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Control-oriented modeling of a high-aspect-ratio flying wing with coupled flight dynamics

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Chinese Journal of Aeronautics 2023年第4期36卷 409-422页

作者： Cong NIU Xiutian yan Boyi CHEN Department of Design Manufacturing&Engineering ManagementUniversity of StrathclydeGlasgow G11XQUK College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The flight-structural dynamics of a high-aspect-ratio wing challenge the flight control *** paper develops a reduced model of coupled dynamics with stability *** structural dynamics are formulated with dihedrals,and the central loads drive the *** control-oriented model with essential coupled dynamics is *** sensitivity anal-ysis and input–output pairing are performed to identify the control ***,an example of flight control design is provided to discuss the necessity of considering structural dynamics in controller *** coupled flight dynamics provide a system-theoretic approach for sta-bility and facilitate model-based control *** results reveal the characteristics of flight-structural coupled dynamics and demonstrate that the influence of flexible modes should be considered in control design,especially in lateral dynamics.

关键词： Flexible couplings Flexible wings Flight control systems Flight dynamics Sensitivity analysis

Impact of small-for-size liver grafts on medium-term and long-term graft survival in living donor liver transplantation: A meta-analysis

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World Journal of Gastroenterology 2019年第36期25卷 5559-5568页

作者： Ka wing Ma Kelly Hiu Ching Wong Albert Chi yan Chan Tan To Cheung wing Chiu Dai James yan Yue Fung Wong Hoi She Chung Mau Lo Kenneth Siu Ho Chok Department of Surgery Queen Mary Hospital Hong Kong China Li Ka Shing Faculty of Medicine The University of Hong Kong Hong Kong China Department of Surgery The University of Hong Kong Hong Kong China Department of Medicine Queen Mary Hospital Hong Kong China

BACKGROUND Small-for-size grafts (SFSGs) in living donor liver transplantation (LDLT) could optimize donor postoperative outcomes and also expand the potential donor pool. Evidence on whether SFSGs would affect medium-term and long-term recipient graft survival is lacking. AIM To evaluate the impact of small-for-size liver grafts on medium-term and longterm graft survival in adult to adult LDLT. METHODS A systematic review and meta-analysis were performed by searching eligible studies published before January 24, 2019 on PubMed, EMBASE, and Web of Science databases. The primary outcomes were 3-year and 5-year graft survival. Incidence of small-for-size syndrome and short term mortality were also extracted. RESULTS This meta-analysis is reported according to the guidelines of the PRISMA 2009 Statement. Seven retrospective observational studies with a total of 1821 LDLT recipients were included in the meta-analysis. SFSG is associated with significantly poorer medium-term graft survival. The pooled odds ratio for 3-year graft survival was 1.58 [95% confidence interval 1.10-2.29, P = 0.014]. On the other hand, pooled results of the studies showed that SFSG had no significant discriminatory effect on 5-year graft survival with an odds ratio of 1.31 (95% confidence interval 0.87-1.97, P = 0.199). Furthermore, incidence of small-for-size syndrome detected in recipients of SFSG ranged from 0-11.4% in the included studies. CONCLUSION SFSG is associated with inferior medium-term but not long-term graft survival. Comparable long-term graft survival based on liver graft size shows that smaller grafts could be accepted for LDLT with appropriate flow modulatory measures. Close follow-up for graft function is warranted within 3 years after liver transplantation.

关键词： Living donor liver transplantation Small-for-size grafts Small-for-size syndrome Graft survival

复合式高速无人直升机飞行动力学建模与控制策略设计

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航空学报 2024年第9期45卷 121-140页

作者：聂博文王亮权黄志银何龙杨仕鹏颜鸿涛章贵川空天飞行空气动力科学与技术全国重点实验室绵阳621000 中国空气动力研究与发展中心低速空气动力研究所绵阳621000 北京航空航天大学航空科学与工程学院北京100191 中国空气动力研究与发展中心空天技术研究所绵阳621000

复合式高速无人直升机主要具有旋翼、机翼、螺旋桨、机身和平/垂尾等气动部件。各个部件之间的气动干扰复杂且会随前飞速度强烈、快速地变化,必须根据前飞速度修正飞行动力学模型参数,以获得较高的模型置信度;同时,必须根据前飞速度调... 详细信息

