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Flow Field Simulation and Parameter Analysis of Hydraulic Unbalanced Bionic Self-recovery Actuator for Rotary Equipment

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Journal of Bionic Engineering 2024年第1期21卷 325-343页

作者： wei li Xin Pan Dehong Ge Jinji gao Key Laboratory of Engine Health Monitoring-Control and Networking of Ministry of Education Beijing University of Chemical TechnologyBeijing 100029China Beijing Key Laboratory of High-End Mechanical Equipment Health Monitoring and Self-Recovery Beijing University of Chemical TechnologyBeijing 100029China

The rotor is the most important component of rotating machinery,and the vibration produced by its mass unbalance has a serious influence on the secure and steady operation of the machine,so an effective online suppression technology is urgently needed.A new hydraulic unbalanced bionic self-recovery system is introduced,imitating the way of manually repairing faulty *** accomplish the effect of actuator mass redistribution,the technology employs pressurized air to drive the quantitative transfer of liquid in the reservoir cavity at opposite *** can complete the online adjustment of the equipment's balancing state and suppress the unbalanced vibration of equipment in real time,which gives the equipment the ability to maintain an autonomous health state and improve equipment *** composition and working principle of the system are introduced in detail,and the key performance parameters,such as the minimum running speed and the balancing liquid transfer speed,are analyzed *** fluid-solid coupling model of the actuator was established,and the two-phase flow from inside the hydraulic unbalanced bionic self-recovery actuator was simulated under multiple working conditions and the performance parameters were quantitatively analyzed.A balancing simulation test bed was built,and its effectiveness was verified by performance parameter tests and unbalanced bionic self-recovery *** experimental results show that the mass distribution adjustment of the balancing disk can be achieved using different viscosity balancing liquid,and the response of liquid viscosity 10 cSt is faster than that of liquid viscosity 100 cSt in the process of balancing liquid transfer,and the time is reduced by more than 75%;the system can reduce the simulated rotor amplitude from 18.3μm to 10.6μm online in real time,which provides technical support for the subsequent development of a new generation of bionic intelligent equipment.

关键词： Engineering self-recovery-Bionics Simulation analysis Self-recovery regulation

Effect of oxide inclusions on MnS precipitates and tensile mechanical property of high-strength low-alloy steel

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Journal of Iron and Steel Research International 2024年第5期31卷 1210-1220页

作者： Xiao-yong gao Hong wei li-feng Zhang School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Materials Science and Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing100144China

The key role of oxide inclusions on the microstructure and mechanical property of a high-strength low-alloy steel was *** field emission scanning electron microscope equipped with energy-dispersive spectrometry was used to characterize MnS *** inclusions play an important role in the shape control of MnS *** oxides fovored to decrease the size and the aspect ratio of MnS *** less oxide inclusions in the steel,approximately over 16.7%MnS precipitates were with aspect ratio a>5 and pure MnS precipitates accounted for 75.9%in ***,with more oxide inclusions in the steel,only 7.4%MnS precipitates were with a>5 and pure MnS precipitates accounted for 60.1%in *** of MnS by oxide inclusions improved the strength and inhibited the *** oxide inclusions in the steel increased the yield strength and tensile strength of the steel in both longitudinal and transverse directions,and lowered the anisotropy of the mechanical property.

关键词： High-strength low-alloy steel MnS Oxide inclusion Mechanical property Anisotropy

Variable Selection for Generalized linear Model with Highly Correlated Covariates

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1458-1480页

作者： li li YUE wei Tao WANG gao Rong li School of Statistics and Data Science Nanjing Audit UniversityNanjing 211815P.R.China School of Mathematics Statistics and MechanicsBeijing University of TechnologyBeijing 100124P.R.China School of Statistics Beijing Normal UniversityBeijing 100875P.R.China

The penalized variable selection methods are often used to select the relevant covariates and estimate the unknown regression coefficients simultaneously,but these existing methods may fail to be consistent for the setting with highly correlated *** this paper,the semi-standard partial covariance(SPAC)method with Lasso penalty is proposed to study the generalized linear model with highly correlated covariates,and the consistencies of the estimation and variable selection are shown in high-dimensional settings under some regularity *** simulation studies and an analysis of colon tumor dataset are carried out to show that the proposed method performs better in addressing highly correlated problem than the traditional penalized variable selection methods.

