Short-Term Scheduling of Combined Cycle Units Using Mixed Integer Linear Programming Solution

Combined cycle plants (CCs) are broadly used all over the world. The inclusion of CCs into the optimal resource scheduling causes difficulties because they can be operated in different operating configuration modes based on the number of combustion and steam turbines. In this paper a model CCs based on a mixed integer linear programming approach to be included into an optimal short term resource optimization problem is presented. The proposed method allows modeling of CCs in different modes of operation taking into account the non convex operating costs for the different combined cycle mode of operation.

Effect of Combined Microwave-Ultrasonic Pretreatment on Anaerobic Biodegradability of Primary, Excess Activated and Mixed Sludge

This work deals with the effect of combined microwave-ultrasonic pretreatment on the anaerobic biodegradability of primary, excess activated and mixed sludge. The characteristics, biodegradability and anaerobic digester performance for untreated primary, excess activated and mixed sludge were compared to combined microwave-ultrasonic pretreated primary, excess activated and mixed sludge. All sludge samples were subjected to Microwave treatment at 2450 MHz, 800 W and 3 min followed by ultrasonic treatment at a density of 0.4 W/mL, amplitude of 90%, Intensity of 150 W, pulse of 55/5 for 6min. Methane production in pretreated primary sludge was significantly greater (11.9 ml/g TCOD) than the methane yield of the untreated primary sludge (7.9 ml/g TCOD). Cumulative methane production of pretreated Excess Activated Sludge (EAS) was higher (66.5 ml/g TCOD) than the methane yield from pretreated mixed sludge (44.1 ml/g TCOD). Furthermore, digested EAS showed significantly higher dewaterability (201 s) than digested primary sludge (305 s) or mixed sludge (522 s). The average Methane: Carbondioxide ratio from EAS (1.85) was higher than that for mixed untreated sludge (1.24). VS reduction was also higher for EAS than the other two sludge types. However, pretreatment of EAS resulted in significant reduction in dewaterability due to higher percentage of fine floc particles in the pretreated EAS.

RP/SP融合数据的Mixed Logit和Nested Logit模型估计对比

分析了RP/SP(revealed preference/stated preference)融合数据对交通行为研究的重要性,通过实际调查的RP/SP融合数据,对比了用Mixed Logit和Nested Logit模型的估计结果.得出了以下结论:RP/SP融合数据中,有时同类型交通方式的关联性要比RP和SP数据之间的关联性强,应用不同的Nested Logit模型分层方法进行估计对比;Mixed Logit考虑了个体的异质性,假定参数为随机分布,同时体现了RP/SP数据的关联性和同类型交通方式的关联性,能够得到更好的参数估计结果;Mixed Logit模型能更现实地反映不同交通方式使用者对时间和费用敏感性的不同(时间价值的不同),体现小汽车使用者比公共交通使用者具有更高时间价值的现实情况.

Women with overweight, mixed hyperlipidemia, intolerance to glucose and diastolic hypertension

Primarily healthy women who attended a practice of General Medicine were examined and coded data were evaluated using two statistical methods (n = 248, aged 36 ± 14 years). It was found that participants with LDL-related (mixed) hyperlipidemia showed higher blood pressure, a higher proportion of alcohol problems and/or smoking compared to normolipidemic women (p ≤ 0.05). These hyperlipidemic women who reported alcohol problems and/or smoking more often showed proteinuria and/or hematuria, rise of LDL/HDL, critical fasting blood glucose and lower HDL-cholesterol compared to hyperlipidemic women reporting healthy lifestyle (p ≤ 0.05). Likewise, high triglycerides were associated with rise of blood pressure and intolerance to glucose (p ≤ 0.05) and also with elevated total cholesterol. Alcohol-related hypertriglyceridemia overlapped with diastolic hypertension, rise of body weight and urine pathology, lowering of HDL-cholesterol and critical fasting blood glucose. The motivating message was that women with mixed hyperlipidemia and healthy lifestyle had functionally renal endothelium and healthy HDL-related baseline measures. Altogether, LDL-related hyperlipidemia and/or high triglycerides were correlated with diastolic hypertension whereby critical alcohol consumption declined renal endothelium and lowered HDL-cholesterol implicating baseline strategies to neutralize early risk factors.

