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81.
以6个抗褐飞虱Nilaparvata lugens(Stl)水稻品种为试材,采用盆栽淹水试验方法,研究淹水胁迫对抗褐飞虱水稻品种主要营养物质的影响及其与褐飞虱取食量的关系。结果表明:TN1、Babawee、RHT、Ptb33、RP1976-18-6-4-2和570011游离氨基酸含量受淹水胁迫的影响很大,其中RHT游离氨基酸含量在淹水后均高于对照,RP1976-18-6-4-2和570011在淹水达3d以上时高于对照,IR56游离氨基酸含量仅在淹水3d时高于对照;TN1可溶性糖含量受淹水胁迫影响波动较大;IR56、Babawee、RHT、Ptb33和570011可溶性糖含量受淹水胁迫的影响很大,在淹水后均低于对照;RP1976-18-6-4-2可溶性糖含量在淹水3d以内高于对照,在淹水5d以上低于对照;淹水后稻茎游离氨基酸和可溶性糖含量综合影响褐飞虱生物型Ⅱ和孟加拉型雌成虫在TN1上的取食量及褐飞虱孟加拉型雌成虫在IR56、Babawee和RP1976-18-6-4-2上的取食量,且2种褐飞虱在RHT、Ptb33、和570011上的取食量及其生物型Ⅱ在RP1976-18-6-4-2的取食量均与可溶性糖含量呈显著正相关;生物型Ⅱ在Babawee上的取食量与可溶性糖含量呈显著负相关。  相似文献   
82.
刘瑜 《排灌机械》1996,14(2):21-23
在分析泵转子和电机转子轴向运动情况及其相互关系的基础上,提出了注水泵联轴器间隙的一种确定方法。  相似文献   
83.
The majority of rice grown in south-east Australia is continuously flooded for much of its growing season, but reduced irrigation water availability brought about by a combination of drought and environmental flow legislation has presented a need to maintain (or even increase) rice production with less irrigation water. Delaying the application of continuous flooding until prior to panicle initiation can increase input water productivity by reducing non-beneficial evaporation losses from free water and the soil. A field experiment was conducted over two growing seasons, 2008/9 and 2009/10, comparing a conventional dry seeded treatment (the control - continuous flooding from the 3 leaf stage) with delayed continuous flooding (10-20 days prior to panicle initiation) with several irrigation scheduling treatments prior to flooding commencement. In the first year, the delayed water treatments were irrigated at intervals of 40, 80 and 160 mm of cumulative reference evapotranspiration (ETo) prior to delayed continuous flooding, thereby imposing differing degrees of crop water stress. In year 2, the 80 and 160 mm treatments were modified by use of a crop factor (Kc) when the plants were small and the 40 mm treatment was replaced with a continuously flooded treatment throughout the crop duration.Decreases in net water input (irrigation + rain − surface drainage) and increases in input water productivity were achieved by reducing the flush irrigation frequency during the pre-flood period. Savings of 150 and 230 mm (10 and 15%) were achieved in Year 1 from the 80 and 160 mm cumulative ETo irrigation frequency treatments, respectively, in comparison to the control. In the second year, net water input savings of 230 and 330 mm (15 and 22%) were achieved with the 80/Kc and 160/Kc mm treatments, respectively. Input water productivity of the 160 mm treatment was 0.06 kg/m3 (8%) higher than the control in Year 1, while in Year 2 a 0.15 kg/m3 (17%) increase in input water productivity above the control was achieved by the 160/Kc mm treatment. Delaying the application of continuous flooding in the second year greatly extended the period of crop growth suggesting the need for earlier sowing (by 7-10 days) to ensure pollen microspore still occurs at the best time to minimise yield loss due to cold damage. Nitrogen fertiliser management is an important issue when delaying continuous flooding, and nitrogen losses appeared to increase with the frequency of irrigation prior to continuous flooding. This was likely due to increased denitrification from alternate wetting and drying of the soil. Further research is required to determine the most appropriate nitrogen management strategies, and to also better define the optimal pre-flood irrigation frequency.  相似文献   
84.
