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Design and analysis of spiral bevel gears with seventh-order function of transmission error

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Chinese Journal of Aeronautics 2013年第5期26卷 1310-1316页

作者： su Jinzhan fang Zongde Cai Xiangwei Key Laboratory of Road Construction Technology and Equipment Ministry of EducationChang’an University School of Mechanical Engineering Northwestern Polytechnical University

This paper proposes a new approach to mial function of transmission error （TE） for spiral design and implement a seventh-order polyno- bevel gears with an aim to reduce the running vibration and noise of gear drive and improve the loaded distribution of the tooth. Based on the constraint conditions of predesigned seventh-order polynomial function curve and the theory of linear algebra, the polynomial coefficients of the seventh-order polynomial function of transmission error can be obtained. By applying a method named reverse tooth contact analysis, the modified roll coefficients as well as parts of machine-tool settings for the face-milling of spiral bevel gears can be individually determined. Therefore, a predesigned seventh-order polynomial function of transmission error for spiral bevel gears can be obtained by the modified roll with high-order coef- ficients, and comparisons of the seventh-order polynomial and parabolic functions of transmission error are also performed. The achievement of spiral bevel gears with the seventh-order function of transmission error can be accomplished on a universal Cartesian-type hypoid gear generator or a numerically controlled cradle-style hypoid gear generator due to its simple generating motion of axes of the cradle and the work piece. The results of a numerical example show that the bending stresses of the tooth of seventh-order are less than those of a parabolic one, while the contact stresses remain almost eouivalent.

关键词： Loaded tooth Modified roll Spiral bevel gear Tooth contact analysis Transmissions

Inheritance of Powdery Mildew Resistance in Cucumber (Cucumis sativus L.) and Development of an AFLP Marker for Resistance Detection

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Agricultural Sciences in China 2007年第11期6卷 1336-1342页

作者： ZHANG su-qin GU Xing-fang ZHANG Sheng-ping ZOU Zhi-rong Institute of Vegetables and Flowers Chinese Academy of Agricultural Sciences Beijing 100081 P.R.China Agricultural College Guizhou University Guiyang 550025 P.R.China College of Horticulture Northwest A ＆ F University Yangling 712100 P.R.China

Cucumber powdery mildew is one of the most destructive diseases of cucumber throughout the world. In the present study, inheritance of powdery mildew resistance in three crosses, and linkage of resistance with amplified fragment length polymorphism （AFLP） markers are studied to formulate efficient strategies for breeding cultivars resistant to powdery mildew. The joint analysis of multiple generations and AFLP technique has been applied in this study. The best model is the one with two major genes, additive, dominant, and epistatic effects, plus polygenes with additive, dominant, and epistatic effects （E-l-0 model）. The heritabilities of the major genes varied from 64.26% to 97.82%, and susceptibility was incompletely dominant for the two major genes in the three crosses studied. The additive effects of the two major genes and the dominant effect of the second major gene were high, and the epistatic effect of the additive-dominant between the two major genes was the highest in cross I . In cross II, the absolute value of the additive effect, dominant effect, and potential ratio of the first major gene were far higher than those of the second major gene, and the epistatic effect of the additive-additive was the highest. The genetic parameters of the two major genes in cross III were similar to those in cross II. Correlation and regression analyses showed that marker E25/M63-103 was linked to a susceptible gene controlling powdery mildew resistance. The marker could account for 19.98% of the phenotypic variation. When the marker was tested on a diverse set of 29 cucumber lines, the correlation between phenotype and genotype was not significant, which suggested cultivar specialty of gene expression or different methods of resistance to powdery mildew. The target DNA fragment was 103 bp in length, and only a small part was found to be homologous to DNA in the other species evaluated, which indicated that it was unique to the cucumber genome.

关键词： cucumber (Cucumis sativus L.) powdery mildew resistance inheritance amplified fragment lengthpolymorphism (AFLP) molecular marker

An Interfacial Dynamic Crosslinking Approach toward Catalyst-free and Mechanically Robust Elastomeric Vitrimer with a Segregated Structure

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Chinese Journal of Polymer Science 2021年第2期39卷 201-210,I0007页

作者： Yong Zhu Jing-Li Gao Lin-Jun Zhang Yan Peng Hao Wang fang-Wei Ling Guang-su Huang Jin-rong Wu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu 610065China