基于Mixed Erlang-Pareto组合分布的巨灾风险评估——以中国地震灾害为例

巨灾损失数据具有尖峰厚尾的特征,通常的损失分布模型很难对其进行有效地拟合。针对常见的各类分布(如Gamma,Lognormal,Weibull)和POT-GPD损失分布对巨灾风险损失数据拟合的不足,将截断形式的Mixed Erlang分布与Pareto分布进行组合,构建组合分布模型,充分应用了Mixed Erlang分布对阈值之前损失数据拟合分布形式的灵活性和精确性,以及Pareto分布对阈值之后尾部损失数据拟合的优良性,从而与以往方法相比,能够从整体上更精确地拟合巨灾风险损失数据。在此基础上,对中国1990—2018年4.5级以上地震所造成的直接经济损失数据进行组合分布建模,探讨该组合分布在VaR、TVaR和地震巨灾保险定价等方面的具体应用。研究发现:构建的Mixed Erlang-Pareto组合分布可以较好地拟合地震巨灾风险损失数据,且拟合优度高于Mixed Erlang-GDP组合分布;在忽略其他因素影响下,假定参保率为30%时,应用Mixed Erlang-Pareto分布计算的地震巨灾保险人均纯保费为40~43元左右,和四川省宜宾市城乡居民住宅地震巨灾保险保费相近,说明该地震巨灾保险保费的确定存在一定合理性。此外,对Mixed Erlang-Pareto组合分布拟合优度进一步检验,得出该组合分布也可以较好地拟合洪水损失数据,进一步表明该组合分布对巨灾损失数据拟合的优良性和适用性。本研究可以为巨灾损失风险评估提供一种新的备选模型,也可以作为评估巨灾保险定价机制合理与否的精算依据。

Some Inequalities for L_p-mixed Affine Surface Area

In this paper, the concepts of the ith L;-mixed affine surface area and Lp-polar curvature images are introduced, some new inequalities connecting these new notions with Lρ-centroid bodies and ρ-Blaschke bodies are showed. Moreover, a Blaschke-Santalo type inequality for Lρ-mixed affine surface area is established. Our results also imply the similar to the inequalities for Marcus-Lopes, Bergstrom and Ky Fan.

Prediction of a maximum pull-out load of anchor bolts using an optimal combination model

The mixed model of improved exponential and power function and unequal interval gray GM(1,1)model have poor accuracy in predicting the maximum pull-out load of anchor bolts.An optimal combination model was derived using the optimally weighted combination theory and the minimum sum of logarithmic squared errors as the objective function.Two typical anchor bolt pull-out engineering cases were selected to compare the performance of the proposed model with those of existing ones.Results showed that the optimal combination model was suitable not only for the slow P-s curve but also for the steep P-s curve.Its accuracy and stable reliability,as well as its prediction capability classification,were better than those of the other prediction models.Therefore,the optimal combination model is an effective processing method for predicting the maximum pull-out load of anchor bolts according to measured data.

Identification of Probable Type of Bituminous Mix Depending on Higher Combined Index of Stone Aggregates

The stone aggregates constitute over 90% of the mass of a pavement and hence its properties play a very vital role in design of satisfactory unbound as well as bituminous mixes. Also since the aggregates availability is continuously becoming scarce, attempts have to be made to identify use of some marginal as well as inferior aggregates without sacrificing the desirable qualities of resulting mixes. One of the most important properties therefore is the combined index of aggregates which deals with aggregates shape and is the sum of flakiness and elongation indices of aggregates measured related to their thickness and length respectively. The Ministry of Road Transport and Highways （MoRTH） specifies an upper limit of 30% combined index for different types of bituminous mixes. In the field, many times the aggregates supplied have combined index of more than 30%. A pre determined mix such as bituminous concrete, dense or semi dense bituminous macadam etc. has to be designed using such aggregates. It may be easy to design the mix but to get the aggregates with desirable combined index is often very difficult. In order to overcome this, in many projects, secondary crushers are used to crush the aggregates for the second time just to bring down the combined index. This obviously increases the project cost. It is quite possible that the aggregates with higher combined index may be suitable for a particular type of mix. It is therefore appropriate to study what type of a bituminous mix can be satisfactorily prepared depending on the availability of aggregates with generally higher values of combined index. Hence, it was attempted to determine the usual Marshall test properties of two most commonly used types of bituminous mixes namely bituminous concrete and dense bituminous macadam using aggregates with combined index 30%, 40% and 50%. It was found that aggregates with higher combined index are more suitable to design dense bituminous macadam mix than bituminous concrete.

