全文获取类型
收费全文 | 8131篇 |
免费 | 505篇 |
国内免费 | 463篇 |
专业分类
林业 | 698篇 |
农学 | 614篇 |
基础科学 | 73篇 |
827篇 | |
综合类 | 3110篇 |
农作物 | 706篇 |
水产渔业 | 356篇 |
畜牧兽医 | 798篇 |
园艺 | 661篇 |
植物保护 | 1256篇 |
出版年
2024年 | 67篇 |
2023年 | 159篇 |
2022年 | 285篇 |
2021年 | 336篇 |
2020年 | 451篇 |
2019年 | 358篇 |
2018年 | 221篇 |
2017年 | 306篇 |
2016年 | 386篇 |
2015年 | 316篇 |
2014年 | 367篇 |
2013年 | 465篇 |
2012年 | 505篇 |
2011年 | 561篇 |
2010年 | 427篇 |
2009年 | 449篇 |
2008年 | 438篇 |
2007年 | 409篇 |
2006年 | 368篇 |
2005年 | 277篇 |
2004年 | 241篇 |
2003年 | 188篇 |
2002年 | 188篇 |
2001年 | 176篇 |
2000年 | 140篇 |
1999年 | 156篇 |
1998年 | 94篇 |
1997年 | 101篇 |
1996年 | 84篇 |
1995年 | 95篇 |
1994年 | 82篇 |
1993年 | 70篇 |
1992年 | 80篇 |
1991年 | 52篇 |
1990年 | 55篇 |
1989年 | 49篇 |
1988年 | 21篇 |
1987年 | 20篇 |
1986年 | 11篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1962年 | 2篇 |
1955年 | 7篇 |
排序方式: 共有9099条查询结果,搜索用时 31 毫秒
961.
962.
采用L_9(3~3)正交试验研究梨汁的配方,在单因素试验的基础上,确定生产出风味纯正的梨汁的最佳配方为:梨加入量2.5 kg,糖质量分数6.5%,糖水添加量6.0 kg。 相似文献
963.
通过单因素和正交试验研究了蛋清稀释程度、pH值、酶解温度及酶与底物比对碱性蛋白酶酶解蛋清的影响,得到最佳的酶解条件为:将蛋清液稀释至60%后变性,按照酶与底物比为2.5:100(mL:g)加入碱性蛋白酶,酶解温度为60℃,反应初始时不调节pH值,待pH值降至7.5时通过加入NaOH使pH值保持在7.5进行酶解。 相似文献
964.
施肥对油菜菌核病发生的影响 总被引:4,自引:0,他引:4
对5个油菜品种,设氮肥(对照、施氮),磷肥(对照、施磷)和钾肥(对照、施钾)试验,分析了氮磷钾肥对油菜产量和菌核病发生的影响.结果表明,施氮油菜平均增产203.7%,菌核病病情指数平均增加17.7%;施磷油菜平均增产47.2%,菌核病病情指数平均下降31.0%;施钾油菜平均增产30.1%,菌核病病情指数平均下降21.9%.分析认为,施氮因病原菌获得更多的营养物质,以及油菜枝繁叶茂提高田间阴湿度致使油菜病害加重;施磷为油菜抗性生理活动提供了物质基础;施钾通过对植株代谢过程的调控和植物形态学的调节提高了油菜对菌核病的抗性.生产上可以通过调控氮肥施用,合理增施磷钾肥,达到既提高油菜产量又有效减轻菌核病危害的目的. 相似文献
965.
G.A.S. Premakumara W.K.S.M. Abeysekera W.D. Ratnasooriya N.V. Chandrasekharan A.P. Bentota 《Journal of Cereal Science》2013
Brans of 23 traditional and 12 improved (both red and white) rice varieties in Sri Lanka were screened for anti-amylase and anti-glycation activities in vitro. Varieties which showed the highest inhibitory activities at screening were further investigated for anti-glucosidase and glycation reversing as anti-diabetic properties. The same varieties were studied for selected antioxidant properties. Significantly high anti-amylase and anti-glycation activities were observed for bran extracts of red varieties compared to white varieties at screening. Traditional red rice varieties, Masuran, Sudu Heeneti, Dik Wee and Goda Heeneti, exhibited significant and dose dependent anti-amylase, anti-glycation and glycation reversing activities. These varieties also showed marked antioxidant properties. It is concluded that brans of Sri Lankan traditional red rice varieties Masuran, Sudu Heeneti, Dik Wee and Goda Heeneti may be potential food supplements for diabetes. 相似文献
966.
甘蔗赤腐病菌生物学特性研究 总被引:1,自引:0,他引:1
对采集的甘蔗赤腐病典型病叶进行了病原菌的分离与鉴定,进而对该病菌进行了致病性及基础生物学特性测试.结果表明:甘蔗赤腐病由Colletotrichum falcatum引起;生物学特性结果表明,该菌在燕麦片和Richards培养基生长最好;菌丝体生长最适温度为25 ~30℃;适宜pH 6~8;而光照条件对病原菌的生长影响并不明显:该菌分生孢子的致死温度为60℃,10 min.本研究为甘蔗赤腐病的合理预测和科学防治提供了理论依据. 相似文献
967.
968.
《Plant Production Science》2013,16(4):359-364
AbstractOur objective was to clarify whether rice cultivars with a higher grain dry-matter increase rate (GIR) under elevated temperature condition show a higher percentage of milky white rice kernels (MWK). The rate of MWK judged using a rice-quality selector significantly varied with the cultivar and experimental year. The spikes of the cultivars detached 5–7 days after heading were solution-cultured with an adequate nutrient supply for one week at 25, 28 and 33ºC. GIR was overall the highest at 28ºC, and GIR at this temperature was considered to reflect the potential GIR in all the grains tested. There was a close correlation between the rate of MWK and the GIR at 28ºC under field conditions when temperatures during the grain-filling period were approximately over 25ºC. It was suggested that cultivars with a higher potential GIR under elevated temperature conditions have a higher risk of the formation of MWK. 相似文献
969.
C.S. Dannhauser 《African Journal of Range and Forage Science》2013,30(3):120-121
A small plot experiment with Digitaria eriantha, Panicum maximum and Anthephora pubescens, established on Valsrivier and Westleigh soil forms, was conducted at Potchefstroom during the 1986/87 and 1987/88 seasons. The yield of P. maximum was the highest of the three species during the drier 1986/87 season (478 mm), while the yield of D. eriantha was the highest during the wetter 1987/88 season (803 mm). Yield was not influenced significantly by soil form. The quality of all species, in terms of protein and digestibility, was adequate for animal production. 相似文献
970.
Protoplast isolation is relevant for many different applications and has been principally used in proceduresnvolving genetic manipulation. In this study, the age of mycelium, osmotic stabilizers, enzyme, incubation temperature and incubation time were evaluated in terms of their effects on protoplast yield. The young mycelia (3 d) of Tulasnella calospora were digested for 6 h at 30℃ in a mixture of 1.2 mol·L-1 MgSO_4 + 10 mmoI·L-1 K2HPO4 as the osmotic stabilizer, with a 1.0% lysing enzyme and 1.5% driselase: more than 106 protoplasts mL-1 were obtained. When collected 3y density gradient centrifugation, the concentration of protoplasts can reach 107-108 protoplasts mL-1, an amount suitable enough for experiments of transformation in fungi. For every 10_5 protoplasts, about 15-25 protoplasts can egenerate after 24-36 h cultivation in a liquid medium and after 8-10 d in an agar medium. This study produced an efficient method for protoplast production, reverting them into a typical mycelia morphology using a Tulasnella calospora solate. 相似文献