forstwissenschaftliches Centralblatt》1954,73(5-6):185-192
Ohne Zusammenfassung 相似文献
33.
34.
35.
Atawodi SE Pfundstein B Haubner R Spiegelhalder B Bartsch H Owen RW 《Journal of agricultural and food chemistry》2007,55(24):9824-9828
Varieties of kola nuts (Cola nitida alba, Cola nitida rubra A. Chev, and Cola acuminata Schott & Endl), a group of popular Nigerian and West African stimulants, were analyzed for their content of secondary plant metabolites. The three varieties of the kola nuts contained appreciable levels of (+)-catechin (27-37 g/kg), caffeine (18-24 g/kg), (-)-epicatechin (20-21 g/kg), procyanidin B 1 [epicatechin-(4beta-->8)-catechin] (15-19 g/kg), and procyanidin B2 [epicatechin-(4beta-->8)-epicatechin] (7-10 g/kg). Antioxidant capacity of the extracts and purified metabolites was assessed by two HPLC-based and two colorimetric in vitro assays. Extracts of all varieties exhibited antioxidant capacity with IC 50 values in the range 1.70-2.83 and 2.74-4.08 mg/mL in the hypoxanthine/xanthine oxidase and 2-deoxyguanosine HPLC-based assays, respectively. Utilization of HPLC-based assays designed to reflect in situ generation of free radicals (e.g., HO(*)), as opposed to general assays (DPPH, FRAP) in common use which do not, indicate that, of the major secondary plant metabolites present in kola nut extracts, caffeine is potentially the more effective cancer chemopreventive metabolite in terms of its antioxidant capacity. 相似文献
36.
Andrea Ganthaler Helmut Bauer Andreas Gruber Michaela Mayr Walter Oberhuber Stefan Mayr 《European Journal of Forest Research》2014,133(2):201-211
Norway spruce trees in the subalpine forests of the European Alps are frequently attacked by the needle rust Chrysomyxa rhododendri. The obligate parasite undergoes a complex life cycle with a host shift between rhododendrons (Rhododendron sp.) and Norway spruce [Picea abies (L.) Karsten] and causes a yellowing and defoliation of the current-year needles in summer. Infected trees show several anatomical, morphological and physiological modifications, including a decrease in pigment content and net photosynthesis of infected needles, lower biomass production and reduced radial and height growth. The consequences are diminished timber yield and cripple growth. Because of repeated heavy infections in recent years, forest managers report increasing difficulties in both natural regeneration and afforestation at high elevation sites, where rhododendrons occur. This review gives a summary of the present knowledge about the effects of C. rhododendri infections on Norway spruce, including so far unpublished findings and with particular attention to the phenomena of resistant trees. Implications for subalpine forests and counter strategies are discussed. 相似文献
37.
Three-spined stickleback Gasterosteus aculeatus, males were implanted with Silastic capsules filled with different aromatase
inhibitors; 1,4,6-androstatriene-3,17-dione or the non-steroidal CGS16949 A, 4-(5,6,7,8-tetrahydrimidazol [1,5-a]pyridin-5-yl)
benzonitrile monohydrochloride or empty capsules. The fish were then exposed to long or short photoperiod. Under the long
photoperiod most fish in all treatments displayed a hypertrophied kidney (a secondary sexual character in sticklebacks) and
completed, quiescent spermatogenesis, similar as in the natural spawning period. Under the short photoperiod the controls
had unstimulated kidneys and an active spermatogenesis, whereas the males implanted with both aromatase inhibitors had stimulated
kidneys, though not to the extent as in the long photoperiod, and completed, quiescent spermatogenesis. These findings suggest
that aromatization is of importance for the inhibitory effects of short photoperiod on reproduction in the stickleback.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
38.
