全文获取类型
收费全文 | 1214篇 |
免费 | 74篇 |
国内免费 | 10篇 |
专业分类
林业 | 77篇 |
农学 | 85篇 |
基础科学 | 29篇 |
453篇 | |
综合类 | 116篇 |
农作物 | 118篇 |
水产渔业 | 62篇 |
畜牧兽医 | 213篇 |
园艺 | 32篇 |
植物保护 | 113篇 |
出版年
2023年 | 17篇 |
2022年 | 55篇 |
2021年 | 77篇 |
2020年 | 75篇 |
2019年 | 97篇 |
2018年 | 125篇 |
2017年 | 112篇 |
2016年 | 86篇 |
2015年 | 44篇 |
2014年 | 53篇 |
2013年 | 140篇 |
2012年 | 67篇 |
2011年 | 75篇 |
2010年 | 49篇 |
2009年 | 32篇 |
2008年 | 41篇 |
2007年 | 34篇 |
2006年 | 30篇 |
2005年 | 15篇 |
2004年 | 7篇 |
2003年 | 8篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有1298条查询结果,搜索用时 312 毫秒
231.
Muawuz Ijaz Muhammad H. Jaspal Zafar Hayat Muhammad K. Yar Iftikhar H. Badar Sana Ullah Zubair Hussain Sher Ali Muhammad U. Farid Muhammad Z. Farooq Aneeqa Sardar 《Animal Science Journal》2020,91(1)
The study was aimed to investigate the influence of animal age, post‐slaughter chilling rate, and aging time on meat quality of M. longissimus dorsi (LD) of water buffalo (Bubalus bubalis) and humped cattle (Bos taurus indicus) bulls. After slaughtering, one side of carcasses was subjected to rapid chilling (RC) (0 ± 2°C) and other side was hanged in controlled room temperature (25 ± 2°C) for 3 hr, then allowed to the chiller (0 ± 2°C). The meat quality traits were analyzed at 1, 7, and 14 days of storage. It was noted that rapidly chilled carcasses from the younger animals of both species missed the ideal pH/temperature window, which affects the toughness of the meat. Buffalo meat presented higher shear force, color L* values, and lower b* value as compared to the cattle meat. Moreover, meat shear force values decreased while all color coordinates and cooking loss values increased with lengthening the storage time in both age groups of cattle and buffalo. In conclusion, the tenderness of cattle meat was superior to that of buffalo and RC adversely affect the shear force values of young cattle and both age groups of buffalo bulls. 相似文献
232.
Jesus Manuel Palomino Gabriela F. Mastromonaco Miriam P. Cervantes Reuben J. Mapletoft Muhammad Anzar Gregg P. Adams 《Reproduction in domestic animals》2020,55(1):54-63
Two experiments were done using a two-by-two design to determine the effects of season and superstimulatory protocol on embryo production in wood bison. In Experiment 1 (in vivo-derived embryos), ovarian superstimulation was induced in female bison during the ovulatory and anovulatory seasons with either two or three doses of FSH given every-other-day (FSH × 2 vs. FSH × 3, respectively). Bison were given hCG to induce ovulation, inseminated 12 and 24 hr after hCG, and embryos were collected 8 days after hCG (n = 10 bison/group). In Experiment 2 (in vitro embryo production), ovarian superstimulation was induced in female bison during the ovulatory and anovulatory seasons with two doses of FSH, and in vivo maturation of the cumulus–oocyte complexes (COC) was induced with hCG at either 48 or 72 hr after the last dose of FSH. COC were collected 34 hr after hCG, and expanded COC were used for in vitro fertilization and culture. In Experiment 1, the number of follicles ≥9 mm, the proportion of follicles that ovulated, the number of CL, and the total number of ova/embryos collected did not differ between seasons or treatment groups, but the number of transferable embryos was greater (p < .05) in the ovulatory season. In Experiment 2, no differences were detected between seasons or treatment groups for any end point. The number of transferable embryos produced per bison was greatest (p < .05) using in vitro fertilization and was unaffected by season (1.5 ± 0.2 and 1.1 ± 0.3 during anovulatory and ovulatory seasons, respectively), in contrast to in vivo embryo production which was affected by season (0.1 ± 0.01 and 0.7 ± 0.2 during anovulatory and ovulatory seasons, respectively). Results demonstrate that transferable embryos can be produced throughout the year in wood bison by both in vivo and in vitro techniques, but the efficiency of embryo production of in vivo-derived embryos is significantly lower during the anovulatory season. 相似文献
233.
