Nonlinear Dynamic Analysis of Coupled Gear-Rotor-Bearing System with the Effect of Internal and External Excitations

Extensive studies on nonlinear dynamics of gear systems with internal excitation or external excitation respectively have been carried out. However, the nonlinear characteristics of gear systems under combined internal and external excitations are scarcely investigated. An eight-degree-of-freedom（8-DOF） nonlinear spur gear-rotor-bearing model, which contains backlash, transmission error, eccentricity, gravity and input/output torque, is established, and the coupled lateral-torsional vibration characteristics are studied. Based on the equations of motion, the coupled spur gear-rotor-bearing system（SGRBS） is investigated using the Runge-Kutta numerical method, and the effects of rotational speed, error fluctuation and load fluctuation on the dynamic responses are explored. The results show that a diverse range of nonlinear dynamic characteristics such as periodic motion, quasi-periodic motion, chaotic behaviors and impacts exhibited in the system are strongly attributed to the interaction between internal and external excitations. Significantly, the changing rotational speed could effectively control the vibration of the system. Vibration level increases with the increasing error fluctuation. Whereas the load fluctuation has an influence on the nonlinear dynamic characteristics and the increasing excitation force amplitude makes the vibration amplitude increase, the chaotic motion may be restricted. The proposed model and numerical results can be used for diagnosis of faults and vibration control of practical SGRBS.

Balanced Development of Internal and External Trade

The CMC International and Domestic Trade Division under the China National Machinery Import & Export Corporation has, in accordance with the CMC’s strategic goals, worked out the following business guidelines: internal trade is the basis of external trade, and external trade is a supplementary to internal trade; domestic and overseas markets and resources should be used effectively, and internal trade and external trade should be coordinated and handled in a unified way. The Division’s business concept is to conduct trade-dominated business backed by

District Policy---Social Practice Through Internal and External Discourses： How the Implementation of a Single Regional Political Instrument Is Perceived, Understood and Communicated

This paper focuses on how the implementation of a single regional political instrument is perceived, understood and communicated. Designed as a regional political instrument, the Norwegian Ministry of Transport and Communications started a pilot project： ＂Driver education as a part of upper secondary school in district Norway＂. The focal point in this paper is to explore how the professional participants understand and interpret the project as a regional political instrument in order to maintain the local community, identity and local belonging. The theoretical approach is based on Giddens＇s actor/structure theory, while the analysis based on discourse analysis, in the analysis we separated the arguments used in the professional discourse. We detected different categories of argument in the discourses among the professionals. In addition to the professional discourse, we became aware of a personal discourse. In both discourses the political instrument was perceived to be important in order to maintain the local community, create equality and maintain local identity and a sense of belonging.

Internal and External Consciousness of Japanese Students’Intercul­tural Language Communication

Japanese strictly distinguish between inside and outside,that is,they have a strong sense of inside and outside.The character has penetrated the study and life of Japanese students.Living in a different cultural environment,Japanese students are more influenced by Internal and External Consciousness in cross-cultural communication.The purpose is to draw out the influence of Internal and External Consciousness on the intercultural communication of Japanese students and put forward targeted teaching strategies accordingly by listing the misunderstandings among Japanese students in intercultural communication through the HSK dynamic corpus of Beijing Language and Culture University.

Professor Renting Li's Combination of Internal and External Treatment of Traditional Chinese Medicine in Treating Radiation Enteritis

Radiotherapy is a common treatment for abdominal and pelvic malignancies with bone metastases.However,some patients develop radiation enteritis(RE)during the treatment or 2 months or more after the treatment,which seriously affects their quality of life.At present,the curative effect of western medicine is poor.Professor Renting Li believes that radiation kills tumor cells but at the same time,it damages the healthy Qi of the human body.Radiation causes heat and poison to accumulate in the intestinal tract,consumes and hurts Yin fluid,bums the vein,leads to deficiency of healthy Qi and poor detoxification,as well as cause blood stasis after a period of time.All these result in the combination of heat,blood stasis,and poison,manifesting as abdominal pain,diarrhea,mucus in stools,purulent and bloody stools,etc.Therefore,Professor Renting Li proposed the use of traditional Chinese medicine retention enema combined with oral traditional Chinese medicine to reduce symptoms,remove toxins,and improve the quality of life of patients.

