共查询到20条相似文献，搜索用时 187 毫秒
1.
Input-output budgets for nitrogen in a typical purple soil sloping ploughland in Three Gorges areas 总被引：2，自引：0，他引：2
The Xinzheng watershed in Zhongxian county, Chongqing, is a typical purple soil sloping ploughland in the Three Gorges areas. In 2009, the input-output budgets in this watershed is investigated and the results indicate that the nitrogen input is 918.26 kg/(hm2·a) and the output are 569.46 kg/(hm2·a). Furthermore, chemical fertilizer nitrogen is the main input source, accounting for 57.63%, and the main output track is nitrogen in crops, accounting for 36.22%. In this small watershed, the nitrogen loss load is 258.77 kg/(hm2·a). And the primary lost nitrogen is gaseous species, which is approximately 65.11% of the total lost nitrogen. In addition, nutrient nitrogen balance index is 3.4 in this watershed and the nitrogen surplus load is 348.80 kg/(hm2·a), much higher than the risk value, indicating potential occurrence pollution in ploughland. 相似文献
2.
The activation of black soil (analog the lignite) by electro-hydraulic impulse is proposed. The abundant insoluble nitrogen, phosphorus, potassium and other organic elements in black soil are activated as the green fertilizer by this way. The new method is provided for activating sludge produced by treating wastewater. For several kinds of black soil, the experiment result indicates that electro-hydraulic impulse increases the percentage of absorbable nitrogen by 1 to 4 times and the percentage of insoluble organic elements by 4 times, which is a valuable reference to sludge treatment. 相似文献
3.
Theoretical analysis and experimental study on the effect of the different components of porous medium gypsum on porosity 总被引：1，自引：0，他引：1
This paper uses a variety ways to prepare the gypsum(CaSO4·2H2O) and measured its physical properties, including vertical suction height h, the water velocity u in the horizontal state, the porosity η and the average pore radius. The results show that the way of preparation of the porous medium gypsum has great relationship with its properties. The gypsum is formed by adding some proper water into the CaSO4 , and its porosity is increasing with the increase of the water, but the strength is decreasing. Adding a bit of potassium citrate in the water can improve the performance of the gypsum , and the vertical suction height, the water’s horizontal velocity and the porosity can reach 120 cm, 4.2 mm/min and 69.4% respectively, so the gypsum can be used as the filling materials of the capillary suction liquid core radiator. 相似文献
4.
The water quality comprehensive evaluation and cluster analysis on drinking source water in Chongqing 
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下载免费PDF全文 Recent researches on the Yangtze River and the Jialing River water in Chongqing section of the Three Gorges Reservoir indicate that the pH value is relatively high and the CODMnconcentration is more than 4.5 mg/L in most of the time. Especially the proportion of dissolved molecule organic is high, as well as the high turbidity during the summer flood period. And the organic contamination is relatively serious. The fuzzy weighted water quality coefficient and hierarchical cluster analysis methods are applied to evaluate and sort the characteristic qualities of two-river water sources. During the research period, the results show that the Yangtze River water source quality is characterized by high turbidity and polluted of summer stage, middle temperature and micro-polluted of spring-autumn stage and low temperature and micro-polluted of winter stage. The Jialing River water source quality is characterized by low turbidity stage, high alga-polluted of early spring stage and high temperature and polluted of winter stage. Due to the various water qualities of two-river water sources at different periods, it is hard to meet the requirement of Standards for Drinking Water Quality (GB 5749-2006) by using traditional water treatment technologies. So the research on enhanced treatment is necessary. 相似文献
5.
Virtual prototype technology is a new method in R&D,which can effectively improve the product quality,decrease the new product developing time and reduce the production cost. A virtual prototype of rotary actuator is built up for simulation. According to double involute-spiral-pairs,which are the key parts of the hydraulic rotary actuator,a research is done on the relationship between input pressure and output torque. After simulation and experiment,it’s found that system pressure and output torque is in a positive linear programming. And another experiment is carried out on the relationship between different helix angles and output torques under same pressure. Through three series simulations within helix angles of 30°,45° and 60°,it’s found that we’d better design a helix gear in around 45° helix angle without any gear modification,so that we can get a optimized output torque. If a bigger output torque is wanted without higher pressure,the initial way is to increase the gear radial dimension. 相似文献
6.
