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991.
Viruses alter the structure and the function of mitochondria for survival. Electron microscopy analysis of the cells infected with bovine adenovirus 3 revealed extensive damage to the inner mitochondrial membrane characterized by dissolution of the cristae and amorphous appearance of mitochondrial matrix with little or no damage to the outer mitochondrial membrane. There were fewer cristae with altered morphology. Potential patches of protein synthesis machinary around mitochondria could be observed at 12 hours post infection (hpi). At 24 hpi, the multi vascular bodies were evident throughout the infected cell. ATP production, mitochondrial Ca2+ and mitochondrial membrane potential (MMP) peaked at 18 hpi but decreased significantly at 24 hpi. This decrease coincided with the increased production of superoxide (SO) and reactive oxygen species (ROS), at 24 hpi indicating acute oxidative stress in the cells and suggesting a complete failure of the cellular homeostatic machinary. The results reveal an intericate relationship between Ca2+ homeostasis, the ATP generation ability of cells, SO and ROS production, and regulation of MMP following infection by bovine adenovirus 3. 相似文献
992.
993.
Sodium chlorate (NaClO(3)) crystals are optically active although the molecules of the compound are not chiral. When crystallized from an aqueous solution while the solution is not stirred, statistically equal numbers of levo (L) and dextro (D) NaClO(3) crystals were found. When the solution was stirred, however, almost all of the NaClO(3) crystals (99.7 percent) in a particular sample had the same chirality, either levo or dextro. This result represents an experimental demonstration of chiral symmetry breaking or total spontaneous resolution on a macroscopic level brought about by autocatalysis and competition between L- and D-crystals. 相似文献
994.
995.
Levan AJ Tanvir NR Cenko SB Perley DA Wiersema K Bloom JS Fruchter AS Postigo Ade U O'Brien PT Butler N van der Horst AJ Leloudas G Morgan AN Misra K Bower GC Farihi J Tunnicliffe RL Modjaz M Silverman JM Hjorth J Thöne C Cucchiara A Cerón JM Castro-Tirado AJ Arnold JA Bremer M Brodie JP Carroll T Cooper MC Curran PA Cutri RM Ehle J Forbes D Fynbo J Gorosabel J Graham J Hoffman DI Guziy S Jakobsson P Kamble A Kerr T Kasliwal MM Kouveliotou C Kocevski D Law NM Nugent PE Ofek EO Poznanski D 《Science (New York, N.Y.)》2011,333(6039):199-202
Variable x-ray and γ-ray emission is characteristic of the most extreme physical processes in the universe. We present multiwavelength observations of a unique γ-ray-selected transient detected by the Swift satellite, accompanied by bright emission across the electromagnetic spectrum, and whose properties are unlike any previously observed source. We pinpoint the event to the center of a small, star-forming galaxy at redshift z = 0.3534. Its high-energy emission has lasted much longer than any γ-ray burst, whereas its peak luminosity was ~100 times higher than bright active galactic nuclei. The association of the outburst with the center of its host galaxy suggests that this phenomenon has its origin in a rare mechanism involving the massive black hole in the nucleus of that galaxy. 相似文献
996.
Chromosomal aberrations induced in barley by LSD 总被引:1,自引:0,他引:1
Seeds of hulled barley (Hordeum vulgare) were germinated and then treated with LSD. Preparations of squashed root tips stained with Feulgen revealed extensive chromosomal aberrations, most of which were chromosome breaks. Nearly half of the breaks occurred in the region of the primary constriction. 相似文献
997.
On the basis of an analysis of historic worldwide emissions and removal mechanisms for carbon tetrachloride, a possible precursor for stratospheric ozone destruction, it has been demonstrated that the present atmospheric loading and distribution of carbon tetrachloride is primarily attributable to man-made emissions and no natural sources need be invoked to explain its presence in the atmosphere. 相似文献
998.
Summary Cowpea and mung bean were subjected to three irrigation schedules during summer dry months (May–June). In general, cowpea had higher rates of net photosynthesis (P
n
,Figs. 1, 2), dark respiration (R
d
,Table 1), absorption of photosynthetically active radiation (PAR, Table 2), and growth (Fig. 7) than mung bean. Mung bean reflected more PAR and maintained a slightly cooler canopy than cowpea (Table 2). Moisture stress decreased P
n
, R
d
,absorption coefficient of PAR, evaporative cooling and growth in both the species. However, the reductions in P
n
rates of stressed leaves were more than the decreases in R
d
.Restoration of water supply to stressed cowpea resulted in a more rapid recovery of growth as compared to mung bean. 相似文献
999.
Application of SALTMOD in Coastal Clay Soil in India 总被引:1,自引:1,他引:1
SALTMOD is a simulation model whichpredicts root zone soil salinity, drainagewater quality and water table depth inagricultural land under differentgeo-hydrological conditions and varyingwater management scenarios. The model wasapplied to the data from coastal AndhraPradesh of India where subsurface drainagesystem is laid out at several drainspacings at the experimental site. Fielddata for 1999, 2000 and 2001 were collectedfrom 35 and 55 m drain spacing plots forSALTMOD application. Modelling was doneconsidering two simulation approaches. Thefirst approach (Simulation-I) used the sameinitial values for the entire simulationperiod. In the second approach(Simulation-II), the computations wereperformed year-by-year, giving each yearthe current input values obtained from thesimulation results of the previous year.Results of these two approaches weredifferent from each other. Simulation-IIgave better predictions than that ofSimulation-I in terms of closeness to theobserved values. Simulation results ofsoil salinity in the root zone, drainagewater quality and quantity and depth towater table revealed that the salinity ofroot zone was predicted more accuratelythan that of drainage water quality anddepth to water table. Also throughsimulation, it was found that the salinityof drainage water was relativelyindependent of the root zone soil salinity. Model application study suggests thatSALTMOD can be used with confidence toevaluate various drain spacings of asubsurface drainage system and facilitatereasonable prediction of the reclamationperiod. 相似文献
1000.