A STUDY ON THE CHARACTERISTICS OF INTERNAL ANDEXTERNAL WALL SURFACE TEMPERATUREIN THE URBAN AREA

Internal and external wall surface temperatures (Tws) in April, August and December in Kunming, a city in low latitude plateau, were investigated. Results showed that the Tws in April were of the highest among the three, followed by August and December. The Tws differences among walls with different orientation were higher in April and December when the weather tends to be sunny, and lower in August with more cloudy days in the time. In April and August, Tws of E-wall was the highest, followed by S- and N-wall. But in December Tws of S-wall might be sometimes higher than E one. Diurnal range of internal Tws was usually smaller than that of the external, with also a time lag for the occurrence of its maximum and minimum. The results can serve as a basis for further research on building microclimate and urban architecture designs. It also gives suggestions for similar studies in other areas.

"External main and internal auxiliary" treatment on refractory radiation proctitis

Radiotherapy is an essential method in the comprehensive treatment of malignant tumors.However,radiation proctitis(RP)is a common complication of pelvic tumors after radiotherapy.Due to RP's various etiology and complex pathogenesis,it is currently no standard for traditional Chinese medicine(TCM)treatment.Professor Yuan-hong Zhao believes that refractory RP,which is named chronic hemorrhagic radiation proctitis(CHRP),should be classified as"Intestinal Wind Bleeding"(Bleeding like a note before defecation,bright red blood,no swelling and pain in the anus)and"Intestinal Afflux"(Refers to the symptoms of pus and blood in the lower mucus,similar to ulcerative colitis,peptic ulcer and other diseases in modern medicine.)in TCM.The critical pathogenesis of CHRP lies in local stasis and collaterals injury of intestinal collaterals.In general,it is a syndrome of excess and scarcity.External treatment with TCM is the preferred treatment strategy for CHRP,and the primary way is to disperse blood stasis and detoxify and nourish the intestinal collaterals.

Internal and external disturbances aware motion planning and control for quadrotors

Resilient motion planning and control,without prior knowledge of disturbances,are crucial to ensure the safe and robust flight of quadrotors.The development of a motion planning and control architecture for quadrotors,considering both internal and external disturbances(i.e.,motor damages and suspended payloads),is addressed.Firstly,the authors introduce the use of exponential functions to formulate trajectory planning.This choice is driven by its ability to predict thrust responses with minimal computational overhead.Additionally,a reachability analysis is incorporated for error dynamics resulting from multiple disturbances.This analysis sits at the interface between the planner and controller,contributing to the generation of more robust and safe spatial–temporal trajectories.Lastly,the authors employ a cascade controller,with the assistance of internal and external loop observers,to further enhance resilience and compensate the disturbances.The authors’benchmark experiments demonstrate the effectiveness of the proposed strategy in enhancing flight safety,particularly when confronted with motor damages and payload disturbances.

Design and realization of security physical isolation system

A physical isolation system based on PCI (peripheral component interconnect),embedded with intelligence card technology, strong identity authentication technology and securityaudit, etc., is introduced. The system can physically isolate the internaland external networks. Thehardware of the system, including PCI interface control circuits, network interface circuits andlogic control circuits, is designed to automatically adapt its operation speed and mode to thenetwork and securely isolate the internal and external networks; the software of the system,including the security strategy management module, the security audit module, the database recordexchanging module, the file exchanging module and the mail exchanging module, is designed toefficiently exchange and manage the data transference between the internal and external networks.Also the driver of the system is implemented with Windows driver development kits (DDK) based onNetwork Driver Interface Specification (NDIS). The prototype ofthe system developed has beenemployed in the Police Fire Protection Bureau of Hubei Province, which performs consistently andefficiently. The technological cruxes discussed have practical values for related subjects.

Tribology Performance and Adhesive Strength Evaluation of TiAlSiN Coating

Scratch test and friction test were performed to evaluate the internal and external interface behaviors of TiAISiN coating, respectively. The critical compressive and shearing stress of coating failure during scratch test were calculated and the values are 30.84 MPa and 4.98 MPa respectively. The average friction coefficients of TiAISiN coat- ing against 2Crl2Ni4Mo3VNbN steel are 0.70 （sliding speed 50 m/rain）, 0.63 （sliding speed 100 m/min）, and 0.81 （sliding speed 150 m/min）. The elements diffusion was analyzed by EDS. A1 and Si element of coating material dif- fuse to the steel disc, except Ti element. The oxidation decreases with the increase of sliding speed, but the adhesion increases with the increase of sliding speed. More A1 element diffuses to the steel disc at the high sliding speed, but the diffusion of Si element keeps almost constant at dlfferent sliding speeds.

