基于15N质量平衡法研究养殖消化废水中氨氮的去除机理

为避免养猪场消化废水对环境造成的污染,利用微藻去除消化废水中营养物质的二次处理方法受到了广泛关注。采用¹⁵N质量平衡法研究了鞘藻去除氨氮的主要机理,重点研究了鞘藻生长与氨氮去除的关系以及氨氮去除的主要途径。经高压灭菌后的消化废水在鞘藻培养期的氨氮去除率为96.2%,鞘藻特定生长率为0.04~0.15;稀释后的原消化废水氨氮的去除率为94.1%,鞘藻特定生长率为-0.14~0.13。通过曝气的汽提效应对氨的去除有显著的促进作用,尤其在高pH值试验条件下更有利于脱氨。¹⁵N同位素质量平衡分析表明,原始消化废水中存在的细菌对氨氮的去除影响小,在鞘藻培养期去除原消化废水中氨氮的主要途径是鞘藻的吸收和气体的损失,分别占总氮量的40.97%和32.59%。氨氮的去除与主要影响因素间的回归和通径分析表明,要提高氨氮去除率,需要提高鞘藻Chl-a含量和DO浓度,同时限制或保持pH值在弱碱性状态。     

WiNoC中基于Edge first算法的流量平衡设计

在无线片上网络中,无线节点拥塞以及不同子网和全局网络内的流量平衡情况对整个片上网络的通信效率有着重要的影响,为此提出了基于Edge first算法的全局流量平衡机制（GTB）。首先优化了划分有线无线数据包的机制,减少了无线节点处的拥塞;其次根据无线路由器（WR）的拥塞情况,提出Edge first路由算法平衡子网内的流量;最后在全局网络中提出了全局子网拥塞感知（GSCA）判断机制,使得长距离数据包优先从低拥塞子网通过,平衡了全局网络的流量。实验表明,该方案在可接受的硬件开销、功耗开销下,保证较低的网络延迟和较高的网络吞吐率,并且大幅的提升了网络的流量平衡性能。     

Contrasting Rootstock-Mediated Growth and Yield Responses in Salinized Pepper Plants (Capsicum annuum L.) Are Associated with Changes in the Hormonal Balance

Salinity provokes an imbalance of vegetative to generative growth, thus impairing crop productivity. Unlike breeding strategies, grafting is a direct and quick alternative to improve salinity tolerance in horticultural crops, through rebalancing plant development. Providing that hormones play a key role in plant growth and development and stress responses, we hypothesized that rootstock-mediated reallocation of vegetative growth and yield under salinity was associated with changes in the hormonal balance. To test this hypothesis, the hybrid pepper variety (Capsicum annuum L. “Gacela F1”) was either non-grafted or grafted onto three commercial rootstocks (Creonte, Atlante, and Terrano) and plants were grown in a greenhouse under control (0 mM NaCl) and moderate salinity (35 mM NaCl) conditions. Differential vegetative growth versus fruit yield responses were induced by rootstock and salinity. Atlante strongly increased shoot and root fresh weight with respect to the non-grafted Gacela plants associated with improved photosynthetic rate and K⁺ homeostasis under salinity. The invigorating effect of Atlante can be explained by an efficient balance between cytokinins (CKs) and abscisic acid (ABA). Creonte improved fruit yield and maintained the reproductive to vegetative ratio under salinity as a consequence of its capacity to induce biomass reallocation and to avoid Na⁺ accumulation in the shoot. The physiological responses associated with yield stability in Creonte were mediated by the inverse regulation of CKs and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid. Finally, Terrano limited the accumulation of gibberellins in the shoot thus reducing plant height. Despite scion compactness induced by Terrano, both vegetative and reproductive biomass were maintained under salinity through ABA-mediated control of water relations and K⁺ homeostasis. Our data demonstrate that the contrasting developmental and physiological responses induced by the rootstock genotype in salinized pepper plants were critically mediated by hormones. This will be particularly important for rootstock breeding programs to improve salinity tolerance by focusing on hormonal traits.     

基于SiC器件的三电平半桥单电感均压电路

针对辅助变流器中充电机输入端支撑电容电压不均衡导致变压器出现磁饱和的问题,研究一种基于Si C MOSFET器件的单电感均压电路。对单电感均压电路的4种工作模态进行分析,通过两个开关管的互补导通,利用电感实现能量在支撑电容之间的重新分配,可实现支撑电容电压的均衡。对单电感均压电路的3种典型开关状态类型进行分析,并根据其开关状态类型计算单电感均压电路电感选取范围。仿真和小功率实验结果表明单电感均压电路具有较强的均压能力。     

Stereocomplex Crystallization Induced Significant Improvement in Transparency and Stiffness–Toughness Performance of Core-Shell Rubber Nanoparticles Toughened Poly(l-lactide) Blends

