A novel adaptive sampling based methodology for feasible region identification of compute intensive models using artificial neural network

Identification of feasible region of operations in multivariate processes is a problem of interest in several fields. This is particularly challenging when the process model is black-box in nature and/or is computationally expensive, as analytical solutions are not available and the number of possible model evaluations is limited. An efficient methodology is required to identify samples where the model is evaluated for developing a computationally efficient surrogate model. In this work, an artificial neural network based surrogate model is proposed which is integrated with a statistical-based approach (Jack-knifing) to estimate the variance of the surrogate model prediction. This allows implementation of an adaptive sampling approach where new samples are identified close to the feasible region boundary or in regions of high prediction uncertainty. The proposed approach performs better than a previously published kriging based method for different dimensionality case studies.     

Computer Network Assisted Test of Spoken English

With the development of computer network technology, the means of foreign language teaching have changed. Computer aided spoken English test is a new test method, and there is a great advantage compared with the traditional oral test. In order to further understand the superiority of the computer aided spoken English test, this study took the sophomores of Foreign Language Department in Henan University of Chinese Medicine, China, as the subjects and carried out the traditional interview-type spoken English test and computer-assisted spoken English test. The score system based on Hidden Markov Model (HMM) was used, and then the two tests were carried out. The performance in the two tests was compared, and the attitudes of the participants to the computer assisted Spoken English test were analyzed in the form of questionnaires. The results showed that the computer aided spoken English test could better reflect the true level of the students, and the teachers and students clearly stated that the computer aided spoken English test could relieve tension and reduce the burden of teachers. The research verified the feasibility of the computer-assisted spoken English test, which provides a reference for the promotion of the computer-assisted spoken English test.     

西铭矿7号煤层蹬空开采可行性分析

本文针对西铭矿7号煤层蹬空开采可行性的问题,采用理论分析、数值模拟和现场实测等手段,对下部8、9号煤层工作面开采后的顶板覆岩破坏高度进行了研究,通过六种方法的结果对比分析,确定西铭矿7号煤层蹬空区域不可安全开采。     

On the feasibility of on-farm biogas-to-electricity conversion: To what extent is solid oxide fuel cells durability a threat to break even the initial investment?

Despite their promising features, adverse economic feasibility still hamper SOFCs wide implementation and this effect is emphasized as long as the system size is reduced. According to previous investigations, the biogas pre-treatment section represents a burden for the economic viability. Aiming at reducing the extent of installation costs in SOFC-based configurations, biogas partial upgrading through CO₂ gas-separation membranes is put forth as innovative solution against reforming. This innovative system concept is expected to make SOFCs more cost-effective, yet resulting feeding gas might cause a quicker SOFC performance decay. Besides solving this trade-off, the economic viability results strongly sensitive to subsidiary electricity prices in force according to the regulatory framework.This paper presents a comparative economic assessment regarding biogas-to-electricity conversion via Solid Oxide fuel cells (SOFCs) and mature technologies as internal combustion engines (ICEs). Results highlighted that, the innovative SOFC system is far more viable than reforming-based one, exhibiting a reasonable payback time, with an adequate subsidized electricity sale price (4 and 5 years for small/medium and large-size plants respectively when subsidy is 0.28 €/kWh), up to 1%_1000h degradation rate. On the other hand, whilst considering a SOFC degradation rate of 0.03%_1000h, the reforming-based system appears feasible only on large-size plants, yet recovering the initial capital expenditure in 9 years. Moreover, once the break-even point is reached, the gain in the net revenue produced by the innovative system is amplified in the event of small-size installation. This allows the possibility to undertake the risk of higher degradation rates (up to 2%_1000h) without jeopardizing the economic profitability. Therefore, in the present regulatory framework and under current capital costs projections, the innovative SOFC system appears as much profitable as ICE mature technology. Such effort in the design of the fuel pre-treatment unit can lever SOFC broad spreading into the market of small biogas producers.     