高强度混凝土结构施工技术及性能优化

结合工程案例,介绍了高强度混凝土材料的特性表现,从强度提升、收缩变形、抗渗性能、抗裂性能等方面论述了高强度混凝土结构的优化策略,从配合设计、搅拌工艺、浇筑及养护技术等方面探讨了施工技术的改进措施,从而保证高强度混凝土结构的整体性能和施工质量。

Study on the optimization of the combined blown converter process in Chongqing Iron and Steel Company

The effects of lance height and bottom blown flowrate on the mixed time, the splashing amount, the penetrating depth, and the level fluctuation of an 85 t combined blown converter have been studied using a water model. The results show that the maximal stirring energy is provided to the bath at the top lance height of about 50-100 mm. When the top lance height is in the range ofg0- 110 mm, the splashing amount caused by the top jet can reach the maximal value. The appropriate operational parameters of Chongqing Iron and Steel Company （CISC） converter have been established that the top lance height is 1600-1760 mm and the bottom blowing flowrate is 240-480 Nm^3/h in the primary phase of a heat, 1100-1300 mm and 160-200 Nm^3/h in the second phase, and 1040-1120 mm and 200-350 Nm^3/h in the end phase. Also, the trial shows that the metallurgical result of the studied blow pattern is better than that of the former pattern. At the starting 3-4 min of a heat, the strong splashing is eliminated. 2008 University of Science and Technology Beijing. All rights reserved.

Advanced Ramming Mix Based on Fused Zirconia Stabilized by Com-bined Additives of CaO and MgO for Lining of Carbon Black Production Reactor

Fused materials from ZrO2 stabilized by CaO or MgO, or the combined additive consisting of CaO and MgO are made. With using chemical, petrographic, X-ray phase and electron microscopic researches the main characteristics of these materials are determined. It is shown that, the materials of all compositions have low water absorption; they are characterized by equal struc-ture. The materials stabilized by the combined additive consisting of CaO and MgO are presented by generally the cubic phase and a small amount of tetragonal and monoclinic ZrO2 phases. Depending on CaO： MgO ratio in the materials the tetragonal ZrO2 phase settles down in a cubic matrix in the form of separate grains, and sites of net like structure in the form of a ＂woven＂ interlacing （2.9% of CaO and 2. 6% of MgO ）. An influence of the above mentioned fused stabilized ZrO2 materials and quantity of monoclinic zirconia, on the forming of zirconia mix on a phosphate bond and properties of＂ .fired samples is studied. The samples from mix based on ZrO2 stabilized by the combined additive consisting of 2.9% CaO and 2.6% MgO with 20% of monoclinic Zr02 are characterized by the highest properties： after .firing at 1 580 ~C open porosity of 14. 3% - 14. 8%, apparent density of 4. 67 -4. 69 g · cm^-5, cold crushing strength of 62 - 68 MPa, thermal shock resistance （ 1 300℃←→air） of 15 thermal cycles, linear growth of 0. 2%. The manufacturing technology of powders mix-ture for ramming mix based on the new fused material .from ZrO2 stabilized by the combined additive is developed and its production is mastered. From this mixture the large-size, shaped products on the phosphate bond are made at one carbon black production plant, which are installed in the combustion chamber of the carbon black production reactor.

