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Static balancing of planar articulated robots

Giuseppe QUAGLIA,Zhe YIN

《机械工程前沿(英文)》 2015年 第10卷 第4期   页码 326-343 doi: 10.1007/s11465-015-0355-9

摘要:

Static balancing for a manipulator’s weight is necessary in terms of energy saving and performance improvement. This paper proposes a method to design balancing devices for articulated robots in industry, based on robotic dynamics. Full design details for the balancing system using springs are presented from two aspects: One is the optimization for the position of the balancing system; the other is the design of the spring parameters. As examples, two feasible balancing devices are proposed, based on different robotic structures: The first solution consists of linkages and springs; the other consists of pulleys, cross mechanisms and (hydro-) pneumatic springs. Then the two solutions are compared. Pneumatic, hydro-pneumatic and mechanical springs are discussed and their parameters are decided according to the requirements of torque compensation. Numerical results show that with the proper design using the methodology presented in this paper, an articulated robot can be statically balanced perfectly in all configurations. This paper therefore provides a design method of the balancing system for other similar structures.

关键词: robotics     static balancing     pneumatic spring     mechanical spring     torque compensation    

硅微z轴谐振陀螺仪负电刚度效应分析及实验验证

夏敦柱,周百令,王寿荣

《中国工程科学》 2007年 第9卷 第8期   页码 66-68

摘要:

介绍了在开环工作状态下硅微z轴谐振陀螺仪由于加工工艺缺陷所导致的误差机理。为减小陀螺仪初始电容差和抑制正交耦合误差,提出了一种闭环控制检测策略。重点分析了其力矩反馈器的电刚度效应并给出其线性数学模型表示式。通过对硅微z轴陀螺仪敏感模态的反馈力与谐振频率的关系分析,间接得出了在敏感方向上电负刚度与力矩器所施电压的内在联系,并在实验上进一步验证电刚度效应。这将为下一步闭环控制方案的设计奠定重要基础。

关键词: 硅微z轴陀螺仪     负电刚度     力矩反馈器     微机电系统    

Analysis and characterization of wind-solar-constant torque spring hybridized model

Shantanu ACHARYA,Subhadeep BHATTACHARJEE

《能源前沿(英文)》 2014年 第8卷 第3期   页码 279-289 doi: 10.1007/s11708-014-0312-z

摘要: Solar and wind are the most promising renewable energy resources. But their unpredictable and varying nature prevents them from being used as the sole resource for power generation. This paper presents a model of wind and solar thermal hybrid power plant with a spring storage system which is expected to play an efficient role in combating with the drawbacks related to renewable power generation. In the proposed scheme, wind energy is harnessed by a hybrid vertical axis wind turbine, solar energy is utilized by a Stirling engine, and the surplus energy is stored in a winding spring. The paper discusses the working methodologies and analyses the performance of such 2.6 kW hybrid power plant model. It has been observed that the plant is capable of consistently generating 50% of its rated capacity irrespective of limitations in solar and wind resources.

关键词: hybrid vertical axis wind turbine     Stirling engine     solar-thermal energy     wind energy     constant torque spring    

Back to the spring of Wuhan: facts and hope of COVID-19 outbreak

Guangbiao Zhou, Saijuan Chen, Zhu Chen

《医学前沿(英文)》 2020年 第14卷 第2期   页码 113-116 doi: 10.1007/s11684-020-0758-9

A perspective of “Nuclear Hot Spring” for long-term sustainable economy of the world

Yingzhong LU

《能源前沿(英文)》 2011年 第5卷 第4期   页码 349-357 doi: 10.1007/s11708-011-0168-4

摘要: The rapid growth of human economy in the late 20th century gave rise to great concern over sustainability of the world. A pessimistic “Full World Model” forecasts that human economy could not develop further. The nuclear fission (and fusion later), however, could release huge amount of energy to create sufficient useful material resources and turn the said pessimistic modelinto a new optimistic “Sustainable World Model”.The dilemma of nuclear energy (Military Giant vs. Civil Dwarf) jeopardizes its performance as a “Technologic Fixer”. According to Mother Nature’s teachings, the elimination of the root-causes of the design-based risk factors could solve this problem. Recent technology break-through from inherent safety to natural safety has been made in China. The proposed full-power natural circulation “Nuclear Hot Spring (NHS)” reactor could operate solely on natural forces without complex man-made coolant circulation equipment and human-operated control systems. The cheap, unlimited supply of energy from nuclear energy could change the geopolitics forever, and finally eliminate the root-causes of most international and regional conflicts.

