Design and analysis of an advanced thermal management system for the solar close observations and proximity experiments spacecraft

In this paper,the mission and the thermal environment of the Solar Close Observations and Proximity Experiments(SCOPE)spacecraft are analyzed,and an advanced thermal management system(ATMS)is designed for it.The relationship and functions of the integrated database,the intelligent thermal control system and the efficient liquid cooling system in the ATMS are elaborated upon.For the complex thermal field regulation system and extreme space thermal environment,a modular simulation and thermal field planning method are proposed,and the feasibility of the planning algorithm is verified by numerical simulation.A solar array liquid cooling system is developed,and the system simulation results indicate that the temperatures of the solar arrays meet the requirements as the spacecraft flies by perihelion and aphelion.The advanced thermal management study supports the development of the SCOPE program and provides a reference for the thermal management in other deep-space exploration programs.

Application of Large-diameter and Long-span Micro-expansive Pumping Concrete Filled Steel Tube Arch Bridge

In this article the high strength micro-expansive concrete that has been applied on big-diameter and long-span steel arch bridge is researched. The applications show that the concrete has some merits, such as good fluidity, low bleeding ratio and no segregation, low slump loss, high early strength and high later strength, micro-expansion etc.

Insider threat detection approach for tobacco industry based on heterogeneous graph embedding

In the tobacco industry,insider employee attack is a thorny problem that is difficult to detect.To solve this issue,this paper proposes an insider threat detection method based on heterogeneous graph embedding.First,the interrelationships between logs are fully considered,and log entries are converted into heterogeneous graphs based on these relationships.Second,the heterogeneous graph embedding is adopted and each log entry is represented as a low-dimensional feature vector.Then,normal logs and malicious logs are classified into different clusters by clustering algorithm to identify malicious logs.Finally,the effectiveness and superiority of the method is verified through experiments on the CERT dataset.The experimental results show that this method has better performance compared to some baseline methods.

Thoughts on Cultivating New Quality Productive Forces in the Field of Distributed Energy

The 2024 Government Work Report proposes to promote the development and utilization of distributed energy.This marks the inaugural inclusion of“distributed energy”in the Government Work Report.In constructing China’s new energy system,distributed energy stands to encounter substantial growth prospects and urgently requires addressing industry challenges and enhancing the market ecosystem for its advancement.

China's Hydropower Construction and Science Technology Progress in the Five Decades

The achievements of China’s hydropower construction in five decades are shown in the following statistical data. The concise analyses have been made in the aspects of technical economy, geologic exploration, dam construction technique, underground engineering, flood discharging and energy dissipation etc, which represent the achievements and experiences in hydropower technologies.

Constructal design of a rectangular porous fin considering minimization of maximum temperature difference and pumping power consumption

A heat dissipation model of a rectangular porous fin is established based on constructal theory. First, the constructal design of rectangular porous fin is conducted by selecting a complex function minimization, which composed of linear weighting sum of maximum temperature difference and pumping power consumption, as optimization objective. Effects of gap height, air inlet velocity, total porous fin volume and porosity on the optimal constructs are investigated, respectively. The findings show that the complex function can attain its double minimum at a value of 0.802 when the fin length and number are optimized, and the corresponding optimal fin length and number are 8.01 mm and 10, respectively. In comparison to original design, the complex function and maximum temperature difference after twice optimization are decreased by 19.80% and 66.31%, respectively.Second, the comprehensive performance of porous fin is improved by simultaneously optimizing the fin length and number. The artificial neural network is applied to predict the fin performances, which is used to conduct multi-objective optimization based on NSGA-II algorithm. Optimal structure of porous fin for multiple requirements is gained by LINMAP and TOPSIS decisionmaking strategies. The findings in this study can serve as theoretical guides for fin thermal designs of electronic devices.