Middle or low water pressure direct spiral double helix converging nozzle structure optimization and flow field analysis

In order to solve the problem of using new nozzle is proposed in fire rescue robot. middle or low water pressure to form fine water mist, a Existing water mist nozzles are basically used for high pressure and in large size, complex structure and poor low pressure atomization effect in comparison with requirement of snake-like fire rescue robots. On the basis of comprehensive typical spray noz- zles, a direct spiral double helix converging nozzle （DSDHCN） is proposed, which has the advanta- ges of small volume, light weight, simple structure, and convenient installation. To make the spray nozzle have good performance, and meet the requirements of more efficient fire extinguishing, a nu- merical study is carried out to analyze the internal and external full flow field of nozzle. A gas-liquid two-phase flow is applied to simulate the external full flow field of nozzle with VOF model in fluent software. The simulation results show the real situation of water flow out of the atomization nozzle and the water jet trajectory. Some simulations about middle or low water pressure direct spiral double he- lix converging optimized nozzle have been done in 30bar pressure. The simulation results show that the optimized nozzle structure not only makes the spray droplets have a good cone angle, but also have a sufficient axial velocity,which proves the structure rationality of the proposed optimized nozzle.

Quality Assurance Mechanisms and Strategies for the Internationalization of Chinese Higher Education

This study comprehensively analyzes the current state,challenges,and strategies for the internationalization of Chinese higher education.It underscores the significance of internationalization in enhancing the soft power of the nation and cultivating globally-minded talents.The research concludes that robust internal quality assurance mechanisms and external quality assurance frameworks are fundamental to ensuring the quality of education and propelling its internationalization.By comparing different countries’higher education quality assurance mechanisms,valuable experiences and insights have been drawn.The study proposes strategic recommendations aimed at reforming and innovating to comprehensively improve the international quality of Chinese higher education.However,the research has limitations,including data constraints and a focus primarily on undergraduate education,with less exploration of other educational levels.Future research should employ empirical investigations and quantitative analyses to further verify the conclusions and recommendations of this study.

Relative Chemical Shifts for Obtaining Accurate Chemical Shifts of Hydrogen Atoms in CH Groups

Accurate chemical shifts of hydrogen atoms in CH groups are difficult to obtain. To solve this problem, relative chemical shifts are introduced. Internal and external standard methods were used to measure the chemical shifts in a whole-concentration of N-methylacetamide- water system. Determination of the chemical shifts of hydrogen atoms, especially those of CH groups, according to the two methods yielded significant differences. Relative chemical shifts were proven to be independent of the reference and may be applied to other systems.

Effect of Cone Angle on the Hydraulic Characteristics of Globe Control Valve

Globe control valve is widely used in chemical, petroleum and hydraulic industries, and its throttling feature is achieved by the adopting of valve plug. However, very limited information is available in literature regarding the influence of valve plug on the internal and external features in globe control valves. Thus the effect of valve plug is studied by CFD and experiment in this paper. It is obtained from external features that the pressure drop between upstream and downstream pressure-sampling position increases exponentially with flow rate. And for small valve opening, the increment of pressure drop decreases with the increase of cone angle（β）. However, with the increase of valve opening, the effect of cone angle diminishes significantly. It is also found that the cone angle has little effect on flow coefficient（Cv） when the valve opening is larger than 70%. But for the cases less than 70%, Cv curve varies from an arc to a straight line. The variation of valve performance is caused by the change of internal flow. The results of internal flow show that cone angle has negligible effect on flow properties for the cases of valve opening larger than 70%. However, when valve opening is smaller than 70%, the pressure drop of orifice decreases with the increase of β, making the reduction in value and scope of the high speed zone around the conical surface of valve plug, and then results in a decreasing intensity of adjacent downstream vortex. Meanwhile, it is concluded from the results that the increase of cone angle will be beneficial for the anti-cavitation and anti-erosion of globe control valve. This paper focuses on the internal and external features of globe control valve that caused by the variation of cone angle, arriving at some results beneficial for the design and usage of globe control valve.