The composition and heavy metals content of sludge, solid wastes and coke breeze is detected in the test. Sludge, solid wastes and coke breeze compost the organic composite fertilizer. The experiments on it for rice fertilization were conducted. The results show that the contents of organic matter and N, P, K in wastewater sludge and solid wastes of Guilin are very abundant and heavy metals remain under the criteria. There is a significant efficiency for the organic composite fertilizer applied in raising rice yield, providing an extensive applicability. 相似文献
7.
From the point of psychological state programming research for the main teaching district special renewing of Tsinghua University,this essay approaches how to apply the theory and method of "SD" architectural programming to the practice.As a result,an innovative conceptual design proposal has come out.This paper also illustrates that the key factor to rational design is the application of the theory and method of "SD"architectural programming. 相似文献
8.
Performance analysis of transcritical organic rankine cycle 总被引：1，自引：0，他引：1
The performance analysis of a transcritical organic Rankine cycle system driven by exhaust heat is presented by using 24 organic working fluids. Four parameters, such as the net power output, thermal efficiency, exergy efficiency, and mass flow rate of working fluid, are used to evaluate the performance of this recovery cycle. The results reveal that the maximum net power can be obtained for the saturated ORC, when T1/TC is about 0.98～0.99,and the working fluid with higher critical temperature has more net power output. For the supercritical ORC, the higher expander inlet temperature will benefit the net power output, thermal efficiency, and exergy efficiency, as long as the expander inlet pressure isnnot too low. However, the influences of expander inlet pressure on these performance parameters are linked with the expander inlet temperature and working fluids. The capability of doing power output of supercritical ORC is not always better than that of subcritical ORC. Parameters, such as net power, thermal efficiency, and exergy efficiency, and mass flow rate are discontinuous in the process from subcritical conditions to supercritical conditions. 相似文献
9.
Productivity analysis is the main instrument exploring the source of growth, and the important means to determine the growth quality. From the World War II, the focus of productivity research in the world changed from partial factor productivity to total factor productivity, and this is the beginning of modern productivity research. On the basis of reviewing the total-factor productivity research in China and abroad, the research status is briefly discussed, and some suggestions are given to our research. 相似文献
10.
The experiment took bath wastewater as research object and adopted aluminum, iron and organic macromolecule as coagulants to examine the removal rates of LAS from bathing wasterwater,Determinted the PAC as the furthest coagulation,and the influenced factors such as the dosage of coagulation,the pH value,the sedimentation time,the stirring speed and stirring time were discussed using a method of one factor experiment,the result showed that the best operating conditions is that the doesage of45mg/L for PAC, 6.0~8.0 pH, 15min sedimentation time, 150r/min for 3min and 50r/min for 10min, the removal rates of LAS is 45.75%. 相似文献
11.
南平市植烟土壤氮、磷、钾养分状况与演变趋势 总被引：4，自引：2，他引：2
为更好地了解南平烟区植烟土壤主要养分状况及其演变趋势,指导烟区土壤保育和烤烟平衡施肥提供依据。利用南平市植烟土壤普查资料,分析土壤氮、磷、钾养分状况与演变趋势,结果表明：土壤全氮、磷、钾平均分别为(1.61±0.47) g/kg、(0.57±0.31) g/kg、(16.34±6.31) g/kg,碱解氮和速效磷、钾平均分别为(146.05±38.76) mg/kg、(28.80±26.11) mg/kg、(90.02±52.12) mg/kg;土壤磷、钾属强变异,氮素属中等变异。土壤碱解氮含量与质地、有机质和全氮含量之间,速效磷含量与pH和全磷含量之间,速效钾含量与pH、质地、有机质、全钾和缓效钾含量之间均呈极显著正相关。土壤供氮和供钾能力均呈降低趋势,而供磷能力则呈增加趋势,且均表现出长期连续种烟的老烟区更加突出。从土壤保育和优质烟叶生产角度,南平烤烟生产应施用白云石粉等提高土壤pH,增施有机肥和钾肥,控制烤烟当季施氮量,总体应减少磷肥施用量,但土壤速效磷＜10 mg/kg的烟区仍需重视施用磷肥。 相似文献
12.