Isolated carp hepatocytes cultured in serum-free, chemically defined medium were used to investigate within the same cell
preparation characteristics of the binding of insulin as well as effects of insulin on cellular metabolism. The binding of
human [125I]-insulin to carp hepatocytes was studied in kinetic, saturation and displacement experiments. A dependency of insulin binding
on the collagenase used for cell isolation was demonstrated. Insulin binding decreased during the first 12h of culture but
remained constant during the following 12h. The kinetic experiments revealed that [125I]-insulin binding reached a steady state within 20–30 min of incubation. The mathematical analysis of the saturation experiments
demonstrated the existence of two populations of binding sites, one with high affinity (Kd1 = 5.5 pM) and low capacity (Bmax1 = 0.14 fmol/mg protein or 77 binding sites/cell) and one with low affinity (Kd2 = 2.4 nM) and high capacity (Bmax2 = 17.6 fmol/mg protein or 9623 binding sites/cell). In competition experiments, 312 pM [125I]-insulin was displaced by cold insulin, IGF-I and IGF-II with IC50 values of 2.2, 7.9 and 20.3 nM, respectively. Glucagon was without effect. Binding of insulin to carp hepatocytes resulted
in a significant reduction of glucose release and a significant increase of protein synthesis as of de novo fatty acid synthesis.
dedicated to Prof. Dr. W. Hanke on the occasion of his 65th birthday. 相似文献
39.
- The history of conservation of the Amazon can be viewed as a war involving many battles with interests in agribusiness on one side and in biodiversity conservation and sustainability on the other side. Trends in large-scale deforestation in the 1970s spurred a series of policies, stakeholder alliances and international and grass-roots movements, which decades later led to the establishment of protected areas and interventions in soy and beef supply chains of agribusiness. Together, these advances epitomized a conservation framework for the Amazon, which at one point nearly curbed deforestation in the Brazilian Amazon, although it included very few protections for freshwater ecosystems.
- While those conservation advances were taking place, however, a series of policy changes started to undermine them through expansions in deforestation, river regulation and mining activities. The election of Brazil's President Jair Bolsonaro in 2019 then hit the Amazon conservation framework much like a tsunami of policy setbacks and the re-establishment of the economic policies that sparked the Amazon war in the past.
- The current trajectory is one of large-scale degradation of Amazonian ecosystems and biodiversity with consequent impacts on local people. Because freshwater ecosystems are highly sensitive to human activities on water and on land, these growing impacts are particularly large.
- It is too early to know, but four decades of institutional and policy developments to conserve the Brazilian Amazon may soon be pushed past the point from which they will be able to recover. Four conditions will be pivotal to allowing the Amazon conservation framework to recoup: (a) the end of Bolsonaro’s mandate in 2022 or earlier; (b) remobilization of stakeholders; (c) investments in environmental research, policy and multiple collaborations; and (d) moving conservation beyond terrestrial landscapes to also encompass freshwater ecosystems and their people.
40.
Helmut Brandl 《Small-Scale Forestry》2002,1(1):13-24
Changes in the economic environment, including increased international competition caused by globalisation, low-priced imports
and high costs of labour, are influencing the economic situation of all agricultural enterprises, and naturally including
those on forest land. As a result, changes are taking place in the structure of agricultural enterprises, with smaller units
disappearing. Enterprises with greater areas of agricultural and forest land strive to expand by purchasing or leasing more
agricultural area or forests, depending on their labour and financial resources. Another way to overcome the economic needs
and to survive as a family enterprise in the future is to find new sources of income. In a case study in the Southern Black
Forest an investigation of 32 family-enterprises with agricultural and forest land and members of an accounting network was
carried out in order to register all types of income of the family which contribute economically to their costs of living.
Besides the traditional income from agriculture and forestry, income was found to be derived from renting rooms or flats for
holiday-makers, employment outside the enterprise, contract-working,a nd direct-marketing of own products. This paper presents
the results of the study, showing the overall distribution of the total income of the family to the various types of activities
of the family. On average, agriculture, forestry and the other income sources are found to each contribute about one third
to overall income. The great variety of income combinations are illustrated in diagrams and clustered to different types of
organization of family-farm enterprise. It is also notable that the amount of the total income varies from very high to very
low between individual enterprises. 相似文献