Optimization of lithium extraction solar pond in Zabuye Salt Lake: Theoretical calculation combined with field experiments

This research optimized the structure of lithium extraction solar ponds to enhance the crystallization rate and yield of Li_(2)CO_(3).Using the response surface methodology in Design-Expert 10.0.3,the authors conducted experiments to investigate the influence of four factors related to solar pond structure on the crystallization of Li_(2)CO_(3) and their pairwise interactions.Computational Fluid Dynamics(CFD)simulations of the flow field within the solar pond were performed using COMSOL Multiphysics software to compare temperature distributions before and after optimization.The results indicate that the optimal structure for lithium extraction from the Zabuye Salt Lake solar ponds includes UCZ(Upper Convective Zone)thickness of 53.63 cm,an LCZ(Lower Convective Zone)direct heating temperature of 57.39℃,a CO32−concentration of 32.21 g/L,and an added soda ash concentration of 6.52 g/L.Following this optimized pathway,the Li_(2)CO_(3) precipitation increased by 7.34% compared to the initial solar pond process,with a 33.33% improvement in lithium carbonate crystallization rate.This study demonstrates the feasibility of optimizing lithium extraction solar pond structures,offering a new approach for constructing such ponds in salt lakes.It provides valuable guidance for the efficient extraction of lithium resources from carbonate-type salt lake brines.

Long-term cross-border electricity trading model under the background of Global Energy Interconnection

Environmental problems caused by traditional power production and the unbalanced distribution of energy resources and demand limit the development of sustainable societies. A feasible method to optimize the resource allocation has been proposed, and it involves cross-border and cross-regional electricity transactions. However, the uncertainty of renewable energy and the specific features of the cross-border electricity market are key issues which need to be considered in the trading mechanism design. Based on this, this paper sets up a long-term cross-border electricity trading model considering the uncertainty of renewable energy. First, annual transactions are matched according to the declared data of bidders with consideration of cross-border interconnection development benefits, potential benefit risks, and transmission costs. Second, for annual contract decomposition, the model uses the minimum generation cost function with a penalty item for power shortages to allocate electricity to each month. Additionally, the scenario reduction algorithm is combined with the unit commitment to construct a stochastic generation plan. Finally, a case study of the numerical results for the multinational electricity market in northeast Asia is used to show that the proposed trading model is feasible for cross-border electricity trading with high penetration of renewable energy.

Steel bar penetrating cervical spinal canal without neurological injury:A case report

BACKGROUND We report a rare case of cervical spinal canal penetrating trauma and review the relevant literatures.CASE SUMMARY A 58-year-old male patient was admitted to the emergency department with a steel bar penetrating the neck,without signs of neurological deficit.Computed tomography(CT)demonstrated that the steel bar had penetrated the cervical spinal canal at the C6–7 level,causing C6 and C7 vertebral body fracture,C6 left lamina fracture,left facet joint fracture,and penetration of the cervical spinal cord.The steel bar was successfully removed through an open surgical procedure by a multidisciplinary team.During the surgery,we found that the cervical vertebra,cervical spinal canal and cervical spinal cord were all severely injured.Postoperative CT demonstrated severe penetration of the cervical spinal canal but the patient returned to a fully functional level without any neurological deficits.CONCLUSION Even with a serious cervical spinal canal penetrating trauma,the patient could resume normal work and life after appropriate treatment.

Surface Oxygen Injection in Tin Disulfide Nanosheets for Efficient CO_(2) Electroreduction to Formate and Syngas

Surface chemistry modification represents a promising strategy to tailor the adsorption and activation of reaction intermediates for enhancing activity.Herein,we designed a surface oxygen-injection strategy to tune the electronic structure of SnS_(2) nanosheets,which showed effectively enhanced electrocatalytic activity and selectivity of CO_(2) reduction to formate and syngas(CO and H_(2)).The oxygen-injection SnS_(2) nanosheets exhibit a remarkable Faradaic efficiency of 91.6%for carbonaceous products with a current density of 24.1 mA cm^(−2) at−0.9 V vs RHE,including 83.2%for formate production and 16.5%for syngas with the CO/H_(2) ratio of 1:1.By operando X-ray absorption spectroscopy,we unravel the in situ surface oxygen doping into the matrix during reaction,thereby optimizing the Sn local electronic states.Operando synchrotron radiation infrared spectroscopy along with theoretical calculations further reveals that the surface oxygen doping facilitated the CO_(2) activation and enhanced the affinity for HCOO*species.This result demonstrates the potential strategy of surface oxygen injection for the rational design of advanced catalysts for CO_(2) electroreduction.