准东煤灰提取氧化铝和白炭黑技术研究

为实现准东煤灰的绿色化综合利用,笔者研究设计了从准东煤灰中制取氧化铝和白炭黑的工艺流程,确定了最佳工艺条件,并通过SPSS双变量分析比较不同影响因素对提取率影响程度。试验采用准东煤--将军庙原煤,破碎并用马弗炉模拟煤粉炉静态燃烧方式制取灰样。准东煤灰的成分分析和元素分析表明:SiO2占48.84%,Al2O3占31.26%。参照标准制备灰样,对灰样进行SEM分析,发现粘黏性严重,因此试验前先进行机械研磨。采用煤灰与硫酸铵焙烧法制备氧化铝,工艺分为焙烧过程和酸浸过程。因滤液中含有大量杂质铁、钙等元素,采用pH调节法除杂并对除杂效果进行检验,检验结果为除杂率接近100%。从提铝渣中制备白炭黑分为碱浸过程和多次碳分过程。在提铝工艺焙烧过程中,通过提铝率变化曲线及节能角度确定了各因素的最佳试验条件为:焙烧温度600℃,焙烧时间60 min,焙烧配料比1∶6;在提铝工艺酸浸过程中,得到最佳试验条件为:酸浸温度60℃、酸浸时间20 min、H2SO4浓度0.2 mol/L、酸浸液固比50。从提铝渣制备白炭黑研究中,通过SEM观察到提铝渣疏松多孔,有利于进一步的提硅试验。通过XRD对提铝渣分析,得出提铝渣中含有大量硅、钙元素;用K值法(RIR法)求得提铝渣中Si含量及经提铝后的Si损失率为7.64%。得出碱浸过程最佳试验条件为:碱浸温度60℃、碱浸时间30 min、碱浸NaOH浓度3 mol/L、碱浸液固比70,此时Si提取率为99%。采用多次碳分法进行提硅能够满足不同硅含量纯度要求,得到最佳碱浸工艺条件为碳分pH=9.5、CO2通气速率24 m L/min、碳分NaOH浓度0.2 mol/L、碳分液固比80。通过双变量相关性分析,得到各因素对提铝率、SiO2提取率及H2SiO3沉淀率影响程度大小分别为:焙烧温度>焙烧时间>焙烧配料比,酸浸时间>酸浸温度>H2SO4浓度>酸浸液固比,碱浸液固比>碱浸温度>NaOH浓度>碱浸时间,碳分pH>碳分液固比>碳分NaOH浓度>CO2通气速率。通过经济性及可行性分析,说明提出的工艺能有效实现准东煤灰的绿色化综合利用。从提铝后的滤液中重新提取(NH4)2SO4,实现生产原料的再利用;碳分过程后的Na2CO3溶液可通过加入石灰苛化的方式实现NaOH可循环利用于提取工艺生产;本工艺除生产氧化铝和白炭黑外,还能获得Na2SO4等附加产品。     

北洺河铁矿全尾砂胶结充填治理塌陷区的可行性研究

北洺河铁矿为践行“绿水青山就是金山银山”的绿色发展理念,探索利用选厂尾矿治理地表塌陷区方案。通过对北洺河铁矿塌陷区稳定性分析以及对全尾砂膏体制备、输送、胶结充填技术可行性试验研究,并结合经济估算、环境和社会效益等综合分析,认为全尾砂胶结充填治理塌陷区的方案可行。     

日照市官山榴辉岩矿地质特征及开发评价

近年来,日照市投入大量资金对榴辉岩矿进行了勘查,基本查明了官山榴辉岩矿的地质特征和矿床特征,并结合矿床开采的地质和技术条件对矿床开采的可行性做出了评价。     

梨树煤矿新建复合式干法选煤的可行性研究

针对梨树煤矿3号煤层的实际情况,经过长期论证和对比筛选各种煤炭加工工艺,最终认为采用复合式干法选煤是最佳选择,通过筛分和试验证明复合式干法选煤是可行的,可提高企业的综合效益.     

发展循环经济,实现我国矿业可持续发展

阐述了循环经济的产生背景、概念、基本特征及国内外应用实践；论述了发展循环经济以实现矿业可持续发展的必要性与可行性，并对矿产资源领域如何发展循环经济提出了相应的对策建议。     

卡轨车做主提升设备的可行性探讨

提出用卡轨车做副暗斜井提升设备的方案，并对其可行性加以研究。