全文获取类型
收费全文 | 319篇 |
免费 | 14篇 |
国内免费 | 1篇 |
专业分类
林业 | 16篇 |
农学 | 20篇 |
基础科学 | 2篇 |
76篇 | |
综合类 | 9篇 |
农作物 | 22篇 |
水产渔业 | 14篇 |
畜牧兽医 | 121篇 |
园艺 | 8篇 |
植物保护 | 46篇 |
出版年
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 6篇 |
2020年 | 11篇 |
2019年 | 8篇 |
2018年 | 9篇 |
2017年 | 14篇 |
2016年 | 11篇 |
2015年 | 10篇 |
2014年 | 17篇 |
2013年 | 31篇 |
2012年 | 23篇 |
2011年 | 26篇 |
2010年 | 17篇 |
2009年 | 15篇 |
2008年 | 15篇 |
2007年 | 18篇 |
2006年 | 11篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有334条查询结果,搜索用时 0 毫秒
31.
Phosphorus dynamics and solubilizing microorganisms in acid soils under different land uses of Lesser Himalayas of India 总被引:1,自引:0,他引:1
Ranjan Paul Raj Deo Singh A. K. Patra D. R. Biswas Ranjan Bhattacharyya K. Arunkumar 《Agroforestry Systems》2018,92(2):449-461
Although chemical and some soil physical properties have been studied under different land uses of the Lesser Himalayas of India, very limited information is available on soil biochemical properties. Hence we investigated phosphorus (P) fractions [total P (TP), inorganic P (Pi), organic P (Po), available P, microbial biomass P (MBP)], enzyme activities [dehydrogenase, phosphatases, phytase], phosphate solubilizing bacteria (PSB) and fungi (PSF), and their correlations of acid soils (0–15 and 15–30 cm depths) under different land uses (viz, organic farming, maize–wheat, apple orchard, undisturbed oak forest and uncultivated land of the Indian Himalayas). All land use systems differed significantly for the P fractions, except TP. The highest values for TP, Pi, available P and MBP were found in soils under oak forest and lowest in uncultivated land. However, Po content was highest in apple orchard. The organic farming (organic manures field under garden pea-french bean cropping system for > 10 years) maintained highest activities of dehydrogenase, acid phosphatase and alkaline phosphatase. The highest phytase activity and highest numbers of PSB (99 × 103 g?1 soil) and PSF (30 × 103 g?1 soil) were observed in the rhizosphere soils of oak forest. Significant relationships between soil P fractions and enzyme activities, except alkaline phosphatase, were recorded in surface soil layer. PSB and PSF population were also correlated significantly with P fractions and enzyme activities. This would lead us to understand the level of degradation of P pools due to cultivation over forest system and the suitable management practices needed for soil quality restoration. 相似文献
32.
Savita Kolhe Raj Kamal Harvinder S. Saini 《Computers and Electronics in Agriculture》2011,76(1):16-27
This paper suggests a new approach for providing intelligence in the system for diagnosis of diseases of the oilseed-crops. It reports the development of a web-based intelligent disease diagnosis system (WIDDS). The WIDDS is based on a new fuzzy logic approach. The approach is based on use of a rule-promotion methodology. This approach enables the drawing of inferences with the enhanced intelligence. The WIDDS also incorporates new features that improve the presently existing expert systems. The new features are (i) object-oriented (O-O) inference model, (ii) dynamic knowledge base creation strategy. The dynamically promoted rules are derived from those diagnosis sessions, which resulted in successful decisions. This enables more efficient decision-making in the future sessions, (iii) audio-visual-graphical user interface using text-to-speech (TTS) conversion tools. The WIDDS results in decreasing not only the number of interactive question-answer sessions with the clients but also leads to acceptable diagnosis. Further, the inferences are drawn faster compared to the traditional approach, which is the expert based reasoning method. The suggested WIDDS, which is based on rule-promotion approach, has been tested for three oilseeds crops - soybean, groundnut and rapeseed-mustard. 相似文献
33.