Elastomeric vitrimers with covalent adaptable networks are promising candidates to overcome the intrinsic drawbacks of conventional covalently-crosslinked elastomers;however, most elastomeric vitrimers show poor mechanical properties and require the addition of exogenous catalysts. Herein, we fabricate a catalyst-free and mechanically robust elastomeric vitrimer by constructing a segregated structure of sodium alginate (SA) in the continuous matrix of epoxidized natural rubber (ENR), and further crosslinking the composite by exchangeable hydroxyl ester bonds at the ENR-SA interfaces. The manufacturing process of the elastomeric vitrimer is facile and environmentally friendly without hazardous solvents or exogenous catalysts, as the abundant hydroxyl groups of the segregated SA phase can act as catalyst to activate the crosslinking reaction and promote the dynamic transesterification reaction. Interestingly, the segregated SA structure bears most of the load owing to its high modulus and small deformability, and thus ruptures preferentially upon deformation, leading to efficient energy ***, the periodic stiffness fluctuation between rigid segregated SA phase and soft ENR matrix is beneficial to the crack-resisting. As a result,the elastomeric vitrimer manifests exceptional combination of catalyst-free, defect-tolerance, high tensile strength and toughness. In addition,the elastomeric vitrimer also exhibits multi-shape memory behavior which may further broaden its applications.

关键词： Tough Defect-tolerant Elastomeric vitrimer Interfacial dynamic crosslinks Segregated structure

Role of ammonium sulfate in sulfurization flotation of azurite:Inhibiting the formation of copper sulfide colloid and its mechanism

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International Journal of Mining Science and Technology 2022年第3期32卷 575-584页

作者： Jinpeng Cai Chao su Yinyu Ma Xingcai Yu rong Peng Jiangli Li Xiaolin Zhang Jianjun fang Peilun Shen Dianwen Liu State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Yunnan Key Laboratory of Green Separation and Enrichment of Strategic Metal ResourcesFaculty of Land Resources EngineeringKunming University of Science and TechnologyKunming 650093China Shandong Gold Group Co. LtdJinan 250014China Yunnan Posphate Group Co. LtdKunming 650600China

In this study,the role of(NH_(4))_(2)SO_(4)during the sulfurization of azurite and its response to flotation were *** flotation results showed that adding(NH_(4))_(2)SO_(4)prior to sulfurization decreased the formation of colloid in flotation pulp,and the floatability of the suppressed azurite caused by excess sodium sulfide was *** adding(NH_(4))_(2)SO_(4)prior to sulfurization,the formation of Cu(NH_(3))_(n) ^(2+)intermediate products changed the path of the sulfurization reaction,which slowed the direct impact of HSon the azurite *** nucleation rate was reduced,and the growth of copper sulfide crystal was ***(syn,CuS)with larger crystal grains was formed on the azurite surface,thereby enhancing the mechanical stability of copper sulfide products onto the mineral ***,the generated copper sulfide colloid significantly reduced,ultimately promoting the effective adsorption of xanthate on the azurite surface.

关键词： Azurite sulfurization flotation Ammonium sulfate Colloid Inhibition Crystal growth

Decadal-to-interdecadal response and adjustment of the North Pacific to prescribed surface forcing in an oceanic general circulation model

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Acta Oceanologica Sinica 2006年第3期25卷 11-24页

作者： fang Jiabei rong Xinyao YANG Xiuqun Institute of Severe Weather ＆ Climate Nanjing University Nanjing 210093 China

The simulation of a higher-resolution oceanic GCM forced with COADS surface conditions during 1945 ～ 1993 was analyzed with insight into how the North Pacific responds to the surface forcing. The decadal-to-interdecadal variabilities in the thermal and dynamical fields especially those associated with the 1976/1977 regime shift in the North Pacific were investigated. The model successfully captures the dominant SST anomaly mode on the decadal-to-interdecadal time scales as well as the major feature of SST anomalies in the 1976/1977 regime shift. The model also successfully reproduces two typical subduction events that link the tropical and extratropical oceanic temperature anomalies during the 1970s and the 1980s. Most importantly, the model simulates the dynamical adjustment of the upper ocean under the surface wind forcing. The typical surface circulation anomaly is characterized by a pattern that is simultaneously related to the wind stress anomalies. The typical anomalous pattern for the entire upper-ocean is characterized by coherent anomalies of two oceanic gyres, i.e. , the subtropical and subpolar gyres. The delayed response and slower adjustment of the gyres, especially of the subpolar gyre, give rise to a persistent SST anomaly in the central North Pacific. The upper-ocean heat budgets in three target regions, i.e. , the central North Pacific, the Californian coastal region and the KOE region, are examined. The cooling in the central North Pacific around 1976/1977 is attributed to the heat flux and mefidional advection anomalies. The associated warming in the Californian coastal region is only due to the heat flux anomaly. A cooling shift in the KOE region which lags that in the central basin by 3 to 4 a is largely due to the meridional advection anomaly and the heat flux acts only as a damping role.

