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991.
Does Auxin Play a Role in the Release of Apical Dominance by Shoot Inversion in Ipomoea nil? 总被引:1,自引:0,他引:1
Prasad T. K.; Li X.; Abdel-Rahman A. M.; Hosokawa Z.; Cloud N. P.; Lamotte C. E.; Cline M. G. 《Annals of botany》1993,71(3):223-229
According to the auxin-inhibition hypothesis of apical dominance,apically produced auxin moves down the stem and inhibits axillarybud outgrowth, either directly or indirectly. This hypothesishas been examined further by monitoring changes in basipetalauxin transport and endogenous auxin concentration in Ipomoeanil caused by shoot inversion, a stimulus that releases apicaldominance. The results indicate that inversion reduces auxintransport in the main stem. In upright shoots of intact plants,a 16-h pretreatment with [3H]IAA 4 cm below the apex resultsin downward movement of label and accumulation in nodes, especiallythe cotyledonary node. Label does not accumulate in the lateralbuds. GC-MS determinations of endogenous free auxin level inthe fourth node, where a lateral bud grows out following inversionof the upper part of the shoot, show no changes at 3 and 8 hafter inversion, the range of times for inversion-induced budrelease, or at 24 h, when bud outgrowth is continuing. However,inversion did cause a just-detectable decrease (approx. 10%)in the IAA level of the shoot's elongation region. Althoughauxin transport in segments of the main stem is partially inhibitedby inversion over a period shorter than the latent time of budrelease, thus providing a means for the expected depletion ofauxin in the fourth node, no depletion could be detected there.These results suggest that either a decrease in IAA level inthe main stem is not causal of bud release or that the decreasedIAA pool responsible for bud release is compartmented and cannotbe measured in whole-tissue extracts.Copyright 1993, 1999 AcademicPress Apical dominance, auxin content, auxin transport, axillary bud release, GC-MS, Ipomoea nil, Pharbitis nil, shoot inversion 相似文献
992.
Shaik Hajira Jillela Santhosh Vijitha Sanjay Janrao Dhoble Borelli Deva Prasad Raju Busireddy Sudhakar Reddy 《Luminescence》2024,39(1):e4612
Red and green rare-earth ion (RE3+) (RE = Eu, Tb):MgLa2V2O9 micro-powder phosphors were produced utilizing a standard solid-state chemical process. The X-ray diffraction examination performed on the phosphors showed that they were crystalline and had a monoclinic structure. The particles grouped together, as shown in the scanning electron microscopy (SEM) images. Powder phosphors were examined using a variety of spectroscopic techniques, including photoluminescence (PL), Fourier-transform infrared, and energy dispersive X-ray spectroscopy. Brilliant red emission at 615 nm (5D0 → 7F2) having an excitation wavelength (λexci) of 396 nm (7F0 → 5L6) and green emission at 545 nm (5D4 → 7F5) having an λexci = 316 nm (5D4 → 7F2) have both been seen in the emission spectra of Tb3+:MgLa2V2O9 nano-phosphors. The emission mechanism that is raised in Eu3+:MgLa2V2O9 and Tb3+:MgLa2V2O9 powder phosphors has been explained in an energy level diagram. 相似文献
993.
Kishore Kumar Aitha Dantala Dinakar K. V. R. Murthy A. S. Sai Prasad Divi Haranath 《Luminescence》2024,39(1):e4623
Direct white light emitting phosphors play a significant role in the display industry due to their ability to improve the quality, efficiency, and versatility of lighting sources used in most of the displays. The currently investigated phosphor SrZr2CaLa2O8:Eu3+ was prepared by a conventional solid-state reaction method. It has been observed that the stoichiometric ratio of all precursors plays an important role in determining the characteristics of the final phosphor. From X-ray diffraction (XRD) analysis, the phosphor was observed to have a hexagonal phase and a crystal size of ~28 nm. Scanning electron microscopy (SEM) observations revealed a cluster of rod-like structures with an average diameter of ~0.2 μm. The excitation peak maximum observed at 280 nm is due to charge transfer between Eu3+-O2− ions. The energy transitions 7F0 → 5L6 and 7F0 → 5D2 are responsible for the appearance of other excitation peaks at ultraviolet (UV) (395 nm), blue (~467 nm), green (~540 nm), orange (~590 nm), and red (~627 nm) attributed to 5D0 → 7FJ (J = 0–4) transitions of europium ion (Eu3+). The Commercial International de I'Eclairage (CIE) chromaticity coordinates were estimated to be (0.37, 0.0.33) and (0.67, 0.33) for the emissions corresponding to 395 and 590 nm, respectively. The characteristic emissions of Eu3+ ions allow this novel phosphor to be used to generate direct white light in light-emitting diodes (LEDs), which is otherwise difficult to achieve in single-component systems. 相似文献
994.
995.
