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排序方式: 共有268条查询结果,搜索用时 15 毫秒
261.
D Kucharczyk R Kujawa M Luczynski J Glogowski I Babiak E Wyszomirska 《Aquaculture Research》1997,28(2):139-144
Induced spawning in bream, Abramis brama (L), was studied using acetone-dried common carp pituitary (CP) and bream pituitary (BP) with or without the addition of human chorionic gonadotrophin (hCG). The total dose administered to fish was of 5.0 mg kg?1 BP or 4.0 mg kg?1 CP with or without 2000-2200 IU hCG kg?1 for females and 2.5 mg kg?1 BP or 2.0 mg kg?1 CP with or without 1000–1100 IU HCG kg?1 for males. In all male treated groups 100% of spermiation was observed: in females the most effective method was a triple injection with hCG and carp pituitary, resulting in 79% of females ovulated (over 68% of eyed eggs). Biological quality of eggs, expressed as a percentage of eyed eggs, was negatively correlated with time elapsing between resolving (final) injection and ovulation. Spawning success, expressed as a value of Se (spawning effectiveness coefficient), was higher in fish treated with triple injection. 相似文献
262.
The reversal and splitting of traveling concentration waves was observed in a one-dimensional Belousov-Zhabotinski reaction medium under the influence of low-intensity electric field gradients ( approximately 10 V per centimeter). The wave reversal and splitting were strongly correlated with a characteristic transformation of the shape of both the wave front and the refractory tail of a wave in the local field gradient. The secondary role of generated hydrodynamic flow on wave transformation was also investigated. 相似文献
263.
Banks JA Nishiyama T Hasebe M Bowman JL Gribskov M dePamphilis C Albert VA Aono N Aoyama T Ambrose BA Ashton NW Axtell MJ Barker E Barker MS Bennetzen JL Bonawitz ND Chapple C Cheng C Correa LG Dacre M DeBarry J Dreyer I Elias M Engstrom EM Estelle M Feng L Finet C Floyd SK Frommer WB Fujita T Gramzow L Gutensohn M Harholt J Hattori M Heyl A Hirai T Hiwatashi Y Ishikawa M Iwata M Karol KG Koehler B Kolukisaoglu U Kubo M Kurata T Lalonde S Li K Li Y Litt A Lyons E Manning G Maruyama T Michael TP 《Science (New York, N.Y.)》2011,332(6032):960-963
264.
Marek Wełnicki Jacek L. Skrzeczkowski Włodzimierz Zagorski Stanisława Skrzeczkowska Anna Kowalska-Noordam Mirosława Was Waldemar Marczewski 《Potato Research》1990,33(4):497-503
Summary To assess the reliability of dot-spot hybridization assay for the Potato Spindle Tuber Viroid, more than 1000 potato samples
were cross-tested by biological and hybridization methods. Both methods gave similar results with a range of cultivars. The
dot-spot hybridization test was reproducible with formaldehyde-denaturated cell-sap samples stored at room temperature for
over 6 months. This finding means that samples can be transported from field stations to a diagnostic laboratory and allows
for cross-checking of results between laboratories. The data suggest that dot-spot hybridization is suitable for breeding
and quarantine purposes. 相似文献
265.
B. Hao Q. Xue T. H. Marek K. E. Jessup X. Hou W. Xu E. D. Bynum B. W. Bean 《Journal of Agronomy and Crop Science》2016,202(4):269-280
Drought‐tolerant (DT) maize (Zea mays L.) hybrids have potential to increase yield under drought conditions. However, little information is known about the physiological determinations of yield in DT hybrids. Our objective was to assess radiation‐use efficiency (RUE), biomass production, and yield in two hybrids differing in drought tolerance. Field experiments were conducted in 2013 and 2014 with two hybrids, P1151HR (DT hybrid) and 33D49 (conventional hybrid) under well‐watered (I100) and drought (I50) conditions. I100 and I50 refer to 100 % and 50 % evapotranspiration requirement, respectively. On average, P1151HR yielded 11–27 % greater than 33D49 at I100 and about 40 % greater at I50, At I100, greater yield in P1151HR was due to greater biomass at physiological maturity (BMpm) resulting from greater post‐silking biomass accumulation (BMpost). At I50, both hybrids had similar BMpm but P1151HR showed a higher harvest index and greater BMpost. RUE differed significantly (P < 0.05) between the hybrids at I100, but not at I50. At I100, the RUE values for P1151HR and 33D49 were 4.87 and 4.28 g MJ?1 in 2013, and 3.71 and 3.48 g MJ?1 in 2014. At I50, the mean RUE was 3.89 g MJ?1 in 2013 and 3.16 g MJ?1 in 2014. Results indicate that BMpost is important for maintaining high yield in DT maize. 相似文献
266.
