光储系统并网功率波动平抑及储能优化配置

【目的】电池储能是保证光伏发电系统可靠性、提高光伏发电利用率的有效手段之一,但在光储电站中存在功率波动平抑难、储能容量配置不合理等问题,为解决这些问题,开展了相关研究。【方法】针对能量型电池储能,分析了调度模式和自主模式特性,提出了一种基于储能运行在调度模式的光储系统限功率平抑策略,以实现功率平抑和减少储能充放电频繁切换。建立了以最小光储系统弃电损失为优化目标,以功率波动越限概率等作为约束条件的优化模型,并利用算法对储能配置进行求解和优化。以西藏朗明桑珠孜50 MW光储电站为例,验证了所提平抑策略的有效性。【结果】所提平抑策略在不增加储能充放电切换次数的前提下,将光储系统并网功率波动越限概率由25.64%降至6.41%,且并网功率波动越限概率为5%时,该50 MW并网光伏电站储能系统最优配置为14.5 MW/94 MW·h。【结论】所提抑策略及储能优化配置方法可为并网光储电站优化设计和运行提供技术参考。

Meter-Scale Thin-Walled Structure with Lattice Infill for Fuel Tank Supporting Component of Satellite:Multiscale Design and Experimental Verification

Lightweight thin-walled structures with lattice infill are widely desired in satellite for their high stiffness-to-weight ratio and superior buckling strength resulting fromthe sandwich effect.Such structures can be fabricated bymetallic additive manufacturing technique,such as selective laser melting(SLM).However,the maximum dimensions of actual structures are usually in a sub-meter scale,which results in restrictions on their appliance in aerospace and other fields.In this work,a meter-scale thin-walled structure with lattice infill is designed for the fuel tank supporting component of the satellite by integrating a self-supporting lattice into the thickness optimization of the thin-wall.The designed structure is fabricated by SLM of AlSi10Mg and cold metal transfer welding technique.Quasi-static mechanical tests and vibration tests are both conducted to verify the mechanical strength of the designed large-scale lattice thin-walled structure.The experimental results indicate that themeter-scale thin-walled structure with lattice infill could meet the dimension and lightweight requirements of most spacecrafts.

A Hybrid Level Set Optimization Design Method of Functionally Graded Cellular Structures Considering Connectivity

With the continuous advancement in topology optimization and additive manufacturing(AM)technology,the capability to fabricate functionally graded materials and intricate cellular structures with spatially varying microstructures has grown significantly.However,a critical challenge is encountered in the design of these structures–the absence of robust interface connections between adjacent microstructures,potentially resulting in diminished efficiency or macroscopic failure.A Hybrid Level Set Method(HLSM)is proposed,specifically designed to enhance connectivity among non-uniform microstructures,contributing to the design of functionally graded cellular structures.The HLSM introduces a pioneering algorithm for effectively blending heterogeneous microstructure interfaces.Initially,an interpolation algorithm is presented to construct transition microstructures seamlessly connected on both sides.Subsequently,the algorithm enables the morphing of non-uniform unit cells to seamlessly adapt to interconnected adjacent microstructures.The method,seamlessly integrated into a multi-scale topology optimization framework using the level set method,exhibits its efficacy through numerical examples,showcasing its prowess in optimizing 2D and 3D functionally graded materials(FGM)and multi-scale topology optimization.In essence,the pressing issue of interface connections in complex structure design is not only addressed but also a robust methodology is introduced,substantiated by numerical evidence,advancing optimization capabilities in the realm of functionally graded materials and cellular structures.

Full-Scale Isogeometric Topology Optimization of Cellular Structures Based on Kirchhoff-Love Shells

Cellular thin-shell structures are widely applied in ultralightweight designs due to their high bearing capacity and strength-to-weight ratio.In this paper,a full-scale isogeometric topology optimization(ITO)method based on Kirchhoff-Love shells for designing cellular tshin-shell structures with excellent damage tolerance ability is proposed.This method utilizes high-order continuous nonuniform rational B-splines(NURBS)as basis functions for Kirchhoff-Love shell elements.The geometric and analysis models of thin shells are unified by isogeometric analysis(IGA)to avoid geometric approximation error and improve computational accuracy.The topological configurations of thin-shell structures are described by constructing the effective density field on the controlmesh.Local volume constraints are imposed in the proximity of each control point to obtain bone-like cellular structures.To facilitate numerical implementation,the p-norm function is used to aggregate local volume constraints into an equivalent global constraint.Several numerical examples are provided to demonstrate the effectiveness of the proposed method.After simulation and comparative analysis,the results indicate that the cellular thin-shell structures optimized by the proposed method exhibit great load-carrying behavior and high damage robustness.