以1年生红皮柳(Salix integra cv.hongpi)和青皮柳(Salix integra cv.qingpi)为试验材料,研究了人工模拟淹水胁迫对两个杞柳品种的生长、气体交换及叶绿素荧光的影响.经过75d的淹水处理,两个品种的存活率均为100%.在试验过程中,红皮柳和青皮柳都产生了有利于吸收氧气的不定根和肥大的皮孔,但在产生的时间上红皮柳较青皮柳迟lOd左右.渍水处理促进了青皮柳的生长和光合作用,而红皮柳在渍水和轻度淹水胁迫处理下的生长、叶绿素含量(Chl)、净光合速率(PN)和气孔导度(Gs)都明显低于对照.随着淹水时间的增加,红皮柳的非光化学淬灭系数(NPQ)持续增加并高于对照,最大光化学量子效率(Fv/Fm)持续下降且明显低于对照;青皮柳的非光化学淬灭的值增加幅度较小,最大光化学量子效率一直在0.8-0.85之间波动,与对照相比都无显著差异.以上的实验结果表明在淹水胁迫下红皮柳的光合运转机构受到了一定程度的损伤,而渍水处理则促进了大青皮的生长,因此青皮柳较红皮柳而言更耐淹,更适合在河岸带和消落区生长.  相似文献   
85.
针对胜利油田现河稠油,研究了7种油溶性降黏剂(Y-1~Y-7)及其复配体系的降黏性能,考察了降黏剂加量、原油含水率对降黏效果的影响,研究了降黏剂对蒸汽驱油效果的影响。结果表明:当油溶性降黏剂质量分数小于5%时,原油降黏率随降黏剂加量的增加而迅速增大,之后增加缓慢,加量为15%时的降黏率可达90%以上(Y-4除外)。Y-3和Y-7按质量比1:1复配后的降黏效果最好,总加量5%、10%时的原油降黏率分别为76.1%和93.14%。不含降黏剂时,随原油含水率增加原油黏度先增加后降低,原油含水50%时的黏度是不含水原油的3.9倍,形成W/O型乳状液。不同含水率下,加入降黏剂后原油黏度大幅降低;随含水率增加,原油降黏率先降低后增加,含水率10%时达到最低(Y-1除外)。稠油蒸汽驱前注入0.009~0.027 PV油溶性降黏剂,采收率增幅为2.8%~6.0%。  相似文献   
86.
旱涝交替胁迫增强水稻抗倒伏性能   总被引:6,自引:5,他引:1  
茎倒伏是水稻减产的重要影响因素。本文采用小区试验,分析了旱涝交替胁迫下旱后浅蓄(T1)、旱后深蓄(T2)与目前常用的浅水勤灌(CK,对照)模式下,水稻茎秆生长指标和抗倒伏指标的差异,并结合水稻茎秆的细观特征,对水稻抗倒伏能力的影响机制进行了探讨。结果表明,与对照相比,适宜的旱涝交替胁迫处理(T1)基部节间长度降低,茎粗、茎杆截面面积增加,但差异不显著;茎杆的抗弯截面模量和累积破坏能量分别增加12.4%和9.4%,差异达到显著水平;茎杆壁厚、维管束数量、维管束面积增加,维管束细胞趋于密实,使得茎杆的抗折力增加,倒伏指数下降。但旱后淹水深度过深(T2),水稻抗倒伏指标下降。地上部分鲜重增加是 T2处理倒伏指数增加的主要原因。上述情况表明,适宜的干旱胁迫能够拮抗淹水胁迫造成的抗倒伏能力下降,提高后期抗倒伏能力。现有节水模式下适当加大雨后蓄水深度不会增加倒伏风险。  相似文献   
87.