Joint electricity and carbon market for Northeast Asia energy interconnection

Decarbonization of the electricity sector is crucial to mitigate the impacts of climate change and global warming over the coming decades.The key challenges for achieving this goal are carbon emission trading and electricity sector regulation,which are also the major components of the carbon and electricity markets,respectively.In this paper,a joint electricity and carbon market model is proposed to investigate the relationships between electricity price,carbon price,and electricity generation capacity,thereby identifying pathways toward a renewable energy transition under the transactional energy interconnection framework.The proposed model is a dynamically iterative optimization model consisting of upper-level and lower-level models.The upper-level model optimizes power generation and obtains the electricity price,which drives the lower-level model to update the carbon price and electricity generation capacity.The proposed model is verified using the Northeast Asia power grid.The results show that increasing carbon price will result in increased electricity price,along with further increases in renewable energy generation capacity in the following period.This increase in renewable energy generation will reduce reliance on carbon-emitting energy sources,and hence the carbon price will decline.Moreover,the interconnection among zones in the Northeast Asia power grid will enable reasonable allocation of zonal power generation.Carbon capture and storage (CCS) will be an effective technology to reduce the carbon emissions and further realize the emission reduction targets in 2030-2050.It eases the stress of realizing the energy transition because of the less urgency to install additional renewable energy capacity.

Fundamental Issues Towards Unified Design Theory of Recycled and Natural Aggregate Concrete Components

In the past 20 years,recycled aggregate concrete(RAC),as a type of low-carbon concrete,has become a worldwide focus of research.However,the design methodology for RAC structural components remains a challenge.Consequently,demands for a unified design of natural aggregate concrete(NAC)and RAC components have been presented.Accordingly,this study analyses the necessity of a unified design theory and provides an in-depth demonstration of the strength determination,compressive constitutive relationship,and design method of concrete components.The coefficient of variation of RAC strength is found to be generally higher than that of NAC strength.The compressive and tensile strengths of RAC can be defined and determined using the same method as that used for NAC.The uniaxial compressive constitutive relationship between NAC and RAC has a unified mathematical expression.However,the elastic modulus of RAC decreases,and its brittleness exhibits an increasing trend compared with that of NAC.Finally,to unify the design formulae of RAC and NAC components for bearing capacity,modification factors for RAC components are proposed considering safety and reliability.Additionally,the feasibility of the proposed unified time-dependent design theory is demonstrated in terms of conceptual design and structural measures considering the effects of strength degradation and reinforcement corrosion.It is believed that this study enriches and develops the basic theory of concrete structures.

浅埋大断面黄土隧道大变形特性及其控制措施研究

依托银西客运专线某浅埋大断面隧道,基于数值计算和现场监测等手段对隧道变形特性进行分析,结果表明浅埋大断面黄土隧道拱顶沉降量大、变形时间长,初支封闭成环后变形速率变缓,但在二衬施作前隧道变形速率依旧较大,围岩未达到稳定状态。隧道施工过程中会在拱脚和墙脚形成塑性区,围岩塑性变形导致地层的不均匀沉降使围岩受到的拉应力或剪应力大于土体的强度,极易形成可见的地表裂缝。采用袖阀管注浆+洞内超前中管棚的控制措施能有效控制浅埋大断面隧道变形,保证施工安全。

一种Profibus现场总线故障诊断系统的设计与实现

随着电厂数字化和智能化建设日益提速,现场总线技术的应用大大减轻了电力生产现场的线缆敷设密集度和控制复杂度,结合DCS系统实现了可靠的生产设备操控和设备状态监视,同时也带来了一定的检修困难,尤其是设备层面的问题排查,为了降低总线检修的复杂性,更好地定位设备层面故障,设计开发了一套基于Profibus总线设备信息的故障诊断系统,采集存储和分析设备传输的有效信息,在线实时监视设备层面状态并提示报警,同时可历史追溯参数状态变化并计算故障率等信息,后续可以为大数据层面应用提供支撑,系统在火电厂进行了应用,结果表明,系统可以快速准确定位设备和具体故障,有效减轻检修工作量。

Adjustable robust low-carbon dispatch for interconnected power systems in Northeast Asian countries

Interconnected power systems that link several countries and fully utilize their individual resources in a complementary manner are becoming increasingly important.As these systems enhanee accommodation of renewable energy,they also represent a move toward low-carbon and low-emissi on power systems.In this paper,a low-carb on dispatch model is proposed to coo rd i nate the gen erati on output betwee n several coun tries where the carb on emissi on constraint is a priority.An adjustable robust optimization approach is used to find the optimal solution under the worst-case scenario to address the uncertainties associated with renewable energy resources.A specific constraint is that the area control error for each country should be self-balanced.Furthermore,a reformation using participation factors is presented to simplify the proposed robust dispatch model.Simulation results for practical interconnected power systems in northeast Asian countries verify the effectiveness of the proposed model.