Relationship between Calligraphy and Meteorology

Since ancient times,calligraphy and meteorology have had an inseparable relationship.Wang Xizhi s Prologue to the Collection of Poems Composed at the Orchid Pavilion records the beautiful scenery of mild wind and bright sun,as well as the relaxed and joyful mood of people in such weather.Su Shi s Cold Food Calligraphy Copybook records the scenery of solar terms and the author s psychological changes during these solar terms through calligraphy.The Quick Snow and Clear Time Calligraphy Copybook also reflects the grandeur of snowy days and the customs of literati recording weather and sharing it with friends.In Sun Guoting s Shupu,it is clearly stated that the third element of the"five harmony and five obedience"refers to the clear sky,humid air,and pleasant climate,and excellent climatic conditions are conducive to writing.

急性缺血性脑卒中血管腔内治疗后对比剂外渗影像学研究现状

对比剂外渗(CE)和出血性转化(HT)是急性缺血性脑卒中血管腔内治疗(EVT)后的常见并发症,两者有相似的影像学表现,不同的临床治疗方法和转归。早期鉴别诊断CE和HT,对临床治疗和预后至关重要。本文就临床CE影响因素,常规CT、双能CT(DECT)及MRI诊断EVT后CE研究现状作一综述,为预防CE和早期鉴别诊断提供帮助。

多光谱瞬态测温系统最优测温波段的分析研究

针对多光谱瞬态温度的测量系统中波长的选择问题。研制了一套适用于反演爆炸场瞬态温度的测试系统,该系统从辐射测温的原理出发,通过分析温度随波长灵敏度的变化关系,确定温度精度最高时的波长,并结合天鹰优化器约束算法,对蜡烛燃烧的火焰现场测试加以验证,结果表明:选择各个波段的最优待测波长测量时,测量的温度误差最小,不超过±2.1%,减小因波长的选择而引起的误差。

基于Self-X认知制造网络实现认知大规模个性化定制--一种工业知识图谱及图嵌入技术使能的途径

1.Introduction Facilitated by cutting-edge information and communication technologies(ICTs),smart manufacturing is emerging as an overwhelming wave,reforming global manufacturing systems[1].The ubiquitous connection and interoperability of manufacturing resources can be achieved through the Industrial Internet of Things(IIoT)[2,3],and the generated high volume,velocity,variety。

An Intelligent Manufacturing Platform of Polymers:Polymeric Material Genome Engineering

Polymeric materials with excellent performance are the foundation for developing high-level technology and advanced manufacturing.Polymeric material genome engineering(PMGE)is becoming a vital platform for the intelligent manufacturing of polymeric materials.However,the development of PMGE is still in its infancy,and many issues remain to be addressed.In this perspective,we elaborate on the PMGE concepts,summarize the state-of-the-art research and achievements,and highlight the challenges and prospects in this field.In particular,we focus on property estimation approaches,including property proxy prediction and machine learning prediction of polymer properties.The potential engineering applications of PMGE are discussed,including the fields of advanced composites,polymeric materials for communications,and integrated circuits.

Necessary and Sufficient Conditions for Feasible Neighbourhood Solutions in the Local Search of the Job-Shop Scheduling Problem