复合式高速无人直升机主要具有旋翼、机翼、螺旋桨、机身和平/垂尾等气动部件。各个部件之间的气动干扰复杂且会随前飞速度强烈、快速地变化,必须根据前飞速度修正飞行动力学模型参数,以获得较高的模型置信度;同时,必须根据前飞速度调整飞行控制策略,动态实现整个速度包线稳定可控飞行。为此,建立了复合式高速无人直升机飞行动力学机理模型,利用全机组合风洞配平试验数据进行了模型修正,有效提高了数学模型置信度;在配平点处,将非线性动力学模型线性化,获得了开环本体动力学特性随前飞速度的演化规律,并评估了控制增稳系统对闭环操稳性能的改善效果;在经典控制架构基础上,针对复合式高速无人直升机的升力、推力和偏航复合特性,设计了前馈补偿、回路加权和控制分配策略,并开展了仿真和试飞验证。研究结果表明:所建立的非线性动力学模型具有较高置信度,数学模型配平结果与风洞试验配平试验结果一致性较好;高/低阶线性模型的特征根分布规律基本一致,操纵响应历程与非线性动力学模型吻合较好;速度包线范围内升力、推力、航向复合飞行控制策略的有效性通过了飞行仿真检验;成功开展了国内首款300 kg级复合式高速无人直升机原理样机试飞,验证了悬停和小速度状态下的飞行控制策略有效性。

关键词：复合式高速直升机飞行动力学风洞试验控制策略飞行仿真飞行试验

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Liver Transplantation for Hepatitis B Virus-related Hepatocellular Carcinoma in Hong Kong

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Journal of Clinical and Translational Hepatology 2018年第3期6卷 283-288页

作者： Ka wing Ma Kenneth Siu Ho Chok James yan Yue Fung Chung Mau Lo Department of Surgery The University of Hong KongHong KongChina State Key Laboratory for Liver Research The University of Hong KongHong KongChina Department of Medicine The University of Hong KongHong KongChina

Hepatocellular carcinoma(HCC)is the fifth most common cancer and the third most common cause of cancer-related deaths *** resection is frequently limited in Hong Kong by hepatitis B virus-related cirrhosis,and liver transplantation is the treatment of *** transplanta-tion has been shown to produce superior oncological benefits,when compared to hepatectomy for *** developments in the context of patient selection criteria,modification of organ allocation,bridging therapy,salvage liver transplanta-tion and pharmaceutical breakthrough have improved the survival of HCC *** this article,we will share our experience in transplanting hepatitis B virus-related HCC patients in Hong Kong and discuss the recent progress in several areas of liver transplantation.

关键词： Liver transplantation Hepatitis B Hepatocel ular carcinoma Review

The Hong Kong consensus statements on unresectable hepatocellular carcinoma:narrative review and update for 2021

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Hepatobiliary Surgery and Nutrition 2023年第3期12卷 366-385页

作者： Tan-To Cheung Simon Chun-Ho Yu Stephen L.Chan Ronnie T.P.poon Philip Kwok Ann-Shing Lee Anna Tai Derek Tam Chin-Cheung Cheung Tak-wing Lai Nam-Hung Chia Ada Law Tracy Shum Yim-Kwan Lam Vince Lau Victor Lee Charing Chong Chung-Ngai Tang Thomas Yau Department of Surgery Queen Mary HospitalThe University of Hong KongHong KongChina Department of Imaging&Interventional Radiology Prince of Wales HospitalThe Chinese University of Hong KongHong KongChina State Key Laboratory of Translational Oncology and Department of Clinical Oncology Sir YK Pao Centre for CancerPrince of Wales HospitalThe Chinese University of Hong KongHong KongChina Department of Radiology and Imaging Queen Elizabeth HospitalHong KongChina Department of Clinical Oncology Tuen Mun HospitalHong KongChina Department of Clinical Oncology Queen Elizabeth HospitalHong KongChina Department of Surgery United Christian HospitalHong KongChina Department of Surgery Tuen Mun HospitalHong KongChina Department of Surgery Princess Margaret HospitalHong KongChina Department of Surgery Queen Elizabeth HospitalHong KongChina Department of Clinical Oncology Pamela Youde Nethersole Eastern HospitalHong KongChina Department of Clinical Oncology Princess Margaret HospitalHong KongChina Department of Medicine and Geriatrics United Christian HospitalHong KongChina Department of Radiology Queen Mary HospitalHong KongChina Department of Clinical Oncology Queen Mary HospitalThe University of Hong KongHong KongChina Department of Surgery Prince of Wales HospitalThe Chinese University of Hong KongHong KongChina Department of Surgery Pamela Youde Nethersole Eastern HospitalHong KongChina Department of Medicine Queen Mary HospitalThe University of Hong KongHong KongChina

