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101.
有机中微肥的生产及其应用前景   总被引:1,自引:0,他引:1  
我国中低产田面积占总耕地面积70%以上,其中大部分存在有机质和中微量元素缺乏和肥料利用率低的问题。为防止中微量元素施入土壤后被固定而失效,提出利用废弃资源,生产有机中微肥(如氨基酸、木质素磺酸、腐植酸中微肥等),其生产成本比EDTA螯合中微肥低,并简要介绍了各种有机中微肥的生产工艺过程。只要做到测土施肥,有针对性加入有机中微肥,即可达到提高作物产量、品质,提高肥料利用率,提高土壤肥力的良好效果。  相似文献   
102.
ICP-MS法测定陶瓷容器中重金属元素的研究   总被引:2,自引:0,他引:2  
采用电感耦合等离子体—质谱(ICP—MS)法同时测定了陶瓷容器中重金属元素PB、CA、Cr、Ni,对影响其测量的各种因素进行了较为详细的研究,确定了实验的最佳测定条件。结果表明,方法的检出限为0.002—0.008μg/L,回收率为90.0%-110.0%,RSD小于9.21%。该法准确、快速、简便,应用于陶瓷容器中重金属元素的测定,结果满意。  相似文献   
103.
Abstract. Three linear methods for estimating parameter values of vector auto-regressive moving-average (VARMA) models which are in general at least an order of magnitude faster than maximum likelihood estimation are developed in this paper. Simulation results for different model structures with varying numbers of component series and observations suggest that the accuracy of these procedures is in most cases comparable with maximum likelihood estimation. Procedures for estimating parameter standard error are also discussed and used for identification of nonzero elements in the VARMA polynomial structures. These methods can also be used to establish the order of the VARMA structure. We note, however, that the primary purpose of these estimates is to generate initial estimates for the nonzero parameters in order to reduce subsequent computational time of more efficient estimation procedures such as exact maximum likelihood.  相似文献   
104.
针对传统物流行业报表的制作、呈现、管理都是由报表业务人员进行操作,不能及时的将报表呈现的数据信息反馈给决策者,导致信息的延误。通过对JSP以及SQL Server Reporting Service(SSRS)的分析介绍,提出把SSRS报表嵌套在JSP中,加入到网络物流系统操作平台。基于SQL Server 2008 R2数据库以及Spring MVC框架,运用Spring注解方式与JSP技术进行系统开发,直接将SSRS报表嵌套在JSP页面供决策者分析。结果表明,JSP页面可以嵌套带有参数要求的SSRS报表,并且可以准确的读取操作SSRS报表,获得满意的嵌套效果。  相似文献   
105.
106.
采用电感耦合等离子体发射光谱法测定二次精制盐水中Ca、Mg、Sr、Fe、Ba、S i等微量元素含量。方法简便、快速、精密度高,结果准确可靠。  相似文献   
107.
One major constraint of the agricultural uses of fly ash (FA) is the low availability of different plant nutrients despite their high occurrence in the total amount. However, degrading FA through increased microbial activity can improve the availability of these nutrients substantially. It has been found that intestines of epigeic earthworms contain a high concentration of different microorganisms. Therefore, in the present study we addressed the effects of vermicomposting technology on the solubility of some micronutrient cations (Fe, Mn, Cu, and Zn) and some heavy metals (Pb, Cd, and Cr) in different combinations of fly ash and organic matter, applied in the form of cow dung (CD). Various combinations of FA and CD were treated with and without an epigeic earthworm (Eisenia fetida) and the solubility of different trace elements in the treatments were estimated periodically. The results revealed that the inclusion of epigeic earthworm Eisenia fetida in different combinations of fly ash and cow dung converted a considerable amount of the micronutrients into bio-available forms. On the other hand, the solubility of heavy metals tended to be reduced by the microorganisms, presumably by formation of some organo-metallic complex. Application of these vermicomposted FA and CD combinations to a red lateritic soil was found to improve the soluble Fe, Mn, Cu, and Zn status of the soil. Furthermore, the use of vermicomposted FA and CD (1:1) in potato cultivation demonstrated that use of this mixture at 10 ton per hectare (t ha−1; fresh weight) was able to compensate 80% of the recommended NPK fertiliser, along with farm yard manure application, without compromising the crop yield.  相似文献   
108.