The meta-heuristic algorithm with local search is an excellent choice for the job-shop scheduling problem(JSP).However,due to the unique nature of the JSP,local search may generate infeasible neighbourhood solutions.In the existing literature,although some domain knowledge of the JSP can be used to avoid infeasible solutions,the constraint conditions in this domain knowledge are sufficient but not necessary.It may lose many feasible solutions and make the local search inadequate.By analysing the causes of infeasible neighbourhood solutions,this paper further explores the domain knowledge contained in the JSP and proposes the sufficient and necessary constraint conditions to find all feasible neighbourhood solutions,allowing the local search to be carried out thoroughly.With the proposed conditions,a new neighbourhood structure is designed in this paper.Then,a fast calculation method for all feasible neighbourhood solutions is provided,significantly reducing the calculation time compared with ordinary methods.A set of standard benchmark instances is used to evaluate the performance of the proposed neighbourhood structure and calculation method.The experimental results show that the calculation method is effective,and the new neighbourhood structure has more reliability and superiority than the other famous and influential neighbourhood structures,where 90%of the results are the best compared with three other well-known neighbourhood structures.Finally,the result from a tabu search algorithm with the new neighbourhood structure is compared with the current best results,demonstrating the superiority of the proposed neighbourhood structure.

智能制造

Intelligent manufacturing is a type of manufacturing that adopts computer-integrated manufacturing, high-level adaptability and rapid design personalization, system reconfiguration, the digitalization of manufacturing processes and resources, and flexible and organized technical labor training. This Special Issue focuses on the application of advanced information and communication technologies—such as artificial intelligence (AI), advanced topology optimization methods, edge computing, cloud computing, 5G networks, the Industrial Internet, and the Internet of Things—to address problems that arise during the design, materials and manufacturing, logistics, and services associated with intelligent manufacturing. In this issue, we present eight articles contributed by scholars and experts from countries around the world, including China, Sweden, the United Kingdom, and New Zealand. The published works examine intelligent manufacturing, with a particular focus on the phases of engineering design and materials and manufacturing.

Mechanical deformation properties of Continuous Welded Rail on kilometer-span suspension bridge for high-speed railway

The complex bridge-track interaction between kilometer-span bridges and continuous Welded Rail(CWR)brings great challenges to CWR designing.Taking a suspension bridge with laying CWR as a case,the mechanical properties of CWR on the bridge are analyzed to reveal the sensitive areas of the track,and the design method of CWR and track structures on the beam ends are proposed.The results show that the unidirectional Rail Expansion Joints(REJ)need to be installed on the beam end of the kilometer-span bridge to reduce rail longitudinal force.Due to the bridge characteristics,there is no CWR fixed area on the kilometer-span bridge,and rail longitudinal force on the main span caused by bending loads needs to be concerned.The deformation of track on the beam end is complex,which is the weak area on the kilometer bridge,the large relative displacement between the stock rail of REJ and the main beam can cause poor stability of ballast bed on beam end,small resistance fasteners need to be laid on the sides of stock rail on the main beam to increase the stability of ballast and fasteners on the beam end.To improve the driving safety and comfort of beam end,the Sleeper-Supporting Apparatus(SSA)should be specially designed to ensure the uniform transition of track on beam ends.Temperature and wind loads have a significant impact on track regularity on the kilometer span bridge,the dynamic response of trains and bridges under those loads needs to be attended to.

Research on railway BIM platform framework based on homemade graphics engine

At present,BIM platforms rely on foreign software.Homemade software and industry applications are mostly secondary developments,which present stranglehold problems caused by interruptions to the software supply.To solve the problem,key technical research on the 3D integrated design of railway engineering was stuedied based on homemade graphics engines to propose an innovative railway BIM platform framework.The entire process was completed from the top-level design to the engineering verification of the platform.The co-designed mechanism of a"center model and link"hybrid mode was constructed,which solved the difficulties of data management and increment synchronization at a large scale,achieving teamwork among surveying and mapping,alignments,and bridges.The results of this study could provide strong support for the development of BIM software for a whole railway and all majors.

七氟烷调节CARMA3靶向NF-κB通路抑制胃癌细胞迁移、侵袭

目的研究七氟烷对胃癌(gastric cancer, GC)细胞迁移、侵袭的影响,并探讨其作用机制.方法运用Transwell法检测细胞迁移、侵袭量;将siCAR MA3组(转染siCARMA3)、NC组(转染siControl)、CARMA3组(转染pcDNA3.1-CARMA3)、Vector组(转染pcDNA3.1)均用脂质体法转染至SGC7901细胞;用qRT-PCR检测细胞中CARMA3 mRNA表达;Westernblot检测细胞中CARMA3、p-p65、p65蛋白表达.结果与对照组相比,七氟烷抑制GC细胞迁移、侵袭,且抑制CARMA3表达;沉默CARMA3抑制GC细胞迁移、侵袭,过表达CARMA3促进GC细胞迁移、侵袭,且CARMA3靶向NF-κB通路;七氟烷可抑制CARMA3失活NF-κB通路抑制GC细胞迁移、侵袭.结论七氟烷可抑制GC细胞迁移、侵袭,其机制可能与失活CARMA3/NF-κB信号通路有关,将可为七氟烷用于临床治疗GC提供依据.