关键词： Generalized linear model highly correlated covariates Lasso penalty semi-standard partial covariance variable selection

A brief review of tribological properties for black phosphorus

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Friction 2024年第5期12卷 823-844页

作者： Fanfan LV wei WANG Jinjin li Yuan gao Kuaishe WANG College of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710055China State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing10084China

Black phosphorus (BP) is a new class of two-dimensional (2D) layered material, which shows the unanticipated characteristics in many aspects including electronics, transistors, sensors, energy storage, batteries, photocatalysis, and other applications due to its high charge carrier mobility, tunable direct bandgap, and unique in-plane anisotropic structure. In addition, BP has drawn tremendous attention in the field of tribology due to the low shear strength, the layered structure, and the weak connected force between the layers by van der Waals interaction. In recent years, many significant progresses have been made in experimental studies on BP materials as solid lubricants or lubrication additives. This work offers a review of researching regarding the tribological properties of BP. Moreover, the lubrication mechanisms of BP as the lubrication additive including the formation of the tribo-film, micro-bearing effect, and self-repair performance are also summarized. Finally, the current challenges and prospects of BP material as lubricant are proposed.

关键词： black phosphorus(BP) two-dimensional(2D)layered material lubrication additives tribological mechanisms

Effects of microwave post-treatments on leaching resistance of ACQ-D treated Chinese fir

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Forestry Studies in China 2010年第1期12卷 1-8页

作者： YU li-li gao wei CAO Jin-zhen TANG Zhen-zhong College of Materials Science and Technology Beijing Forestry University Beijing 100083 P. R. China

In order to improve the leaching resistance of active ingredient-copper in ammoniacal copper quat-type D （ACQ-D） treated Chinese fir （Cunninghamia lanceolata Hook.）, microwave post-treatments were carried out. The percentages of leached copper from ACQ-D treated Chinese fir with different microwave post-treatments were obtained after leaching tests by analyzing the copper retention in treated wood. The fixation mechanism of copper in the treated wood was determined with the help of SEM and FTIR spectra, while the valence conversion of copper after microwave post-treatments was studied by UV spectroscopy. Our experimental results show that the percentage of leached copper was reduced significantly after microwave post-treatment over time. This development was reinforced by allowing even more time for the treatment as well as with an increase in the power of microwave post-treatment. The leaching resistance of copper in wrapped samples was better than that in unwrapped samples, which is attributed to the combined effects of temperature and moisture content. Compared with air-dried samples, the valence conversion in the samples with microwave post-treatments changed slightly, which demonstrates that microwave post-treatments cannot impair the natural decay resistance of ACQ-D treated wood. SEM and FTIR spectra showed the presence of crystal particles formed by chemical reactions between copper and wood ingredients in wood cell walls and wood pits. Only a small amount of copper reacted with cellulose, while lignin and hemicellulose were the major bonding sites for copper in wood. Given the experimental results of mechanical properties, microwave post-treatments had a slight effect on the compression strength parallel to the grain and on the erystallinity of ACQ-D treated Chinese fir.

关键词： Chinese fir (Cunninghamia lanceolata Hook.) ammoniaeal copper quaternary ammonium salts type D (ACQ-D) copper leaching resistance microwave post-treatment

Dynamic shielding of bacterial outer membrane vesicles for safe and efficient chemo-immunotherapy against tumors

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Nano Research 2024年第2期17卷 836-847页

作者： Shuping li Xin li Jiaqi Meng weier Bao Shuang Wang Peng Ye Xiao-Dong gao wei wei Key Laboratory of Carbohydrate Chemistry and Biotechnology Ministry of Education School of BiotechnologyJiangnan UniversityWuxi 214122China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

Bacterial outer membrane vesicles(OMVs)are potent immunostimulants of regulating the tumor microenvironment(TME)for immunotherapy,and can be used to deliver ***,the severe systemic inflammatory response triggered by OMVs upon intravenous(i.v.)injection has limited their ***,we developed a safe and effective strategy by conjugating doxorubicin-loaded serum albumin(SA-DOX,AD)onto the surface of OMVs using a matrix metalloproteinase(MMP)-cleavable peptide linker(cL).This approach enabled the dynamic shielding of OMVs to reduce the systemic side effects while simultaneously enhancing the anti-tumor effects through ***,the resulting OMV-cL-AD formulation exhibited significantly enhanced accumulation at the tumor site after ***,facilitated by the SA decoration on the OMVs ***,the shield on the OMV-cL-AD was cleaved by the over-expressed MMP in the TME,leading to the release of both OMVs and *** process provided OMV-induced immunotherapy and DOX-induced chemotherapy,resulting in synergistic tumor *** conclusion,our work demonstrated the potential of OMV-cL-AD as an effective immunochemotherapy strategy that can prolong the survival time of mice without inducing side effects.

