CALCULATION OF THREE－DIMENSIONAL SOLDER JOINT FORMATION IN MICROELECTRONIC SURFACE MOUNT TECHNOLOGY

A finite element analysis for calculating three-dimensional(3-D) solder joint shape between chip component and substrate pad was carried out, and the effects of solder volume and pad extension beyond the edge of component on solder joint shapes were investigated. The resonable design ranges of solder volume and pad extension have been put forward.

Joint Bearing Mechanism of Coal Pillar and Backfilling Body in Roadway Backfilling Mining Technology

In the traditional mining technology,the coal resources trapped beneath surface buildings,railways,and water bodies cannot be mined massively,thereby causing the lower coal recovery and dynamic disasters.In order to solve the aforementioned problems,the roadway backfilling mining technology is developed and the joint bearing mechanism of coal pillar and backfilling body is presented in this paper.The mechanical model of bearing system of coal pillar and backfilling body is established,by analyzing the basic characteristics of overlying strata deformation in roadway backfilling mining technology.According to the Ritz method in energy variation principle,the elastic solution expression of coal pillar deformation is deduced in roadway backfilling mining technology.Based on elastic-viscoelastic correspondence principle,combining with the burgers rheological constitutive model and Laplace transform theory,the viscoelastic solution expression of coal pillar deformation is obtained in roadway backfilling mining technology.By analyzing the compressive mechanical property of backfilling body,the time formula required for coal pillar and backfilling body to play the joint bearing function in roadway backfilling mining technology is obtained.The example analysis indicates that the time is 140 days.The results can be treated as an important basis for theoretical research and process design in roadway backfilling mining technology.

The study of measuring technology on the dynamic mechanical properties of welded joint with high strainrate

In this paper, to meet the needs of studying work of dynamic mechanical properties of welded joint, the dynamic mechanical properties of welded joint were measured by means of SHPB(Split Hopkinson Pressure Bar).The dynamic mechanical property's curves of every part of welded joint were obtained. For studying the dynamic behavior of mechanical heterogeneity of welded joint, important data were offered. The method of test creates a new way of studying dynamic mechanical properties of welded joint.

Implementing an innovated liver ex-situ machine perfusion technology:The 2018 Joint International Congress of ILTS,ELITA and LICAGE

The 2018 Joint International Congress of ILTS,ELITA and LICAGE were held in Lisbon,Portugal on May 23–26,2018.The exciting and innovative program brought together 1144 experts in liver transplantation(LT)such as surgeons,physicians or basic scientists from 61 countries.The presentations included 110 invited speakers,181 oral presentations,and 545 posters.This editorial highlights some of the most innovative and impactful presentations in

National Joint Engineering Research Center of High Performance Metal Wear Resistant Materials Technology

Founded in 2012,the National Joint Engineering Research Center of High Performance Metal Wear Resistant Materials Technology at Jinan University,one of the'211'key national universities in China,specializes in the research and development of iron based wear resistant materials and their casting technologies to provide support to the production process.The Research Center serves the'Guangdong Province Ceeusro Innovation Platform for Common Technology of High Performance Wear Resistant Materials”,“Guangdong Province Engineering Research Center for Wear Resistant and Special Functional Materials”.

The First China-USA Joint Conference on Distillation Technology (CUJCDT'2004) Call for Papers

For boosting the research and development of distillation technology, the First China-USA Joint Conference on Distillation Technology (2004) will be held in Tianjin University on June 15-17, 2004. The conference is sponsored by Separation Division of AIChE, National Natural Science Foundation of China, Chemical Industry and Engineering Society of China, and

The First China-USA Joint Conference on Distillation Technology (CUJCDT'2004) Call for Papers

For boosting the research and development of distillation technology, the First China-USA Joint Conference on Distillation Technology (2004) will be held in Tianjin University on June 15-17, 2004. The conference is sponsored by Separation Division of AIChE, National Natural Science Foundation of China, Chemical Industry and Engineering Society of China, and

JOINT EFFORTS FOR FURTHER DEVELOPMENT——Prospects for Science and Technology Cooperation between Hong Kong and the Mainland

There is a long tradition of friendly exchange and cooperation between the Chinese Academy of Sciences (CAS) and the universities in Hong Kong. In recent years, both sides have been increasingly realizing the importance of furthering their Collaboration and exchange and the cooperation has become more active, laying greater

Research on Decision Model of Control over Technology Standard Alliance

Technology standard alliance, as vectors of research, development and circulation for technology standard, has already become an important transformation form from laboratory standard to fact standard for all countries. However, during the process of forming the technology standard alliance, it is a focus for members in the alliance to take control over others. How to construct a scientific and reasonable decision model of control over technology standard alliance is closely related to each enterprise member＇s interest. Under the condition that the risk is neutral, the paper explored necessary and sufficient conditions of knowledge sharing and the most endeavor among enterprise members through constructing a decision model of control over technology standard alliance, and put forward that the joint control model was the best decision model for constructing the technology standard alliance.