Qaisar Shahzad Muhammad Waqas Liping Pu Armughan Ahmed Wadood Long Xie Asma Ul Husna Kailin Yang Jingyuan Wang Huiyan Xu Kehuan Lu Yangqing Lu 《Reproduction in domestic animals》2020,55(9):1115-1123
Buffalo is considered short-day breeder in tropical and subtropical part of the world and seasonality and photoperiodism impart major influence on its fertility. However, its impact on in vitro embryo production (IVEP) remains elusive. Therefore, this study investigated the effect of seasonal variations and photoperiodism on morphological and molecular parameters of IVEP in buffalo. For this purpose, we conducted two different experiments on the oocytes obtained by aspirating follicles from abattoir derived ovaries. In Exp. I, retrospective analysis was performed for oocyte recovery, blastocyst and hatching rate, during four consecutive seasonal periods (i.e. January–March, April–June, July–September and October–December). In Exp. II, oocytes from peak breeding and non-breeding seasons were subjected to 24 hr in vitro maturation and evaluated for polar body extrusion to assess maturation rate. Results showed that embryo development was markedly low during second quarter (April–June) and maximum during fourth quarter (October–December) of the year; referred as non-breeding and breeding seasons, respectively. Comparative data analysis demonstrated that poor oocyte quality is major reason for lesser efficiency of embryo production during non-breeding season than peak breeding season as suggested by poor oocyte recovery (2.31 ± 0.10 vs. 3.65 ± 0.27) and maturation rate (33.32 ± 2.1 vs. 63.15 ± 7.31). Subsequently, comparative gene expression analysis of blastocysts during peak breeding season significantly upregulated pluripotency gene (OCT-4) and downregulated heat shock protein 90, as compared to non-breeding season. Therefore, it could be divulged from the present study that seasonal variations and photoperiodism have profound effect on oocyte quality and subsequent embryo development. It is recommended to find suitable additives for in vitro maturation that could mitigate seasonal effects. 相似文献
234.
Rahman Naeem Ur Mehmood Shahid Ahmad Sohail Javid Arshad Mahmud Athar Hussain Jibran Shaheen Muhammad Shabir Usman Muhammad Mohayud Din Hashmi Syed Ghulam 《Tropical animal health and production》2020,52(3):1125-1131
Tropical Animal Health and Production - This study examined the analysis of personal and production performance of broiler farming in 10 cities of central Punjab (Lahore, Sheikhupura, Kasur, Okara,... 相似文献
235.
Orunmuyi M. Muhammad H. Musa A. A. Olutunmogun A. K. Nwagu B. I. 《Tropical animal health and production》2020,52(5):2395-2403
Tropical Animal Health and Production - The effect of hemoglobin polymorphism on performance traits in Nigerian indigenous chicken types was investigated in this research. The chickens were... 相似文献
236.
Muhammad Fuad Anshori Bambang Sapta Purwoko Iswari Saraswati Dewi Sintho Wahyuning Ardie Willy Bayuardi Suwarno 《水稻科学》2021,28(4):368-378
This study determined the indirect selection index of doubled haploid(DH) rice using a multivariate analysis approach to select lines adaptive to salinity stress, comprising three experiments. The first experiment involved the selection of good agronomic characters in a field experiment conducted at an experimental station in Bogor, Indonesia. The second experiment involved salinity tolerance screening through hydroponic cultures using 0 and 120 mmol/L NaCl, conducted at a greenhouse in Bogor. The third experiment involved the validation of the indirect adaptability selection index(IASI) through a field experiment in Sukra(saline area). Field experiments followed a randomized complete block design(RCBD), whereas an RCBD nested factorial design was used for the greenhouse experiment. The first and second experiments used 56 DH lines and four check varieties with three replications. In the second experiment, Pokkali and IR29 varieties were also added as tolerant and sensitive checks of salinity, respectively. The third experiment used 28 selected DH lines, Inpari 29 and one sensitive DH line. The good agronomic index(GAI) was 0.465 yield + 0.433 number of productive tillers + 0.31 number of filled grains. This generated 24 DH rice lines with good agronomic traits. The salinity tolerance index(SaTI) was developed through the average of standardized salinity tolerance score and salinity selection index based on discriminant analysis. This generated 34 DH rice lines with good salinity stress tolerance. The IASI(IASI = GAI – Sa TI) selected 28 DH rice lines adaptive to salinity stress and it was considered effective by Sukra validation. 相似文献
237.
