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181.
沙本才  刘鸿高  王元忠 《安徽农业科学》2009,37(27):12904-12905
[目的]建立简便、快速、精确的大百合中高含量铜、锰的测定方法。[方法]采用次灵敏线(铜327.4nm、锰280.1nm)确定大百合中高含量铜、锰的分析条件,建立大百合中高含量铜、锰的次灵敏线原子吸收光谱测定方法,并考察酸及酸含量、共存离子等对测定结果的影响。[结果]含量低于10%的盐酸、硝酸、王水、高氯酸、硫酸对5mg/L铜和锰的测定结果无影响;2000mg/L K+、Na+,1000mg/LFe3+、Zn2+、mg2+、Ca2+100mg/LAl3+、Si4+及50mg/LPb2+、Cd2+、Cr6+、Ni2+均不干扰铜、锰的测定;铜、锰的线性jia范围分别为0-25、0—12mg/L,相对标准偏差分别为0.42%和0.66%,加标回收率分别为96%~103%和97%-102%。[结论]该研究建立的大百合中铜、锰含量的测定方法简便、快速、实用性强。  相似文献   
182.
    
Cobalt(Co)exists in significant quantities in naturally occurring manganese(Mn)oxides and alters the growth of Mn oxide crystals.Four-layered Mn oxides,Na-buserite(Na-bus)and three Co-doped Na-buserite samples prepared from oxidation of Mn(OH)2 with 5%,10%,and 20% Co/(Mn+Co)molar ratios(5Co-Na-bus,10Co-Na-bus,and 20Co-Na-bus),were used to prepare todorokite,a common Mn oxide on the Earth's surface,using Mg2+/Co2+ ions as a template.The results showed that todorokites could be obtained by reflux treatment of...  相似文献   
183.
    
The role of intact extraradical mycelium (ERM) as the most effective fungal propagule in the formation of the tripartite symbiosis between indigenous arbuscular mycorrhizal fungi (AMF), rhizobia and subterranean clover was investigated under conditions of Mn toxicity. ERM was previously developed in 8 L pots under greenhouse conditions by growing plants, which exhibited various levels of mycotrophicity and were tolerant to the levels of Mn in the soil used in the experiment (Silene gallica L, Lolium rigidum L, Ornithopus compressus L. and Rumex bucephalophorus L). Contrasting conditions of the integrity of the ERM at the planting of subterranean clover were created by soil disturbance (ERM fragmented – soil disturbed; ERM intact – soil undisturbed). Where an intact ERM was present at the time of planting, growth of subterranean clover was 2.5 times greater after 21 days and 3.9 times after 42 days relative to other forms of AMF propagule. This enhanced growth was associated with a reduction in the Mn concentration of roots due to a greater AMF colonization at 21 days after planting. The protection granted by an enhanced AMF root colonization allowed a greater root nodule development, leading to more N acquisition and plant growth. The ERM can be developed in the soil by mycotrophic plants tolerant to the stressing agent and kept intact at the seeding of the crop to be protected by adopting appropriate tillage techniques.  相似文献   
184.
    
Analysis and research on the nutrition of some Australian native plants as well as diagnostic analysis of failed native plant gardens reinforces the view that manganese (Mn) availability is a major factor in the edaphology and cultivation of Australian native species. Yellow Kandosol soils on sandstone show a unique endemic floral assemblage. These soils show low total soil Mn levels of only 20–30 mg/kg. Despite this, endemic species such as Eucalyptus haemastoma and Acacia suaveolens show greater foliar Mn levels (around 291 and 389 mg/kg, respectively) than iron (Fe) levels, with Fe/Mn ratios as low as 0.14 and 0.27. During pot trial work on artificial soils created from crushed sandstone and green waste compost that were designed to research phosphorus (P) and calcium (Ca) nutrition, some interesting data on Mn uptake were collected. Levels of foliar Mn as high as 1250 and 389 mg/kg, respectively, accumulated in E. haemastoma and A. suaveolens when soils were artificially acidified to pH 4.7 (CaCl2) using ferrous sulfate. These Mn levels were associated with visible toxicity symptoms in foliage of E. haemastoma but not in A. suaveolens. Foliar Mn in both species showed a strong inverse correlation (R2 > 0.93) with soil pH. Previous research has shown that eucalypts from this floral assemblage are prone to Mn toxicity when grown in conditions of high soil Mn availability. Diagnostic analysis of soils and foliage for a client with horticultural problems in a native plant landscape showed severe chlorosis in a wide range of native species due to Mn deficiency induced by neutral soil pH (around 7.0 in CaCl2). Such soil pHs are considerably greater than those of the plant’s natural distribution. Despite apparently elevated soil P and the appearance of what looked like P toxicity, foliar P levels were not sufficiently elevated to conclude acute P toxicity but rather simple and severe Mn deficiency. The work suggests that induced Mn deficiency and toxicity may be underdiagnosed problems in the cultivation of many Australian native plants.  相似文献   
185.
    