Toughening modification of poly(l -lactide) (PLLA) with rubber particles is often realized at the cost of transparency, mechanical strength, and modulus because high rubber loadings are generally required for toughening. In this work, a promising strategy to simultaneously improve the transparency and stiffness–toughness performance of poly(butyl acrylate)-poly(methyl methacrylate) (BAMMA) core-shell rubber nanoparticles toughened PLLA blends by utilizing the stereocomplex (SC) crystallization between PLLA and poly(d -lactide) (PDLA) is devised. The results reveal that the construction of SC crystallites in PLLA matrix via melt-mixing PLLA/BAMMA blends with PDLA can prevent BAMMA nanoparticles from aggregation and promote them to form network-like structure at lower contents. As a result, not only higher toughening efficiency with less rubber contents but also superior transparency is achieved in the PLLA/PDLA/BAMMA blends as compared with the PLLA/BAMMA ones where large aggregated BAMMA clusters are formed. Moreover, the outstanding reinforcement of SC crystallites network for PLLA can impart an enhanced tensile strength and modulus to PLLA/PDLA/BAMMA blends, thus improving the stiffness–toughness performance of PLLA/PDLA/BAMMA blends to a higher degree. This work demonstrates that SC crystallization is a promising solution to solve the contradiction between transparency and mechanical properties and then obtain superior comprehensive performances in rubber toughened PLLA blends.     

新钢基于多元数据采集的电弧炉炼钢过程能量监控系统

电弧炉炼钢过程中能量多元且复杂,采用单一的数据采集方式不能满足对电弧炉炼钢过程各工序能量构成分析要求。通过多元数据采集方式,准确采集电弧炉炼钢过程各工序实际生产数据,并使用Visual Studio 2013、Microsoft SQL Server 2012数据库等软件建立电弧炉炼钢过程能量监控系统。该系统通过实时动态采集到的电弧炉炼钢过程各项冶炼数据,量化电弧炉炼钢过程各工序能量,实现电弧炉炼钢过程能量监控;对电弧炉炼钢过程各工序能量消耗、能量流动、能量利用等方面进行分析,为电弧炉生产过程能量高效利用提供理论依据。     

余热利用供热系统蒸汽负荷平衡调节方案选择

阐述了在余热利用区域的供热系统中 ,蒸汽负荷平衡调节的措施、特点及方案选择。通过工程方案选择的实例 ,指出调节好余热源设备生产出的蒸汽平衡 ,与余热利用同等重要。     

Sn-Ag-Cu-Ce无铅钎料合金体系的热力学计算及预测

利用周模型对Sn—Ag—Cu—Ce无铅钎料合金体系进行了热力学计算预测。热力学计算结果表明，Ag、Cu含量(质量分数)分别为0．5％-4．5％时，当Ce的含量(质量分数)超过0．05％时，体系达到化学平衡状态；当Ce的含量(质量分数)达到0．6％左右时，Sn、Ag、Cu分别都出现了“等活度系数”现象。这一研究结果可为无铅钎料合金的成分设计提供理论指导。     

Phosphorus content in soil, uptake by plants and balance in three European long-term field experiments

The fate of phosphorus (P) derived from mineral fertilisers and organic manures, and the effective P balance, have been assessed in three long-term field experiments at Rothamsted (UK), Bad Lauchstaedt (Germany) and Skierniewice (Poland). This paper discusses the plant availability, uptake and overall utilisation of P over the last 30 years, based on soil test P availability indices and crop analyses determined by the standard methods used in each of the three countries. The data suggest that differences in soil type significantly influence the dynamics of P at the three locations, but most significantly between a loess Chernozem at Bad Lauchstaedt with a high organic matter content and the soils at the other two locations which have a low organic matter content. The application of P either as inorganic fertiliser or organic manure had a considerable influence on the availablity, uptake, leaching or fixing of P, but the crop recovery rate of P from mineral fertiliser did not exceed 35% with the smallest recovery (average 18%) occurring in the soil with the highest clay content at Rothamsted. At Bad Lauchstaedt and Rothamsted the most efficient utilisation of P (averages of 47% and 37%, respectively) was from soils treated with farmyard manure (FYM), with the greater quantity of P either leached or fixed (8 and 25 kg ha^-1 y^-1, respectively) occurring in soils treated with superphosphate. At Skierniewice, however, the reverse was true. Overall, the most efficient crop utilisation from mineral P (30% average) was from the loamy sand at Skierniewice. P balances for the three locations show that quantitatively, for the same P input, the amount of P either leached from or fixed in the plough layer of Broadbalk field, Rothamsted, was 2–3 times greater than at Skierniewice and 3–6 times greater than at Bad Lauchstaedt. The results suggest that differences in the soil physico-chemical properties, climate, the availability of other major nutrients, and the form in which P is applied, all influence the effectiveness of P fertilisation and P balance. The investigation highlights the importance of maintaining long-term field experiments and archived soil and crop samples on a world-wide basis for understanding nutrient cycling and fertility dynamics.     

MES在聚氯乙烯生产中的应用

介绍了MES在聚氯乙烯生产中乙炔站、氯乙烯、聚合各工序的生产平衡、实时参数及关联参数优化、辅助材料的核算等应用情况。