全文获取类型
收费全文 | 230篇 |
免费 | 16篇 |
专业分类
林业 | 16篇 |
农学 | 42篇 |
基础科学 | 1篇 |
58篇 | |
综合类 | 7篇 |
农作物 | 30篇 |
水产渔业 | 6篇 |
畜牧兽医 | 44篇 |
园艺 | 3篇 |
植物保护 | 39篇 |
出版年
2023年 | 3篇 |
2022年 | 9篇 |
2021年 | 13篇 |
2020年 | 9篇 |
2019年 | 3篇 |
2018年 | 17篇 |
2017年 | 22篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 5篇 |
2013年 | 23篇 |
2012年 | 11篇 |
2011年 | 18篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 16篇 |
2007年 | 5篇 |
2006年 | 8篇 |
2005年 | 8篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 8篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有246条查询结果,搜索用时 46 毫秒
191.
Kuljit Kaur Cheema Navtej S. Bains Gurjit S. Mangat Aparna Das Yogesh Vikal Darshan S. Brar Gurdev S. Khush Kuldeep Singh 《Euphytica》2008,160(3):401-409
Modern rice varieties that ushered in the green revolution brought about dramatic increase in rice production worldwide but
at the cost of genetic diversity at the farmers’ fields. The wild species germplasm can be used for broadening the genetic
base and improving productivity. Mining of alleles at productivity QTL from related wild species under simultaneous backcrossing
and evaluation, accompanied by molecular marker analysis has emerged as an effective plant breeding strategy for utilization
of wild species germplasm. In the present study, a limited backcross strategy was used to introgress QTL associated with yield
and yield components from Oryza rufipogon (acc. IRGC 105491) to cultivated rice, O. sativa cv IR64. A set of 12 BC2F6 progenies, selected from among more than 100 BC2F5 progenies were evaluated for yield and yield components. For plant height, days to 50% flowering and tillers/plant, the introgression
lines did not show any significant change compared to the recurrent parent IR64. For yield, 9 of the 12 introgression lines
showed significantly higher yield (19–38%) than the recurrent parent IR64. Four of these lines originating from a common lineage
showed higher yield due to increase in grain weight and another three also from a common lineage showed yield increase due
to increase in grain number per panicle. For analyzing the introgression at molecular level all the 12 lines were analyzed
for 259 polymorphic SSR markers. Of the total 259 SSR markers analyzed, only 18 (7.0%) showed introgression from O. rufipogon for chromosomes 1, 2, 3, 5, 6 and 11. Graphical genotypes have been prepared for each line and association between the introgression
regions and the traits that increased yield is reported. Based on marker trait association it appears that some of the QTL
are stable across the environments and genetic backgrounds and can be exploited universally. 相似文献
192.
A field experiment was conducted to compute the water use and productivity of turmeric as a function of straw mulching and irrigation scheduling at Punjab Agricultural University, Ludhiana, during 2013 and 2014. The experiment was laid out in split plot design, keeping mulch levels (no mulch and straw mulch 6 t/ha) and irrigation methods (drip and check basin) in main plots and irrigation schedules at 0.6, 0.8, 1.0 and 1.2 irrigation water/cumulative pan evaporation (IW/CPE) in subplots. Turmeric yield was 125.2 % higher with mulching than no mulch with 50 % saving in irrigation water. Drip irrigation resulted in significantly higher turmeric yield and benefit/cost (B/C) than check basin. Irrigation scheduling at 1.2 IW/CPE recorded significantly higher turmeric yield than other schedules. Drip irrigation at 0.8 IW/CPE resulted in statistically at par yield with check basin irrigation at 1.2 IW/CPE, thus saving 40 % irrigation water with significantly higher B/C. However, turmeric yield was at par between drip irrigation at 1.2 and 1.0 IW/CPE schedule, while a significant reduction in yield was recorded in check basin at 1.0 IW/CPE compared to 1.2 IW/CPE. Turmeric should be irrigated with drip at 1.0 and with check basin at 1.2 IW/CPE to realize potential yield. 相似文献
193.