内蒙古半干旱冷凉地区燕麦与箭筈豌豆混播生产性能及营养价值评价

为筛选出适宜内蒙古半干旱冷凉地区燕麦(Avena sativa)与箭筈豌豆(Vicia sativa)最佳混播组合、比例和刈割期,本研究以燕麦‘蒙饲燕1号’(‘Mengsiyan 1’)、‘蒙饲燕2号’(‘Mengsiyan 2’)、‘青引1号’(‘Qing yin1’)分别和箭筈豌豆混播为研究对象,对不同混播组合和比例的饲草在不同刈割期生产性能、营养品质及土壤养分等指标进行测定分析与综合评价。结果表明:1)不同混播能够显著提高箭筈豌豆的株高、鲜重和干重(P <0.05);以燕麦150 kg·hm^(−2)和箭筈豌豆75 kg·hm^(−2)单播量配比的‘蒙饲燕1号’+箭筈豌豆混播(3:1)在乳熟期、‘蒙饲燕2号’+箭筈豌豆混播(1:1)在乳熟末期干草产量最高;‘青引1号’+箭筈豌豆混播在各刈割期干草产量均低于同期燕麦单播产量。2)不同混播处理粗蛋白含量较燕麦单播基本呈增加趋势,粗蛋白含量从抽穗期、乳熟期到乳熟末期逐渐降低;水溶性碳水化合物(WSC)含量均在乳熟末期达到最高;不同混播组合在1:3的比例下酸性洗涤纤维(ADF)和中性洗涤纤维(NDF)含量均最低。3)燕麦与箭筈豌豆混播能够显著提高土壤有机质和速效氮含量。通过隶属函数法对混播饲草产量与营养品质进行综合评价,各混播组合中‘蒙饲燕1号’+箭筈豌豆混播(1:3)、‘蒙饲燕2号’+箭筈豌豆混播(1:1)和‘青引1号’+箭筈豌豆混播(1:3)分别在乳熟末期刈割隶属综合评价值较高,其中‘蒙饲燕1号’+箭筈豌豆混播(1:3)最佳(0.70)。

三江源区适宜的小黑麦和饲用豌豆混播比例及施肥方法

【目的】三江源区地处青藏高原,是中国母亲河的发源地,也是牦牛等典型牲畜的重要草场。探索适宜的施肥方法和牧草作物混播比例,旨在提高牧草产量,减轻生态重要地区天然草场的放牧压力。【方法】于2022年在三江源地区进行了小黑麦和饲用豌豆的田间试验,试验材料为小黑麦品种‘青饲麦1号’和饲用豌豆品种‘青建1号’。设置3个施肥处理:不施肥(A_(1))、单施氮肥(尿素75 kg/hm^(2),A_(2))、氮磷配合施用(尿素75 kg/hm^(2)和过磷酸钙300 kg/hm^(2),A3);每个施肥处理下,分别设小黑麦和豌豆混合播种比例70∶30(B1)、50∶50(B_(2))和30∶70(B_3)。在豌豆盛花期刈割前,调查小黑麦和饲用豌豆株高、叶片形态指标(面积、周长、长度、宽度),及生物量和营养品质。【结果】与不施肥处理A_(1)相比,施肥处理(A_(2)和A_3)显著提高了牧草的鲜重和干重、蛋白质产量以及两种作物的株高和叶面积。A_(2)和A_3处理在上述指标上没有显著差异,但A_3处理叶宽的增幅显著高于A_(2)。A_(2)和A_3处理对两种牧草粗蛋白、可溶性糖、中性和酸性洗涤纤维含量均无显著影响,但A_(2)处理增加了粗脂肪含量。小黑麦和饲用豌豆的播种比例对两种作物的鲜重、干重、蛋白质产量和株高没有显著影响,但降低小黑麦播种比例增加了饲草粗脂肪和可溶性糖含量,显著降低了中性与酸性洗涤纤维含量。播种比例与施肥有显著的交互作用,A_3B_(1)的牧草鲜重和干重最高,分别比其他处理高36.09%~180.08%和62.27%~281.59%,叶面积和蛋白质、可溶性糖含量也最高。A_3B_(1)处理的小黑麦叶片周长比A_(1)B_(1)、A_(1)B_(2)和A1B3处理分别高15.76%、40.29%和54.51%,饲用豌豆叶面积比A1B1、A1B2和A1B3处理分别提高20.31%、14.06%和64.65%,饲草中性洗涤纤维含量分别比A1B1、A1B2和A1B3处理增加了7.15%、27.14%和17.89%。【结论】氮磷配施可显著提高牧草生产性能、叶片形态和牧草质量。小黑麦和饲用豌豆按70∶30的比例混合播种,牧草生产性能、叶片形态和质量均优于其他处理。因此,在高寒地区,建议推广小黑麦和饲用豌豆按70∶30的比例混合播种,并配施氮、磷肥。