Impact of Drug-Drug Interaction between CDK4/6 Inhibitors and Proton Pump Inhibitors on Survival Outcomes in the Treatment of Metastatic Breast Cancer—Real World Data from a Portuguese Center

Introduction: Proton pump inhibitors (PPi) are widely prescribed, including in patients undergoing treatment for advanced breast cancer (ABC). Due to the pharmacokinetic characteristics of the CDK4/6 inhibitor (Ci) palbociclib a drug interaction with PPi was hypothesized. It was shown in a retrospective study that this association was an independent predictive factor for worse progression-free survival (PFS). Objective: To verify the impact of concomitant administration of PPi with Ci on overall survival (OS) and PFS. Material and Methods: This is a retrospective cohort study of patients treated with Ci for HR+HER2-ABC in the period from Feb/2017 to Aug/2020. SPSS software was used for data processing. Univariate analysis was done by the Kaplan-Meier method and log-rank test, and multivariate analysis by COX regression. P-value < 0.05 was considered significant. Results: 80 patients were included. The median age at diagnosis of ABC was 56 years (25 - 75). Treatment with Ci was 1st line for ABC in 68.8%. Choice of Ci was palbociclib in 73.8% (n = 59) and ribociclib in 26.3% (n = 21). The hormone partner was a nonsteroidal aromatase inhibitor in 45.0%, and fulvestrant in 55.0% of cases. 37.5% of patients were on PPi, and 70.0% of them were during the entire treatment (23.3% omeprazole, 73.4% pantoprazole, 3.3% others). Patients taking concomitant PPi and Ci had lower OS (OS-3 years 42.6% vs. 63.4%, p = 0.254) and PFS (PFS med 15 m. vs. 21 m., p = 0.733), although with no statistically significant difference. Discussion: In the sample, there was a numerical difference, without the statistical significance in the use of PPi in the survival of patients under Ci. This difference could be more evident with a longer follow-up and a larger sample size. This study intends to alert to the growing importance of checking for drug interactions. Polymedication, advanced age and the presence of several comorbidities are real problems in patients with ABC. Conclusion: Real-world data from this center demonstrate a negative, non-statistically significant impact of PPi treatment on survival outcomes, in patients treated with Ci for HR+HER2-ABC.

地方大学数学类一流课程建设与实践--以临沂大学数学分析课程为例

课程是人才培养的核心要素,课程质量直接决定人才培养质量。数学类课程是大学理工科人才培养的重要支撑,对学生后续学习和发展后劲影响重大,受益面广。该文以临沂大学数学类专业学科基础课程数学分析为例,构建“厚学科基础,强化师资队伍、强化课程思政,优化教学设计、优化教学方法、优化教学考核”的地方大学数学类一流课程建设实践,将师资队伍建设、一流课程建设和教学改革研究紧密结合,在教学质量工程和人才培养等方面取得很好的成效。数学分析课程被教育部认定为首批国家一流课程,建设经验可为数学类专业后继课程和理工科专业高等数学类课程提供重要参考。

构建要素、逻辑序位与路径依赖:农村集体经济从“锁定”到“进阶”实证

农村集体经济是农村集体成员利用集体所有的资源要素开展经济活动的一种经济形态,这意味着最大化资源要素效用是农村集体经济发展的应有之义,是农村与城市一道实现共同富裕的重要途径。文章从经济组织资源要素配置研究文献切题,缕析了农村集体经济发展必备资源要素,并基于案例分析提出打开“黑箱”的逻辑线索,即“开眼”识资源、“格物”纠序位、“优术”明道路“三步进阶”理论假说。同时利用收集的案例数据,依次分析地理区位、制度(政策)、带头人(企业家精神)对农村集体经济发展的作用。结果表明,农村集体经济高质量发展的要素构成中,存在普适性的“地理区位→制度(政策)→带头人(企业家精神)→资本→技术→劳动力→土地”排列逻辑序位,不同序位的资源要素内生经济发展路径依赖。认为坚持最优序位要素本位、依赖精英农民、要素序位纠偏、精准立地最优序位要素引入外部要素是集体经济高质量发展良性路径依赖的四种表现,强化带头人能力提升、建立发展资源县域基础数据库、建立资源要素对接响应及纠偏机制等措施有助于推动农村集体经济高质量发展。

钻爆法机械化施工隧道随钻地震波超前地质探测技术研究

为适应我国隧道建设机械化、智能化、无人化发展趋势,围绕钻爆法机械化施工隧道,提出以凿岩台车破岩振动为震源的钻爆法机械化施工隧道随钻地震波超前地质探测技术。针对凿岩台车多震源连续激发带来的地震数据波场混叠、有效信息难以识别问题开展相关研究,提出VMD-SVD-RobustICA三臂混合先导信号分离方法与脉冲反褶积-小波域互相关地震记录重构方法,可实现三臂混合先导信号的分离与有效反射信号的提取。工程实践证明,利用凿岩台车搭载式无线高精度探测装备,该技术可初步实现“边钻边探”,降低预报环节对钻爆法机械化施工隧道正常施工带来的影响。最后,明确该技术目前存在的问题及解决思路。

