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Mechanics of a Grip System of Three-Key-Board Hydraulic Tongs Developed for Offshore Oil Pipe Lines

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China Ocean Engineering 1999年第1期14卷 101-108页

作者： Zhao, JY Guo, AJ Ding, KQ liu, ct Petr Univ China Shangdong 257012 Peoples R China Chinese Acad Sci Inst Mech Beijing 100080 Peoples R China

This paper carries out the analysis of mechanics of a grip system of three-key-board hydraulic tongs developed for offshore oil pipe lines which has been successfully used in oil fields in China. The main improvement of this system is that a lever frame structure is used in the structural design, which reduces greatly the stresses of the major components of the oil pipe tongs. Theoretical analysis and numerical calculation based on thirteen basic equations developed Show that the teeth board of the tongs is not easy to slip as frequently happens to other systems and is of higher reliability.

关键词： grip system three-key-board hydraulic tongs offshore oil pipe lines stress analysis

The value of 11C-choline PET/ct imaging for differentiating malignant from benign prostate lesions

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The value of 11C-choline PET/CT imaging for differentiating ...

首届全国分子核医学暨分子影像学学术交流会

作者： LI XIN, liu QINGWEI PET/ct CENTER OF SHANDONG PROVINCIAL HOSPITAL

Objective 11C-choline is a new radiopharmaceutical which has a high uptake in prostate tumor and negligible secretion into the urinary system. The aim of this study was to investigate the potential of 11C-choline PET/ct imaging for differentiating prostate cancer from benign prostate hyperplasia. Methods A total of 45 patients with prostate lesions underwent 11C-choline PET/ct imaging. PET/ct imaging were

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整合素β_1在肝纤维化中的表达

中国组织工程研究与临床康复 2007年第43期11卷 8741-8744页

作者：刘晨婷郭传勇南京市妇幼保健院江苏省南京市210007 同济大学附属第十人民医院消化内科上海市200072

目的:观察黏附分子整合素β1在肝纤维化中的表达情况。方法:实验于2005-03在上海市第十人民医院中心实验室完成。①实验分组:雄性SD大鼠20只,随机分为肝纤维化模型组10只和正常对照组10只。②实验干预:正常对照组不给予任何干预措施正... 详细信息

目的:观察黏附分子整合素β1在肝纤维化中的表达情况。方法:实验于2005-03在上海市第十人民医院中心实验室完成。①实验分组:雄性SD大鼠20只,随机分为肝纤维化模型组10只和正常对照组10只。②实验干预:正常对照组不给予任何干预措施正常喂养,肝纤维化模型组给予400g/LCCl47.5mL/kg腹壁皮下注射造模,于造模后12周处死动物,取1cm×1cm×1cm肝组织备用。③指标检测:反转录-聚合酶链反应半定量检测整合素mRNA在肝组织中的表达;常规苏木精-伊红染色了解肝纤维化的程度。结果:20只大鼠均进入结果分析。①整合素在正常肝脏和肝纤维化阶段均有表达;正常对照组整合素β1的表达量低于模型对照组(66.81±4.36,83.39±4.04,P<0.01)。②肝纤维化模型组大鼠肝组织可见肝细胞广泛的变性坏死,正常小叶结构消失。在高倍镜下可见纤维隔形成。结论:整合素β1在正常和病理肝脏均有表达,在肝纤维化过程中表达明显增高。

关键词：整合素-β1 肝纤维化大鼠

Frequency Regulation of VSC-MTDC System with Offshore Wind Farms

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 275-286页

作者： Haoyu liu Chongru liu North China Electric Power University Beijing 102206China

Frequency regulation of voltage source converter-based multi-terminal high-voltage direct current(VSC-MTDC)system with offshore wind farms enhances the frequency stability by compensating the power for a disturbed AC ***,it is difficult to reasonably allocate frequency-regulation resources due to a lack of coordination mechanisms between wind farms and the MTDC ***,it is difficult for the frequency control of the wind farms to manage changes in wind speed;and the risk of wind-turbine stalls is ***,based on the kinetic energy of wind turbines and the power margin of the converters,the frequency-regulation capability of wind turbines is evaluated,and a dynamic frequency-support scheme considering the real-time frequency-support capability of the wind turbines and system frequency evolution is proposed to improve the frequency-support performance.A power adaptation technique at variable wind speeds is developed;the active power in the frequency-support stage and restoration stage is switched according to the wind speed.A hierarchical zoning frequency-regulation scheme is designed to use the frequency-regulation resources of different links in the MTDC system with wind *** simulation results show that the novel frequency-regulation strategy maintains frequency stability with wind-speed changes and avoids multiple frequency dips.