Karol Ujházy Mariana Ujházyová Katarína Bučinová Marek Čiliak Stanislav Glejdura Ivan Mihál 《European Journal of Forest Research》2018,137(2):169-183
The effect of forest management on biodiversity is a crucial issue for sustainable forestry and nature conservation. However, the ways in which management affects macrofungal and plant communities and diversity of mountain temperate forests still remain poorly understood. We performed a random sampling stratified by stand age and stand type on the sites of temperate montane fir–beech forests. Diversity of macrofungi and the vascular plant understorey in beech- and spruce-dominated managed stands was investigated and compared to primeval forests located in the Po?ana Biosphere Reserve, Western Carpathians. Both the vascular plant and the macrofungal communities were altered by management, and the response of the macrofungal species (especially wood-inhabiting fungi) was more pronounced in terms of species composition change. Species turnover evaluation seems to be an important tool of forest natural status assessment, because alpha diversity did not change as much as species composition. Certain species of Carpathian primeval forests were confirmed as good indicators for natural forest change; others were proposed. Species pool and mean number of species per plot were the highest in unmanaged fir–beech forests, and species diversity significantly decreased in spruce plantations. The number of species decreased significantly due to the change of canopy tree species composition only in the macrofungal communities. As an outcome for forest management, we recommend keeping mixed forests involving all natural tree species and providing at least a minimal amount of dead wood necessary for wood-inhabiting organisms and leaving some area of unmanaged natural forests within complexes of managed stands. 相似文献
267.
K. Palińska‐Żarska D. Żarski S. Krejszeff J. Nowosad M. Biłas K. Trejchel A. Brylewski K. Targońska D. Kucharczyk 《Aquaculture Nutrition》2014,20(3):281-290
The effect of burbot weight (BW) and length (TL) on the efficiency of weaning under controlled conditions was investigated. Growth, survival rate, cannibalism and histological analysis of digestive tract were examined. The experiment lasted 49 days (40–89 days post hatch [DPH]). The fish (BW 0.12 g; TL 14.1 mm) were divided into four groups: a control group (C) exclusively fed Artemia sp. nauplii and groups F40, F47 and F54 that were weaned to dry feed on 40, 47 and 54 DPH, respectively. The highest survival rate was observed in groups C (78%) and F54 (58%). In group F54, similar TL (53.8 mm) and higher BW (1.36 g) at the end of experiment, in comparison with group C (43.9 mm, 0.84 g for TL and BW, respectively), were obtained. At the end of the experiment, the length of enterocytes in groups C and F54 was at a similar level (over 23 μm), whereas in group F47 was significantly lower (approximately 20 μm; P < 0.05). This study for the first time presents successful weaning of the burbot. The data indicate that live food should be offered until the fish reach 25 mm and 0.20 g. 相似文献
268.
Change in Sox9 protein localization through gonad development in Russian sturgeon (Acipenser gueldenstaedtii) 下载免费PDF全文
Maciej Kamaszewski Aleksandra Gosk Marek Skrobisz Teresa Ostaszewska 《Aquaculture Research》2017,48(6):3111-3120
The Russian sturgeon is a highly prized species reared in aquaculture. The process of gonad development in this critically endangered species is poorly understood. The aim of this study was to describe the localization of Sox9 protein during gonad development of the Russian sturgeon from the day of hatching to the 1440 day post hatching (dph). The larvae at age 1, 10, 25 dph and prepared gonads of 300, 720, 1440 dph individuals were immunohistochemistry‐stained for Sox9 detection. Sox9‐positive regions were detected in larvae in primordial germ cells cytoplasm. Analysis of 300 dph sturgeon gonads revealed the presence of the Sox9 protein in cytoplasm of some oocytes in the chromatin nucleus stage. In testes at 720 dph, Sox9 was observed in the cytoplasm of type A and early B spermatogonias. In the ovaries, Sox9 was observed in the cytoplasm of diplotene oocytes and prefollicular cells. In testes of 1440 dph sturgeon, Sox9 was present in the nucleus of the spermatocytes and in types A and B spermatogonias cytoplasm. Analysis of ovaries at 1440 dph reveals multiple diplotene oocytes with a Sox9‐positive cytoplasm. Furthermore, in 720 and 1440 dph, sturgeon presence of intersexual gonads was detected. In intersex gonads, Sox9 was observed in the cytoplasm of diplotene oocytes and type A spermatogonias. This study may be the first attempt to determine Sox9 protein localization during ontogenesis of the Russian sturgeon. Localization of Sox9 protein may become a useful marker of the maturation level in testis of the Russian sturgeon. 相似文献