Sunil A. Patil Venkata Prasad Surakasi Sandeep Koul Shrikant Ijmulwar Amar Vivek Y.S. Shouche B.P. Kapadnis 《Bioresource technology》2009,100(21):5132-5139
Feasibility of using chocolate industry wastewater as a substrate for electricity generation using activated sludge as a source of microorganisms was investigated in two-chambered microbial fuel cell. The maximum current generated with membrane and salt bridge MFCs was 3.02 and 2.3 A/m2, respectively, at 100 Ω external resistance, whereas the maximum current generated in glucose powered MFC was 3.1 A/m2. The use of chocolate industry wastewater in cathode chamber was promising with 4.1 mA current output. Significant reduction in COD, BOD, total solids and total dissolved solids of wastewater by 75%, 65%, 68%, 50%, respectively, indicated effective wastewater treatment in batch experiments. The 16S rDNA analysis of anode biofilm and suspended cells revealed predominance of β-Proteobacteria clones with 50.6% followed by unclassified bacteria (9.9%), α-Proteobacteria (9.1%), other Proteobacteria (9%), Planctomycetes (5.8%), Firmicutes (4.9%), Nitrospora (3.3%), Spirochaetes (3.3%), Bacteroides (2.4%) and γ-Proteobacteria (0.8%). Diverse bacterial groups represented as members of the anode chamber community. 相似文献
996.
Jatin Kakkar Kamal Kumar Chaudhary Chekkara Venkata Satya Siva Prasad 《Bioinformation》2013,9(15):777-781
The HIV-1 Nef protein has the ability to down regulate important molecules at the immune synapse. These include class I and class
II (Human Leukocyte Antigen) HLA on the Antigen Presenting Cells (APC). The receptors in these molecules consist of SH-3
domain and their interaction with the HIV-1 Nef is critical. Therefore, it is important to inhibit this HIV-Nef and human SH3
domain interaction. Thus, we used a combinatorial library to screen for molecules to inhibit this interaction. The exercise identified
a group of top ranking compounds for further consideration. 相似文献
997.
998.
Cynthia S. Ricard Janelle M. Jakubowski John W. Verbsky M. Alejandro Barbieri William M. Lewis G. Esteban Fernandez Marion Vogel Christina Tsou Vinoy Prasad Philip D. Stahl Gabriel Waksman Clarissa M. Cheney 《Genesis (New York, N.Y. : 2000)》2001,31(1):17-29
Summary: Rab GTPases are essential for vesicular transport. Rab GDP dissociation inhibitor (GDI) binds to GDP‐bound rabs, removes rabs from acceptor membranes and delivers rabs to donor membranes. We isolated lethal GDI mutations in Drosophila and analyzed their developmental phenotypes. To learn how these mutations affect GDI structure, the crystal structure of Drosophila GDI was determined by molecular replacement to a resolution of 3.0 Å. Two hypomorphic, missense mutations are located in domain II of GDI at highly conserved positions, but not in previously identified sequence conserved regions. The mutant GDIs were tested for ability to extract rabs from membranes and showed wild‐type levels of rab membrane extraction. The two missense alleles showed intragenic complementation, indicating that domain II of GDI may have two separable functions. This study indicates that GDI function is essential for development of a complex, multicellular organism and that puparium formation and pole cell formation are especially dependent on GDI function. genesis 31:17–29, 2001. © 2001 Wiley‐Liss, Inc. 相似文献
999.
Essential oils isolated from leaves (LO), bast (BO), heartwood (HO), and ethereal extract of resin (EER) of Shorea robusta were bioassayed with electroantennograph (EAG) and wind tunnel to study the behavioral response of male and female beetles, Hoplocerambyx spinicornis Newm., the most injurious heartwood borer of the tree. LO, BO, HO, and EER were shown to exhibit the electrophysiological activity in the female beetle, while LO and BO in the male beetle. In wind-tunnel studies, only BO elicited the attractant activity to both the sexes. A possible correlation of the constituents of the BO identified by GC/MS with the bioactivity is also presented. 相似文献
1000.
Kazunobu Okazaki Ken-ichi Iwasaki Anand Prasad M Dean Palmer Emily R Martini Qi Fu Armin Arbab-Zadeh Rong Zhang Benjamin D Levine 《Journal of applied physiology》2005,99(3):1041-1049
Aging results in marked abnormalities of cardiovascular regulation. Regular exercise can improve many of these age-related abnormalities. However, it remains unclear how much exercise is optimal to achieve this improvement or whether the elderly can ever improve autonomic control by exercise training to a degree similar to that observed in healthy young individuals. Ten healthy sedentary seniors [71 +/- 3 (SD) yr] trained for 12 mo; training involved progressive increases in volume and intensity. Static hemodynamics were measured, and R-wave-R-wave interval (RRI), beat-to-beat blood pressure (BP) variability, and transfer function gain between systolic BP and RRI were calculated at baseline and every 3 mo during training. Data were compared with those obtained in 12 Masters athletes (68 +/- 3 yr) and 11 healthy sedentary young individuals (29 +/- 6 yr) at baseline. Additionally, the adaptation of these variables after completion of identical training loads was compared between the seniors and the young. Indexes of RRI variability and baroreflex gain were decreased in the sedentary seniors but preserved in the Masters athletes compared with the young at baseline. With training in the seniors, baroreflex gain and resting BP showed a peak adaptation after moderate doses of training following 3-6 mo. Indexes of RRI variability continued to improve with increasing doses of training and increased to the same magnitude as the young at baseline after heavy doses of training for 12 mo; however, baroreflex gain never achieved values equivalent to the young at baseline, even after a year of training. The magnitude of the adaptation of these variables to identical training loads was similar (no interaction effects of age x training) between the seniors and the young. Thus RRI variability in seniors improves with increasing "dose" of exercise over 1 yr of training. In contrast, more moderate doses of training for 3-6 mo may optimally improve baroreflex sensitivity, associated with a modest hypotensive effect; however, higher doses of training do not lead to greater enhancement of these changes. Seniors retain a similar degree of "trainability" as young subjects for cardiac autonomic function to dynamic exercise. 相似文献