Genotypic variation for nitrogen uptake and assimilation using hydroponic culture technique in wheat
Hydroponic culture technique is an alternative way of studying nitrogen metabolism. In this study, the response of six wheat genotypes (PBW 621, PBW 636, GLU 1356, BW 8989, GLU 700, and PBW 343) with respect to nitrogen-metabolizing enzymes in relation to accumulation of soluble proteins and amino acids at two concentrations of nitrogen (2 and 6 mM) was studied. Activities of nitrate reductase (NR) and glutamine synthetase as well as soluble proteins, amino acids, and nitrogen content increased in all six genotypes with increasing concentration of nitrogen in roots as well as shoots. Shoots maintained higher activities of NR and glutamine synthetase; apparently contents of soluble protein, amino acid, and nitrogen were also higher. The upregulation of NR and glutamine synthetase activities with increased concentration of nitrogen possibly contributes to higher nitrogen assimilation efficiency of three genotypes (PBW 621, PBW 636, and GLU 1356) compared to other genotypes. 相似文献
194.
Lignocellulosic biomass is a useful but an inconvenient form of energy, and paddy straw (PS) is one of the most abundant lignocellulosic wastes on the earth. Lignocellulosics generally have a high content of cellulose having combustion energy of 15 kJ/g which, when converted to methane, have a combustible energy of 50 kJ/g. But lignin and silica are the main deterrents for the microbial action on the cellulose/hemi-cellulose component of PS. In order to break the protective shield made by lignin and silica and to enhance the PS digestibility, the PS was pretreated with different concentrations (2, 4, 6, 8 and 10 %) of sodium carbonate by soaking the PS in sodium carbonate solution for the periods of 24 and 48 h and simultaneously irradiating the other set with microwaves (power 720 W, temperature 180 °C) for 30 and 60 min. The change in chemical composition of PS was the factor determining the enhancement in PS digestibility. Sodium carbonate (4 %) + microwave (60 min) pretreatment was found to be the best amongst the other pretreatments with 84.9 % desilication of PS and 44.3 and 54.4 % increase in cellulose and biogas production, respectively. 相似文献
195.
Gurpreet Singh Dhillon Harinder Singh OberoiSurinder Kaur Sunil BansalSatinder Kaur Brar 《Industrial Crops and Products》2011,34(1):1160-1167
Solid-state fermentation (SSF) was performed to evaluate the potential of agricultural residues for the production of cellulase and hemicellulase using individual and mixed cultures of Aspergillus niger and Trichoderma reseei. The maximum filter paper (FP) cellulase activity of 13.57 IU/gram dry substrate (gds), 22.89 IU/gds and 24.17 IU/gds and β-glucosidase activities of 21.69 IU/gds, 13.58 IU/gds and 24.54 IU/gds were obtained with wheat bran medium at 96 h incubation period with A. niger, T. reseei and mixed-cultures of A. niger and T. reseei, respectively. Mixed-culture SSF using rice straw supplemented with wheat bran in the ratio 3:2 resulted in higher FP cellulase, β-glucosidase, endoglucanase (CMCase) and xylanase activities, compared to the activities obtained using mono-cultures. Similarly, higher FP cellulase, β-glucosidase, CMCase and xylanase activities of 35.8 IU/gds (96 h), 33.71 IU/gds (96 h), 131.34 IU/gds (120 h) and 3106.34 IU/gds (120 h) were achieved in the tray fermentation using rice straw with wheat bran in the ratio of 3:2. Results of present investigation showed that higher cellulase activity and an optimal combination of cellulase and β-glucosidase can be achieved through mixed-culture SSF in trays. The approach of utilizing negative cost agricultural wastes through tray fermentation for cellulase and hemicellulase production is expected to serve the objectives of: (a) management of wastes which would otherwise cause environmental pollution problems; (b) production of hydrolytic enzymes at low cost and; (c) simple technique requiring no sophisticated instruments with practical applications. 相似文献
196.
