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Biased Partitions and Judicious k-Partitions of Graphs

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Acta Mathematica Sinica,English Series 2017年第5期33卷 668-680页

作者： Qing hou ZENG jian feng hou Jin DENG Xia LEI Center for Discrete Mathematics Fuzhou University Fuzhou 350003 P. R. China Hu'nan College of Information Changsha 410200 P. R. China School of Software Engineering Xiamen University of Technology Xiamen 361024 P. R. China

Let G =（V, E） be a graph with m edges. For reals p ∈ [0, 1] and q = 1-p, let m;（G） be the minimum of qe（V;） + pe（V;） over partitions V = V;∪ V;, where e（V;） denotes the number of edges spanned by V;. We show that if m;（G） = pqm-δ, then there exists a bipartition V;, V;of G such that e（V;） ≤ p;m-δ + p（m/2）;+ o（√m） and e（V;） ≤ q;m-δ + q（m/2）;+ o（√m） for δ = o(m;). This is sharp for com;lete graphs up to the error term o（√m）. For an integer k ≥ 2, let fk（G） denote the maximum number of edges in a k-partite subgraph of G. We prove that if fk（G） =（1-1/k）m + α,then G admits a k-partition such that each vertex class spans at most m/k;-Ω(m/k;) edges forα = Ω（m/k;）. Both of the above im;rove the results of Bollob′as and Scott.

关键词： Graph Max-Cut biased partition judicious partition

List Total Colorings of Planar Graphs without Triangles at Small Distance

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Acta Mathematica Sinica,English Series 2011年第12期27卷 2437-2444页

作者： Bin LIU jian feng hou Gui Zhen LIU Department of Mathematics Ocean University of China Qingdao 266100 P. R. China Center for Discrete Mathematics Fuzhou University Fuzhou 350002 P. R. China School of Mathematics Shandong University Ji＇nan 250100 P. R. China

Suppose that G is a planar graph with maximum degree △. In this paper it is proved that G is total-（△ ＋ 2）-choosable if （1） △ ≥ 7 and G has no adjacent triangles （i.e., no two triangles are incident with a common edge）; or （2） △ ≥6 and G has no intersecting triangles （i.e., no two triangles are incident with a common vertex）; or （3） △ ≥ 5, G has no adjacent triangles and G has no k-cycles for some integer k ∈ {5, 6}.

关键词： List total coloring choosability planar graph

Gallai's Conjecture on Path Decompositions

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Journal of the Operations Research Society of China 2023年第3期11卷 439-449页

作者： Geng-Hua Fan jian-feng hou Chui-Xiang Zhou Center for Discrete Mathematics Fuzhou UniversityFuzhou350003FujianChina

Gallai's conjecture asserts that every connected graph on n vertices can be decomposed into at most n+1/2 *** E-subgraph of a graph G,denoted by G_(e),is the subgraph induced by the vertices of even degree in G.A triangle pair is a graph consisting of two triangles with exactly one vertex in *** this paper,it is proved that Gallai's conjecture is true for graphs G in which G_(e)contains no triangle pair and each block of G_(e)has maximum degree at most 3.

关键词： Gallai's conjecture Path Triangle Decomposition

Study on the Cloning, Expression, and Bioactivity of Recombinant Chicken IGF-Ⅰ

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Agricultural Sciences in China 2006年第6期5卷 462-467页

作者： ZHANG jian-feng hou Jia-fa ZHANG Jiao YAO Jing College of Veterinary Medicine Nanjing Agricultural University Nanjing 210095 P.R. China

The DNA sequence encoding the chicken＇s insulin-like growth factor Ⅰ （IGF-Ⅰ） was amplified with the reverse transcription polymerase chain reaction （RT-PCR）, which was then cloned into vector pMD18-T and sequenced. The sequencing result showed that there was 100% homology among the documented sequences and the sequence reported in this article, which was successfully inserted into the expressing plasmid pRLC and was highly expressed in ***. The Tricine-SDS- PAGE result showed that the cloned recombinant protein was expressed in the form of inclusion bodies in the *** cell with molecular weight of 7.6 kD and was amount to 23% of the whole protein in the *** cell. Western blotting indicated that recombinant protein had the antigenicity of IGF- Ⅰ. The inclusion bodies were subsequently dissolved in 7 M guanidine chloride and renatured with dilution in refolding buffer containing 0.5 M arginine. To obtain pure protein, the renatured chicken IGF- Ⅰ was desalting by Hiprep 26/10 and purified by Hiprep Sephacryl S-200 chromatography. The biological activities of IGF- Ⅰ product were assayed in NIH 3T3 cells and osteoblastic cells of embryonic chicken by using MTT method. The results show that the expressed IGF- Ⅰ can obviously stimulate NIH3T3 cells and osteoblastic cells to proliferate at the concentration ranging from 100, 200, 400 to 800 ng mL^-1, suggesting that the protein has its biological activities.

