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1.
通过对棉花不同时期去主茎叶、叶枝叶、果枝叶和全部叶片的研究,初步探讨了棉花叶源对库的影响.结果表明:无论蕾期还是盛铃期,叶片是棉花光合产物的主要来源,没有叶片棉花就不能正常生长,也很难保证其产量;不同部位的叶片中,主茎叶的作用显著,蕾期去主茎叶后株高日增长量减少0.5 cm以上,干物质积累明显下降,盛铃期则导致棉铃大量脱落,成铃平均减少2个以上;去果枝叶的作用相对较小,去叶枝叶几乎无影响. 相似文献
2.
依据干旱胁迫下数种植物幼苗体内游离脯氨酸、叶气孔、叶水量的变化,剖析了植物与环境因子、气孔因子、氧气因子、酶因子及能量因子之间的相互依存关系,提出了PRO积累系统(PAS)。认为水分胁迫下植物体内PRO的大量积累是氧化受抑和合成受激共同调控的结果。氧气最有可能为直接触发因子。 相似文献
3.
A field experiment was conducted during the winter seasons of 1992–93 and 1993–94 at Anand to study the effect of FYM, nitrogen and source of fertilizer on growth and yield of mustard [ Brassica juncea (L.) Czernj & Cosson]. The results showed significant variation in leaf area index (LAI), crop growth rate (CGR), dry matter production and seed yield. The direct effect of farmyard manure (FYM) was conspicuous in improving the growth of mustard. FYM application at 10 tonnes ha−1 significantly increased the LAI, CGR and dry matter accumulation per plant at almost all the stages during first year study (1992–93) and in pooled analysis. Similarly, nitrogen application registered maximum LAI, CGR at 75 kg level and RGR and NAR at 50 kg level at almost all the during both years. Sulphur carrying source (Ammonium sulphate plus single super phosphate) increased all stages growth characters. Maximum dry matter accumulation per plant and seed yield were recorded with highest levels of FYM (20 tonnes ha−1 ), N (75 kg ha−1 ) and source having S. Seed yield was strongly associated with LAI and dry matter accumulation per plant at all the stages. 相似文献
4.
陆地棉功能叶不同生育时期酶活性及脂质过氧化作用的研究 总被引:5,自引:0,他引:5
对不同熟性棉花品种功能叶几种酶活性及脂质过氧化水平(以丙二醛含量表示)的研究结果表明,超氧物歧化酶(SOD)活性在吐絮前呈波动上升,吐絮盛期争剧下降;丙二醛(MDA)含量吐絮前缓慢上升,吐絮后明显增加;过氧化氢酶(CAT)活性在结铃以前随叶片发育而上升,结铃后急剧下降;过氧化物酶(POD)活性始终呈上升趋势。进一步对POD同工酶进行电泳发现,其酶谱构成随生育进程而变化,早熟品种在开花期酶带条数最多 相似文献
5.
Infection processes of Pyrenophora semeniperda on seedling and adult wheat leaves and wheat ears were investigated. Almost 100% germination of conidia occurred on seedling leaves, compared with 20–30% on adult leaves. Appressoria formed over the anticlinal epidermal cell walls and haloes always accompanied infection. Sometimes papillae formed within the leaves as a resistance mechanism. Infection hyphae ramified through the intercellular spaces of the mesophyll resulting in cellular disruption. The infection processes on floral tissues were similar to those observed on leaves; however, no infection occurred on anther, stigmatic or stylar tissues. Infection of ovarian tissue occurred both with and without appressoria formation. Hyphae grew mainly in the epidermal layers and appeared unable to breach the integumental layer as no growth was observed in endosperm or embryo tissues. The optimum dew period temperature for conidial germination was 23·6°C, compared with 19·9°C for lesion development, 20·4°C for the production of infection structures on seedling leaves and 23·7°C for floret infection. Leaf disease development occurred in a logistic manner in response to dew period, with maximum infection observed after 21 h compared with > 48 h in seeds. An initial dark phase during the dew period was necessary for infection and temperature after the dew period had an effect, with significantly more numerous and larger lesions being formed at 15°C compared with 30°C. Seedling leaves were found to be more susceptible than older leaves, under both field and controlled environment conditions. Infection of wheat seeds following inoculation of ears, or after harvest burial of inoculated disease-free seeds, was demonstrated. In the latter, 3-week-old seedlings were slightly stunted, whereas older plants were unaffected. The apparent unimportance of this plant pathogen as a cause of leaf disease in relation to its poor adaptation to dew periods and dew period temperature is discussed, along with the importance of its seed borne characteristics. 相似文献
6.
引起糖甜菜细菌性叶斑病的萎蔫短小杆菌新致病变种 总被引:3,自引:0,他引:3
1995年在内蒙古临河市新发现了糖甜菜细菌性叶斑病,从病斑所分离的10个细菌菌株经柯赫氏法则验证,均确系该病的病原菌。采用形态观察、表型特征和生理生化特性测定、数值分析、血清学反应、细胞化学成分分析、DNA G+C mol%和DNA-DNA同源性测定进行了鉴定,并与植物病原棒形细菌15个标准菌株进行了比较。该病原菌为革兰氏阳性细菌,不规则短杆状,有一根鞭毛、亚极生或侧生,结合其生理生化特性、细胞化学成分和DNA G+C mol%和DNA-DNA同源性测定结果,认为应属于短小杆菌属(Curtobacterium)的萎蔫短小杆菌(Cur. flaccumfaciens),数值分析也支持这一结论。此外,据血清学反应结果及其对短小杆菌属的其它植物寄主的致病情况,认为该病原菌应是萎蔫短小杆菌种下的一个新的致病变种,定名为Curtobacterium flaccumfaciens pv. beticola pv. nov. Chen et al.,2000(萎蔫短小杆菌糖甜菜致病变种)。 相似文献
7.
8.
岳阳市观赏植物造景应用评价 总被引:1,自引:0,他引:1
在对岳阳市城市观赏植物区系、植被与群落调查基础上,对观赏植物进行了园林应用分类,并对秋色叶植物和观果植物进行应用评价,提出了观赏植物造景应用方式. 相似文献
9.
10.
连续自然接虫研究表明,长豇豆和丝瓜开花结实期美洲斑潜蝇产量损失与幼虫密度关系分别符合上列方程:Y=-0.01138+0.00035X(r=0.9953);Y=-0.005527+0.00061X(r=0.9634)。根据当前价格和防治费用等因素,得出两种蔬菜在开花结实期的美洲斑潜蝇幼虫防治指标分别为百株884-1029头和1772-1945头。 相似文献