关键词: natural safety reactor     full power natural circulation     sustainable world economy    

Spectral reflectance indices as proxies for yield potential and heat stress tolerance in spring wheat

Caiyun LIU, Francisco PINTO, C. Mariano COSSANI, Sivakumar SUKUMARAN, Matthew P. REYNOLDS

《农业科学与工程前沿(英文)》 2019年 第6卷 第3期   页码 296-308 doi: 10.15302/J-FASE-2019269

摘要:

The application of spectral reflectance indices (SRIs) as proxies to screen for yield potential (YP) and heat stress (HS) is emerging in crop breeding programs. Thus, a comparison of SRIs and their associations with grain yield (GY) under YP and HS conditions is important. In this study, we assessed the usefulness of 27 SRIs for indirect selection for agronomic traits by evaluating an elite spring wheat association mapping initiative (WAMI) population comprising 287 elite lines under YP and HS conditions. Genetic and phenotypic analysis identified 11 and 9 SRIs in different developmental stages as efficient indirect selection indices for yield in YP and HS conditions, respectively. We identified enhanced vegetation index (EVI) as the common SRI associated with GY under YP at booting, heading and late heading stages, whereas photochemical reflectance index (PRI) and normalized difference vegetation index (NDVI) were the common SRIs under booting and heading stages in HS. Genome-wide association study (GWAS) using 18704 single nucleotide polymorphisms (SNPs) from Illumina iSelect 90K identified 280 and 43 marker-trait associations for efficient SRIs at different developmental stages under YP and HS, respectively. Common genomic regions for multiple SRIs were identified in 14 regions in 9 chromosomes: 1B (60–62 cM), 3A (15, 85–90, 101–105 cM), 3B (132–134 cM), 4A (47–51 cM), 4B (71–75 cM), 5A (43–49, 56–60, 89–93 cM), 5B (124–125 cM), 6A (80–85 cM), and 6B (57–59, 71 cM). Among them, SNPs in chromosome 5A (89–93 cM) and 6A (80–85 cM) were co-located for yield and yield related traits. Overall, this study highlights the utility of SRIs as proxies for GY under YP and HS. High heritability estimates and identification of marker-trait associations indicate that SRIs are useful tools for understanding the genetic basis of agronomic and physiological traits.

关键词: genome-wide association study (GWAS)     heat tolerance     spectral reflectance     spring wheat    

Host protection against Omicron BA.2.2 sublineages by prior vaccination in spring 2022 COVID-19 outbreak

《医学前沿(英文)》 2023年 第17卷 第3期   页码 562-575 doi: 10.1007/s11684-022-0977-3

摘要: The Omicron family of SARS-CoV-2 variants are currently driving the COVID-19 pandemic. Here we analyzed the clinical laboratory test results of 9911 Omicron BA.2.2 sublineages-infected symptomatic patients without earlier infection histories during a SARS-CoV-2 outbreak in Shanghai in spring 2022. Compared to an earlier patient cohort infected by SARS-CoV-2 prototype strains in 2020, BA.2.2 infection led to distinct fluctuations of pathophysiological markers in the peripheral blood. In particular, severe/critical cases of COVID-19 post BA.2.2 infection were associated with less pro-inflammatory macrophage activation and stronger interferon alpha response in the bronchoalveolar microenvironment. Importantly, the abnormal biomarkers were significantly subdued in individuals who had been immunized by 2 or 3 doses of SARS-CoV-2 prototype-inactivated vaccines, supporting the estimation of an overall 96.02% of protection rate against severe/critical disease in the 4854 cases in our BA.2.2 patient cohort with traceable vaccination records. Furthermore, even though age was a critical risk factor of the severity of COVID-19 post BA.2.2 infection, vaccination-elicited protection against severe/critical COVID-19 reached 90.15% in patients aged ≥ 60 years old. Together, our study delineates the pathophysiological features of Omicron BA.2.2 sublineages and demonstrates significant protection conferred by prior prototype-based inactivated vaccines.

