全文获取类型
收费全文 | 314篇 |
免费 | 18篇 |
专业分类
林业 | 23篇 |
农学 | 14篇 |
基础科学 | 1篇 |
85篇 | |
综合类 | 42篇 |
农作物 | 33篇 |
水产渔业 | 33篇 |
畜牧兽医 | 65篇 |
园艺 | 12篇 |
植物保护 | 24篇 |
出版年
2023年 | 1篇 |
2022年 | 6篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 10篇 |
2018年 | 22篇 |
2017年 | 12篇 |
2016年 | 16篇 |
2015年 | 7篇 |
2014年 | 16篇 |
2013年 | 26篇 |
2012年 | 31篇 |
2011年 | 17篇 |
2010年 | 15篇 |
2009年 | 11篇 |
2008年 | 15篇 |
2007年 | 13篇 |
2006年 | 9篇 |
2005年 | 8篇 |
2004年 | 13篇 |
2003年 | 6篇 |
2002年 | 12篇 |
2001年 | 1篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 4篇 |
1970年 | 1篇 |
1966年 | 1篇 |
1965年 | 2篇 |
1954年 | 1篇 |
1949年 | 1篇 |
排序方式: 共有332条查询结果,搜索用时 12 毫秒
61.
Equine group A rotavirus (RVA) strain H-1 (RVA/Horse-tc/GBR/H-1/1975/G5P9[7]) was found to have VP4, VP6-7, NSP1 and NSP4 genes of porcine origin. In order to obtain conclusive information on the exact origin and evolution of this unusual equine strain, the remaining six genes (VP1-3, NSP2-3 and NSP5 genes) of strain H-1 were analyzed in the present study. By whole genomic analysis, strain H-1 exhibited a porcine RVA-like genotype constellation (G5-P[7]-I5-R1-C1-M1-A8-N1-T1-E1-H1), different from those of typical equine RVA strains. The VP2-3 and NSP2-3 genes of strain H-1 were found to originate from porcine RVAs. On the other hand, it was difficult to pinpoint the exact origin of the VP1 and NSP5 genes of strain H-1, though phylogenetically, these genes appeared to be possibly derived from porcine or Wa-like human strains. Taken together, at least nine (VP2-4, VP6-7 and NSP1-4 genes) of the 11 gene segments of strain H-1 were found to be of porcine origin, revealing a porcine RVA-like genetic backbone. Therefore, strain H-1 is likely a porcine RVA strain that was transmitted to horses. 相似文献
62.
Effects of low‐density lipoproteins as additive on quality parameters and oxidative stress following cryopreservation of mithun (Bos frontalis) spermatozoa 下载免费PDF全文
P Perumal SK Srivastava SK Ghosh KK Baruah S Bag JS Rajoria K Kumar C Rajkhowa M Pande N Srivastava 《Reproduction in domestic animals》2016,51(5):708-716
Artificial breeding of mithun poses several challenges including lack of standard protocol for cryopreservation of spermatozoa. This is further complicated by harmful effects of hen's egg yolk (EY) as additive in extender. Purified low‐density lipoproteins (LDL) extracted from EY have been shown as beneficial over EY extender for long‐term semen storage in several species. This investigation explored use of LDL versus EY on semen quality and oxidative stress following freezing–thawing of spermatozoa. A total of 25 of 50 ejaculates based on biophysical parameters were selected for the experiment. After diluting with the Tris‐citrate‐glycerol (TCG) extender, each sample was split into three equal aliquots: Group I, control, EY; Group II and Group III contained 8% and 10% purified LDL, respectively. Frozen–thawed samples were evaluated for motility parameters (progressive, and in the bovine cervical mucus penetration test [BCMPT]), viability, sperm and nuclear abnormality, acrosome integrity, and enzymatic (leakage of intracellular contents) and biochemical (oxidative stress) profiles and in vitro fertility (IVF) assay. Study revealed a significant (p < .05) improvement in viability, sperm and nuclear abnormality, acrosome integrity, motility (progressive and in cervical mucus), cholesterol content, and reduction in the leakage of intracellular enzymes in Group II. Moreover, intactness of acrosome and biochemical membranes was protected significantly (p < .05) in addition to significant (p < .05) improvement in binding per cent and binding index in IVF assay in extender containing 8% LDL. These results demonstrate that although cryopreservation of mithun's spermatozoa in EY was comparable with other species, addition of 8% LDL holds a clear advantage over EY or 10% LDL. 相似文献
63.