Raj Sukhbir Singh B. K. Bansal D. K. Gupta 《Tropical animal health and production》2017,49(8):1623-1629
The present study was aimed to investigate the relationship between selected morphological traits of teat and subclinical mastitis (SCM) in Frieswal crossbred dairy cows. A total of 1040 quarters from 261 lactating cows were evaluated for teat shape (bottle/fleshy/collapsed/conical/normal/pencil and short), teat-end shape (dished/flat/funnel/pocketed/pointed and rounded), teat orientation (aligned/misaligned) and teat position (front and rear; left-sided and right-sided). Each udder quarter was screened with California Mastitis Test (CMT) for the purpose of defining quarter health status. Data were analysed using Chi-square test and multivariable logistic regression procedure. An overall prevalence of SCM (CMT positive) at quarter level was 30.6%. Most of the teats had normal or cylindrical shapes (48%), dished teat-ends (40.7%), and aligned (central or squared) in orientation (65%). At bivariable level, significant association of SCM with teat shape, teat position, teat orientation, parity, and stage of lactation was observed (P < 0.05 to P < 0.001). Teat-end shapes showed some association with SCM (P = 0.07). Results of multivariable analysis showed that pencil-shaped teats were least associated with SCM (P < 0.05) as compared to other teat shapes. Prevalence of SCM was also higher in rear teats (P = 0.015), misaligned teats (P = 0.01), and cows in second or higher parities (P < 0.01) and late stage of lactation (P < 0.001). The results of the present study indicate that selected morphological traits of teat are associated with SCM in Frieswal crossbred cows; therefore, selection towards desirable morphological traits could help reduce mastitis in this breed. 相似文献
34.
Hari Prasad Aithal MVSc PhD Prakash Kinjavdekar MVSc PhD Abhijit Motiram Pawde MVSc PhD Gaj Raj Singh MVSc PhD Harish Chandra Setia MSc 《Veterinary surgery : VS》2010,39(5):621-626
Objectives: To report the repair of tibial diaphyseal fractures in 2 calves using a circular external skeletal fixator (CEF). Study Design: Clinical report. Animals: Crossbred calves (n=2; age: 6 months; weight: 55 and 60 kg). Methods: Mid‐diaphyseal tibial fractures were repaired by the use of a 4‐ring CEF (made of aluminum rings with 2 mm K‐wires) alone in 1 calf and in combination with hemicerclage wiring in 1 calf. Results: Both calves had good weight bearing with moderate lameness postoperatively. Fracture healing occurred by day 60 in 1 calf and by day 30 in calf 2. The CEF was well maintained and tolerated by both calves through fracture healing. Joint mobility and limb usage improved gradually after CEF removal. Conclusions: CEF provided a stable fixation of tibial fractures and healing within 60 days and functional recovery within 90 days. Clinical Relevance: CEF can be safely and successfully used for the management of selected tibial fractures in calves. 相似文献
35.
36.
R. Raj Bhansali J. Driver D. J. Durzan 《The Journal of Horticultural Science and Biotechnology》2013,88(5):601-605
Cell suspension cultures were derived from adventitious somatic embryos induced on cotyledons of rescued peach embryos. Embryogénie calli were induced and established on modified MS medium supplemented with 2,4-D, BAP, KN and inositol. Development of embryos during suspension cultures was identified by growth pattern and by histological and cytological examination, using acetocarmine stain. More embryogenic calli were produced using 2,4-D (5 (µM) than NAA. A gradual reduction of 2,4-D increased the recovery of globular embryos. Heart-stage embryos were developed on high-nitrogen salt medium, with added Ca(N03)2 (1000 mg I"1) and 6% sucrose. Somatic embryos turned green and sometimes red under white light. Embryo viability was highest when subculturing every 14 days. Viability of cells and differentiating embryos was assessed, microscopically, with Alexander’s stain. Viable embryos reacted pink to red while non- viable embryos reacted green to blue. Embryogenic cell suspension cultures were maintained for over ten months by regular subculturing after two weeks on modified MS medium with low 2,4-D, BAP and KN. 相似文献
37.
Koppad S Raj GD Gopinath VP Kirubaharan JJ Thangavelu A Thiagarajan V 《Research in veterinary science》2011,91(3):384-390
Calcium phosphate (CaP) particles were coupled with inactivated Newcastle disease virus (NDV) vaccine. The surface morphology of CaP particles coupled to NDV was found to be spherical, smooth and with a tendency to agglomerate. The mean (± SE) size of CaP particles was found 557.44 ± 18.62 nm. The mean percent encapsulation efficiency of CaP particles coupled to NDV assessed based on total protein content and haemagglutination (HA) activity in eluate was found to be 10.72 ± 0.89 and 12.50 ± 2.09, respectively. The humoral and cell mediated immune responses induced by CaP coupled NDV vaccine were assessed in comparison to a commercial live vaccine (RDV ‘F’). CaP coupled NDV vaccine elicited prolonged haemagglutination inhibition (HI) and enzyme linked immunosorbent assay (ELISA) titres in the serum even at fourth and fifth week post-vaccination (PV), unlike RDV ‘F’ inoculated chickens whose titres declined to insignificant levels by this time. CaP coupled NDV vaccine could stimulate HI antibodies in tracheal washings and tears from second and first week PV, respectively. IgA ELISA antibodies were also seen in tracheal washings of these birds from third week PV and in tears from second week PV. CaP coupled NDV vaccine elicited cell mediated immune responses (CMI) from two to four weeks PV. The stimulation indices obtained after stimulation with specific antigen was not significantly different between CaP coupled antigen and live NDV virus except on first week PV. However, CaP coupled antigen did not cause suppression of lympo proliferation as indicated by statistically similar responses to mitogen, concanavalin A between the two groups. Overall, CaP coupled NDV vaccine elicited stronger and prolonged immune responses in comparison to the commercial live vaccine. No increase in the serum calcium and phosphorous levels were seen in CaP coupled NDV vaccine inoculated chickens. 相似文献
38.