在增施有机肥料的基础上,开展最佳目标产量水平下的减量化施肥试验,根据不同水平试验区组产量进分析,确定可以接受的减量水平.通过试验得出：施有机肥240kg/667m2,尿素（N 46％）12.33kg/667 m2,氯化钾（K2O 60％）5.77kg/667m2,单产578.0kg/667m2,与产量最高的施肥处理相比,低1.7％,产量差异不显著,但比最高单产处理施尿素（N46％）18.48kg/667m2、普钙（P2O5 14％）46.43kg/667m2、氯化钾（K2O60％）11.67kg/667m2的减少化肥用量58.48kg/667m2. 相似文献
13.
不同施肥方式对辣椒产量和经济效益的影响研究 总被引：5，自引：2，他引：3
为确定辣椒最佳施肥方式,采用L9(34)正交设计,分别选取氮磷钾施肥总量、氮磷钾配比、有机肥用量、各时期施肥分配量4个因素,各3个水平,测定辣椒在关键生育期的生长性状各指标和经济性状;在收获期进行实验室考种,考察产量并核算经济效益。结果表明,施肥方式的最优组合为：氮磷钾施肥总量为900 kg/hm2,其中氮肥300 kg/hm2、磷肥225 kg/hm2、钾肥375 kg/hm2,需要有机肥15000 kg/hm2,该组合下,辣椒的产量可达35335.60 kg/hm2,产值可达49906.96~61214.35元/hm2。 相似文献
14.
中国农田土壤磷平衡现状及驱动因子分析 总被引：8，自引：1，他引：7
结合GIS平台对1996及2002年我国县域农田土壤磷平衡状况分析结果表明,全国农田土壤磷平衡存在很大的时空变异。1996年及2002年县域农田土壤磷盈亏范围分别为-20～425 kg/ha及 -17～450kg/ha。农田土壤磷盈余量在20～50 kg/ha的县市占全国总县市的比例从1996年的34.2%下降到2002年的24.1%,而磷盈余量在50～100kg/ha的县市所占比例从29.3%增加到33.4%,农田土壤磷盈余量在6年间普遍提高了一个等级。区域尺度上,化肥磷投入是影响磷平衡空间分异的直接因素,而有机肥的影响不明显;种植业结构变化是影响磷平衡时空变化的间接因素;农业收入是经济欠发达地区影响磷肥投入的主要原因之一。 相似文献
15.
有机无机氮肥配施对山地烤烟生长、抗病性及香吃味的影响 总被引：4，自引：0，他引：4
为探讨有机无机氮不同配比对山地烤烟生长发育、抗病性和香吃味的影响。采用田间试验与室内分析相结合的方法,在等氮量条件下,开展了有机无机氮不同配比田间试验。结果表明：（1）施用有机肥能够显著促进烟株生长发育,改善烟株抗逆能力,表现为烟株长势强,烟叶发育充分,烟株发病率较低;（2）有机肥的施用能够有效改善烟叶的等级结构,提高上中等烟叶比例,提高单位面积的产量和产值效益;（3）有机肥的施用能提高烤烟烟叶的香吃味;（4）山地烤烟20%有机氮与80%无机氮配施的综合效应最好。综上所述,在亩施纯氮7.5 kg的施肥水平下,20%有机氮与80%无机氮配比对山地烤烟具有最好的综合效应。 相似文献
16.
沼液施用量对小麦产量及土壤理化性质的影响 总被引：3，自引：0，他引：3
为给沼液循环利用提供科学理论依据,以‘扬麦16’为材料,研究了沼液施用量对小麦群体质量、产量及土壤理化性质的影响。结果表明,与对照处理（不施沼液CK）相比,施用沼液能增加小麦分蘖数和分蘖成穗率,随着沼液施用量的增加SPAD值、叶面积指数、干物质积累量也相应提高;施用沼液处理土壤容重下降,孔隙度增加,其中TR5（基肥60000 kg/hm2沼液+150 kg/hm2尿素）和TR6（75000 kg/hm2沼液+150 kg/hm2尿素）处理土壤容重达到了1.0 g/cm3以下。施用沼液可明显提高土壤氮磷钾含量,最大增幅分别为15.3%（全氮）、34.5%（有效磷）、16.2%（缓效钾）;施用沼液处理均较对照增产,且差异达极显著水平,其中TR5（基肥60000 kg/hm2沼液+150 kg/hm2尿素）处理小麦产量最高,达6525.00 kg/hm2,比对照产量高6.5%。沼液施用量以60000~75000 kg/hm2之间效果较佳。 相似文献
17.