STUDY ON HIGHLY ACTIVE ZIEGLERNATTA CATALYSTS FOR POLYMERIZATION OF OLEFINS

In this paper, highly active Ziegler-Natta catalysts of MgCl_2 supported TiCl_4 for synthesis ofpolyolefins, using di-n-butyl phthalate (DNBP) as internal donor and diphenyl dimethoxyl silane(DPDMS) as external donor, have been prepared. The conditions controlling the treatment ofsupport were studied. The interactions of various components present in the catalysts and theirinfluences on catalytic performance were investigated. It is found that by using DNBP and DPDMSas internal and external donors together the polymer products with higher isotactic index can beobtained. Plausible structure model and mechanism were proposed.

Professor Liu Guobin used traditional Chinese medicine to cure a case of primary erythema limb pain

Primary erythema limb pain is a very rare disease,and its pathogenesis is not clear.Usually,the pain symptoms of patients exist for a long time,which seriously affect the daily life of patients and increase the economic burden of patients.Professor Liu Guobin,who has been engaged in the diagnosis and treatment of peripheral vascular diseases for nearly 30 years,believes that heat-toxin and blood stasis collaterals are closely related to the disease,and emphasizes the principle of heat-toxin and evil qi causing the disease.It is emphasized that clearing heat and detoxification,promoting blood circulation and dispersing blood stasis are the main treatment principles.This paper selects a typical case to describe Professor Liu's clinical experience in the treatment of primary erythema limb pain by oral and external use of traditional Chinese medicine,so as to provide an effective method of traditional Chinese medicine for the treatment of primary erythema limb pain.

The Game Changer China Pakistan Economic Corridor （CPEC）： A SWOT Analysis

China Pakistan Economic Corridor （CPEC） is dreamed to be the game changer not only for China and Pakistan but other 50 regional, Middle East, Central Asian Republics, and European countries too. It is one of its kind a huge project with billion US$ investment by China. Since its inception, the internal controversies and disputes in Pakistan on the sharing of benefits as well as interests and concerns of the regional and international players are posing threats to it. The review article aims to investigate and analyze the strengths and weakness and opportunities and threats （SWOT） for CPEC. To analyze the qualitative data, a computer based software program ATLAS.ti was used by employing multiple methods like discourse, hermeneutics, and heuristic by Moustakas. The schematic model of the theoretical framework elaborates the association and impact between and on the dependent, independent, and mediating variables of the study. It was found that if the security, political support, internal and external threats, coordination and cooperation and involvement of stakeholders are properly addressed, the CPEC will bear the fruits.

Reform and opening up in the area of circulation:a retrospect

China＇s reform and opening up in the area of circulation are an important component of the establishment of a socialist mgrket economy system. Prior to reform and opening up, this area had long been characterized by a high level of centralization, closedness and segmentation. The domestic market was isolated from the overseas market and internal trade from foreign trade, and each had its own management system and policy environment. The thirty years of reform and opening up, however, have put a new face on the institutional environment of circulation： an open and modern system of circulation has been basically established, an embryonic WTO-consistent business administration system is taking shape, and the extension Of business and trade service ixidustries has facilitated institutional innovation. The main experience of reform is the following： first, taking opening up as the leading principle and making use of opening up to promote reform; second, following an incremental path of dealing with the easier issues before the harder ones, building up while you tear down, and gradual improvement; and third, breaking through the traditional framework of commodity circulation and establishing new business systems that accommodate more service industries. The economic implication of China＇s reform experience is as follows： an export-oriented strategy must inevitably be chosen as the point of entry for reform; there is an inherent linkage between market structure and human capital in the circulation of goods and services; and expanding the circulation of non-material goods is an important basis for institutional innovation.

Building an open economic powerhouse driven by domestic demand

This paper,starting from an accounting of internal and external demand,first examines the relationship between the two under strict conditions and then points out the preferences of different countries for internal demand and external demand by relaxing the hypothesis gradually.On the basis of general theories,the evolution of the relationship between internal and external demand in China’s economic growth is studied to explain that expanding internal demand and establishing an open economic powerhouse driven by internal demand is a realistic choice.Specific suggestions on such aspects as investment,urbanization,income,consumption,and distribution are also proposed in the hope of being conducive to related future research.