Background and Objective:Hong Kong,like many parts of Asia,faces a high burden of hepatocellular carcinoma(HCC)caused by high endemic rates of hepatitis B virus *** Kong clinicians have developed a high level of expertise in HCC treatment across surgical,transarterial,ablative,radiotherapeutic and systemic *** publication summarizes the latest evidence-based recommendations on how these modalities should be ***:In two meetings held in 2020,a multidisciplinary panel of surgeons,oncologists and interventional radiologists performed a narrative review of evidence on the management of HCC,with an emphasis on treatment of HCC not amenable to surgical *** attention was paid to new evidence published since the previous version of these statements in *** Content and Findings:The expert panel has formulated 60 consensus statements to guide the staging and treatment of unresectable *** the previous version of these statements,considerable additions have been made to the recommendations on use of targeted therapies and immunotherapies because of the large volume of new ***:Our consensus statements offer guidance on how to select HCC patients for surgical or non-surgical treatment and for choosing among non-surgical modalities for patients who are not candidates for *** particular,there is a need for more evidence to aid physicians in the selection of second-line systemic therapies,as currently most data are limited to patients with disease progression on first-line sorafenib.

关键词： Hepatocellular carcinoma(HCC) Hong Kong guidelines consensus

Liver transplantation:would it be the best and last chance of cure for hepatocellular carcinoma with major venous invasion?

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Hepatobiliary Surgery and Nutrition 2021年第3期10卷 308-314页

作者： Ka wing Ma Albert Chi yan Chan Kenneth Siu Ho Chok Wong Hoi She Tan To Cheung wing Chiu Dai James yan Yue Fung Chung Mau Lo Department of Surgery The University of Hong KongHong KongChina Department of Medicine The University of Hong KongHong KongChina

Background:Hepatocellular carcinoma(HCC)with portal vein tumour thrombus(PVTT)signifies advanced disease,whether LT confers any survival superiority over resection remains ***:A propensity score matched(PSM)analysis of liver transplantation(LT)and liver resection(LR)for HCC with PVTT was ***:A consecutive series of 88 patients who received either LT(10 DDLTs and 3 LDLTs)or LR(n=75)respectively were *** PSM,the LT group has a higher MELD score(17.3 vs.7.8,P<0.001),lower serum AFP levels(96 vs.2,164 ng/mL,P=0.017)and smaller tumour size(4 vs.10 cm,P<0.001).The 5-year overall survival for LT and LR were 55.4%and 15.9%respectively(P=0.007).After matching for serum AFP levels and tumour size,1-,3-and 5-year overall survival for LT were 81 ng/mL,3.9 cm,80%,70%and 70%and the corresponding rates for LR were 1,417 ng/mL,5.3 cm,51.8%,19,6%and 9.8%(P value=0.12,0.27 and 0.009 respectively).Conclusions:LT is associated with significantly better oncological outcomes in HCC patients with PVTT involving the lobar or segmental level.A modest expansion of selection criteria to include small HCC with segmental PVTT should be considered.

关键词： Liver transplantation(LT) portal vein tumour thrombus liver resection(LR)

聚醚有机硅PSPE助剂对25%噻虫嗪水分散粒剂在豇豆花瓣表面润湿性能影响

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农药 2024年第6期63卷 401-407页

作者：叶火春闫超朱发娣张静许致远冯岗中国热带农业科学院环境与植物保护研究所海口571101 农业农村部热带作物有害生物综合治理重点实验室海口571101

[目的]了解豇豆花瓣表面润湿性能,提高防治药剂精准施药水平。[方法]采用座滴法测定豇豆花的旗瓣内外侧、翼瓣内外侧和龙骨瓣外侧等5个花瓣表面的接触角,采用朱定一(ZDY)法计算其固体表面自由能,进一步测定了25%噻虫嗪水分散粒剂(WG)稀... 详细信息