高原高寒地区局部阴影下光伏阵列输出功率提升实验研究

高原高寒地区太阳能资源充足,利用光伏发电技术有利于改善当地电源结构。光伏电站出力不足是业内普遍存在的技术难题,光伏组件老化、表面温度高、局部阴影等都会降低光伏电站出力。以4×2光伏阵列为例,通过Matlab/Simulink建模仿真,对不同结构的光伏阵列在局部阴影下的输出特性进行对比,分析表明重构网状(RTCT)结构优于其他3种结构,且最大输出功率平均提升7.7%,为光伏阵列输出功率提升奠定实验基础。基于拉萨搭建的光伏阵列输出功率提升实验平台,采用改变光伏阵列拓扑结构和增加直流优化器2种方法,研发光伏阵列输出功率提升技术。结果表明,采用以上2种方法均能有效提升光伏阵列输出功率,可为光伏电站优化设计和运行提供解决方案。

三维动脉自旋标记与磁敏感加权血管造影评价急性缺血性脑血管病颅内动脉狭窄

目的评价三维动脉自旋标记(3D-ASL)明亮血管征(BVS)及磁敏感加权血管造影(SWAN)磁敏感血管征(SVS)诊断急性缺血性脑血病(AICVD)颅内动脉狭窄的价值。方法对101例AICVD患者采集颅脑3D-ASL及SWAN图像,以Kappa检验评价观察者间诊断BVS和SVS的一致性。以CT血管造影(CTA)结果为标准(39例阳性),评价BVS与SVS检出颅内动脉狭窄的效能;根据动脉狭窄位置分为大动脉狭窄亚组(n=16)和中小动脉狭窄亚组(n=23),比较BVS与SVS检出大动脉狭窄与中小动脉狭窄的一致性及其诊断差异。结果观察者间判断BVS及SVS的一致性高(Kappa均≥0.8,P均<0.05)。3D-ASL显示BVS阳性30例、阴性71例,SWAN显示SVS阳性23例、阴性78例;根据BVS及SVS诊断颅内动脉狭窄的敏感度、特异度和准确率分别为74.36%、98.39%及89.11%和56.41%、98.39%及82.18%。BVS与SVS判断颅内大动脉狭窄的一致性良好(Kappa=0.61,P=0.01),诊断差异无统计学意义(P>0.05);BVS与SVS诊断颅内中小动脉狭窄的一致性中等(Kappa=0.43,P=0.01),而BVS阳性率(82.61%,19/23)显著高于SVS(56.52%,13/23)(P<0.05)。结论BVS与SVS诊断AICVD颅内动脉狭窄的效果均较好,二者对大动脉狭窄诊断效能相近,BVS对中小动脉狭窄更优。