Amanullah Muhammad Asif Lal K. Almas Amanullah Jan Zahir Shah Hidayat ur Rahman 《Journal of plant nutrition》2013,36(3):331-341
The use of appropriate source of phosphorus (P) fertilizer at different planting densities has considerable impact on growth, grain yield as well as profitability of maize (Zea mays L). Field experiment was conducted in order to investigate the impact of P sources [(S0 = P not applied, S1 = SSP (single super phosphate) S2 = NP (nitrophos), and S3 = DAP (diammonium phosphate)] on maize growth analysis, yield and economic returns planted at different planting densities (D1 = 40,000, D2 = 60,000, D3 = 80,000, and D4 = 100,000 plants ha?1) at the New Developmental Agricultural Research Farm of Khyber Pakhtunkhwa Agricultural University, Peshawar, Pakistan, during summer 2006. This paper reports the profitability data with two objectives: 1) to compare agronomic efficiency and profitability of P-fertilizers, and 2) to know whether plant densities affect agronomic efficiency and profitability of P-fertilizers. Application of DAP and SSP resulted in higher partial factor productivity (PFP) (63.58 and 61.92 kg grains kg?1 P), agronomic efficiency (AE) (13.01 and 13.71 kg grains kg?1 P) and net returns (NR) (Rs. 16,289 and 16,204 ha?1), respectively, while NP stood at the bottom in the ranking with lower PFP (57.16 kg grains kg?1 P), AE (8.94 kg grains kg?1 P) and NR (Rs. 4,472 ha?1). Among the plant densities, D3 stood first with maximum PFP (69.60 kg grains kg?1 P), AE (18.21 kg grains kg?1 P) and NR (Rs. 21,461 ha?1) as compared to other plant densities. In conclusion, the findings suggest that growing maize at D3 applied with either SSP or DAP is more profitable in the wheat-maize cropping system in the study area. 相似文献
238.
Abdul Wakeel Shazia Arif Muhammad Asaad Bashir Zeeshan Ahmad Hafeez ur Rehman Aysha Kiran 《Journal of plant nutrition》2013,36(19):2507-2524
One sixth of the world’s population is suffering from hidden hunger that indicates a gross malnutrition particularly among children and women of third world countries. The deficiency of micro nutrients, especially iron (Fe) causes a number of ailments such as megaloblastic anemia and neural tube defects in poor population. There is a dire need to supplement iron in the diet. Current efforts implicate fortification of wheat flour and other grains with different iron formulations such as ethylenediaminetetraacetic acid (EDTA), FeSO4 and elemental iron. However, all such interventions are not sustainable due to logistic and quality assurance problems in resource-limited settings. For a long term solution, development of crop plants with increased micronutrients and iron bioavailability is essential. Therefore, biofortification of cereal grains using translational genomics approaches for enhancement of folate through genome editing in cereals is inevitable to mitigate the folate deficiency in poor remote population in a cost effective manner. 相似文献
239.
Rashid Iqbal Khan Ishfaq Ahmad Hafiz Touqeer Ahmad Ishaq Ahmed Abdul Ahad Qureshi 《Journal of plant nutrition》2013,36(18):2309-2319
The study was set up to evaluate the efficiency of amino acids and seaweed on vegetative growth, reproductive phase, yield, and postharvest storage quality of hydroponically grown bell pepper cultivars “Sven Rz F-1” and “Red Knight.” Different concentrations of amino acid and seaweed were sprayed on bell pepper plants under hydroponic conditions. Pre-harvest foliar application of amino acids and seaweed significantly increased plant height, number of leaves, leaf area, yield per plant, number of marketable fruits per plant, average fruit diameter, fruit wall thickness, and average single fruit weight. Amino acid and seaweed significantly improved postharvest physicochemical quality of both bell pepper cultivars under extended cold storage conditions. Conclusively, amino acid as well as seaweed extract not only improved growth, development, yield, and overall quality of bell pepper cultivars but also increased storage life with reduced weight loss and decay along with better physicochemical quality. 相似文献
240.
Nazia Hassan Muhammad Sohail Saddiq Saqib Bashir Shahbaz Khan Muhammad Ashfaq Wahid 《Journal of plant nutrition》2013,36(14):1676-1692
AbstractOne of the problems in obtaining high wheat yield is the unavailability of micronutrients in balanced quantities. Zinc is an essential micronutrient due to its involvement in many metabolic processes in plant. In this experiment, seeds of two wheat cultivars (Faisalabad-2008 and Lasani-2008) were subjected to soak in aerated Zn solution of 0.1 and 0.01?M for 12?hr. For the seed coating, Zn was adhered to the wheat seeds by using Arabic gum by using zinc sulfate (ZnSO4·7H2O) as a source. Untreated dry seeds were considered as a control. Results indicated that field emergence was improved by Zn seed treatments, maximum numbers of seedlings were observed in seed priming with 0.01?M Zn solution. Seed osmoprimed with 0.01?M Zn solution improved the grain yield, biological yield, and other yield related traits. Grain and straw Zn enrichment were also enhanced in seed osmoprimed with 0.01?M Zn solution. 相似文献