考虑多能耦合共享储能的微网多智能体混合博弈协调优化

冷热电耦合的共享储能可以更显著地提高微网多种能源的利用效率与消纳水平。然而,多能耦合的共享储能进一步增加了多微网之间协调运行的难度,故而提出了一种考虑多能耦合共享储能的微网多智能体混合博弈协调优化模型。首先,围绕多能耦合共享储能进行建模,从冷、热、电3个维度构建元件的运行模型。其次,提出了一种计及多能耦合共享储能协作的微网混合博弈双层协调调度模型。上层部分为基于主从博弈的微网运营商日内电价优化模型,以微网运营商的日内收益最大化为目标,综合考虑电价上下限约束和购售电价平均值约束,为下层协作运行提供响应电价;下层部分为基于合作博弈的微网间协作运行策略模型,以产消者和共享储能电站的合作成本为目标,综合考虑机组出力上下限约束和功率平衡约束,为上层反馈合作成本用于指导电价优化调整。然后,在混合博弈模型求解时,以电价变动率为收敛判据,同时采用二分法处理电价约束以加速模型求解。最后,采用多智能体协调优化的微网系统验证了所提方法的有效性。

不同豆禾混播组合在帕米尔高原牧区产草量和营养品质的比较

试验旨在探究豆禾牧草混播组合在帕米尔高原牧区的产草量和营养品质,开展了以箭筈豌豆(Vicia sativa)分别和燕麦(Avena sativa)、小黑麦(Triticale)及黑麦(Secale)的混播组合研究。试验设置单播边锋255 kg/hm^(2)(B-D)、凯速255 kg/hm^(2)(K-D)、速捷255 kg/hm^(2)(S-D)、捷达冬牧70 255 kg/hm^(2)(J-D)、陇箭2号150 kg/hm^(2)(L-D)为对照,混播边锋210 kg/hm^(2)+陇箭2号120 kg/hm^(2)(BL-H)、凯速210 kg/hm^(2)+陇箭2号120 kg/hm^(2)(KL-H)、速捷210 kg/hm^(2)+陇箭2号120 kg/hm^(2)(SL-H)、捷达冬牧70 210 kg/hm^(2)+陇箭2号120 kg/hm^(2)(JL-H)为处理组,试验共9个处理,测定生产性能和营养指标,并运用灰色关联度进行综合评价。结果显示,混播组合中,JL-H总干草产量最高(15.58 t/hm^(2)),极显著高于其他混播组合(P<0.01);SL-H的粗蛋白含量为12.73%,显著高于其他混播组合(P<0.05);混播处理的中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)含量总体低于单播禾草,高于豆草;混播组合中,BL-H的NDF含量和ADF含量最低,分别为56.27%和36.63%。研究表明,SL-H混播组合综合评价值最高(0.218),若兼顾产量和营养品质,SL-H混播组合(速捷210 kg/hm^(2)+陇箭2号120 kg/hm^(2))适合在帕米尔高原牧区种植应用。

刚果(金)地区超大型铜钴矿资源选冶工艺研究与实践

非洲铜钴矿床主要分布于赞比亚—刚果(金)铜矿带,具有储量大、品位高、矿石性质复杂等特点,这些铜钴矿石按氧化程度与脉石矿物的特性差异,可分为原生硫化铜钴矿石、低钙混合铜钴矿石、高钙混合铜钴矿石、低钙氧化铜钴矿石和高钙氧化铜钴矿石,指出应根据矿石氧化率、脉石矿物的类型(对于碱性脉石矿物必须关注Ca、Mg含量)、矿石中铜钴矿物的赋存状态、金属回收率及加工成本等因素确定其开发利用工艺,并列举了这5类代表性矿石的生产工艺及生产指标。概括说,除低钙氧化铜钴矿石宜采用直接浸出工艺外,其余各类矿石均宜采用选冶联合工艺,但浮选工艺各有特色。研究与生产实践表明,针对不同性质的矿石选用不同的选冶工艺,是获得理想分选指标的关键。