5个油茶物种的耐涝性   总被引:1,自引:0,他引:1  
以5个油茶(Camellia spp.)物种1年生实生苗为试材,通过调查淹水处理后不同时间植株的受害情况对其耐涝性进行研究,结果表明:普通油茶(C.oleifera)和广宁红花油茶(C.semiserrata)具有较强的耐涝性,淹水处理32天才完全死亡,而香花油茶(C.osmantha)、博白大果油茶(C.gigantocarpa)和陆川油茶(C.vietnamensis)耐涝性极强,整个试验期60天后均有10%以上的植株还存活,5个物种的耐涝性由强到弱依次为香花油茶>博白大果油茶>陆川油茶>广宁红花油茶>普通油茶;5个物种内不同单株间耐涝性均有差异,其中香花油茶单株耐涝性分离最大,其次是博白大果油茶和陆川油茶.  相似文献   
88.
水库集雨区沟渠湿地耐寒植物五节芒耐淹性研究   总被引:1,自引:0,他引:1  
选取浙江省长潭水库集雨区上游农田沟渠湿地中生长的耐寒牧草五节芒(Miscanthus floridulus),通过盆栽模拟试验,测定其在涝渍逆境下叶片的光合色素含量、气孔导度、胞间CO2浓度、蒸腾速率和净光合速率,并与生长于堤岸上的五节芒进行比较.结果表明:涝渍逆境虽然造成沟渠湿地生长的五节芒叶片光合色素含量减少、蒸腾速率和净光合速率降低,但与在堤岸中生长的五节芒相比,下降幅度较小.说明生长于沟渠湿地上的五节芒具有较强的涝渍逆境适应性.因此,在浙南山区水库集雨区农田沟渠湿地耐寒植物五节芒能强化沟渠湿地生态效应,降低水库水体富营养化的风险.  相似文献   
89.
J M Osca 《Weed Research》2013,53(6):479-488
Due to the rapid spread of two subspecies of Leptochloa fusca through the Valencia rice‐growing region in the east of Spain, a 3‐year field study was carried out to establish the frequency, distribution and infestation level of the two subspecies in rice paddies in the area. A total of 3650 fields were visited, of which 1235 were visited in each year of the study period. Leptochloa fusca ssp. uninervia and Leptochloa fusca ssp. fascicularis were found to be widely distributed in the area, increasing from a frequency of 5.3% in 2008 to 20.1% in 2010. Leptochloa fusca ssp. uninervia was the largest contributor to the infestations, but subspecies fascicularis is now on the increase and represents a serious threat to rice crops, as it is found within the rice fields themselves. The irrigation system and the farm machinery used in the rice fields also contribute to the rapid spread of these weeds. Severe infestations have been caused by periodic water shortages, and the fact that new herbicides used to control Echinochloa spp. do not affect Leptochloa subspecies. Spatial differences in the distributions of the two subspecies are attributed to the different water management systems and also to differences in the germination and dormancy of both subspecies.  相似文献   
90.
Farmers in South East Asia are adopting rice crop establishment methods from transplanting to direct wet or dry seeding as it requires less labour and time and comparatively less energy than transplanting.In contrast to irrigated condition,in rainfed lowland,direct seeding is a common practice.Early flooding controls weeds but decreases seedling establishment in direct seeded rice.Anaerobic germination is an important trait to counteract damages caused by early flooding.Management options which can help in crop establishment and improve crop growth under flooding might remove the constraints related to direct seeding.The investigation was carried out with two near isogenic lines Swarna and SwarnaSub1.Swarna-Sub1 is tolerant to submergence whereas Swarna is susceptible.Seed priming was done with water and 2% Jamun(Syzygium cumini) leaf extract,and it improved seedling establishment under flooding.Acceleration of growth occurred due to seed pretreatment,which resulted longer seedling and greater accumulation of biomass.Seed priming greatly hastened the activities of total amylase and alcohol dehydrogenase in Swarna-Sub1 than in Swarna.Swarna-Sub1 outperformed Swarna when the plants were cultivated under flooding.Weed biomass decreased significantly under flooding compared to non-flooding conditions.Seed priming had positive effects on yield and yield attributing parameters both under non-flooding and early flooding conditions.  相似文献   
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