关键词： Wind generation voltage source converter-based multi-terminal high-voltage direct current(VSC-MTDC) frequency regulation cooperative control adaptive control variable wind speed

A Novel Design of a Pre-separation Panel Structure to Protect Against the Impact of an Explosion in an Aircraft Plenum Chamber

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Acta Mechanica Solida Sinica 2024年第1期37卷 166-180页

作者： Zongxing liu Xiang Yang Jun liu School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China COMAC Shanghai Aircraft Design and Research Institute Shanghai 201210China

To reduce the damage of the pressurizing panel structure of a fuselage caused by an explosion at the“least risk bomb location”in an aircraft structure,a new pre-separation panel structure was designed to resist blast ***,the dynamic strain response and morphology of impact damage of the new pre-separation panel were measured in an impact damage ***,the commercial software LS-DYNA was used to calculate the propagation of the blast shock wave,and the results were compared with empirical equations to verify the rationality of the numerical calculation ***,the fluid–structure coupling method was used to calculate the damage process of the pre-separation panel structure under the impact of an explosion wave and an impact *** calculated results were in good agreement with the test results,which showed the rationality of the calculation method and the *** residual strength of the damaged pre-separation panel was significantly higher than that of the original damaged *** results show that the new pre-separation panel structure is reasonable and has certain significance for guiding the design of plenum chambers with strong resistance to implosion for aircraft fuselages.

关键词： Pre-separation panel structure Explosive response Residual strength Aircraft plenum chamber Least risk bomb location

Effectiveness and safety of acupuncture in treatment of pregnancyrelated symptoms:a systematic review and Meta-analysis

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Journal of Traditional Chinese Medicine 2024年第1期44卷 16-26页

作者： liu Tingting liu Tongou liu Mingfu School of Traditional Chinese Medicine Clinical Medicine Hubei University of Traditional Chinese MedicineWuhan 430000China First Clinical College of Hubei University of Traditional Chinese Medicine Wuhan 430000China Department of Acupuncture and Tuina Affiliated Hospital of Hubei University of Traditional Chinese MedicineHubei Provincial Hospital of Traditional Chinese MedicineWuhan 430000China

OBJEctIVE:To systematically evaluate the efficacy and safety of acupuncture(AM)in the treatment of pregnancyrelated symptoms such as acute vomiting during ***:We comprehensively searched the available literature up to November 2021,including Pub Med,Embase,Cochrane Library,Chinese Biomedical Literature Database,and China National Knowledge Infrastructure Database,for randomized controlled trials(Rcts)on AM for the treatment of severe vomiting,insomnia,pharyngeal and pelvic pain,mood abnormalities,and dyspepsia during ***:Sixteen Rcts with a cumulative sample size of 1178 cases were *** these,964 patients were included in the *** Meta-analysis results showed that AM was more efficient than Western medicine in treating discomfort during pregnancy[odds ratio(OR)=1.19,95%confidence interval(CI)(1.11,1.28),Pcts between the AM and sham-AM groups and the analgesic drug group[OR=0.70,95%CI(0.39,1.28),P=0.25],but the treatment and control groups had mild adverse effects with a low ***:AM is more effective than other treatments or pharmacotherapy alone in the treatment of pregnancy-related symptoms,and is relatively ***,the quality of the included trials was rather poor,and high-quality studies are required to confirm our findings.

关键词： acupuncture pregnancy nausea vomiting sleep initiation and maintenance disorders low back pain pelvic pain mood abnormalities Meta-analysis systematic review

Devolatilization of high viscous fluids with high gravity technology

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Chinese Journal of Chemical Engineering 2024年第7期71卷 249-257页

作者： Jibing Qi Youzhi liu Yandong liu Taiyuan University Taiyuan 030032China Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering North University of ChinaTaiyuan 030051China

Volatile organic compounds(VOCs)are generally toxic and harmful substances that can cause health and environmental *** removal of VOCs from polymers has become a key *** effective devolatilization to remove VOCs from high viscous fluids such as polymer is necessary and is of great *** this study,the devolatilization effect of a rotating packed bed(RPB)was studied by using polydimethylsiloxane as the viscous fluid and acetone as the *** devolatilization rate and liquid phase volume(KLa)have been *** results indicated that the optimum conditions were the high-gravity factor of 60,liquid flow rate of 10 L·h^(-1),and vacuum degree of 0.077 *** dimensionless correlation of KLa was established,and the deviations between predicted and experimental values were less than±28%.The high-gravity technology will result in lower mass transfer resistance in the devolatilization process,enhance the mass transfer process of acetone,and improve the removal effect of *** work provides a promising path for the removal of volatiles from polymers in combination with high-gravity *** can provide the basis for the application of RPB in viscous fluids.