液态空气储能耦合综合能源系统热电联储联供优化配置研究

液态空气储能(LAES)在多能耦合的综合能源系统中极具应用前景,合理的储能容量配置更有利于综合能源系统低碳经济运行,但目前研究未充分考虑LAES热电联储联供强相关的特性和优势。因此,本文提出了一种LAES耦合综合能源系统的热电联储联供优化配置方法,针对综合能源系统的基本架构,构建了各组成单元的热电联储/供调度约束模型,并以设备初始投资成本、设备运维成本、购能成本、弃风弃光成本等为目标函数,考虑了系统能量平衡约束、设备容量约束、设备出力约束、外网交互功率约束以及储能约束,建立了相应的优化配置模型,并基于混合整数线性规划方法进行模型求解。以某实际园区为例,设置了5种场景进行优化结果对比分析,结果表明:考虑LAES热电联储联供特性的综合能源系统能实时有效地满足系统用能需求,同时能实现更好的经济效益和环境效益,相较于传统分供系统,系统总经济成本下降37.1%,实现碳减排71.50%,并在消纳可再生能源和减少弃光弃风方面更具潜力。本研究可为LAES耦合系统热电联储联供优化模型的有效性提供理论依据,有助于推动LAES在综合能源系统中的商业化应用。

磁场强化非均相分离技术的工业应用进展

概述了磁场分离技术在分离多相混合介质中的研究和应用进展,对磁场分离技术的应用原理和分离优势进行了分析。根据混合相内的介质类别,分别针对固、液、气不同应用领域,介绍了磁场分离工艺在矿物精选、污水处理、气体除杂中的典型应用,并分析了相应运行工况下的磁场排布规律和介质分离特性。从组合工艺的研究视角出发,总结了磁场分离技术与气浮分离技术、膜分离技术、旋流分离技术的耦合应用现状,并分析了上述组合工艺的技术特点、运行成效。为拓宽磁场分离技术的适用范围,讨论了磁种在磁场分离工艺中的辅助应用,以强化该技术对无磁性介质的分离。

考虑风电消纳的电热联合系统优化调度模型

电热联合系统能够有效整合电能和热能,具有显著的能源利用优势。为了分析电热联合调度的经济节能效果,在分时电价以及负荷波动的条件下,建立了包含风电场、能源集线器(energy hub,EH)、热泵和蓄热罐的电热联合系统优化调度模型。电热联合系统以日运行成本最小为目标,考虑了稳态电热联合潮流、储能设备动态特性、管道温度降方程等实际约束条件。为提高优化效率,采用方程线性化和分段McCormick凸包络技术处理约束中的非线性项,将原本的非凸优化问题转化为混合整数二次规划(mixed integer quadratic programming,MIQP)问题求解。通过算例分析验证了所提模型的有效性,在4种场景下比较了风电制热以及热网传输损耗对系统日运行成本和弃风量的影响,并确定了风电场接入热网的最佳节点。结果表明,电热联合系统能够将不稳定的风能转化为稳定的热能,从而有效提升风电消纳空间和系统经济效益。

基于改进云物元的模拟机协同训练质量评价

为进一步提高飞行员-签派员积极应对复杂真实运行环境风险的能力,提升学员培训质量,基于考虑胜任力培训和评估理念的ADDIE模型,提出了一种基于协同决策的飞行员-签派员协同训练满意度评价体系,并采用基于混合赋权的改进云物元模型进行评估。通过构建混合权重矩阵,计算评价指标间的综合云隶属度,量化评价指标的模糊性和随机性,得出最终的满意度综合评价等级。以某航飞行员-签派员协同训练结果为例进行了实证分析,验证了协同训练满意度评价指标及其评价方法的科学性和适用性,有效克服协同训练效果评价信息主观性和模糊性的不足,为后续飞行员-签派员协同训练方法及其结果评估方法的改进提供了思路和借鉴。