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51.
笔者根据多年的实践经验 ,阐述以尿素为氮源 ,生产高氮〔w(N)≥ 2 0 %〕复肥的现实意义及生产技术要点 ,具体介绍 2个高氮复肥 (2 30 7)、(2 0 10 15 )的配方实例及操作要点 相似文献
52.
简述了在团粒法工艺的基础上,用尿素熔融尿液或尿素车间二段蒸发器的尿液进行喷浆造粒生产复合肥的改造方案、改造内容、改造效果和投资情况。 相似文献
53.
The phosphate sorption isotherms are needed to explain differential plant responses to P fertilization in soils. Laboratory and greenhouse experiments investigated the use of phosphorus sorption isotherms in relation to P fertilizer requirement of wheat in ten benchmark soils of Punjab, India. The modified Mitscherlich Equation (3) was used to describe plant response observed in different soils. Maximum obtainable yield (MOY) ranged from 11.6 g pot–1 in Gurdaspur (I) sandy clay loam to 7.0 g pot–1 in Nabha sandy clay loam. Response to P applied @ 25 mg P kg–1 soil was maximum (77%) in Bathinda sand and minimum in Chuharpur clay loam (33%). The response curvature varied from 3.74 × 10–2 in Nabha sandy clay loam to 4.43 × 10–2 in Kanjli sandy loam. The soil solution P required to produce optimum yield (90% MOY) varied from 1.61 µg ml–1 in Bathinda sand to 0.10 µg ml–1 in Sadhugarh clay. Dry matter yield obtained at 0.2 µg ml–1 solution P concentration ranged from 55% in Bathinda sand to 85% of MOY in Gurdaspur (II) clay loam. At the same solution P concentration (0.1 µg P ml–1), dry matter yield was 91% in Sadhugarh clay, 80% in Gurdaspur (II) clay loam and, 43% of MOY in Bathinda sand and eventually coincided with the decreasing maximum buffer capacity (MBC) in these soils. At the same level of sorbed P (100 mg P kg–1 soil) the yield was observed to be inversely proportional to MBC. The study, therefore, concludes that, soils should be grouped according to their P sorption characteristics and MBC before using critical soil solution P as a criterion for obtaining optimum yields. 相似文献
54.
In a field study P and K uptake by two corn (Zea mays L.) genotypes which differed in root growth was investigated. The effect of differences in root growth on P and K uptake was assessed using a mechanistic-mathematical model which describes nutrient uptake by growing plant roots in soil. Nitrogen was applied at 0 and 227 kg ha–1 to Pioneer 3732 and B73xMo17 corn grown on Raub silt loam (fine-silty, mixed, mesic Aquic Argiudoll) and at 227 kg N ha–1 to these two genotypes on Chalmers silt loam (finesilty, mixed, mesic, Typic Haplaquoll). Root growth and P and K uptake by the two corn genotypes was measured 31, 47, 75 and 91 d after planting on the Raub and 31, 47, 61 and 75 d after planting on the Chalmers soil.Root growth and P and K uptake by B73xMo17 was greater than that of Pioneer 3732 on N-fertilized Raub soil. On Chalmers soil the difference in root growth between the two genotypes resulted in an increase in K but not P uptake. The higher soil P level of the Chalmers appears to have offset possible differences in P uptake due to root size. There were no differences between the two genotypes in either the percentage of roots with root hairs, or the density or length of root hairs. Phosphorus and K uptake calculated with the simulation models for both corn genotypes on both soils over each of three growth periods agreed with observed P (Y = 0.68X + 1.71; r = 0.944**) and K (Y = 0.88X + 15.52; r = 0.928**) uptake. Differences in P and K uptake between B73xMo17 and Pioneer 3732 resulted primarily from the difference in root growth in the topsoil. A high correlation was found between root surface area and P (r = 0.893**) and K (r = 0.928**) uptake by both corn genotypes on both the soils.Journal paper No. 10,316 Purdue Univ. Agric. Exp. Stn., W. Lafayette, In 47906. Contribution from the Dep. of Agron. This paper was supported in part by a grant from the Tennessee Valley Authority. 相似文献
55.
Intensification of agriculture by irrigation and enhanced use of fertilizers may generate pollution by increased levels of nutrients in underground and surface waters. Most of the irrigation is by open systems having a relatively low efficiency of water application. A higher efficiency may be gained by pressurized irrigation systems. Drip irrigation generates a restricted root system requiring frequent nutrient supply that may be satisfied by applying fertilizers in irrigation water, i.e. by fertigation. Maximization of crop yield and quality and minimization of leaching below the rooting volume may be achieved by managing fertilizers concentrations in measured quantities of irrigation water, according to crop requirements. 相似文献
56.
概述了察尔汗盐湖的自然条件、地质条件与资源状况,阐明了我国钾肥工业的现状以及察尔汗盐湖资源开发对发展我国钾肥工业的重要作用。 相似文献
57.
58.
粉煤灰磁化肥在水稻土上对水稻作物试验结果表明:粉煤灰磁化肥在水稻土上一般用量为926kg/hm2左右.粉煤灰磁化肥比对照增产27.7%,增产1977.8kg/hm2;比当地农民习惯施肥增产10.6%,增产870kg/hm2; 比未磁化粉煤灰复混肥增产5.9%,增产507 kg/hm2.最高产量施用粉煤灰磁化肥为1169 kg/hm2,水稻产量为9253 kg/hm2;最佳产量施用粉煤灰磁化肥为926 kg/hm2,水稻产量为9131 kg/hm2.粉煤灰磁化复混肥在改善水稻生物学及经济性状,提高叶绿素含量和光合速率方面有显著的效应. 相似文献
59.
A variety of P compounds can accumulate in soils as residues of fertilizer and may influence soil test versus plant yield relationships. This work evaluates specific chemical extractants for their capacity to identify such Al, Fe and Ca phosphates in soils as a basis for increasing the precision of yield prediction. Aluminium phosphate, iron phosphate, calcium phosphate (apatite) and P sorbed onto gibbsite, goethite and calcite were added to four Western Australian lateritic soils. These soils were then subjected to sequential selective extraction using a modified Chang and Jackson procedure in order to evaluate the selectivity of these extractants for the different forms of P with the sequence of extraction: 1 M NH4Cl, 0.5 M NH4F, 0.1 M NaOH + 1 M NaCl, citrate-dithionite-bicarbonate (CDB), 1 M NaOH and 1 M HCl. The results show that the procedure is not sufficiently specific and thus might be of little value for estimating the forms and amounts of residues of phosphate rock fertilizers in soils. 相似文献
60.
保水长效复合肥的生产及其应用 总被引:5,自引:0,他引:5
在NPK的基础上添加微量元素和功能性吸水性树脂制成的保水长效复合肥具有保水、保肥和增产的作用。经施用证明,其效果理想,经济效益显著。 相似文献