关键词： North Pacific Ocean decadal-to-interdecadal variability subtropical gyre subpolar gyre

Inductive Rings and Systems of Diophantine Equations

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Acta Mathematica Sinica,English Series 2006年第5期22卷 1549-1556页

作者： rong fang BIE Shi Qiang WANG College of Information Science Beijing Normal University Beijing 100875 P. R. China School of Mathematical Sciences Beijing Normal University Beijing 100875 P. R. China

In this paper, by using model-theoretic methods, it is shown that some systems of unsolved cubic diophantine equations in number theory can have solutions in certain inductive extension rings of the ring I of rational integers. These inductive rings are not fields, and every element of them is a sum of 4 cubes and a sum of 3 squares. Also some of them satisfy the Goldbach conjecture and some others don＇t.

关键词： Inductive rings Systems of unsolved cubic diophantine equations Model theory

Nonlinear Instability of Phillips Model

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Acta Mathematicae Applicatae Sinica 2016年第3期32卷 669-684页

作者： rong-fang WANG Hong-jun GAO Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical Sciences Nanjing Normal University Institution of Mathematics Jilin University

We investigate the instability of two-layer Phillips model in this paper, which is a prototypical geophysical fluid model. Using the results of Guo and Strauss et al, we obtained linear instability implies nonlinear i... 详细信息

关键词： nonlinear instability Lyapunov exponent Phillips model

Polynomial Approach to Optimal One-wafer Cyclic Scheduling of Treelike Hybrid Multi-Cluster Tools via Petri Nets

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IEEE/CAA Journal of Automatica Sinica 2018年第1期5卷 270-280页

作者： Fajun Yang Naiqi Wu Yan Qiao rong su Department of Industrial Engineering School of Electro-Mechanical Engineering Guangdong University of Technology Guangzhou 510006 China School of Electrical and Electronic Engineering at Nanyang Technological University 639798 Singapore Institute of Systems Engineering Macao University of Science and Technology Taipa Macao 999078 China school of Electro-Mechanical Engineering Guangdong University of Technology Guangzhou 510006 China IEEE

A treelike hybrid multi-cluster tool is composed of both single-arm and dual-arm cluster tools with a treelike topology. Scheduling such a tool is challenging. For a hybrid treelike multi-cluster tool whose bottleneck individual tool is process-bound, this work aims at finding its optimal one-wafer cyclic schedule. It is modeled with Petri nets such that a onewafer cyclic schedule is parameterized as its robots' waiting *** on the model, this work proves the existence of its onewafer cyclic schedule that features with the ease of industrial implementation. Then, computationally efficient algorithms are proposed to find the minimal cycle time and optimal onewafer cyclic schedule. Multi-cluster tool examples are given to illustrate the proposed approach. The use of the found schedules enables industrial multi-cluster tools to operate with their highest productivity.

关键词： Multi-cluster tool Petri nets scheduling semiconductor manufacturing

Randomized controlled trial of uncut Roux-en-Y vs Billroth Ⅱ reconstruction after distal gastrectomy for gastric cancer: Which technique is better for avoiding biliary reflux and gastritis?

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World Journal of Gastroenterology 2017年第34期23卷 6350-6356页

作者： Dong Yang Liang He Wei-Hua Tong Zhi-fang Jia Tong-rong su Quan Wang Department of Gastrointestinal and Anal surgery The First Hospital of Jilin University Division of Clinical Research The First Hospital of Jilin University

AIM To identify which technique is better for avoiding biliary reflux and gastritis between uncut Roux-en-Y and Billroth Ⅱ reconstruction. METHODS A total of 158 patients who underwent laparoscopyassisted distal gastrectomy for gastric cancer at the First Hospital of Jilin University(Changchun, China) between February 2015 and February 2016 were randomized into two groups: uncut Roux-en-Y(group U) and Billroth II group(group B). Postoperative complications and relevant clinical data were compared between the two groups. REsuLTS According to the randomization table, each group included 79 patients. There was no significant difference in postoperative complications between groups U and B(7.6% vs 10.1%, P = 0.576). During the postoperative period, group U stomach p H values were lower than 7 and group B p H values were higher than 7. After 1 year of follow-up, group B presented a higher incidence of biliary reflux and alkaline gastritis. However, histopathology did not show a significant difference in gastritis diagnosis(P = 0.278), and the amount of residual food and gain of weight between the groups were also not significantly different. At 3 mo there was no evidence of partial recanalization of uncut staple line, but at 1 year the incidence was 13%. CONCLUSION Compared with Billroth II reconstruction, uncut Rouxen-Y reconstruction is secure and feasible, and can effectively reduce the incidence of alkaline reflux, residual gastritis, and heartburn. Despite the incidence of recanalization, uncut Roux-en-Y should be widely applied.

关键词： Gastric cancer Uncut Roux-en-Y Billroth II Bile reflux Alkaline gastritis