《高等桥梁结构理论》英文版教材建设及教学实践

高等桥梁结构理论课程一直是桥梁工程专业研究生的必修课程,也是针对留学生开放的专业课程。从2017—2018学年第一学期开始全英文授课,面向国际学生以及选择英文学习的国内学生。高等桥梁结构理论的英文版教材Advanced Theory of Bridge Structures是在中文版基础上内容适当取舍,主干内容不变,并结合教学课时和教学实践编写的全英文教材。该文首先介绍原中文版课程及教材背景,重点对英文版教材的编写思路、目录编排、选材内容特点等进行较为详细的叙述。同时,经过几年的英文版教学实践,该文也介绍英文版教学在课程建设和学生能力提升等方面的进展情况。

旨在培养科研素养的理工科研究生课程教学改革——以河南大学高级植物生理学为例

培养科研创新能力是研究生教育的核心任务之一,也是研究生培养质量的集中体现。以植物逆境生物学为特色的河南大学生物学科入选国家“双一流”建设行列,对研究生科研创新能力培养提出新的更高要求。高级植物生理学是植物逆境生物学的核心课程,该课程围绕研究生科研素养提升的核心目标采取一系列教学改革举措,通过科研反哺教学、打造精良的教学团队、更新和拓展教学内容、改革教学手段和教学方式、融入课程思政,以及双语教学和考核方式等方面的改革实践,使科研素养培养始终贯穿于课程教学的全过程中,为提升研究生创新意识和创新能力筑牢基础。此课程的教学改革实践为“双一流”大学理工科研究生课程建设提供新的借鉴。

学科交叉背景下研究生“高等数理统计”课程建设路径探析

“高等数理统计”是概率论与数理统计专业研究生的一门核心基础课,其建设质量对研究生后续专业课程的学习和科研素养的提升具有重要意义。文章在学科交叉背景下对该课程的建设路径进行了分析和探索。首先分析了研究生“高等数理统计”课程教学现状,然后从优化教学内容、创新教学模式、强化过程性考核及加强课程思政教育四个维度提出了课程建设的路径,并将课程建设与研究生学术研究背景有机融合,为提升研究生教学质量和培养研究生科研素养提供参考。

高级计算机网络课程建设探讨与实践

计算机网络学科发展迅速,容易造成高级计算机网络课程教学内容滞后于网络技术发展。针对课程建设中存在的这一问题,以及教学过程中存在的重理论轻实践等问题,基于课程实际情况提出建立以网络理论为基础,以前沿技术及应用为内容,以培养科研能力为核心的课程体系,从教学内容和方法、实践教学方式、论文研讨、教学资源共享和课程考核机制等方面进行了分析、探索与实践。教学实践表明,构建的高级计算机网络课程体系不仅培养了学生的专业素养和科学思维方法,而且提升了其实践和创新能力,为其后期从事科研工作奠定了基础。

国家重要先进制造业高地的内涵、特征与建设路径

国家重要先进制造业高地是习近平总书记对新时代湖南在全国大局中的新定位和新要求。深刻认识国家重要先进制造业高地内涵与特征,设计其建设路径,是湖南省绘制制造业发展长远蓝图,制定制造业发展政策的基本前提。研究表明,国家重要先进制造业高地核心是成为具有国际竞争力、国际影响力和发展带动力的先进制造业战略要地,呈现出拥有世界级的先进制造业集群、具有世界先进的核心技术和创新能力、实行绿色集约的发展模式、拥有根植本地能力的产业生态优势、建有开放包容的发展环境、具有示范引领带动作用等六大特征。据此,湖南省打造国家重要先进制造业高地的具体路径可从五方面规划,即打造世界级先进制造业集群、推动先进制造模式示范引领、促进先进制造技术创新、加强先进制造业的人才集聚以及增强先进制造业开放合作活力。

