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121.
122.
In a field trial, a total of 472 Norwegian Dairy goats showing natural estrus were artificially inseminated with frozen-thawed semen. The farmers themselves performed vaginal deposition of 400 × 106 spermatozoa; one half of the does received two straws (200 × 106 spermatozoa/straw) at the same time (single AI), while the other half received two straws (200 × 106 spermatozoa/straw) 12 h apart (double AI). The commercially available extender Andromed® was used for dilution. The does were housed at 15 different farms, and on average 31 does were inseminated per farm. Non return rates (NRR) and kidding rates after single insemination were 64.3% and 58.3%, respectively. Double inseminations resulted in a NRR of 62% and a kidding rate of 57%. No significant difference between single and double AI was seen in the study. This study indicates that single or double vaginal insemination with an equal total number of frozen-thawed spermatozoa (400 × 106) can give acceptable fertility results in Norwegian Dairy goats. However, studies on reducing sperm numbers are called for to allow AI donor bucks to be used to their fullest potential. 相似文献
123.
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125.
E. Renbutsu S. Okabe Y. Omura F. Nakatsubo S. Minami H. Saimoto Y. Shigemasa 《Carbohydrate polymers》2007,69(4):697-706
Novel chitosan derivatives with UV-curable functional groups, such as 3-methoxy-4-(2-hydroxy-3-methacryloyloxypropoxy)benzyl, 3,4-bis(2-hydroxy-3-methacryloyloxypropoxy)benzyl, 3-methoxy-4-methacryloyloxybenzyl, and 3,5-dimethacryloyloxybenzyl groups, were prepared. Introduction of photosensitive functional groups to chitosan was accomplished by reductive N-alkylation via Schiff’s bases using corresponding photosensitive aldehydes. Compared to starting chitosan, UV-curable chitosan derivatives showed better solubility in several organic solvents, such as DMSO and 70% methacrylic acid. The solubility of these compounds increased with an increase in the degree of substitution of the N-alkyl side chains. After UV irradiation for 20 s under a high-pressure mercury lamp at a distance of 15 cm from the samples, acidic methanol solutions of these derivatives were transformed to gels in the presence of photo-initiator, and their dried films adsorbed palladium (II) at pH 1.1 and pH 5.3. The UV-curable chitosan derivatives were successfully used as coating materials for electroless plating on non-conductive substances. 相似文献
126.
Mark S. Castro Keith N. Eshleman Louis F. Pitelka Geoff Frech Molly Ramsey William S. Currie Karen Kuers Jeffrey A. Simmons Bob R. Pohlad Carolyn L. Thomas David M. Johnson 《Biogeochemistry》2007,84(3):333-348
The objective of this study was to evaluate the nitrogen (N) biogeochemistry of an 18–22 year old forested watershed in western
Maryland. We hypothesized that this watershed should not exhibit symptoms of N saturation. This watershed was a strong source
of nitrate (NO3
−) to the stream in all years, with a mean annual export of 9.5 kg N ha−1 year−1 and a range of 4.4–18.4 kg N ha−1 year−1. During the 2001 and 2002 water years, wet deposition of inorganic N was 9.0 kg N ha−1 year−1 and 6.3 kg N ha−1 year−1, respectively. Watershed N export rates in 2001 and 2002 water years were 4.2 kg N ha−1 year−1 and 5.3 kg N ha−1 year−1, respectively. During the wetter water years of 2003 and 2004, the watershed exported 15.0 kg N ha−1 year−1 and 18.4 kg N ha−1 year−1, rates that exceeded annual wet deposition of N by a factor of two (7.5 kg N ha−1 year−1 in 2003) and three (5.5 kg N ha−1 year−1 in 2004). Consistent with the high rates of N export, were high concentrations (2.1–3.3%) of N in foliage, wood (0.3%) and
fine roots, low C:N ratios in the forest floor (17–24) and mineral soil (14), high percentages (83–96%) of the amount of mineralized
N that was nitrified and elevated N concentrations (up to 3 mg N l−1) in soil solution. Although this watershed contained a young aggrading forest, it exhibited several symptoms of N saturation
commonly observed in more mature forests. 相似文献
127.