BIM Technology in Application of Structure Construction in Hubei Olympic Sports Center

With the rapid development of modern large-span and large-complex steel structure buildings,at present the Building Information Modeling(BIM)technology plays an important role from the design to the construction of a building.This study takes the Comprehensive Gymnasium of Hubei Olympic Sports Center as the carrier and introduce the BIM technology from two aspects;The technology;and the management.Further,the optimal application of BIM technology in the complex component nodes,the technical guidance of component processing,and the correction and verification of drawings were emphatically analyzed in this paper.An engineering practice shows that the application of BIM technology has greatly improved the production efficiency,shortened the construction period,reduced unnecessary cost,and lastly laid a solid foundation for the smooth completion of the project.

隧道不良地质识别:方法、现状及智能化发展方向

随着隧道施工对于不良地质识别精度要求的不断提高以及人工智能技术的发展,融合多源信息的不良地质智能化识别已成为发展趋势。本文首先阐述了常见的6种隧道不良地质类型及其地质成因,回顾分析了隧道主要的不良地质识别方法及现状,详细介绍了笔者在不良地质智能化识别方面的探索性研究:基于机器学习利用图像识别技术对隧道围岩岩性与裂隙特征进行智能识别;融合图像和光谱特征进行不良地质识别;将地化分析融入到传统的超前钻探中,融合随钻参数和地化信息进行不良地质随钻识别,既可以发挥超前钻探在感知岩体质量和地层信息变化方面的优势,又可以发挥地化分析在岩性和不良地质异常识别方面的优势;基于地质与物探联合反演进行不良地质识别,旨在实现掌子面前方不良地质体“形”(位置、形态、规模)和“性”(性质和类型)的精确识别。最后,对隧道不良地质智能化识别的发展趋势进行了展望。

磁共振T1rho序列、T2 mapping技术在膝关节早期软骨退变早期诊断中的评估价值

目的探讨磁共振T1rho序列、T2 mapping技术在膝关节早期软骨退变早期诊断中的评估价值。方法选取2020年1月至2022年11月在我院治疗的110例膝关节早期软骨退变患者(观察组),按照疾病严重程度分为轻度退变组及重度退变组,另选取同期在我院进行体检的64例健康者为对照组,受试者均行磁共振T1rho序列、T2 mapping技术扫描,测量受试者T2值及T1ρ值,探讨磁共振T1rho序列、T2 mapping技术在膝关节早期软骨退变早期诊断中的评估价值。结果观察组股骨外侧面、股骨内侧面、胫骨外侧面、胫骨内侧面、髋骨面T2值均明显高于对照组(P<0.05),重度退变亚组患者股骨外侧面、股骨内侧面、胫骨外侧面、胫骨内侧面、髋骨面T2值显著高于轻度退变者(P<0.05);观察组股骨内踝负重区、股骨内踝非负重区、股骨外踝负重区、股骨外踝非负重区、胫骨外侧平台区、胫骨内侧平台区、髌后软骨区磁共振T1ρ值明显高于对照组(P<0.05),重度退变亚组患者股骨内踝负重区、股骨内踝非负重区、股骨外踝负重区、股骨外踝非负重区、胫骨外侧平台区、胫骨内侧平台区、髌后软骨区磁共振T1ρ值明显高于轻度退变亚组患者(P<0.05);磁共振T1rho序列在膝关节早期软骨退变中早期诊断及严重程度评估中的的诊断ROC值及特异度明显高于T2 mapping技术(P<0.05),但后者具有更高的敏感度(P<0.05)。结论磁共振T1rho序列、T2 mapping技术均能有效反映膝关节早期软骨退变中软骨组织学成分变化情况,还可为膝关节软骨退变严重程度评估提供客观依据,二者具有一定互补价值。

周边孔聚能装置间隔装药在光面爆破中的应用研究

隧道光面爆破工程的周边孔需要采用间隔装药方式,而大部分间隔装药方式采用“导爆索+雷管”联合起爆技术,此技术具有一定的局限性且经常发生拒爆现象。如何在保证隧道掘进效率的前提下提高光面爆破效果成为目前亟待解决的难题,从现场试验方面开展相关研究,提出“聚能装置+数码电子雷管”新型联合起爆技术,将其应用于高原某隧道,通过与原始的“导爆索+数码电子雷管”联合起爆技术的爆破后效果进行对比分析。实验结果表明:对比原始技术,新技术炸药单耗降低了0.2 kg/m^(3),半孔留痕率提高了5%,平均装药时间由原来的1.3 h降为1.0 h,稳定循环进尺的同时极大降低了耗材费用,提高了隧道光面爆破效果。