关键词： chicken insulin-like growth factor Ⅰ gene prokaryotic expression MTT

Outcomes of cardiac surgery in senior aged patients with ventricular dysfunction:analysis of a large national database

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Journal of Geriatric Cardiology 2021年第1期18卷 1-9页

作者： Han-Wei TANG Kai CHEN jian-feng hou Xiao-Hong HUANG Sheng LIU Han-Ping MA Sheng-Shou HU Department of Cardiovascular Surgery National Center for Cardiovascular DiseasesState Key Laboratory of Cardiovascular DiseaseFuwai HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Department of Special Medical Treatment Center Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Science and Peking Union Medical CollegeBeijingChina

OBJECTIVE In patients undergoing cardiac surgery,reduced preoperative ejection fraction(EF)and senior age are associated with a worse *** most outcome data available for these patients are mainly from Western surgical populations involving specific surgery types,our aim is to evaluate the real-world characteristics and perioperative outcomes of surgery in senior-aged heart failure patients with reduced EF across a broad range cardiac *** Data were obtained from the China Heart Failure Surgery Registry(China-HFSR)database,a nationwide multicenter registry study in China's *** variable regression analysis was performed in patients over 75 years old to identify risk factors associated with *** From 2012 to 2017,578 senior-aged(>75 years)patients were enrolled in China HFSR,21.1%of whom were *** coronary bypass grafting(CABG)were performed in 71.6%of patients,10.1%of patients underwent isolated valve surgery and 8.7%received CABG combined with valve ***-hospital mortality was 10.6%,and the major complication rate was 17.3%.Multivariate analysis identified diabetes mellitus(odds ratio(OR)=1.985),increased creatinine(OR=1.007),New York Heart Association(NYHA)Class III(OR=1.408),NYHA class IV(OR=1.955),cardiogenic shock(OR,6.271),and preoperative intra-aortic balloon pump insertion(OR=3.426)as independent predictors of in-hospital *** In senior-aged patients,preoperative evaluation should be carefully performed,and strict management of reversible factors needs more ***-aged patients commonly have a more severe disease status combined with more frequent comorbidities,which may lead to a high risk in mortality.

关键词： Western analysis of a large national database Outcomes of cardiac surgery in senior aged patients with ventricular dysfunction

Tungsten pnictides for water electrolysis:advances and perspectives

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Tungsten 2024年第4期6卷 675-695页

作者： Xue Kang Xi-Han Tan Ning Han jian-feng hou Chen-Min Yao Zhi-Jie Chen Bing-Jie Ni Department of Chemistry and Chemical Engineering Lyuliang UniversityLvliang033001China Department of Materials Engineering KU LeuvenLouvain3001Belgium State Key Laboratory of Oral&Maxillofacial Reconstruction and Regeneration Key Laboratory of Oral Biomedicine Ministry of EducationHubei Key Laboratory of StomatologySchool&Hospital of StomatologyWuhan UniversityWuhan430079China School of Civil and Environmental Engineering The University of New South WalesSydneyNSW 2052Australia

Hydrogen fuel is recognized as a promising energy carrier for the sustainable development of global energy system and the green hydrogen production via water electrolysis attracts great *** development of cost-effective electrocatalysts for water electrolysis is important for enhancing green hydrogen production ***,tungsten pnictides(phosphides and nitrides)have emerged as promising catalysts for water electrolysis,and efficient tungsten pnictide-based catalysts with different nanostructures,compositions,and surface chemical properties have been *** this review,recent progress in the design of tungsten pnictide-based electrocatalysts for water electrolysis is comprehensively *** synthesis of tungsten pnictide-based electrocatalysts are discussed ***,current achievements in developing efficient tungsten pnictide electrocatalysts for water electrolysis are detailed,and four key catalyst design strategies(i.e.,nanostructure control,heteroatom doping,defect engineering,and heterostructure design)are *** physicochemical properties-catalytic performance relationship of tungsten pnictide-based electrocatalysts is also *** last,perspectives in this field are put forward for guiding further research on the design and application of high-performance tungsten pnictide-based electrocatalysts.

关键词： Tungsten nitrides Tungsten phosphides Hydrogen evolution reaction Oxygen evolution reaction Electrocatalysts

Surgical left atrial appendage occlusion in patients with atrial fibrillation undergoing mechanical heart valve replacement

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Chinese Medical Journal 2020年第16期133卷 1891-1899页

作者： Ye Zheng Chen-Fei Rao Si-Peng Chen Li He jian-feng hou Zhe Zheng Department of Cardiovascular Surgery Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100037China Information Center Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100037China.