Summary. When calcium carbonate crystals are formed in mulberry (Morus abla) idioblasts, they are deposited in newly formed cell wall sacs. The initial cytological events leading to cell wall sac formation
were observed in the distal end of young idioblasts and tentatively categorized into four stages. The first indication of
formation was the separation of the innermost cell wall layer from the cell wall, which is followed by the deposition of egg-shaped
polysaccharide on the inner cell wall surface. The size of the deposit area increased, while the thickness of the cell wall
significantly decreased during the next stage. Finally, the condensed cellulosic lamella was invaginated into the deposition
area, resulting in the formation of an elongated cell wall sac. The internal cell wall sac was composed of numerous fibers
with different morphologies. Application of gelatin-methenamine-silver staining allowed us to observe the spatial distribution
of cellulosic polysaccharides as electron-dense images.
Correspondence and reprints: Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo,
Kyoto 606-8585, Japan. 相似文献
128.
Changes in leaf cuticular waxes of sesame (Sesamum indicum L.) plants exposed to water deficit 总被引:4,自引:0,他引:4
Sesame (Sesamum indicum L.) is one of the most important oilseed crops, having seeds and oil that are highly valued as a traditional health food. The objective of this study was to evaluate leaf cuticular wax constituents across a diverse selection of sesame cultivars, and the responses of these waxes to drought-induced wilting. Water-deficit was imposed on 18 sesame cultivars by withholding irrigation for 15d during the post-flowering stage, and the effect on seed yield and leaf waxes compared with a well-watered control. Leaf cuticular waxes were dominated by alkanes (59% of total wax), with aldehydes being the next-most abundant class. Compared to well-irrigated plants, drought treatment caused an increase in wax amount on most cultivars, with only three cultivars having a notable reduction. When expressed as an average across all cultivars, drought treatment caused a 30% increase in total wax amount, with a 34% increase in total alkanes, a 13% increase in aldehydes, and a 28% increase in the total of unknowns. In all cultivars, the major alkane constituents were the C27, C29, C31, C33, and C35 homologs, whereas the major aldehydes were the C30, C32, and C34 homologs, and drought exposure had only minor effects on the chain length distribution within these and other wax classes. Drought treatments caused a large decrease in seed yield per plant, but did not affect the mean weight of individual seeds, showing that sesame responds to post-flowering drought by reducing seed numbers, but not seed size. Seed yield was inversely correlated with the total wax amount (-0.466*), indicating that drought induction of leaf wax deposition does not contribute directly to seed set. Further studies are needed to elucidate the ecological role for induction of the alkane metabolic pathway by drought in regulating sesame plant survival and seed development in water-limiting environments. 相似文献
129.
We investigated the responses of photon-saturated photosynthesis rate (P
sat) and its simultaneous acclimation of anatomy and nitrogen use patterns of current needles of Korean pine (Pinus koraiensis) seedlings grown under factorial combinations of two nitrogen levels and irradiances. Although N supply resulted in a significant
increase of N content in needles under both irradiances, the increase of P
sat tended to be suppressed only in shade (S). The significant increase of P
sat in full sunlight (O) was associated with the increase of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) and chlorophyll
(Chl) contents. In contrast, small increase of Chl content and no increase of RuBPCO content were found in S (90 % cut of
full irradiance), which would result in a small increase of P
sat. This result suggests that extra N is stocked in needles under shade for the growth in next season. With N supply, a significant
decrease of specific leaf area (SLA) was detected only in O. This decrease of SLA was due to the increase of density of needle.
Furthermore, the increase of needle density was not due to the increased number and size of mesophyll cells, but the increased
density of each mesophyll cell. Therefore, although SLA changed in O, the change did not involve anatomical adaptation to
use increased N effectively, at least observable by light microscopy. Hence, even though the SLA would change, N deposition
will improve the photosynthetic capacity of Korean pine seedlings, not through the development of needle anatomy but through
improvement of the allocation of N in both irradiances. 相似文献
130.