关键词: SARS-CoV-2     COVID-19     host response     bronchoalveolar lavage fluid (BALF)    

Comparative proteomic analysis of cold responsive proteins in two wheat cultivars with different tolerance to spring

Shujuan ZHANG,Guoqi SONG,Yulian LI,Jie GAO,Jiao WANG,Guiju CHEN,Haosheng LI,Genying LI,Zhendong ZHAO

《农业科学与工程前沿(英文)》 2014年 第1卷 第1期   页码 37-45 doi: 10.15302/J-FASE-2014008

摘要: Spring radiation frost (SRF) is a severe environmental stress which impairs wheat yield and productivity worldwide. To better understand the mechanism of wheat ( ) responding to SRF, a comparative proteomic analysis was performed to analyze the changes of the key proteins in two wheat cultivars Jimai22 and Luyuan301 with high and low tolerance to SRF respectively. A total of 43 differentially expressed proteins (DEPs) which mainly involved in carbohydrate metabolism, amino acid metabolism, resistance proteins and antioxidant enzymes, photosynthesis and cellular respiration proteins, cell-wall related proteins, protein translation/processing/degradation and signal transduction were isolated and identified by two-dimensional electrophoresis and MALDI-TOF-TOF MS. The results revealed that of the 21 DEPs in Jimai22 responding to the SRF, 13 DEPs were upregulated and 8 DEPs were downregulated, and that of the 22 DEPs in Luyuan301, 9 DEPs were upregulated and 13 DEPs were downregulated. These DEPs might be responsible for the stronger cold resistance of Jimai22 compared to Luyuan301. The expression pattern and function analysis of these DEPs were very significant to understanding the mechanism of the SRF responses in wheat.

关键词: common wheat     spring radiation frost     proteomic analysis     2-DE     MALDI-TOF-TOF MS    

螺旋管簧的可靠性优化设计

张义民,贺向东,闻邦椿

《中国工程科学》 2002年 第4卷 第5期   页码 71-74

摘要:

讨论了螺旋管簧的可靠性优化设计问题。在基本随机变量的概率特性已知的情况下,采用二阶矩法和可靠性优化设计方法对螺旋管簧进行了可靠性优化设计,通过计算机程序可以直接实现螺旋管簧的可靠性优化设计,迅速准确地得到螺旋管簧的可靠性优化设计信息。

关键词: 螺旋管簧     可靠性     优化设计     二阶矩技术    

不完全概率信息的车辆常用弹簧的可靠性灵敏度设计

张义民,刘巧伶,闻邦椿

《中国工程科学》 2004年 第6卷 第1期   页码 74-80

摘要:

将可靠性设计理论与灵敏度分析方法相结合,讨论了车辆常用弹簧的可靠性灵敏度设计问题,提出了可靠性灵敏度设计的计算方法,给出了可靠性灵敏度的变化规律,研究了设计参数的改变对车辆常用弹簧可靠性的影响,为车辆常用弹簧的可靠性设计提供了理论依据。

关键词: 车辆常用弹簧     可靠性设计     灵敏度     任意分布参数    

A bionic approach for the mechanical and electrical decoupling of an MEMS capacitive sensor in ultralow