Ali Khammanivong Jhuma Saha Angela K. Spartz Brent S. Sorenson Alexander G. Bush Derek M. Korpela Raj Gopalakrishnan Shirisha Jonnalagadda Venkatram R. Mereddy Timothy D. O'Brien Lester R. Drewes Erin B. Dickerson 《Veterinary and comparative oncology》2020,18(3):324-341
Monocarboxylate transporters (MCTs) support tumour growth by regulating the transport of metabolites in the tumour microenvironment. High MCT1 or MCT4 expression is correlated with poor outcomes in human patients with head and neck squamous cell carcinoma (HNSCC). Recently, drugs targeting these transporters have been developed and may prove to be an effective treatment strategy for HNSCC. Feline oral squamous cell carcinoma (OSCC) is an aggressive and treatment‐resistant malignancy resembling advanced or recurrent HNSCC. The goals of this study were to investigate the effects of a previously characterized dual MCT1 and MCT4 inhibitor, MD‐1, in OSCC as a novel treatment approach for feline oral cancer. We also sought to determine the potential of feline OSCC as a large animal model for the further development of MCT inhibitors to treat human HNSCC. In vitro, MD‐1 reduced the viability of feline OSCC and human HNSCC cell lines, altered glycolytic and mitochondrial metabolism and synergized with platinum‐based chemotherapies. While MD‐1 treatment increased lactate concentrations in an HNSCC cell line, the inhibitor failed to alter lactate levels in feline OSCC cells, suggesting an MCT‐independent activity. In vivo, MD‐1 significantly inhibited tumour growth in a subcutaneous xenograft model and prolonged overall survival in an orthotopic model of feline OSCC. Our results show that MD‐1 may be an effective therapy for the treatment of feline oral cancer. Our findings also support the further investigation of feline OSCC as a large animal model to inform the development of MCT inhibitors and future clinical studies in human HNSCC. 相似文献
39.
Anjali Thakur Raj Paul Sharma Narender Kumar Sankhyan Swapana Sepehya 《Soil Use and Management》2023,39(1):357-367
Imbalanced fertilizer use with intensive cropping has threatened the sustainability of agroecosystems, especially on acid soils. An understanding of the long-term effects of fertilizers and amendments on soil health is essential for sustaining high crop yields. The effects of application of fertilizers, and amendments for 46 years on soil properties and maize yield in an acid Alfisol were investigated in this study. Ten fertilizer treatments comprising different amounts of NPK fertilizers, farmyard manure (FYM) and lime, and one control, were replicated three times in a randomized block design. At 0–15 cm soil depth, bulk density was least (1.20 t/m3), porosity (49.8%) and water holding capacity (61.7%) were greatest in 100% NPK + FYM, corresponding to the largest organic carbon content (13.93 g/kg). Microbial biomass C and dehydrogenase activity in 100% NPK + FYM were 42% and 13.7% greater than 100% NPK, respectively. Available nutrients were significantly more with 100% NPK + FYM and 100% NPK + lime than control and other fertilizer treatments. At 15–30 cm depth, the effect of various treatments was comparable to the surface layer. Grain yield declined by 55% and 53% in 100% NPK(-S) and 100% NP, respectively, compared with 100% NPK, whereas 100% N as urea alone eventually led to crop failure. Soil porosity recorded the greatest positive correlation (r = .933**), whereas bulk density recorded a negative significant correlation (r = −.942**) with grain yield. The results suggest that integrated use of FYM/lime with chemical fertilizers is a sustainable practice in terms of crop yield and soil health, whereas continuous application of urea alone is detrimental to the soil health. 相似文献
40.