关键词： High-gravity technology Devolatilization rate High viscous fluid Volatile organic compounds(VOCs)

Stochastic Unit Commitment with High-Penetration Offshore Wind Power Generation in Typhoon Scenarios

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 535-546页

作者： Yanqi liu Dundun liu Hongcai Zhang State Key Laboratory of Internet of Things for Smart City and Department of Electrical and Computer Engineering University of MacaoMacao 999078China University of Macao Zhuhai UM Science and Technology Research Institute ZhuhaiChina

To tackle the energy crisis and climate change,wind farms are being heavily invested in across the *** China's coastal areas,there are abundant wind resources and numerous offshore wind farms are being *** secure operation of these wind farms may suffer from typhoons,and researchers have studied power system operation and resilience enhancement in typhoon ***,the intricate movement of a typhoon makes it challenging to evaluate its spatial-temporal *** published papers only consider predefined typhoon trajectories neglecting *** address this challenge,this study proposes a stochastic unit commitment model that incorporates high-penetration offshore wind power generation in typhoon *** adopts a data-driven method to describe the uncertainties of typhoon trajectories and considers the realistic anti-typhoon mode in offshore wind farms.A two-stage stochastic unit commitment model is designed to enhance power system resilience in typhoon *** formulate the model into a mixed-integer linear programming problem and then solve it based on the computationally-efficient progressive hedging algorithm(PHA).Finally,numerical experiments validate the effectiveness of the proposed method.

关键词： Unit commitment two-stage stochastic programming offshore wind farm typhoon

Polar solvent induced in-situ self-assembly and oxygen vacancies on Bi_(2)MoO_(6)for enhanced photocatalytic degradation of tetracycline

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Nano Research 2024年第6期17卷 4951-4960页

作者： Fangyan liu Dongyue Su Weizhen liu Baiquan liu Chuan liu Hong Wang Mengye Wang State Key Laboratory of Optoelectronic Materials and Technologies Guangdong Province Key Laboratory of Display Material and TechnologySchool of Electronics and Information TechnologySun Yat-Sen UniversityGuangzhou 510275China School of Materials Sun Yat-Sen UniversityShenzhen 518107China School of Environment and Energy Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and RecyclingSouth China University of TechnologyGuangzhou 510006China

It has been proved to be an effective route to efficiently ameliorate photocatalytic performance of catalysts via designing three-dimensional(3D)hierarchical nanostructures and constructing oxygen vacancies(VOs).However,controlling the self-assembly of organization into 3D hierarchical nanostructures while introducing VOs in photocatalysts remains a ***,we reported an ethylene glycol(EG)mediated approach to craft 3D hydrangea-structure Bi_(2)MoO_(6)with VOs for efficient photocatalytic degradation of *** manipulating the EG concentration during the fabrication process,the influence of EG concentration on the Bi_(2)MoO_(6)structure was systematically *** could promote the self-assembly of Bi_(2)MoO_(6)nanosheets to form a 3D hierarchical *** with 2D nanoplates,3D hierarchical architecture enhanced the surface area and the amount of active sites of Bi_(2)MoO_(6).In addition,the reduction effect of EG on metallic oxide enabled the generation of VOs in Bi_(2)MoO_(6).The VOs adjusted the electronic structure of Bi_(2)MoO_(6),which not only enhanced the light harvesting,but also facilitated the simultaneous utilization of photo-induced electrons and holes to form reactive oxygen species(·O2−and·OH)for the efficient tetracycline decomposition.3D Bi_(2)MoO_(6)hydrangea with VOs achieved a 79.4%removal efficiency of tetracycline after 75 *** work provides a simple yet robust EG-mediated strategy,which not only promotes the self-assembly of nano-catalysts into 3D hierarchical architectures,but also crafts tunable VOs for highly efficient photocatalysis.

关键词： three-dimensional(3D)hierarchical nanostructures tunable oxygen vacancies ethylene glycol(EG)-mediated strategy bismuth molybdate photocatalytic degradation tetracycline