为了分析江西省南新联圩防洪保护区在圩提溃决后洪水在区内的演进过程,根据南新联圩防洪保护区周围湖泊、河流及圩区情况,建立了模拟保护区内洪水演进的MIKE21模型。分别采用2010年和2012年实测洪水资料对模型进行率定和验证,结果表明模型具有较高的模拟精度。在赣江50 a一遇洪水叠加湖口22.5 m洪水位(1954年型)的工况下,利用所建立的模型对防洪保护区内的淹没水深、流速和洪水演进过程等进行计算分析,获得了南新联圩防洪保护区发生溃堤后的受灾发展情况。研究成果可为南新联圩防洪预警及时发布、转移财产、逃生避险等提供技术支撑。  相似文献   
109.
Ten trace elements (Cr, Zn, Fe, Mn, Cu, Co, Ni, Mo, V and Sr) and sulfur were determined in the saturate, aromatic and resin fractions of 15 crude oils from Mara (DM) and Mara Oeste (DMO) fields of the Maracaibo Basin, Venezuela. The oils studied are classified as unaltered or altered by biodegradation. In the altered oil, the depletion of n-alkanes, the absence of isoprenoids and the presence of steranes and hopanes unaltered by biodegradation are indicative of moderate biodegradation. The elements Zn, Fe, Mn, Cu, Ni, and Sr were detected in the saturated hydrocarbon fraction; Cr and V were detected in the aromatic fraction in addition to the above elements; whereas the elements detected for the resin fraction were Cr, Zn, Fe, Cu, Ni, Mo, V, and Sr. Co was not detected in any fractions of the oils analyzed. Sulfur was found in all fractions of the oils studied. It was proposed that Fe, Zn, Sr, and Mn could have entered the oil during migration or Fe, Zn and Mn as pollutants during oil extraction. Cr and Cu may be of biological origin and Mo could be incorporated into the reservoir through bacteria. Only S, V, and Ni in the resin fractions can be used as indicators of the origin and correlation of Mara and Mara Oeste oils. Based on the results obtained in this work, it can be established that the V/(V+Ni) ratio in the resin fraction can be used as a correlation parameter, for these oils.  相似文献   
110.
Batch leaching tests have been performed on fly ashes collected from four Australian power stations fuelled by chemically different coals. Two acidic and two alkaline fly ashes were subjected to long-term (144 h) leaching tests, and the behaviour of As, B, Mo and Se was investigated to obtain data on their potential for mobilisation during fly ash-water interactions. All four elements are mobile under different conditions and over different leaching times. The concentrations of these elements released in leaching solutions with initial pH values of 4, 7 and 10 were used to assess the influence of pH conditions on element mobility from the acidic and alkaline fly ashes. The most mobile of the four elements leached were Mo from alkaline fly ashes and B from acidic fly ashes. Arsenic concentration increased with time in leachate solutions from acidic and alkaline fly ashes; however, in solutions in contact with alkaline fly ashes the As concentration, after reaching a maximum, later decreased with time. Selenium mobility shows a similar pattern to that of As, with similar leaching concentrations. Boron has the highest relative mobility of all four elements. A process possibly responsible for the decrease in concentration of B, As and Se in alkaline leaching solutions is the formation of ettringite. Equilibrium between the solid phase (ash) and the leaching solution was not reached in any of the leaching experiments. The pH of the leaching solution is the key factor affecting the mobility of these trace elements in these fly ashes.  相似文献   
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