Silicon (Si) is one of the most abundant elements in the earth's crust, although its availability may be affected by some edaphic and abiotic factors such as soil moisture and salinity. In a laboratory experiment, effects of silicon (Si), salinity, and soil moisture on changes of extractable Si, iron (Fe), and manganese (Mn) concentrations were investigated on a sandy loam calcareous soil. The experiment was arranged as a factorial completely randomized design with three replications. Two levels of Si (8 and 200 mg per kg of soil), three salinity levels [0.46 dS m?1, 8 dS m?1 as sodium chloride (NaCl), and 8 dS m?1 as four-salt combination], two soil moisture regimes (–20 kPa and waterlogged), and four incubation times (0, 7, 30, and 45 days) were applied. Salt composition consisted of sodium chloride, sodium sulfate, calcium chloride, and magnesium sulfate at a molar ratio of 4:2:2:1. Acetic acid–extractable Si, Fe, and Mn were determined after 0, 7, 30, and 45 days of incubation. Waterlogging caused significant increase in the extractable Si, Fe, and Mn. Soil salinity of 8 dS m?1, only in the form of sodium chloride, resulted in a marked decrease in extractable Si, Fe, and Mn. Silicon addition enhanced the soil Si concentration, with no effect on Fe and Mn. Equilibrium time for Si and Fe was 30 days, whereas Mn concentration reached to a constant level after 1 week of waterlogging. It was concluded that Si, Fe, and Mn fertilizers should be applied in sufficient amounts to the saline soils to prevent their deficiencies in plants. Meanwhile, overfertilization in waterlogged conditions must be avoided, because of the probability of nutrient imbalance or toxicity.  相似文献   
186.
宁夏干旱区玉米锌锰配肥产量效应研究   总被引:1,自引:0,他引:1  
试验采用二因素二次饱和D最优设计方法,对锌锰施用量的配合及基与干旱区玉米产量间的关系进行了研究。结果表明,锌锰肥对玉米均有增产量效应,锌肥作用尤为明显,锌肥的增产效应明显大于锰肥。同时筛选出了锌锰肥配合优化组合方案,玉米产量3800kg/hm^2以上的锌锰配合优化组合方案为:锌3.3008kg/hm^2,锰4.608kg/hm^2。  相似文献   
187.
滇池主要入湖河流水质分析   总被引:11,自引:0,他引:11  
 对滇池流域的4条入湖河流的总磷、总氮、COD污染进行了调查。结果表明,随着流域内旱雨季变化、河流流量变化、河流地段变化,总磷、总氮、COD含量存在明显差异。入湖口水样总磷、总氮、COD含量明显高于同一河流中、上游。雨季河流流量增加,总磷、总氮、COD含量仍明显增高,特别是雨季前期,由于旱季大量有机物在地面堆积,土壤有效P累积,雨后随地表径流进入河道,使COD、TP增加明显,持续降雨后又有下降趋势。  相似文献   
188.
以马来松香乙二醇丙烯酸酯作为交联剂,甲基丙烯酸、甲基丙烯酸甲酯为单体,Fe3O4为磁核,通过化学沉淀法及悬浮聚合制备出松香基磁性微球(Fe3O4@RPM),并优化了制备条件。分别采用红外光谱、扫描电镜、X射线衍射和热重等分析手段,对Fe3O4@RPM的结构进行表征,并采用静态吸附法,研究了具有菲环骨架的高分子磁性微球吸附Mn2+过程中的热力学和动力学。研究结果表明:制备具有菲环骨架的高分子磁性微球条件为70℃,400 r/min,1 g偶氮二异丁腈为引发剂,反应4 h,此条件下磁性微球含磁23.5%。对Mn2+的吸附符合准二级动力学模型;在实验浓度和温度范围内,吸附热力学研究显示,ΔH>0、ΔG<0、ΔS>0,说明该吸附过程为自发的吸热过程。  相似文献   
189.
人工土快滤滤床对耗氧有机污染物的去除机制   总被引:14,自引:0,他引:14       下载免费PDF全文
田光明 《土壤学报》2002,39(1):127-134
通过对人工土快滤系统不同组分的灭菌试验和分析滤床落干恢复过程中土壤有机质的变化 ,对城市生活污水中的耗氧有机物 (COD)进入人工土滤床后的去向进行了研究。结果表明 ,人工土滤床对污水COD的去除是生物与非生物共同作用的结果 ,生物作用机制不仅表现在布水时期的生物降解 ,更反映在滤床落干期对被截留有机物的分解作用。系统好氧与厌氧微生物的周期监测表明 ,人工土滤床对污水COD的降解作用 ,不仅有污水微生物的生物降解 ,还有土壤微生物的矿化分解作用。人工土快滤系统是以好氧生物为主导的生物过程与非生物过程的有机结合  相似文献   
190.
分析了淀粉、纤维素和聚乙烯醇(PVA)这三种慢速可生物降解COD基质在高温(55℃)厌氧升流式污泥床中的降解过程机理。淀粉能够完全转化为挥发性有机酸、微生物污泥、生物气;纤维素颗粒的去除仅是被污泥床截留,而几乎不发生生化反应。少量的PVA基质在厌氧条件下能够被转化成有机酸。  相似文献   
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