基于分层多智能体的多星联合任务规划架构研究

随着卫星规模、种类的不断增长,现有卫星任务规划技术架构已很难满足多类型卫星联合运用的有效性及可扩展性要求。通过深入分析多星任务筹划、单星任务规划、数传资源规划等环节,建立了基于分层多智能体的多星联合任务规划技术架构,设计了与架构匹配的相关优化算法及智能体功能实现机制,实现了多星联合任务规划能力。仿真实验及分析结果表明,该架构对多类型卫星联合任务规划场景有良好的适用性。

iFlow彩色血流编码成像技术在下肢动脉硬化闭塞症诊断中的应用价值

目的研究iFlow彩色血流编码成像技术在下肢动脉硬化闭塞症(LEASO)诊断中的应用价值。方法选择2022年3月至2023年10月期间确诊的106例LEASO患者作为本研究的LEASO组,以一般资料与LEASO组匹配且无动脉病变的80例志愿者作为对照组。两组受试者均进行数字减影血管造影(DSA)并采用iFlow彩色血流编码成像技术检测股骨头区域和踝关节区域达峰时间(TTP)、计算踝关节区域与股骨头区域TTP的差值,测量踝肱指数(ABI)。结果两组研究对象年龄、性别、体质量指数、吸烟史、高血压病史、糖尿病史、冠心病史、股骨头区域TTP的比较,差异无统计学意义(P>0.05);LEASO组踝关节区域TTP及TTP差值均高于对照组,差异有统计学意义(P<0.05);LEASO组中不同Rutherford分类患者股骨头区域TTP的比较以及左侧病变患者与右侧病变患者股骨头区域TTP、踝关节区域TTP、TTP差值的比较,差异无统计学意义(P>0.05),Rutherford分类越高,踝关节区域TTP及TTP差值越低(P<0.05);经Pearson检验,LEASO患者的踝关节区域TTP、TTP差值与ABI呈负相关(P<0.05);经受试者工作特征(ROC)曲线分析,踝关节区域TTP、TTP差值对LEASO具有诊断效能;经Delong检验,TTP差值诊断的ROC曲线下面积高于踝关节区域TTP(P<0.05)。结论iFlow彩色血流编码成像技术测定踝关节区TTP及TTP差值是诊断LEASO的量化指标。

基于能量最小化的CCGA焊点形态仿真研究

为了确定某陶瓷柱栅阵列(CCGA)器件实现高焊接可靠性时的工艺参数组合范围,并研究焊点形态随不同参数变化的规律,以钎料润湿角、钎料体积以及焊柱偏移量作为关键变量因素,利用基于能量最小化原理的Surface Evolver软件,计算了不同因素水平组合下的实际焊点形态,并对参数化建模过程进行了详细介绍。通过对比形态结果与焊点可接收标准,寻找能够产生合格焊点的参量范围,为实际焊点微连接生产工艺提供合理的工艺指导。

地方应用型高校拔尖创新人才培养的实践与思考——以延边大学农学院为例

文章以延边大学农学院为例,分析了在新农科背景下地方应用型大学拔尖创新人才培养存在的问题,并以校企联合技术创新实验室为依托阐述了拔尖创新人才培养的经验做法,提出了日常运行管理模式、创新实验项目运行模式、科研项目运行模式等加快拔尖创新人才培养的模式,旨在深化产学研合作,促进拔尖创新人才创新能力和实验、实践能力提升,为地方应用型高校拔尖创新人才培养提供借鉴和参考。

中俄航空航天类创新型人才国际合作培养模式探索与实践

在当前国际局势复杂多变的背景下,探讨了中俄航空航天领域创新型人才联合培养模式。首先分析了中俄“新时代全面战略协作伙伴关系”的重要意义,指出俄罗斯为我国重要的教育合作对象。随后阐述了中俄高等教育合作的现状和研究进展,提出在航空航天领域开展国际科技合作具有重要意义。强调围绕中俄航空航天类创新型人才联合培养模式的研究空白,急需培养精通航空航天专业知识且熟练掌握俄语的高层次专门人才。最后,明确了研究目标,即探索中俄航空航天类高层人才联合培养模式,为我国培养复合型专门人才及创新型人才教育综合改革提供重要支撑。

区域职业教育与科创产业联动发展的内在逻辑、现实困境及应对策略

科创产业的跨界进阶,使智能机器成为有“智慧”的“能工巧匠”,替代人类劳动的形式日趋多样、边界日趋宽广,为强化人在技术逻辑层面的主体地位,预防大规模“技术性失业”,加快职业教育与科创产业的联动发展成为值得探讨的新路径。职业教育与科创产业联动发展主要表现为科技创新的技能化和技能升级的科技化,推动二者的联动发展,需要运用结构联动—功能联动—价值联动的系统思维,实施科技创新与技能升级双轮驱动,着力解决职业教育与科创产业目标错位、机制失衡、价值偏离的困境,全面促进区域职业教育整体布局与经济社会的和谐发展,这既是教育资源配置的理论问题,也是教育服务民生的实践问题。