[目的]了解豇豆花瓣表面润湿性能,提高防治药剂精准施药水平。[方法]采用座滴法测定豇豆花的旗瓣内外侧、翼瓣内外侧和龙骨瓣外侧等5个花瓣表面的接触角,采用朱定一(ZDY)法计算其固体表面自由能,进一步测定了25%噻虫嗪水分散粒剂(WG)稀释液及其添加PSPE助剂后药液在花瓣表面的静态和动态接触角,并采用最大泡压法测定噻虫嗪药液及其添加助剂后药液动态表面张力(DST)。[结果]豇豆5个花瓣表面除了旗瓣外侧表面为亲水型,其他4个花瓣表面均为疏水型(接触角θ大于90°),花瓣表面自由能值在23.15~60.31 mJ/m^(2)之间。25%噻虫嗪WG的250、125 mg/L处理药液在豇豆花瓣表面上总体润湿性差,添加PSPE助剂后,药液对豇豆花瓣表面接触角在30 s时降至20°以下,静态接触角降低75%以上,显著低于未添加助剂的药液。添加助剂的药液在5个豇豆花瓣表面的接触角下降趋势相似,在0~10 s内快速下降而后平稳降低,DST在50~500 ms内快速降低,在10 s时降至23.15 mN/m及以下。药液添加助剂浓度由0.05%提高至0.1%,DST下降更快,5 s后在旗瓣内侧、翼瓣内外侧和龙骨瓣外侧表面接触角均低于10°,药液DST快速下降区时间提前。[结论]添加聚醚有机硅PSPE助剂可使25%噻虫嗪WG喷雾药液在豇豆花瓣表面快速润湿铺展。

关键词：豇豆花接触角表面自由能动态表面张力喷雾助剂噻虫嗪水分散粒剂

复杂三维CAD装配模型特征信息提取技术研究

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机械设计与制造 2024年第6期400卷 116-120,127页

作者：郝博王杰闫俊伟王婵娟东北大学机械工程与自动化学院辽宁沈阳110819 东北大学航空动力装备振动及控制教育部重点实验室辽宁沈阳110819

针对飞机、大型输送机等复杂三维CAD装配模型具有装配零件多,配合复杂,在提取装配体特征信息过程中,有信息提取不完整、深度不够的问题,提出一种复杂产品装配特征信息提取的方法,该方法以CATIA软件为平台,采用构件的应用编程(Component ... 详细信息

针对飞机、大型输送机等复杂三维CAD装配模型具有装配零件多,配合复杂,在提取装配体特征信息过程中,有信息提取不完整、深度不够的问题,提出一种复杂产品装配特征信息提取的方法,该方法以CATIA软件为平台,采用构件的应用编程(Component Application Architecture,CAA),二次开发快速提取特征信息功能。结合多叉树前序列遍历思想,深度优先搜索的算法,逐层深入,可以完整提取多层嵌套的复杂装配体的配合和约束信息,充分利用复杂三维CAD装配模型特征信息,更有力的支持装配工艺规划。同时,通过选择输送某种民航飞机机翼的输送机为例,验证此方法的可行度。

关键词：装配模型 CATIA 二次开发信息提取多叉树遍历算法深度优先搜索

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The impact of family history of hepatocellular carcinoma on its patients' survival

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Hepatobiliary & Pancreatic Diseases International 2012年第2期11卷 160-164页

作者： wing Chiu Dai Sheung Tat Fan Tan To Cheung Kenneth SH Chok Albert CY Chan Simon HY Tsang Ronnie TP poon Chung Mau Lo Department of Surgery The University of Hong Kong 102 Pokfulam Road Hong Kong China State Key Laboratory for Liver Research The University of Hong Kong 102 Pokfulam Road Hong Kong China

BACKGROUND:Family history of hepatocellular carcinoma(HCC) has been identified as a risk factor for the development of the *** aim of this study is to evaluate the impact of such a history on HCC patients’ ***:Data of all HCC patients(n=4532) managed at our center from 1989 to 2008 were prospectively *** patients were quizzed on their various characteristics including family HCC ***:Totally 475(10.48%) patients had a family history of *** presented the disease at a significantly earlier age(median 53 vs 59 years,P<0.0001) and at an earlier stage(the United Network for Organ Sharing staging system).They had significantly better liver function in terms of ChildPugh classification and serum albumin and bilirubin *** more of them presented the disease without symptoms(44.0% vs 29.4%,P<0.0001).They also had significantly better overall survival under these specifications:patients in the whole study cohort,patients who had minor hepatectomy,patients with stage I disease,patients with stage II disease,and patients with stage III ***:Contrary to what is generally believed,we found in this study cohort that patients with a family history of HCC had better overall survival than those without such a *** believe this was in part due to earlier diagnosis of the disease and better liver function in this group of ***,the effects of genetic factors on the risk of HCC cannot be overlooked and are yet to be identified.

关键词： hepatocellular carcinoma family history resection survival risk factor