桌面云在智慧电厂数据中心建设中的应用与研究

智慧电厂建设的快速发展对发电企业管理信息系统提出了更高要求。基于先进IT技术和云计算的桌面云系统,以其良好的信息安全性、使用便利性和节能环保性,能够较好地弥补传统电脑办公方式的不足,为提升电厂信息安全和办公效率带来新的发展契机。分析了传统电脑办公与桌面云系统的不同,从桌面云系统原理、架构、组网方式、存在的不足及对策等方面讨论了其在智慧电厂数据中心建设中的应用。

黄土隧道围岩特性曲线及其数值计算方法

隧道围岩体系与支护体系的相互作用是隧道工程研究的核心问题。对于黄土隧道而言,基于约束收敛法分析围岩变形规律,进而对围岩稳定性进行评价是一种黄土隧道研究的新方向新思路。本文基于FLAC3D大型通用有限差分软件,采用双线性应变软化遍布节理模型模拟黄土垂直节理特性,对三种不同弹性模量下大断面黄土隧道进行模拟并详细给出围岩特性曲线的数值求解方法。结果表明,在求解复杂边界条件下围岩特性曲线推荐采用数值计算的方法,本文采用的反向荷载计算法能有效地求解复杂围岩条件下黄土隧道的围岩特性曲线。随着位移的增加,也就是支护时机的推后,所需要的支护力在逐渐减小,围岩自承的荷载比重在增大。随着黄土隧道围岩弹性模量的增大,隧道拱顶在达到相同位移所需要的支护力在减小,说明围岩条件较好的时候可以适当减小支护强度。

Development and validation of a new oxide fuel rod performance analysis code for the liquid metal fast reactor

The integrity and reliability of fuel rods under both normal and accidental operating conditions are of great importance for nuclear reactors.In this study,considering various irradiation behaviors,a fuel rod performance analysis code,named KMC-Fueltra,was developed to evaluate the thermal–mechanical performance of oxide fuel rods under both normal and transient conditions in the LMFR.The accuracy and reliability of the KMC-Fueltra were validated by analytical solutions,as well as the results obtained from codes and experiments.The results indicated that KMC-Fueltra can predict the performance of oxide fuel rods under both normal and transient conditions in the LMFR.

660 MW超临界CFB锅炉非金属膨胀节整改

介绍了660 MW超临界CFB锅炉非金属膨胀节的运行情况,重点剖析了高温、正压部位安装的非金属膨胀节的结构,分析了点火风道非金属膨胀节和灰道非金属膨胀节运行后因框架间隙变化频繁出现泄漏的问题,阐述了将非金属膨胀节替换为常规金属膨胀节面临的困难,针对非金属膨胀节存在的问题提出了改进措施,如采取加装防坠板、防脱柱等措施,同时规范非金属膨胀节的安装工序,解决了非金属膨胀节的泄漏问题,为同类型锅炉非金属膨胀节的设计优化和性能提升提供参考和支持。

Preparation and analysis of immunocompetence of recombinant fusion protein of the immunodominant region in chlamydial protease-like activity factor from Chlamydophila pneumoniae and its application in serodiagnosis