Background:Surgical left atrial appendage occlusion(SLAAO)may be associated with a lower risk of thromboembolism in patientswith atrial fibrillation undergoing cardiac ***,evidence regarding the effectiveness of SLAAO in patients undergoingmechanical heart valve replacement(MHVR)is ***,we aimed to evaluate the association between SLAAO and thecardiovascular outcomes in patients with atrial fibrillation undergoing ***:We retrospectively analyzed data for 497 patients with atrial fibrillation;27.6%of the patients underwent SLAAO,andthe remainder of the patients did not(No-SLAAO group).The primary outcome was a composite of ischemic stroke,systemicembolism,and all-cause *** event-free survival rates were estimated using Kaplan-Meier curves,and weperformed multivariate Cox analyses to evaluate the association between SLAAO and *** used one-to-one propensityscore matching to balance patients’baseline characteristics,and analyzed 120 matching ***:Five patients died within 30 days postoperatively,and there were no significant differences between the two groupsregarding in-hospital complications(all P>0.05).After a median follow-up of 14 months,14 primary events ***-Meier curves showed no difference in the cumulative incidence of freedom from the primary outcome(log-rank P=0.830),hemorrhagic events(log-rank P=0.870),and the secondary outcome(log-rank P=0.730),between the two *** proportional hazards regression analysis showed no association between SLAAO and any outcome(all P>0.05).Afterpropensity score matching,cardiopulmonary bypass time and aortic cross-clamp time,and the postoperative length of stay weresignificantly longer in the SLAAO group(all P<0.05);results were similar to the unadjusted ***:Concomitant SLAAO and MHVR was associated with longer length of stay,and cardiopulmonary bypass time andaortic cross-clamp time,but was not associated with add

关键词： Atrial fibrillation Heart valve prosthesis implantation Propensity score

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刀具自动补偿在复杂轮廓中应用技巧研究

组合机床与自动化加工技术 2017年第9期 107-109,113页

作者：苟建峰侯忠坤四川工程职业技术学院四川德阳618000 西安理工大学机械与精密仪器工程学院西安710048 四川建筑职业技术学院四川德阳618000

文章针对数控铣削中复杂轮廓零件,编程困难(往往需要自动编程,程序复杂)的问题。在分析复杂轮廓零件与刀具半径之间的成型特点基础上,采用建立刀具半径数学模型并推导出相关参数表达式,提出利用刀具自动补偿功能及宏程序中全局变量,开... 详细信息

文章针对数控铣削中复杂轮廓零件,编程困难(往往需要自动编程,程序复杂)的问题。在分析复杂轮廓零件与刀具半径之间的成型特点基础上,采用建立刀具半径数学模型并推导出相关参数表达式,提出利用刀具自动补偿功能及宏程序中全局变量,开发出具有较高实用价值的复杂轮廓加工的参数程序。通过验证,该方法大大简化了程序,节省了加工时间,提高了生产效率和加工精度。同时也彻底改变了以往手工编程中需要人工修改刀补的问题,有效地提高了机床利用率及自动化程度。在实际生产中有一定的推广应用价值。

关键词：刀具补偿复杂轮廓应用

不同载体和前驱体对钴基催化剂浆相费托合成性能的影响

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石油大学学报（自然科学版） 2004年第5期28卷 94-98页

作者：李剑锋侯学锋代小平余长春石油大学中国石油天然气集团公司催化重点实验室北京102249

以SiO2和γ Al2O3为载体,以硝酸钴、醋酸钴和氯化钴为前驱体,利用浸渍法制备出钴基细粒子催化剂。用X射线衍射、程序升温还原、比表面测试等技术考察了钴基催化剂的结构和还原性能,分析了不同载体和前驱体对浆相费托反应性能的影响。结... 详细信息

以SiO2和γ Al2O3为载体,以硝酸钴、醋酸钴和氯化钴为前驱体,利用浸渍法制备出钴基细粒子催化剂。用X射线衍射、程序升温还原、比表面测试等技术考察了钴基催化剂的结构和还原性能,分析了不同载体和前驱体对浆相费托反应性能的影响。结果表明,SiO2载体上钴物种的分散度和还原度均高于γ Al2O3载体,因而Co/γ Al2O3催化剂的活性最差,CO转化率远低于Co/SiO2催化剂。不同钴前驱体所制备的Co/SiO2催化剂钴物种的分散度和还原度有很大的差别,其相应的Co/SiO2催化剂的浆相费托活性顺序由大到小依次为:Co(NO3)2,Co(NO3)2+Co(CH3CO2)2,Co(CH3CO2)2,CoCl2。

关键词：前驱体钴基催化剂 SiO2 γ-Al2O3 费托合成载体还原性能程序升温还原分散度 X射线衍射