气相色谱内标法测定发酵产物中2,3-丁二醇的含量

建立了一种发酵产物中2,3-丁二醇的气相色谱定量分析方法。以乙醇为内标物,采用火焰离子化检测器进行检测。2,3-丁二醇的加标回收率在97.70%～101.25%之间,相对标准偏差在0.67%～0.98%之间。该分析方法快速准确,是一种较为理想的定量分析方法。     

计及风偏和地面倾角的线路绕击耐雷性能研究

详细地介绍了计及风偏和地面倾角的电气几何模型(EGM)法原理和有关公式,并以某500 kV输电线路为模型,计算不同大小风速、地面倾角和杆塔保护角对线路绕击跳闸率的影响。最后就输电线路防雷提出加强绝缘设计,采用V型绝缘子串,减小杆塔保护角等措施来降低线路绕击跳闸率。     

光卤石分解过程中K,Na,Mg变化及对分解转化的影响探讨

光卤石在分解过程中,氯化钠在最初低镁的溶液中溶解很快,但随着分解过程的进行,由于镁的溶解速率快速的增加,从而使溶液中氯化钠的饱和度增大,最终使先前溶解的氯化钠重新的结晶析出,这对氯化钾从溶液中结晶析出和后续氯化钾的浮选产生影响。通过相化学,分析了光卤石分解过程中K,Na,Mg变化规律,探讨了氯化钠、氯化镁、洗涤液等对光卤石分解转化的影响。     

硫酸镁热解制氧化镁工艺初探

考察了不同还原介质在不同情性保护气体下由无水奠酸镁高温煅烧制取氧化镁的工艺条件及过程,确定了最优反应条件及还原介质,无水硫酸镁转化率达到90%.     

甲亚胺-H酸分光光度法测定岩盐中总硼

沸水溶解岩盐样品,过滤除去水不溶物,分取部分滤液在pH值5．2～5．6乙酸铵缓冲液中,硼可与甲亚胺-H酸生成可溶性的棕黄色络合物,吸光度与硼的浓度成正比。其标准回收率为94．9％～102．4％,相对标准偏差为0．79％～1．26％（RSD,N=5）。建立的分析方法准确度、灵敏度、精密度高,方法简便、快速,适用于各类岩盐中总硼含量的分析研究。     

Development and Application of On-line Wind Power RiskAssessment System

Because of the large-scale integration of wind power,the dynamic characteristics of power system have many uncertain effects.Based on deterministic analysis methods,traditional on-line security assessment system cannot quantitatively estimate the actual operating conditions of the power system for only considering the most serious and credible accidents.Therefore,the risk theory is introduced into an on-line security assessment system and then an on-line risk assessment system for wind power is designed and implemented by combining with the dynamic security assessment system.Based on multiple data integration,the wind power disturbance probability is available and the security assessment of the power grid can obtain security indices in different aspects.The operating risk index is an expectation of severity,computed by summing up all the products of the result probability and its severity.Analysis results are reported to the dispatchers in on-line environment,while the comprehensive weak links are automatically provided to the power dispatching center.The risk assessment system in operation can verify the reasonableness of the system.     

两部制水电上网电价的计算方法

水电如何进入市场参与竞价,是当前和今后一段时间电力市场改革必须面临的重要课题之一。该文根据水电站本身的直接财务效益和费用,对电力系统进行随机生产模拟,并以随机生产模拟为基础进行电能成本分析,制定水电上网电价定价计算方法,并构建两部制定价模型,最后通过实例,验证所建模型是可行的。     

碳酸锂在碳酸钠溶液中的溶解度与热力学

采用等温溶解平衡法开展碳酸锂在碳酸钠溶液中(278.15～358.15 K)的溶解平衡实验研究,测定平衡体系碳酸锂溶解度和平衡溶液密度,利用E-DH方程对碳酸锂溶解度实验数据进行关联,标准偏差小于0.01;利用Connaughton方程对液相密度数据进行关联,标准偏差小于2×10^-3。实验和计算研究结果表明：在同离子和盐效应协同影响下,碳酸锂在Na₂CO₃-H₂O体系中溶解度随碳酸钠浓度增加先降低后降低趋势变缓,在278.15～358.15 K温度范围内,溶解度转变折点为碳酸钠浓度约为0.1 mol·kg^-1;通过溶解热力学计算,得到碳酸锂在碳酸钠中的溶解焓变(ΔH_d)、熵变(ΔS_d)和Gibbs自由能变(ΔG_d),结果表明溶解过程为放热、熵减的非自发过程,溶解焓变和熵变随着碳酸钠浓度增加而增加,Gibbs自由能变在0.6 mol·kg^-1出现最大值,且溶解过程为熵控制过程。研究结果将为卤水提锂碳化沉锂过程设计提供基础数据。     

东台吉乃尔盐湖夏季卤水变温蒸发实验研究

针对柴达木盆地东台吉乃尔盐湖夏季卤水组成,在实验室进行了卤水冷冻、分阶段连续变温蒸发实验,揭示了卤水冷冻、多温蒸发结晶路线和析盐规律。实验结果表明:夏季盐湖卤水蒸发析盐过程依次为芒硝、水石盐、氯化钠、氯化钾、七水硫酸镁、六水硫酸镁、光卤石、水氯镁石和锂盐(硼酸盐随卤水蒸发不以固体形式析出,富存于老卤中),并将分阶段析盐序列绘制在相应的介稳相图上,实验结果与介稳相图基本吻合。     

A novel synthesis method for manganese ferrite nanopowders: The effect of manganese salt as inorganic additive in electrosynthesis cell

Manganese ferrite nanoparticles were electro-crystallized in an electrochemical cell containing two iron electrodes, and an electrolyte solution of sodium sulfate, sodium butanoate, and manganese sulfate hydrate. The samples were characterized by X-ray diffraction, electron microscopy, magnetometry, and Mössbauer spectroscopy methods. The crystal structure of the samples was studied using X-ray diffraction. Based on obtained results we found that the manganese ferrite nanoparticles are formed in the electrochemical cell containing 0.001 M manganese sulfate hydrate. Also, the formation of a paramagnetic secondary phase in the sample without manganese is suppressed by adding manganese salt in the electrochemical cell. The nanoparticle size, shape, and morphology were characterized using electron microscopy. Magnetization curves show that all samples are magnetically soft and their specific magnetization ranges from 15 A m² kg⁻¹ to 75 A m² kg⁻¹, depending on the growth conditions. Room temperature Mössbauer spectra confirm the formation of nonstoichiometric spinel ferrite of magnetite or manganese ferrite, again depending on the growth conditions. Based on Mössbauer analysis, reduction in the population of octahedral sites provides direct evidence for the presence of the manganese ions substitution in the octahedral sites.