To clone the gene coding the immunodominant region in the chlamydial protease-like activity factor （CPAF） from Chlaroydophila pneumoniae, to analyze immunoeoropetenee of the expressed protein, and to evaluate its value in serodiagnosis, the CPAF immunodominant region gene was amplified, ligated into a pGEX6p-2 vector, and then the expressed recombinant protein was purified with glutathione Stransferase （GST） agarose gel FF after renaturation, then identified by SDS-PAGE and Western blot. A new indirect ELISA was developed with the purified protein as coating antigen. The immunogenicity of the recombinant protein was evaluated by immunization to New Zealand rabbits, and its immunoreactivity was analyzed by reacting with anti-C, pneumoniae antibody. 300 clinical sera samples were respectively detected by mieroimmunofluorescenee （MIF） as reference method and the indirect ELISA, and the difference between the two methods was analyzed. Cross-reactivity against Chlamydia trachomatis was investigated with the indirect ELISA to detect anti-C, trachomatis positive antisera. The results indicated that a 51.3 kDa recombinant protein was obtained. Western blot assay proved that the recombinant protein could merely specifically react with human anti- C. pneurnoniae antisera. The titers of the specific IgG antibodies in the immunized New Zealand rabbits were above 1 ： 16 000. Anti- C. pneumoniae IgG positive and negative reference sera were detected with the indirect ELISA, and the concordance rate of negative and positive results were both 100% （40/40）. The sensitivity and specificity of the indirect ELISA in comparison with MIF were 93.8% （45/48） and 100% （252/252） separately by detecting 300 clinical sera samples, and the concordance rate between the two methods was 99.0%. No cross reaction against C. trachomatis was found with the indirect ELISA to detect anti-C, trachomatis positive antisera. In conclusion, the prepared recombinant protein of the CPAF immunodominant region shows excellent immunocompetence and can be used to develop a new indirect ELISA as a method to detect anti-C, pneumoniae antibody for diagnosis of C. pneumoniae infection.

Economic dispatch constrained by central multi-period security for Global Energy Interconnection and its application in the Northeast Asia

In recent years, the global energy interconnection(GEI) has more and more profound influence around the world, which is a highly practical way for humans to handle the energy crisis. In the studies of GEI, the economic dispatch(ED) is a basic and important content. In this paper, a model of dynamic economic dispatch(DED) of GEI is presented, which include the renewable energy generation. The objective function of this model is composed of the operating costs and the renewable energy curtailment. A series of case studies for the transnational energy interconnection in Northeast Asia are given to verify the superiority of GEI and for further analysis.

Research on recycled concrete and its utilization in building structures in China

Large quantities of construction and demolition(C&D)building waste are being generated as a result of rapid urbanization and natural disasters in China.An increasing awareness of environmental protection is escalating C&D waste disposal concerns.This paper presents a brief introduction to current shaking table test research in China on structures built with recycled aggregate concrete(RAC).Test structures include a cast-in situ frame model,a precast frame model and a block masonry building.The test results prove that it is feasible to use RAC as a structural material in seismic areas,with recommended modifications and proper design,especially in low-rise structures.This paper also presents several successful applications of RAC in civil and structural engineering projects in China,which will serve to promote RAC as a global ecological structural material.

混凝土结构低碳近似概率设计法探索

为应对国家“双碳”目标与建筑业低碳发展挑战,探索并提出了一套以概率理论为基础、以分项系数表达的混凝土结构低碳设计实用方法.面向碳中和目标,建立了低碳极限状态方程,定义了低碳指标以度量混凝土结构满足碳排放限值的水准.依据碳排放的不确定性特点,定义了“恒碳”“活碳”,分别在结构隐含碳与建筑全寿命碳边界内厘清2种低碳设计范式,引入碳排放分项系数将概率化设计简化为基于确定性碳排放评价结果的“近似概率设计法”.开展案例试算,将中国碳中和目标分解为混凝土结构碳排放限值,展示建筑类型对碳排放分项系数的影响特点.结果表明,碳排放分项系数与“恒碳”“活碳”变异性大小、所占比例直接相关,在10–1误差范围内,不同建筑类型有望采取统一分项系数,如目标低碳失效概率为0.05时,“恒碳”和“活碳”分项系数可分别取1.1和1.8.引入3类影响系数,以匹配不同建筑类型碳排放限值的差异化分配需求,适应不同地区、不同碳排放调控情景下的发展需求,助力我国建筑业低碳转型.