日本桥梁施工工艺技术

针对桥梁结构特点和现场施工条件,日本桥梁技术人员在桥梁施工工艺技术方面做了一些有益的尝试。鹫见桥Ⅱ期工程最高墩高125 m,采用预先在工厂制作部分预制构件的方法,加快了施工进度;Ⅱ期、Ⅰ期工程桥梁间距仅50 cm,为避免Ⅱ期工程施工对Ⅰ期工程运营造成影响,采用了智能预警监控系统。日见梦大桥桥塔端斜拉索采用钢锚箱锚固,塔柱混凝土浇筑采用透明模板监控混凝土浇筑质量。杨梅山高架桥支点梁段采用分层浇筑以及钢筋部品化预制安装等施工工艺,缩短了工期。思惟花笑大桥为主跨150 m的连续刚构桥,最高墩高93 m,箱梁腹板与底板相交处钢筋密集,为确保混凝土填充密实,采用混凝土填充模拟系统确定最佳浇筑方法;该桥跨度大、墩身高,混凝土泵送距离长,通过多项混凝土工艺试验,提高了长距离泵送悬臂浇筑施工质量;采用新研发的三眼照相机对钢筋绑扎质量进行检测,实现了钢筋检测作业自动化。

软弱土层的连拱隧道超前支护有限元分析及施工控制

以江苏某地铁站暗挖换乘通道下穿城市引桥工程为背景,研究连拱隧道穿越软弱土层超前支护施工控制问题,提出连拱隧道超前支护施工控制方法。采用MIDAS-GTS NX建立原始土层和全断面深孔注浆加固+超前小导管支护两种工况下连拱换乘通道的三维实体模型,分析通道开挖施工产生的地表沉降、拱顶沉降及对引桥的影响;根据有限元分析模型,确定连拱隧道超前支护注浆液的类型为AC液体、C液V(水玻璃)∶V(水)=0.6∶0.4,初始压力为0.30~0.75 MPa,终止压力为0.5~1.0 MPa,单位长度的注浆量为0.283 m^(3)。研究结果表明,注浆试验段开挖施工完成后,地表沉降最大值为5.57 mm,小于设计要求的沉降控制值10 mm,超前支护效果良好,能够有效提高连拱隧道加固效果。

大中型泵站施工中自密实混凝土运用分析

自密实混凝土能够满足以泵站为代表的水利水电工程建设发展的要求。基于新时期水利工程建设发展的背景,以水泵工程为主要研究对象,在简单介绍自密实混凝土施工技术应用内容的基础上,结合实际的大中型泵站项目案例,探讨其中应用的自密实混凝土施工技术,明确在实际施工中需要重点关注的内容,旨在为相关工程的施工建设提供借鉴的经验和思路。

强富水区山岭隧道穿越断层破碎带施工技术研究

为降低隧道穿越断层破碎带施工中的涌水突泥风险,该文依托古兜山隧道实体工程,采用“TSP+地质雷达+超前地质钻孔”的地质超前预报技术,探明隧道掌子面前方的地层状况和富水程度,提出富水区隧道穿越断层破碎带施工关键技术。提出隧道洞口明挖法与隧道洞内光面爆破技术及洞内围岩段的双侧壁导坑法、单侧壁导坑法、三台阶七部法的开挖方式;采用S-Ⅴb型隧道衬砌结构型式与全断面帷幕注浆、加强泄水等技术相结合的支护方式,其中的整体承载结构为初期支撑系统和二次模筑衬砌的组合结构。该施工关键技术可有效避免古兜山隧道施工的突水涌泥现象,可指导类似工程的施工。

多源分布式换能系统构建理论方法研究与应用

“双碳”背景下分布式换能系统以其在低碳环保方面的显著优势逐渐在集中供热领域得到应用。本文针对分布式换能系统中热泵、太阳能集热器、板式换热器和燃料电池等关键单元提出了单元能耗评价方法,并通过EES软件对各单元进行了热力学建模以定量评价不同单元在不同工况下的经济性,进而提出分布式换能系统的构建方法以获得流程经济性最优化。以此为依据搭建了最优化流程,并以北京地区某小区为例分析了该系统的供暖季性能,最后进行了经济性和碳减排分析。结果表明:室外温度在-10~5℃范围内变化时,该新型分布式换能系统的COP为2.69~4.43,太阳能集热器效率为45.19%~61.87%,燃料电池日发电量为8047.4~32228.0 kW·h;与常规热力站相比,该新型分布式换能系统的运行成本节省率为32.66%~53.92%,碳减排率为69.07%~73.29%。