宁夏银北引黄灌区灌淤土壤养分丰缺状况研究 总被引：2，自引：2，他引：0
为了提出适合宁夏银北引黄灌区农地种植水稻、小麦和玉米的合理施肥量,以氮素、磷素、钾素为试验因子,设无肥(N0P0K0)、无氮(N0P2K2)、无磷(N2P0K2)、无钾(N2P2K0)、氮磷钾(N2P2K2)全施5个处理,重复3次,随机区组排列,对土壤养分丰缺状况的试验研究和评价。结果表明：本地区农地种植水稻,化肥对水稻产量的贡献率是36.5%,其中氮肥对水稻产量的贡献率是11.9%,磷肥对水稻产量的贡献率是10.5%,钾肥对水稻产量没有影响。本地区农地种植小麦,化肥对小麦产量的贡献率是56.3%,其中氮肥对小麦产量的贡献率是28.0%,磷肥对小麦产量的贡献率是9.2%,钾肥对小麦产量的贡献率是1.2%。本地区农地种植玉米（套种）,化肥对玉米产量的贡献率是62.4%,其中氮肥对玉米产量的贡献率是53.2%,磷肥对玉米产量的贡献率是15.5%,钾肥对玉米产量的贡献率是6.9%。因此得出,本地区种植农作物对化肥的依赖性较大,施用化肥具有明显的增产效果,其中氮肥对农作物产量起主要作用,磷肥对农作物的产量影响较小,钾肥对农作物的产量影响不大,可以不施或少施。 相似文献
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19.
为了研究长期施用含SO4=肥料对水稻水稻农艺性状及产量的影响,对红壤地区农业持续发展和科学研究提供原创性的理论依据,刘更另院士于1975年开始在湖南祁阳官山坪中国农业科学院红壤实验站布置了肥料定位试验。试验设三个处理,即：处理一：SO4=,采用含SO4=化肥：(NH4)2SO4 + K2SO4 + 过磷酸钙。 处理二： Cl- ,采用含Cl- 化肥：NH4Cl + KCl + KH2PO4;处理三：隔离区（CK）。施用化肥NPK。即：尿素 +过磷酸钙+ 氯化钾。 三个处理NPK用量相同。通过32年的长期研究,结果表明：1.长期施用含SO4=肥料对水稻产量没有多大影响;2.长期施用含SO4=肥料能够提高水稻生物产量。据1982-2007年26年的总产量（生物产量）统计,SO4=处理（488653.5kg/hm2）,比CK处理（483862.1 kg/hm2）高4791.4kg/hm2,比Cl-处理（477262.5kg/hm2）高11391.0 kg/hm2。3. 长期施用含SO4=肥料能够增加水稻有效穗,但结实率和千粒重较低。 相似文献
20.
栽培因子对转基因棉F1和F2产量构成的影响 总被引：1，自引：0，他引：1
为探索转基因棉在丰产栽培模式,应用农业系统原理和方法,采用四元二次旋转组合设计,以密度、施氮量、施钾量、缩节安为决策变量,转基因棉产量及构成因素为目标函数,建立相应的数学模型。剖析了密度、施氮量、施钾量、缩节安四项综合农艺措施的主效应和交互效应与产量的关系。分析表明,栽培因子对F1产量的影响大小顺序是：密度>缩节安>施氮量>施钾量。对F2产量影响大小顺序是：施钾量>施氮量>密度>缩节安。并寻求了定量生产水平下F1、F2的最佳农艺措施,即F1当密度为21500株/hm2、施氮量为450kg/hm2、施钾量为450kg/hm2、缩节安量为75g/hm2,可能取得最佳产量1556 kg/hm2,F2密度为15000株/hm2、施氮量为750kg/hm2、施钾量为300kg/hm2、缩节安量为135g/hm2可获得最高的皮棉产量1219.35kg/hm2。 相似文献