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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

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炎症性肠病的肠内、肠外营养

临床内科杂志 2019年第2期36卷 88-90页

作者：施嫣红刘占举上海市第十人民医院消化内科 200072

炎症性肠病(IBD)是一种慢性非特异性肠道炎症.分为溃疡性结肠炎(UC)和克罗恩病(CD),主要累及消化道,病情易反复迁延因消化吸收不良、丢失消耗增加、摄入减少、药物及手术等各种原因,无论是在疾病活动期还是缓解期,常可引起不同程度的营... 详细信息

炎症性肠病(IBD)是一种慢性非特异性肠道炎症.分为溃疡性结肠炎(UC)和克罗恩病(CD),主要累及消化道,病情易反复迁延因消化吸收不良、丢失消耗增加、摄入减少、药物及手术等各种原因,无论是在疾病活动期还是缓解期,常可引起不同程度的营养不良。

关键词：炎症性肠病营养

CD177＋中性粒细胞与炎症性肠病肠黏膜损伤关系的研究

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中华消化内镜杂志 2016年第3期33卷 178-182页

作者：宋洋杨文静周广玺刘占举同济大学附属第十人民医院消化内科上海200092

目的通过对比炎症性肠病患者外周血CD177＋中性粒细胞的比例及肠黏膜炎症部位CD177＋中性粒细胞的浸润与正常对照者的差异，探讨CD177＋中性粒细胞与肠道黏膜损伤及临床特征的相关性。方法研究对象为溃疡性结肠炎患者54例、克罗恩病患... 详细信息

目的通过对比炎症性肠病患者外周血CD177＋中性粒细胞的比例及肠黏膜炎症部位CD177＋中性粒细胞的浸润与正常对照者的差异，探讨CD177＋中性粒细胞与肠道黏膜损伤及临床特征的相关性。方法研究对象为溃疡性结肠炎患者54例、克罗恩病患者62例和正常对照者48例。对炎症性肠病患者和正常对照者，分别应用SYBR-green Reahime PCR等方法，分析患者外周血及肠黏膜炎症部位CD177＋中性粒细胞的比例，研究CD177＋中性粒细胞与内镜下疾病活动性及临床疾病活动程度的关系。结果炎症性肠病患者外周血和炎症部位肠黏膜组织中，CD177的表达均显著高于正常对照者及缓解期患者（P〈0．05），CD177＋中性粒细胞的比例显著增加（P〈0．05）。炎症性肠病患者外周血中性粒细胞和炎症部位肠黏膜组织中CD177的表达与内镜下疾病活动性及临床疾病活动程度均呈明显正相关（P〈0．05）。结论在炎症性肠病患者外周血及炎症部位肠黏膜组织中CD177＋中性粒细胞的比例增加，能够反映内镜下疾病活动程度和临床疾病活动程度。CD177＋中性粒细胞可能作为中性粒细胞的一个重要亚群参与肠道的免疫病理过程。

关键词：中性粒细胞抗原,CD177 炎症性肠病内镜下疾病活动程度

CD177+中性粒细胞在炎症性肠病的表达及效应初步研究

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中华炎性肠病杂志（中英文） 2017年第1期1卷 37-40页

作者：周广玺杨文静余天名刘占举同济大学附属第十人民医院消化内科上海200072

目的检测CD177在炎症性肠病患者外周血和肠黏膜组织中的表达,并探究其对中性粒细胞迁移能力的影响.方法收集18例活动期克罗恩病患者、21例溃疡性结肠炎患者以及14例健康对照者的外周血和肠黏膜组织标本,使用流式细胞术检测CD177分子表... 详细信息

目的检测CD177在炎症性肠病患者外周血和肠黏膜组织中的表达,并探究其对中性粒细胞迁移能力的影响.方法收集18例活动期克罗恩病患者、21例溃疡性结肠炎患者以及14例健康对照者的外周血和肠黏膜组织标本,使用流式细胞术检测CD177分子表达.并采用免疫磁珠法分离上述患者和健康对照者外周血中CD177+和CD177-中性粒细胞,用Transwell检测两群细胞迁移能力.结果 CD177+中性粒细胞的比例在活动期克罗恩病和溃疡性结肠炎患者外周血和肠黏膜组织中均显著高于健康对照者(P<0.05).使用免疫磁珠的方法,分离得到外周血高纯度的CD177+和CD177-中性粒细胞,Transwell检测发现CD177+中性粒细胞的迁移能力明显高于CD177-中性粒细胞(P<0.05),且炎症性肠病患者CD177+中性粒细胞的迁移能力亦明显高于健康对照者的CD177+中性粒细胞(P<0.05).结论 CD177在炎症性肠病患者中外周血和肠黏膜组织中表达明显升高,且CD177+中性粒细胞的迁移能力增加,提示CD177+中性粒细胞可能在肠黏膜炎症发生过程中起重要的免疫调节作用.

关键词：炎症性肠病中性粒细胞 CD177 炎症

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重症溃疡性结肠炎的规范化治疗

中华消化病与影像杂志（电子版） 2014年第2期4卷 1-4页

作者：刘占举酒金霞同济大学附属第十人民医院消化内科上海200072 同济大学附属第十人民医院教学办上海200072

溃疡性结肠炎(UC)是发生在结肠,原因不明的慢性非特异性炎症性疾病。UC的病因和发病机制尚不清楚,可能与肠黏膜免疫应答异常有密切关系。重症UC是一种致命性的疾病,内科疗效差,死亡率高,预后差。临床上除了一般常规处理外,应积极给予内... 详细信息

溃疡性结肠炎(UC)是发生在结肠,原因不明的慢性非特异性炎症性疾病。UC的病因和发病机制尚不清楚,可能与肠黏膜免疫应答异常有密切关系。重症UC是一种致命性的疾病,内科疗效差,死亡率高,预后差。临床上除了一般常规处理外,应积极给予内科治疗,包括糖皮质激素、环孢霉素A或生物制剂(抗肿瘤坏死因子单抗)治疗;若仍然无效,则需外科手术治疗。在临床上应及时正确预测病情发展,积极给予合理治疗,提高临床疗效,预防并发症,降低死亡率。

关键词：结肠炎,溃疡性规范化治疗糖皮质激素类环孢霉素A 生物制剂

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

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

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),P<0.01].AM was better than the control group in improving the visual analog scale scores[standard mean difference(SMD)=0.62,95%CI(0.53,0.71),P<0.01].AM was superior to the control group in improving Numerical Rating Scale(NRS)symptom scores[OR=7.31,95%CI(3.36,15.94),P<0.01].There was no significant difference in adverse effects 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)