关键词： outer membrane vesicles doxorubicin tumor microenvironment immunotherapy chemotherapy

Experimental research on the microclimate in the naturally ventilated multi-span greenhouse

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International Journal of Agricultural and Biological Engineering 2024年第3期17卷 68-74页

作者： Zhenjun gao Wenyang li wei li Xiaoming Ding College of Mechanical and Power Engineering China Three Gorges UniversityYichang 443002HubeiChina Guangdong Modern Agricultural Equipment Research Institute Guangzhou 510630China Key Laboratory of Agricultural Facilities Structural Engineering Academy of Agricultural Planning and EngineeringMinistry of Agriculture and Rural AffairsBeijing 100125China

In order to further understand the changing laws of environmental factors in large multi-span greenhouses under natural ventilation conditions and the internal relations between various environmental factors,and ultimately improve the precision of microclimate regulation of large multi-span *** the multi-span greenhouse with a small spire structure in the Demonstration Base of Guangdong Agricultural Technology Extension Station as the research object,under the condition of natural ventilation with butterfly-shaped windows,the changes in temperature,humidity,wind speed and solar light intensity of different monitoring planes in the greenhouse were *** analyzing the monitoring data,it was found that:1)The temperature gradient in the vertical direction in the large multi-span greenhouse is more obvious than that in the small greenhouse,and the highest average temperature difference monitored can reach 7.9℃.The velocity field in the multispan greenhouse is always maintained within the range of 0.3-0.4 m/s,and the ambient wind speed has no effect on the airflow speed in the *** humidity and speed in the multi-span greenhouse show good uniformity.2)In a large multi-span greenhouse,the secondary radiation generated by the internal shading has less impact on the area near the ground,which can effectively reduce the ground temperature.3)Under the conditions studied in this research,the temperature and humidity in the greenhouse follow the external environment as well,showing that the greenhouse design is reasonable,and the air renewal and heat exchange inside and outside the greenhouse are good during natural ventilation.

关键词： natural ventilation multi-span greenhouse environmental factors microclimate

Structural Evolution of Ultra-High Molecular weight Polyethylene Low-Entangled Films with Reserved Shish Crystals During Hot Stretching

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Chinese Journal of Polymer Science 2024年第8期42卷 1227-1242页

作者： Jia-wei gao li Chen Ye-Shun Zhong Chao-wei Xing Yi-Guo li Zong-Bao Wang School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China

Shish crystals are crucial to achieving high performance low-dimensional ultra-high molecular weight polyethylene(UHMWPE)***,high stretch and shear flow fields are necessary for the formation of shish *** this study,UHMWPE gel films with reserved shish crystals were prepared by gel molding,the structural evolution and properties of UHMWPE films stretched at temperatu res of 100,110,120and 130℃were investigated by in situ small-angle X-ray scattering(SAXS)/ultra-small-angle X-ray scattering(USAXS)/wide-angle X-ray diffraction(WAXD)measu rements as well as scanning electron microscopy(SEM)and differential scanning calorimetry(DSC)*** findings showed that the reserved shish crystals can facilitate the formation and structural evolution of shish-kebab crystals during the hot ***,the reserved shish crystals promote the structu ral evolution of UHMWPE films to a greater extent when stretched at 120 and 130℃,compared to 100 and 110℃,resulting in higher crystallinity,orientation,thermal properties,breaking strength and Young's *** pared to UHMWPE high-entangled films with reserved shish crystals prepared by compression molding,UHMWPE low-entangled films with reserved shish crystals prepared by gel molding are more effective in inducing the formation and evolution of shish-kebab crystals during the hot stretching,resulting in increased breaking strength and Young's modulus.

关键词： UHMWPE low-entangled films Reserved shish crystals Structural evolution Hot stretching

Programmable synthetic receptors:the next-generation of cell and gene therapies

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Signal Transduction and Targeted Therapy 2024年第2期9卷 376-400页

作者： Fei Teng Tongtong Cui li Zhou Qingqin gao Qi Zhou wei li University of Chinese Academy of Sciences Beijing 101408China State Key Laboratory of Stem Cell and Regenerative Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijing 100101China Beijing Institute for Stem Cell and Regenerative Medicine Beijing 100101China

Cell and gene therapies hold tremendous promise for treating a range of difficult-to-treat ***,concerns over the safety and efficacy require to be further addressed in order to realize their full *** receptors,a synthetic biology tool that can precisely control the function of therapeutic cells and genetic modules,have been rapidly developed and applied as a powerful *** designed and engineered,they can be applied to finetune the therapeutic activities,i.e.,to regulate production of dosed,bioactive payloads by sensing and processing user-defined signals or *** review provides an overview of diverse synthetic receptor systems being used to reprogram therapeutic cells and their wide applications in biomedical *** a special focus on four synthetic receptor systems at the forefront,including chimeric antigen receptors(CARs)and synthetic Notch(synNotch)receptors,we address the generalized strategies to design,construct and improve synthetic ***,we also highlight the expanding landscape of therapeutic applications of the synthetic receptor systems as well as current challenges in their clinical translation.

关键词： synthetic landscape payload