Antinutritional effects of phytic acid (myoinositol hexaphosphate, IP6) on growth and digestibility in fish have been reported. However, specific effect of IP6 on the digestive enzymes in fish has not been addressed. In this study, inhibitory effect of synthetic IP6 (Phytic acid sodium salt, 90% purity) on the activity of the digestive protease and α‐amylase in rohu, Labeo rohita; catla, Catla catla; and mrigal, Cirrhinus mrigala has been investigated in vitro. Graded levels (12.5, 25, 50, 100, 150, and 200 µg/mL) of IP6 were added to the reaction mixtures containing enzyme extracts and substrate solution in triplicate to detect any change in enzyme activity. Results of the experiment revealed that IP6 significantly inhibit/lower activities of the digestive enzymes in a dose‐dependent manner, as evident from the regression equations (F values significant at P < 0.001 level). Apparently, irrespective of the fish species studied IP6‐induced inhibition of α‐amylase activity was greater than protease activity. Among the three fish species studied, C. mrigala appeared to be more sensitive to IP6 for both α‐amylase and protease activity. Enzyme activity was least affected in C. catla. Results of the study might raise concern while incorporating IP6 rich plant‐derived feed ingredients in aqua feed preparation. 相似文献
64.
A highly sensitive,non‐invasive qPCR‐based strategy for direct quantification of Yersinia ruckeri in fish faeces 下载免费PDF全文
Bikramjit Ghosh Philip B. B. Crosbie Barbara F. Nowak Andrew R. Bridle 《Journal of fish diseases》2018,41(9):1421-1428
Finfish with asymptomatic Yersinia ruckeri infections pose a major risk as they can transmit the pathogen and cause clinical outbreaks in stock populations. Current tools have insufficient quantitative ability for accurately detecting the trace levels of Y. ruckeri typically associated with asymptomatic infection, necessitate invasive or lethal sampling, or require long processing times. This study presents a highly sensitive qPCR‐based method, targeting part of the Y. ruckeri 16S rRNA sequence, that is capable of detecting extremely low levels of Y. ruckeri in noninvasively collected faecal samples. Quantitative precision and accuracy of faecal sample analysis was consistent, despite the complexity of the faecal matrix. The assay demonstrated linearity over a six log‐wide dynamic range. Its limit of detection (LOD) and limit of quantification (LOQ) were 4 and 10 copies of the target sequence, respectively. Sensitivity of the assay was comparable to other qPCR‐based methods without requiring invasive or lethal sampling. Applicability as a screening strategy was tested using passively collected faecal samples. Asymptomatic Y. ruckeri infection was detected in all samples, although none of the fish exhibited overt infection. This method will be beneficial for finfish disease management if developed further as a noninvasive, screening tool against asymptomatic Y. ruckeri infection. 相似文献
65.
Defoliation hastens senescence of the capsule wall, increased seed weight/capsule and harvest index, promotes seed filling and decreased the post-flowering contribution and yield/plant. Defruiting delayed senescence of the subtending leaf. Treatment of kinetin on the capsule wall increased its chlorophyll, sugar and dry weight and also increased yield by increasing harvest index, seed weight/capsule compared to seed treatment as well as control, although post-flowering contribution reduced significantly. When treated on the capsule wall ABA defers senescence of both leaf and capsule wall and also increased the yield parameters but seed treatment although defers senescence of both the source organs, decreased the yield parameters. Treatment of urea defers senescence of the source organs and also increased yield and capsule number though harvest index was reduced.
