Prevention of substrate and product inhibitions by using a dilution strategy during dark fermentative hydrogen production from molasses

Substrate and product inhibitions have a significant effect on dark fermentative hydrogen gas production. Particularly, rapid formation of volatile fatty acids leads to fast pH decreases shifting the metabolic pathway. Therefore, controlling volatile fatty acid accumulation has great importance in maintaining effective hydrogen production. In this context, a dilution strategy was applied to regulate volatile fatty acids levels within the desired concentration range. A three-factor Box-Behnken statistical experiment design was established to assess the effects of dilution time, dilution percentage and initial COD concentration on hydrogen formation yield and rate. Highest hydrogen yield (7.7 mL H₂/mL_reactor) and rate (21. 47 mL H₂/h or 9.38 mmol/L_reactor.h) were achieved when 85 gCOD/L containing fermentation media was diluted with a percentage of 130 of the initial working volume at the 3rd hour of the fermentation period. Moreover, this strategy enabled to start fermentation with 55 g glucose/L.     

应用低贫化放矿的可行性浅析

鉴于鲁中冶金矿山公司现行截止品位放矿方式中存在贫化率较大的问题，提出采用提高截止品位的低贫化放矿方式，通过技术经济指标的分析计算，认为低贫化放矿技术上可行，经济上合理，在现场易于实现，具有应用价值。     

有底柱阶段崩落法的两步骤放矿研究

通过对有底柱阶段崩落法５种放矿方案的分析研究，提出能改善现场放矿指标的两步骤放矿的放矿方案。该方案工艺简单，操作性强，管理方便，已在弓长岭井下铁矿的生产实践中得到应用。取得较好的效果。     

有底柱分段崩落法在生产应用中的若干改进

针对倾斜中厚矿体应用有底柱分段崩落法出现矿石贫化损失指标较大的问题，进行了室内放矿试验，将试验指标与生产指标对比分析之后，提出了若干改进采矿工艺结构参数的措施。     

无底柱分段崩落法出矿贫化程度与矿石回收关系的研究

本文在实验基础上分析了无底柱分段崩落法出矿贫化程度与矿石回收的关系，得出了放矿正常后，采用不同贫化程度出矿，分段矿石回收率趋于一致的结论。研究表明，造成无底柱分段崩落法来出矿石贫比大的根本原因在于采用了不合理的截止品位放矿方式，无贫化放矿是无底柱分段崩落法最为理想的放矿方式。     

黑索今在丙酮-水混合溶剂中介稳区的测定及关联

采用溶析结晶法测定了黑索今在纯丙酮以及丙酮与水混合溶剂中的溶解度与超溶解度,得到了黑索今结晶介稳区。用Apelblat经验方程模拟了黑索今在纯丙酮中溶解特性,用（CNIBS）/Redlich-Kister方程模拟了黑索今在丙酮和水体系中溶解特性,模拟精度均在99%以上。     

FEM modeling and experimental verification for dilution control in laser cladding

A model for the determination of the clad geometry and dilution in laser cladding is presented. The model uses a novel approach to determine the clad geometry. This involves a mathematical transformation of the balance equations describing the physical effects. The correlation between observable melt pool characteristics and dilution is investigated using this model. Simulations were performed for different combinations of cladding speed, laser power (distribution) and substrate temperature. Simulation results are compared to experimental results, showing a high degree of agreement. A high correlation between melt pool width and dilution was found, which was almost independent of the process settings and substrate temperature. This makes the width an excellent sensor for online dilution control.     

卫星导航系统基四选星算法

随着卫星导航系统的发展,可见星数大大增多,为了减少接收机运算量,需选择可见卫星的一个子类。本文分析了卫星导航系统中N个4星最优分布与某4星最优分布中的k(k≤3)个卫星(共4N+k颗卫星)的联合分布GDOP值,并以此为基础提出了一类低复杂度近似最优的基四选星算法。该算法以经典的4星选择算法(最大体积法和四步选择法)为基础,通过多次迭代与部分执行,实现任意多于4星的卫星选择。仿真结果表明该算法与准优算法相比运算复杂度和GDOP值都更低。     

面向区域的GEO红外预警卫星部署研究

面向区域的地球同步轨道(GEO)红外预警卫星能为特定区域反导作战提供及时可靠的预警信息,想定了预警区域的经纬度范围,提出以空域覆盖性能和定位精度为性能准则部署GEO预警卫星。首先基于GEO卫星对地覆盖模型建立了卫星空域覆盖性能模型;然后分析GEO卫星与特定预警区域的空间几何关系,以几何精度衰减因子(GDOP)为定位精度衡量指标,建立了GEO星座对预警区域的定位精度模型;最后通过仿真综合分析了不同卫星部署方式对空域覆盖性能和定位精度的影响,给出了面向区域的GEO红外预警卫星部署的指导性结论。     

Experimental investigation of the effects of separate hydrogen and nitrogen addition on the emissions and combustion of a diesel engine

An experimental investigation of the effects of separate hydrogen and nitrogen addition on the emissions and combustion of a diesel engine was performed and the results are presented in the current paper.