《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-023-0747-1

摘要: Capacitive sensors are efficient tools for biophysical force measurement, which is essential for the exploration of cellular behavior. However, attention has been rarely given on the influences of external mechanical and internal electrical interferences on capacitive sensors. In this work, a bionic swallow structure design norm was developed for mechanical decoupling, and the influences of structural parameters on mechanical behavior were fully analyzed and optimized. A bionic feather comb distribution strategy and a portable readout circuit were proposed for eliminating electrostatic interferences. Electrostatic instability was evaluated, and electrostatic decoupling performance was verified on the basis of a novel measurement method utilizing four complementary comb arrays and application-specific integrated circuit readouts. An electrostatic pulling experiment showed that the bionic swallow structure hardly moved by 0.770 nm, and the measurement error was less than 0.009% for the area-variant sensor and 1.118% for the gap-variant sensor, which can be easily compensated in readouts. The proposed sensor also exhibited high resistance against electrostatic rotation, and the resulting measurement error dropped below 0.751%. The rotation interferences were less than 0.330 nm and (1.829 × 10−7)°, which were 35 times smaller than those of the traditional differential one. Based on the proposed bionic decoupling method, the fabricated sensor exhibited overwhelming capacitive sensitivity values of 7.078 and 1.473 pF/µm for gap-variant and area-variant devices, respectively, which were the highest among the current devices. High immunity to mechanical disturbances was maintained simultaneously, i.e., less than 0.369% and 0.058% of the sensor outputs for the gap-variant and area-variant devices, respectively, indicating its great performance improvements over existing devices and feasibility in ultralow biomedical force measurement.

关键词: micro-electro-mechanical system capacitive sensor     bionics     operation instability     mechanical and electrical decoupling     biomedical force measurement    

Analysis of the dynamic hysteresis characteristic of finger seal

LEI Yanni, CHEN Guoding

《机械工程前沿(英文)》 2007年 第2卷 第1期   页码 32-36 doi: 10.1007/s11465-007-0005-y

摘要: The research about hysteresis characteristic of finger seal (FS), which was carried out based on the model with static loads, could not reflect the dynamics behavior of FS system when the rotor runs at high speed. To solve this problem, the relations between the dynamics parameters, structure parameters as well as working parameters in the system were given out through the analysis of finite element analysis result. A mass spring damper dynamics model of FS system was proposed and the hysteresis characteristic of the FS system was analyzed. This work shows that the dynamics characteristic analysis of the FS is necessary and the dynamics model proposed in this paper is valid. This dynamics model is the basis for the optimization design of FS system.

关键词: FS     necessary     hysteresis characteristic     optimization     spring    

月球车叶片伸缩式步行轮的力学分析和性能优化 Article

杨璐, 蔡博文, 张荣辉, 李克宁, 张子贤, 雷洁浩, 陈百超, 王荣本

《工程(英文)》 2020年 第6卷 第8期   页码 936-943 doi: 10.1016/j.eng.2020.07.009

摘要:

在探月工程计划中,月球车的车轮系统是月球车总体设计系统的重要子系统之一。由于月表地形复杂,同时受限于月球车有限的空间,因此大大增加了车轮系统设计和优化工作的难度。本研究的主要目标是针对自主设计的月球车机械结构,建立一个原理型样机以对其性能进行优化。研究的主要工作包括:为应对月表复杂路况,提出了一种适配月球车正反四边形悬架的新型叶片伸缩式步行轮;以功耗最小化为目标,在保证障碍通过性的前提下,分析车轮运动过程中受力情况以实现对车轮的性能优化;最后,基于数字仿真和综合实验方法,验证了新型车轮系统在实际实验中可以达到按需伸缩叶片和节约能耗的效果。本文的研究成果为中国月球车的研究和开发提供了一种技术参考。

关键词: 特种智能载具     叶片伸缩式步行轮     性能优化     叶片弹簧     月球车    

Determination of mechanical parameters for elements in meso-mechanical models of concrete

Xianglin GU, Junyu JIA, Zhuolin WANG, Li HONG, Feng LIN

《结构与土木工程前沿(英文)》 2013年 第7卷 第4期   页码 391-401 doi: 10.1007/s11709-013-0225-7

摘要: The responses of cement mortar specimens of different dimensions under compression and tension were calculated based on the discrete element method with the modified-rigid-body-spring concrete model, in which the mechanical parameters derived from macro-scale material tests were applied directly to the mortar elements. By comparing the calculated results with those predicted by the Carpinteri and Weibull size effects laws, a series of formulas to convert the macro-scale mechanical parameters of mortar and interface to those at the meso-scale were proposed through a fitting analysis. Based on the proposed formulas, numerical simulation of axial compressive and tensile failure processes of concrete and cement mortar materials, respectively were conducted. The calculated results were a good match with the test results.

