共查询到20条相似文献,搜索用时 93 毫秒
1.
为考察新型植物油包膜控释氮肥对间作玉米-大豆的产量、经济效益、肥料利用率等方面的影响,开展了田间小区试验。试验以不施氮肥(CK)、施用普通尿素(PU)处理为对照;植物油包膜控释氮肥施肥量为全量、减量20%、减量30%等3种,控释氮占总氮量为60%、40%等2种,共设置4个处理。结果表明,在玉米试验中,与PU处理相比,控释氮占总氮量60%的全量、减量20%处理的产量分别显著增产14.70%、7.49%,纯收入分别显著增加3 192.80、2 680.02元/hm2;控释氮肥处理的氮素利用率为50.14%~53.43%,差异显著。在大豆试验中,与PU处理相比,控释氮占总氮量60%的全量处理显著增产16.67%,纯收入显著增加2 725.80元/hm2;控释氮肥处理的氮素利用率为54.12%~57.98%,差异显著。对于玉米-大豆间作栽培,建议全量或减量20%施用控释氮占总氮量60%的植物油包膜控释氮肥。 相似文献
2.
为探索控失尿素的施用方法,发现控失尿素在施用中存在的问题,以冬小麦为试验对象,开展了田间小区试验,考察了不同施肥处理和施肥方式对冬小麦产量、氮素利用率和土壤硝态氮含量的影响。结果表明:施氮处理的冬小麦产量高于不施氮处理的,处理间差异极显著;氮素施用量和施肥方式相同时,控失尿素处理的冬小麦产量高于普通尿素处理的,处理间差异极显著;氮素施用量和肥料品种相同而施肥方式不同时,底施+追施的增产效果优于全底施的,处理间差异显著;控失尿素氮素施用量比普通尿素减少20%的条件下,冬小麦产量无显著性差异;与施用普通尿素的处理相比,施用控失尿素的处理不仅氮素利用率高,且均不同程度地降低了土壤中硝态氮的含量。施用控失尿素可以提高冬小麦的产量和氮素利用率,降低土壤中硝态氮的含量。 相似文献
3.
4.
为寻求南四湖水稻优化施肥模式,根据当地习惯施肥和水稻的需肥特性,设计了7种不同施肥模式,对不同施肥模式下水稻生长因子(水稻地上部干重、植株及籽粒中氮含量)、产量因子(水稻成熟区生物量、产量)、肥料利用率进行对比分析。试验结果显示:控释尿素比普通尿素更符合水稻生长特性,水稻地上部干重优于普通尿素,籽粒氮的吸收量较普通尿素增加15.83%;降低化肥施用量、增施有机肥可提高水稻对养分的吸收和养分向籽粒中的迁移;在等氮磷钾量情况下,控释尿素和20%减量控释尿素配施推荐磷钾肥的水稻产量较普通尿素分别提高8.75%和8.70%;控释尿素配施推荐磷钾肥显著提高了氮磷钾肥的利用率,20%减量控释尿素的氮肥利用率可提高21.40%。从降低施肥成本、提高肥料利用率和控制面源污染角度出发,20%减量控释尿素配施推荐磷钾肥为最优施肥模式。 相似文献
5.
6.
腐植酸功能性肥料在水稻上的应用研究 总被引:1,自引:0,他引:1
采用田间小区试验,以普通尿素为对照,在不同施氮量和施肥次数条件下,探究腐植酸功能性肥料(腐植酸尿素)在太湖流域水稻上的应用效果。研究表明,在常熟推荐施氮量255 kg/hm~2情况下,腐植酸尿素分两次施用的水稻产量和氮肥利用率均高于普通尿素分两次和三次施用,水稻产量分别增加了8.75%和5.06%,氮肥利用率平均提高了10.18%,但在高施氮量和低施氮量时,水稻产量低于相应普通尿素处理,但差异不显著;腐植酸尿素处理降低了稻田田面水铵氮浓度,从而降低氮素向大气(主要以氨挥发途径)和水体(主要指径流)迁移的风险。因此,腐植酸尿素在太湖流域高产水稻田上选择适宜施氮量255 kg/hm~2具有较好的环境和经济效益。 相似文献
7.
8.
9.
为探究尿素中添加不同量的腐殖酸对农作物产量和氮素利用率的影响,以冬小麦为试验对象,以施用普通尿素和不施氮肥处理为对照,与施含腐殖酸尿素的处理进行比对,开展了田间小区试验。结果表明:施氮肥处理的冬小麦增产效果较好,与不施氮肥处理的相比差异达极显著水平,但各施氮肥处理间无显著性差异;与施用普通尿素处理相比,施用含腐殖酸尿素的处理均降低了土壤中硝态氮的含量,且硝态氮含量变化趋势基本一致;与施用普通尿素处理相比,施用含腐殖酸尿素的处理对冬小麦的增产效果并不明显,可能是因为腐殖酸添加量过少、施用时间较短。 相似文献
10.
在湖北省中稻上开展了控释尿素不同施用量的田间试验。研究结果表明,施用控释尿素不仅可以提高中稻产量,而且可以提高氮肥的农学效率及表观利用率,控释尿素70%的用量与普通尿素100%的用量效果相当,并随着控释尿素施用年限的增加,控释尿素施用效果越显著,控释尿素至少可以减少氮肥用量30%。 相似文献
11.
乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
13.
14.
D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
__________
Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
15.
16.
Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
17.
18.
A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%. 相似文献
19.
塔设备改造选型的分析 总被引:2,自引:0,他引:2
就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后,着重介绍一种新型塔板(导向梯形浮阀塔板)和一种新型填料(波环填料——乾隆帕克)。 相似文献