基于MRI影像组学评估肝细胞癌微血管侵犯的Meta分析

目的通过Meta分析系统评价基于MRI影像组学术前评估肝细胞癌(HCC)微血管侵犯(MVI)的诊断效能。方法检索PubMed、Cochrane图书馆、EMBASE、Web of Science、中国知网和万方数据库,检索时间为自建库以来至2021年3月公开发表的有关MRI影像组学评估HCC MVI的临床研究的中英文文献。根据纳入和排除标准对文献进行筛选并提取数据。根据诊断准确性研究质量评价工具-2(QUADAS-2)评价纳入文献的质量,采用RevMan5.4评价偏倚风险及临床适用性。采用Stata15.1软件计算纳入研究的合并敏感度、合并特异度、合并阳性似然比、合并阴性似然比及合并诊断比值比。绘制森林图和总受试者操作特征(SROC)曲线,并计算曲线下面积(AUC)。采用不一致指数(I2)和Chochrane Q指数评估异质性,并采用阈值效应和敏感性分析探讨异质性来源。采用Stata15.1软件绘制漏斗图评估是否存在发表偏倚。结果共纳入10项研究,包括817例病人,纳入研究的合并敏感度、特异度、阳性似然比、阴性似然比、诊断比值比及AUC值分别为0.82(95%CI:0.76~0.87)、0.84(95%CI:0.77~0.89)、5.1(95%CI:3.4~7.7)、0.22(95%CI:0.16~0.29)、24(95%CI:13~44)和0.89(95%CI:0.86~0.91)。敏感度的I2为27.37%,特异度的I2为62.19%,纳入研究间异质性较大。Deek’s漏斗图显示不存在发表偏倚(P=0.83)。结论基于MRI影像组学术前预测HCC的MVI有较高的准确性,可作为术前预测HCC MVI的一种无创性方法。

枫毒蛾的形态学特征及生物学特性

于2017年5月中下旬,从湖南省长沙市岳麓区、湘乡县的天然原始次生枫香树林暴发枫毒蛾林区采集枫毒蛾(LymantrianebulosaWileman)幼虫,于室内饲养,观察记录枫毒蛾幼虫不同发育阶段的形态特征及发育情况。结果表明:枫毒蛾幼虫虫体可视毒毛随着龄期增加而逐渐增多,翻缩腺颜色逐渐加深;随龄期增加,枫毒蛾头宽、体宽及体长均显著加大,其中头宽可作为枫毒蛾幼虫最佳的分龄指标,体长和体宽可作为辅助指标;在27℃的饲养条件下,枫毒蛾幼虫龄期为7龄,完成1个世代约需66.7d,成虫雌、雄比为0.9655,单雌产卵量为(330.43±27.801)粒。

2009—2019年我国地质灾害时空特征分析

进入新世纪以来,全球环境问题日益突出,气候变暖日益严重,极端天气愈加频繁,加上人类不合理的地下空间开发与过度建设,导致了大量地质灾害的发生。我国每年因地质灾害而造成的伤亡人数与经济损失情况排在世界前列,对我国地质灾害的研究已成为了我国防灾减灾的重中之重。因此,作者基于《中国统计年鉴》与《全国地质灾害通报》发布的地质灾害数据,以2009—2019年我国发生的地质灾害为对象,从年际变化与空间分布两个角度,详细分析了过去十年我国地质灾害发生与损失的情况,结论如下:(1)我国地灾发生数量除2010年异常外,年际变化曲线波动不大且呈现出减少的趋势,每年5月到9月为地灾多发期;(2)我国地灾在空间分布上,整体呈现出“西群东单,南多北少,中西南频繁”的规律;(3)我国地灾造成的伤亡人数与直接经济损失,在年际变化上是剧烈波动起伏的,在空间分布上,呈现出明显的地域性与差异性。针对以上研究结果,作者还对我国今后的地灾防治部署提出了几点合理的建议。

Blood-letting punctures at twelve Jing-Well points of the hand can treat cerebral ischemia in a similar manner to mannitol

A rat model of middle cerebral artery permanent occlusion was established using the modified Longa method. Successfully established model animals were treated by blood-letting puncture at twelve Jing-Well points of the hand, and/or by injecting mannitol into the caudal vein twice daily. Brain tissue was collected at 24, 48 and 72 hours after modeling, and blood was collected through the retinal vein before Evans blue was injected, approximately 1 hour prior to harvesting of brain tissue. Results showed that Evans blue leakage into brain tissue and serum nitric oxide synthase activity were significantly increased in model rats. Treatment with blood-letting punctures at twelve Jing-Well points of the hand and/or injection of mannitol into the caudal vein reduced the amount of Evans blue leakage into the brain tissue and serum nitric oxide synthase activity to varying degrees. There was no significant difference between single treatment and combined treatment. Experimental findings indicate that blood-letting punctures at twelve Jing-Well points of the hand can decrease blood-brain barrier permeability and serum nitric oxide synthase activity in rats following middle cerebral artery occlusion, and its effect is similar to that of mannitol injection alone and Jing-Well points plus mannitol injection.