海南坡岗地甘蔗氮磷钾养分优化施用研究

通过"3414"田间肥料效应试验,研究了海南坡岗地甘蔗氮、磷、钾养分用量优化。结果表明,氮、磷、钾养分的合理配比施用,可大幅度提高甘蔗产量。在氮、磷、钾三要素中,氮肥贡献率>钾肥贡献率>磷肥贡献率。根据多元回归方程分析结果,当甘蔗获得最高产量即69967.79kg/hm2时,每公顷相应的氮、磷、钾养分施用量分别为402.82、185.32、502.55kg。氮、磷、钾养分的配比为1∶0.21∶1.25。建议甘蔗氮、磷、钾养分施用的配比以1∶0.2～0.25∶1.2～1.25较为合适,相当于每667m2分别施用尿素58.4kg、过磷酸钙32.5kg、氯化钾55.8kg。

化肥氮钾优化施用及紫云英、秸秆协同还田下的双季稻生产效益

为探讨双季稻化肥氮钾减施技术及效果,通过田间小区试验,研究了双季稻化肥氮钾优化施用及紫云英、秸秆协同还田集成技术对双季稻产量、肥料利用效率、齐穗期剑叶叶片净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)、叶绿素含量(SPAD值)及晚稻收获期土壤理化性质的影响。结果表明:化肥氮钾优化施用及紫云英、秸秆协同还田集成技术能增强双季稻的光合效率,提高水稻产量,增强土壤生物活性,且以T4处理(紫云英和秸秆还田替代30%化肥氮)的水稻产量、肥料利用效率和净光合速率最高,土壤生物活性最强;与常规施肥处理T2相比,T4处理的2季稻谷总产量增加4.1%,其中早稻和晚稻分别增产6.3%和2.4%,齐穗期剑叶叶片Pn、Gs及SPAD值明显提高,土壤活性有机碳含量和氮碱解氮、有效磷、速效钾含量明显增加。

论砂姜黑土的磷肥效应与优化施用技术

砂姜黑土是黄淮海平原的主要低产土壤之一.在该地区磷肥(P_2O_5) 的适宜用量为每亩4—5公斤,氮磷比值为1—2.小麦氮、磷肥配合的经济最佳施用量N为6.88公斤/亩,P_2O_5为4.25公斤/亩.磷肥在砂姜黑土中的固定强度不大.磷肥的有效施用方法为全部撒施掩底或大部分掩底和少量用作种肥.

优化施肥下华北冬小麦／夏玉米轮作体系农田反硝化损失与N2O排放特征

在田间条件下,应用乙炔抑制-原状土柱培养法测定优化施肥下华北冬小麦/夏玉米轮作体系土壤反硝化和N_2O的排放特征。研究表明:冬小麦和夏玉米整个生育期反硝化速率和N_2O排放通量均表现出明显的季节性变化,且均与土壤水分和无机氮浓度呈显著正相关。小麦季和玉米季的反硝化损失量及N_2O排放量均表现出随施肥量的降低而降低,夏玉米季的反硝化损失量和N_2O排放量均高于小麦季。小麦季的反硝化损失量和N_2O排放量习惯施肥处理是氮肥减量后移处理的1.62和1.67倍,玉米季分别为2.01和2.00倍。氮肥减量后移可能是通过改变土壤无机氮浓度而降低反硝化损失量和N_2O排放量。

氮肥总量控制对大白菜产量影响初探

根据大白菜对氮的要求敏感性，优化大白菜氮肥适宜用量，采用优化施氮量，测定氮的增产效果。结果表明，优化氮区处理亩产达6779.98～6974.52kg ，同无氮区相比，增产率达8.03％～11.13％，达到了预期产量目标。

Production Benefits of Double-Cropping Rice Under Optimized Application of Nitrogen and Potassium Fertilizers Combined with Chinese Milk Vetch and Straw Co-Returning to Fields

In order to explore the technology and effects of reducing nitrogen and potassium fertilizer applications in double-cropping rice,a field plot experiment was conducted to study the effects of optimized application of nitrogen and potassium fertilizers combined with returning Chinese milk vetch and straw to fields on yield,fertilizer utilization efficiency,net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO_(2) concentration(Ci),chlorophyll content(SPAD value)and soil physical and chemical properties in late rice harvest period.The results showed that the optimized application of nitrogen and potassium fertilizers combined with the integrated technology of Chinese milk vetch and straw co-returning to the field could enhance the photosynthetic efficiency of double-cropping rice,increase rice yield,and enhance soil biological activity,especially T4 treatment involving the returning of Chinese milk vetch and straw to the field instead of 30%nitrogen fertilizer achieved the highest rice yield,fertilizer use efficiency,net photosynthetic rate and soil biological activity.Compared with the conventional fertilization treatment T2,the total rice yield of T4 treatment increased by 4.1%,among which the early rice and late rice increased by 6.3%and 2.4%,respectively;Pn,Gs and SPAD values of flag leaves at full heading stage significantly increased,and the contents of soil active organic carbon,alkali hydrolyzed nitrogen,available phosphorus and readily available potassium significantly increased.

Joint Power Allocation and Mode Selection for D2D Communications with Imperfect CSI

Device-to-device(D2D) communications can be underlaid with a cellular infrastructure to increase resource utilization, improve user throughput and save battery energy. In such networks, power allocation and mode selection are crucial problems. To address the joint optimization of power and mode selection under imperfect CSI, we propose an optimal, energy-aware joint power allocation and mode selection(JPAMS) scheme. First, we derive the closed-form solution for the power minimization for both D2 D and cellular links while satisfying different quality of service(Qo S) constraints. Second, we address the mode selection problem in presence of imperfect CSI, based on the derived power allocation. Moreover, the theoretical analysis and simulation results are presented to evaluate the proposed scheme for the D2 D communications.

Study on optimization of underlying coal bed exploited depth for tunnel

Combined with highway construction, the analysis on the relationship betweentunnel construction and coal resource exploitation was processed, which was based onthe research of rational exploitation depth of coal.3D FEM numerical analysis for tunnelexcavation was carried out according to engineering geological features of coal measurestrata in the project area.Based on the analysis of displacement and stress of the surroundingrock in the tunnel after excavation, the characteristics for displacement andstress of the tunnel support structure were analyzed when the underlying coal bed wasexploited with sublevel and full caving method.In addition, combined with the related codeand standard, the economic and safe prohibiting exploited depth of the underlying coalbed was proposed, so that a scientific basis for tunnel construction of coal measure strataand reasonable exploitation of the mineral resources in complex geological conditions canbe offered.

Steady State Simulation of a Novel Process for the Co-production of Vinyl Acetate and Acetic Acid

A new process for the co-production of vinyl acetate monomer and acetic acid from ethane feedstock was studied. Various configurations were proposed and simulation results were given for each case to optimize process variables. This new process offers an overall yield values above 70% with minimum separation steps involved and the possibility of utilities integration. The process does not involve any CO production, thus becoming environmentally more favorable. The initial capital investment of the proposed process is much lower compared to the conventional route.