中国喀斯特区最高树原生境森林群落的林层结构及物种组成

望天树是我国热带季节性雨林的标识性树种,其原生境热带森林群落是我国植物热带性最强烈、种类组成最复杂、雨林特征最浓厚的植被类型,但现存分布区域狭窄.近期广西弄岗热带喀斯特峰丛洼地森林发现高72.4 m的望天树,打破了我国喀斯特区域和华南地区的最高树纪录,刷新了以往对热带喀斯特森林植被特征的认知.本文基于弄岗望天树原生境森林群落调查样方,展示了其群落的林层结构、物种组成及生态特征,与我国其他望天树群落对比分析探讨了其植被生态学意义.结果表明:(1)该群落有高50 m以上望天树巨树散生乔木冠层之上;连续乔灌层可分为4层,平均高度分别为36.9、25.6、9.5和2.7 m;在2400 m^(2)样方内乔、灌、藤、草和附生植物分别有64、24、31、26和8种;(2)林冠上层优势种有望天树、人面子等典型热带区系树种,蚬木、肥牛树等喀斯特专性树种,岭南酸枣、白头树等落叶树种;(3)在乔木层的物种中,热带亚洲(印度-马来)分布型占65.6%,大高位芽植物占15.6%,常绿植物占85.9%,复叶植物占39.1%,革质叶片占60.9%,典型喀斯特植物占28.1%;(4)该区域群落乔木层优势属与我国其他望天树群落的相似性从高到低依次为广西那坡县、云南马关和勐腊县、广西巴马、田阳和大化县;群落结构组成差异与气候环境条件显著相关.综上,广西弄岗望天树原生境群落是在热带喀斯特峰丛洼地的局域封闭生境条件下发育形成的巨树散生、林层复杂的热带季节性雨林植被,孕育着丰富的耐旱型的典型喀斯特植物.

超强酸催化Friedel-Crafts反应制备无醚磺化聚芳基质子交换膜

通过三氟甲磺酸催化Friedel-Crafts反应,合成了含有三氟异亚丙基的无醚聚芳前驱体聚合物.考察了不同芳基单体、电子云密度和空间位阻等因素对前驱体聚合物分子量的影响,并优化反应条件,实现了前驱体的合成.特别是,以联苄和三氟丙酮为原料合成的前驱体聚合物PAAF,展现出了高分子量(Mw=201 kDa,Mn=63 kDa)特性;随后,经氯磺酸三甲基硅烷基酯后磺化制备了sPAAF,其不仅保持了高分子量(Mw=201 kDa,Mn=63 kDa),还具备了高离子交换容量(2.40 mmol/g).在80℃完全水合状态下,质子电导率最高可达102 mS/cm,热分解温度为258℃,化学稳定性良好,在芬顿测试后质量衰减率仅为11%,表明该系列材料具有良好的化学稳定性.本研究旨在通过引入不同的亚苯基结构和功能基团,深入探讨聚合物结构与膜性能之间的构效关系,为开发低成本、高性能的无醚聚苯基质子交换膜材料奠定基础.

Study on the discharge coefficient of wind-driven naturally ventilated Chinese solar greenhouses

The Chinese solar greenhouse(CSG)is a prevalent feature in agricultural practices within China.Nevertheless,the regulation of natural ventilation within this architectural structure remains suboptimal.Consequently,the development of a natural ventilation model becomes imperative for the effective management of the greenhouse environment.Of particular significance within these models is the consideration of the discharge coefficient as a pivotal parameter.Conducting a multi-case investigation into the variable-dependent discharge coefficient is crucial for both practical application and model advancement.This research delved into the impact of various factors,including the upper-lower vents area ratio(A_(up)/A_(low)),vent-greenhouse area ratio(A_(low)/A_(greenhouse)),lower vent position height(h/H),the incident angle of the external wind,and altitude,on the discharge coefficient(C_(d))of CSG.A CFD model was developed for a scaled CSG with validation conducted through field experiments and wind tunnel tests.Results indicated a 61.6%reduction in C_(d)on average corresponding to an 80%decrease in A_(up)/A_(low).C_(d)levels remained consistent following the attainment of an A_(up)/A_(low)ratio of 1.0.Besides,there was an average increase of 52.5%in C_(d)levels for every 0.09 decline in h/H,attributed to the blocking effect of the cover.Moreover,the ventilation rate and the pressure coefficient difference were utilized to construct a model of C_(d)pertaining to greenhouse design and ventilation operation,exhibiting a notable accuracy level of R^(2)=0.95.Furthermore,the blocking effect of higher h/H was relieved as the incident angleθdecreased under the windward conditions.The increase in A_(up)/A_(low)and the decrease in A_(low)/A_(greenhouse)were identified as crucial factors contributing to the growth of C_(d)under leeward conditions.Ultimately,the high-altitude environment led to a rise in C_(d)levels in contrast to the low-altitude region.The increasing rate of C_(d)correlated positively with A_(low)/A_(greenhouse)and h/H initially,but exhibited a decline once A_(low)/A_(greenhouse)reached 0.036,remaining stable thereafter once h/H reached 0.18.In summary,a comprehensive examination of the discharge coefficient of CSG was undertaken,addressing a significant knowledge deficiency and laying the groundwork for advancements in the natural ventilation model and the intelligent control system for CSG.