关键词: concrete     meso-mechanical model     discrete element method     size effect     mechanical parameter    

Facile synthesis of polyaniline nanorods to simultaneously enhance the mechanical properties and wear

《化学科学与工程前沿(英文)》 2023年 第17卷 第9期   页码 1254-1266 doi: 10.1007/s11705-023-2297-3

摘要: To enhance the mechanical properties and wear resistance of epoxy resin, polyaniline nanorods were first synthesized using a facile route, and then introduced into the epoxy matrix to yield composites via solution mixing. Several measurements were conducted to investigate the phase structures and compositions of polyaniline nanorods, and their positive influences on the mechanical and tribological properties of epoxy resin were also characterized. The results confirmed that the as-synthesized polyaniline exhibited representative rod-like morphologies and dispersed well in the epoxy matrix, leading to significant enhancements in the tensile strength and elastic modulus of epoxy composites. The highest values of 110.33 MPa and 2.04 GPa were obtained by adding 5%–7% polyaniline nanorods, which were 43% and 62% higher than the pure sample, respectively. The wear rate was increased first and then decreased along with polyaniline nanorods, presenting the lowest value of 2.12 × 10−5 mm3·Nm–1 by adding 5% filler, which was markedly reduced by ca. 70% compared to the control sample. Finally, the possible wear mechanism was proposed and discussed in detail. This study tried to broaden the applications of polyaniline nanorods in the field of tribology.

关键词: epoxy resin     polyaniline nanorods     mechanical property     tribological performance     wear mechanism    

标题 作者 时间 类型 操作

Static balancing of planar articulated robots

Giuseppe QUAGLIA,Zhe YIN

期刊论文

硅微z轴谐振陀螺仪负电刚度效应分析及实验验证

夏敦柱,周百令,王寿荣

期刊论文

Analysis and characterization of wind-solar-constant torque spring hybridized model

Shantanu ACHARYA,Subhadeep BHATTACHARJEE

期刊论文

Back to the spring of Wuhan: facts and hope of COVID-19 outbreak

Guangbiao Zhou, Saijuan Chen, Zhu Chen

期刊论文

A perspective of “Nuclear Hot Spring” for long-term sustainable economy of the world

Yingzhong LU

期刊论文

Spectral reflectance indices as proxies for yield potential and heat stress tolerance in spring wheat

Caiyun LIU, Francisco PINTO, C. Mariano COSSANI, Sivakumar SUKUMARAN, Matthew P. REYNOLDS

期刊论文

Host protection against Omicron BA.2.2 sublineages by prior vaccination in spring 2022 COVID-19 outbreak

期刊论文

Comparative proteomic analysis of cold responsive proteins in two wheat cultivars with different tolerance to spring

Shujuan ZHANG,Guoqi SONG,Yulian LI,Jie GAO,Jiao WANG,Guiju CHEN,Haosheng LI,Genying LI,Zhendong ZHAO

期刊论文

螺旋管簧的可靠性优化设计

张义民,贺向东,闻邦椿

期刊论文

不完全概率信息的车辆常用弹簧的可靠性灵敏度设计

张义民,刘巧伶,闻邦椿

期刊论文

A bionic approach for the mechanical and electrical decoupling of an MEMS capacitive sensor in ultralow

期刊论文

Analysis of the dynamic hysteresis characteristic of finger seal

LEI Yanni, CHEN Guoding

期刊论文

月球车叶片伸缩式步行轮的力学分析和性能优化

杨璐, 蔡博文, 张荣辉, 李克宁, 张子贤, 雷洁浩, 陈百超, 王荣本

期刊论文

Determination of mechanical parameters for elements in meso-mechanical models of concrete

Xianglin GU, Junyu JIA, Zhuolin WANG, Li HONG, Feng LIN

期刊论文

Facile synthesis of polyaniline nanorods to simultaneously enhance the mechanical properties and wear

期刊论文