全文获取类型
收费全文 | 188篇 |
免费 | 9篇 |
国内免费 | 6篇 |
专业分类
林业 | 5篇 |
农学 | 41篇 |
基础科学 | 6篇 |
25篇 | |
综合类 | 31篇 |
农作物 | 22篇 |
水产渔业 | 3篇 |
畜牧兽医 | 21篇 |
园艺 | 2篇 |
植物保护 | 47篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 8篇 |
2019年 | 7篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 5篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 8篇 |
2011年 | 6篇 |
2010年 | 13篇 |
2009年 | 10篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 10篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2000年 | 9篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 9篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1987年 | 6篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有203条查询结果,搜索用时 15 毫秒
81.
为将混凝土双掺和真空脱水工艺在农田水利装配式配套建筑物上应用,在江苏铜山县采用电厂粉煤灰和木钙减水剂配制了双掺混凝土,并进行真空脱水试验。结果表明,双掺混凝土可节约水泥10%~15%,强度也能达到设计要求,具有一定的技术经济效益;混凝土拌和物经真空脱水处理后,早期强度提高,拆模时间提前,可提高工效。 相似文献
82.
曹滨 《东北林业大学学报》1998,26(5):73-76
研究了SF6及N2,CO2,CCl2F2,CCl4二元混合气体的电击穿特性。结果表明:二元混合气体SF6/N2,SF6/CO2中SF6含量为50%_60%时,其耐电强度与SF6的耐电强度接近,而价格低于SF6。 相似文献
83.
Resistance, epidemiology and sustainable management of Rhynchosporium secalis populations on barley 总被引:1,自引:0,他引:1
J. Zhan B. D. L. Fitt H. O. Pinnschmidt S. J. P. Oxley A. C. Newton 《Plant pathology》2008,57(1):1-14
Rhynchosporium secalis is one of the most destructive pathogens of barley worldwide, causing yield decreases of up to 40% and reduced grain quality. Rhynchosporium is a polycyclic disease. Primary inoculum includes conidia produced on crop debris, infected seeds and possibly ascospores, although these have not yet been identified. Secondary disease spread is primarily by splash dispersal of conidia produced on infected leaves, which may be symptomless early in the growing season. Host resistance to R. secalis is mediated by both 'major' or host-specific genes (complete resistance) and 'minor' genes of smaller, generally additive effects (partial resistance). Crop growth stage and plant or canopy architecture can modify the expression of resistance. Resistance genes are distributed unevenly across the barley genome, with most being clustered on the short arms of chromosomes 1H, 3H, 6H and 7H, or in the centromeric region or on the long arm of chromosome 3H. Strategies used to manage rhynchosporium epidemics include cultivar resistance and fungicides, and also cultural practices such as crop rotation, cultivar mixtures and manipulation of sowing date, sowing rate or fertiliser rate. However, the high genetic variability of R. secalis can result in rapid adaptation of pathogen populations to render some of these control strategies ineffective when they are used alone. Sustainable control of rhynchosporium needs to integrate major-gene-mediated resistance, partial resistance and other strategies such as customized fungicide programmes, species or cultivar rotation, resistance gene deployment, clean seed and cultivar mixtures. 相似文献
84.
50%氟虫腈·敌百虫乳油防治水稻稻飞虱田间药效剂量的筛选 总被引:4,自引:0,他引:4
[目的]探讨复配制剂50%氟虫腈.敌百虫乳油防治水稻稻飞虱的最佳剂量。[方法]以50%氟虫腈.敌百虫乳油4506、007、509、00g/hm2为处理,以50 g/L氟虫腈悬浮剂37.5 g/hm2为药剂对照,以清水为空白对照,研究各处理对水稻稻飞虱的防治效果。[结果]田间试验结果表明,处理剂量范围内,药剂对水稻安全,对水稻天敌种群无明显影响;以50%氟虫腈.敌百虫乳油750 g/hm2处理防效最好。[结论]50%氟虫腈.敌百虫乳油是一种高效、低毒的化学复配制剂农药,适于在生产上推广。 相似文献
85.
Zhang Zongyi 《保鲜与加工》1992,(1):54-61
A probabilistic production costing method for multistates and multiblocks of units is presented in this paper. The mixtures of normal distributions are used to represent the power of the system and the load. The energy, reliability and production costs are calculated directly from the analytical formulae. Numeral examples demonstrate that the algorithm presented in the paper is accurate and efficient. 相似文献
86.
几种杀菌剂复配对棉花红腐病菌的联合毒力研究 总被引:4,自引:0,他引:4
测定了世高等7种杀菌剂对棉花红腐病菌的室内毒力,在此基础上进行了复配剂的筛选.结果表明,施保克对棉红腐病菌的毒力最强,EC50为0.0923 mg·L-1;三唑酮、世高、丙环唑、阿米西达毒力依次减弱,代森锰锌的毒力最小.施保克分别与世高、三唑酮、代森锰锌、丙环唑、多菌灵,世高与代森锰锌复配等组合的EC50值均大于单剂或其中之一的EC50值, CTC值均低于50,表现明显的拮抗作用;世高与多菌灵按2∶1,1∶1,1∶2,1∶3,1∶5配比复配对病菌的EC50值范围为0.9742~1.4938 mg·L-1,平均为1.2247 mg·L-1;CTC1∶1> CTC1∶3> CTC1∶2> CTC2∶1> CTC1∶5,表明各配比均有显著的增效作用,其中1∶1配比的EC50值为0.8509 mg·L-1,明显低于单剂的EC50值,CTC为286,增效作用最大.综合经济效益和增效作用两方面考虑,1∶3配比最佳. 相似文献
87.
花生脱壳机脱出物的漂浮系数试验 总被引:9,自引:6,他引:3
为合理设计花生气力分选和二次脱壳气力输送装置,以辽宁主栽花生品种为研究对象,进行了花生脱壳机脱出物主要成分以及杂质等空气动力特性试验,得到了破损花生荚果、未脱净而需要二次脱壳的花生荚果、花生米、花生壳、石头的漂浮系数分别为0.168~0.246、0.102~0.146、0.080~0.186、3.287~6.037、0.031~0.045m-1。结果表明,花生荚果、破损花生荚果、花生米、花生壳和石头之间的漂浮速度的差异较大,有利于气力分选,可作为花生脱壳机分选装置和气力输送装置设计的重要参考依据。 相似文献
88.
Mycosphaerella pinodes is a serious pea disease of worldwide distribution. The increasing interest of sustainable tools for disease control, together with the lack of sufficient levels of genetic resistance has brought our interest in the use of intercropping as a tool for management of this disease. Effect of intercropping on M. pinodes severity was studied in field experiments performed in Spain and Tunisia, in which a susceptible pea cultivar was grown as monocrop and as two species mixed intercrop with either faba bean, barley, oat, triticale or wheat. Disease was significantly reduced in terms of both percent of diseased tissue per plant and vertical progress of lesions when pea was intercropped. Faba bean and triticale intercropped with pea showed the highest suppressive ability with above 60% of disease reduction. Oat, barley and wheat showed low to moderate M. pinodes suppressive effects. Suppressive effects can be ascribed to a combined reduction of host biomass, altered microclimate and physical barrier to spore dispersal. 相似文献
89.
90.