Barjinder Pal Kaur Neelima Kaushik P. Srinivasa Rao H. N. Mishra 《Journal Of Aquatic Food Product Technology》2013,22(3):283-299
The effect of high pressure (HP) treatment (at 100, 270, and 435 MPa for 5 min at 25°C) on microbiological (total viable count and total psychrotrophic count), physical (color, texture, and drip loss), and microstructural characteristics of black tiger shrimp (Penaeus monodon) during storage at 2°C for 35 days was investigated. Pressure treatment increased drip loss, maintained low microorganisms level, imparted cooked appearance to the muscle, and resulted in improved texture. Results of scanning electron microscopy revealed more compact structure in treated samples, confirming the results of texture profile analysis. Pressure treatment of 435 MPa was most effective in preserving the quality of shrimp. 相似文献
197.
The ability of hydrolytic enzyme production by two different isolates of Macrophomina phaseolina was studied on apple pomace as a substrate for solid state fermentation (SSF). Initial moisture level, temperature and fermentation period was optimized so as to achieve higher output. Among the two different isolates, microsclerotial (MphP) and mycelial (MphM), MphP was observed as a potential source of different hydrolytic enzymes as compared to MphM. MphP gave higher enzyme activities (IU/gram dry substrate (gds): filter paper cellulase (FPase) activity 196.21 ± 16.3 (120 h), carboxymethyl cellulase (CMCase) 279.34 ± 28.25 (72 h), β-glucosidase (BGL) 129.82 ± 12.41 (96 h), xylanase 2527.88 ± 46.15 (120 h), and amylase 2780.72 ± 38.13 (96 h), respectively at 70% (v/w) IML. The incubation temperature was also found to have impact on the enzyme production ability of Macrophomina strains. The higher enzyme activities were achieved (IU/gds) as follows FPase 276.13 ± 25.02 (40 °C, 120 h), CMCase 278.11 ± 24.47 (35 °C, 144 h), BGL 189.47 ± 15.05 (30 °C, 144 h), xylanase 3845.77 ± 43.38 (35 °C, 144 h) and amylase activity of 3309.45 ± 29.22 (35 °C, 120 h), respectively using MphP at 70% (v/w) IML. This study reports for the first time the potential of carbohydrate degrading enzyme bioproduction by different isolates of M. phaseolina. 相似文献
198.
199.
Kaur Prabhdeep Filia G. Singh S. V. Patil P. K. Sandhu K. S. 《Tropical animal health and production》2010,42(5):1031-1035
Genotyping of Mycobacterium avium subspecies paratuberculosis (MAP) is important for precise classification of bacterium and for understanding the molecular epidemiology. The present
study reports detection and typing of the MAP from milk. On the basis of clinical signs of diarrhea and/or weakness, the dairy
animals suspected for Johne’s disease were screened by Ziehl–Neelsen staining of fecal samples. The milk samples from 13 selected
animals were processed for DNA extraction and direct IS900 polymerase chain reaction (PCR). MAP identified by IS900 PCR was
genotyped using IS1311 PCR-restriction endonuclease analysis (REA). IS900 milk PCR revealed 30.8% animals positive for MAP,
including 40% of the moderate and 50% of the heavy fecal shedders. All infected animals showed Bison type MAP in IS1311 PCR-REA.
IS900 PCR can be used for screening of milk for MAP; however, the method needs to be evaluated for subclinical cases. IS1311
PCR-REA results indicated the predominance of Bison type MAP in the dairy animals of this region. 相似文献
200.
J.I. Nirmal Kumar Manmeet Kaur Amb Anubhuti Bora 《Pesticide biochemistry and physiology》2010,98(2):168-174
Study was carried out to investigate the chronic response of cyanobacteria, Anabaena fertilissima to chlorophenoxy herbicide 2,4-dichlorophynoxyacetic Acid (2,4-D) ethyl ester at different concentrations 15, 30 and 60 ppm. The influence of 2,4-D on growth (pigments), release of metabolites such as carbohydrates, protein, amino acid, phenols and nitrate reductase and glutamine synthetase activities was analyzed. The test concentrations caused a concentration-dependent decrease in pigments. Depletion in carbohydrate and protein content was registered with rise in herbicide concentrations. However, phenols were found to rise with increased herbicide concentrations but amino acids were reported to decline. The inhibition of nitrate reductase and glutamine synthetase activity was also concentration-dependent and showed more sensitivity for substituted phenoxy herbicide. This study therefore suggests that decrease in metabolite content and enzyme activity can be used as a signal of herbicide toxicity in cyanobacteria. 相似文献