It is concluded that contribution from the capsule wall and deferment of senescence of this organ at the post capsule development period determines yield and in normal condition contribution of source is limited by the sink size. 相似文献
It is concluded that contribution from the capsule wall and deferment of senescence of this organ at the post capsule development period determines yield and in normal condition contribution of source is limited by the sink size. 相似文献
66.
Water quality monitoring procedures effective in calibrating the QUAL2E model for the Kali River in India are described. The stability of dry season conditions for the Kali River are utilized to consider the migration pathways, and hence the calibration efforts necessary for water quality models. Alternative procedures for calibrating values for the reaction rates are utilized for reinforcement of the findings. These alternatives include changes in stream turbidity which are shown to be a useful measure of benthic oxygen demand. Ratios of BOD5 to COD are reported between sugar mills, industrial inputs and municipal sources. 相似文献
67.
Francisco J. Bueso Ralph D. Waniska Rosana Moreira Koushik Seetharaman Lloyd W. Rooney 《Cereal Chemistry》2006,83(4):348-353
Tortilla stiffening should occur between ‐23 to 57°C, showing a maximum rate near the midpoint of this range (17°C). Starch recrystallization below the glass transition temperature (Tg = ‐23°C) in corn tortillas is minimal due to lack of molecular mobility. The objective of this study was to determine the effect of storage temperature (‐20 to 21°C) on the stiffening rate of corn tortillas with or without additives (carboxy‐methylcellulose [CMC] and maltogenic amylase). Tortilla pliability, stiffness, and energy dissipated obtained by stress relaxation, and amylopectin recrystallization determined by differential scanning calorimetry (DSC) showed a second‐order polynomial relationship with temperature. Tortillas became stiff faster during refrigerated storage (3–10°C). Adding 0.25% CMC and 1,650 AU of amylase maintained tortilla softness and flexibility, both at room temperature and under refrigeration for at least three weeks. 相似文献
68.
Neurofibromatosis type 1 (NF1) is one of the most prevalent dominantly inherited genetic diseases of the nervous system. NF1 encodes a tumor suppressor whose functional loss results in the development of benign neurofibromas that can progress to malignancy. Neurofibromas are complex tumors composed of axonal processes, Schwann cells, fibroblasts, perineurial cells, and mast cells. Through use of a conditional (cre/lox) allele, we show that loss of NF1 in the Schwann cell lineage is sufficient to generate tumors. In addition, complete NF1-mediated tumorigenicity requires both a loss of NF1 in cells destined to become neoplastic as well as heterozygosity in non-neoplastic cells. The requirement for a permissive haploinsufficient environment to allow tumorigenesis may have therapeutic implications for NF1 and other familial cancers. 相似文献
69.
Ghosh Uday Chand Dasgupta Manotosh Debnath Sushanta Bhat Subhas Chandra 《Water, air, and soil pollution》2003,143(1-4):245-256
The anion exchange behaviour of hydrous titanium oxide(HTO) has been exploited for the management of industrialwaste effluents contaminated with chromium(VI). Theadsorption of chromium(VI) by HTO (74.0–140.0 micron) in thepH range 0.5–8.0 has been studied. It is found that theadsorption of chromium(VI) by HTO is at a maximum in the pHrange 1.5–2.0. The interference of diverse foreign ionssuch as nitrate, chloride, sulfate, phosphate, calcium,magnesium, nickel, iron(III), barium etc. on the adsorptionof chromium(VI) by HTO at optimum pH has been investigatedby a batch-operation technique. Break-through capacity,adsorption and elution of chromium(VI) using HTO have beenstudied. It is found that HTO could be reused as anadsorbent for chromium(VI). Finally, chromium(VI) wasrecovered as insoluble chromate compound from waste effluentof Hindustan Motor Limited (HML) of Hooghly, West Bengal, India. 相似文献
70.