THE STUDY ON MEASURING TECHNIQUE OF PARTIAL DISCHARGE IN GAS INSULATED SWITCHGEAR USING ULTRA HIGH FREQUENCY METHOD WITH EXTERNAL SENSORS

Objective In order to find early latent faults and prevent catastrophic failures, diagnosis of insulation condition by measuring technique of partial discharge(PD) in gas insulated switchgear (GIS) is applied in this paper, which is one of the most basic ways for diagnosis of insulation condition. Methods Ultra high frequency(UHF) PD detection method by using internal sensors has been proved efficient, because it may avoid the disturbance of corona, but the sensor installation of this method will be limited by the structure and operation condition of GIS. There are some of electromagnetic (E-M) waves leak from the place of insulation spacer, therefore, the external sensors UHF measuring PD technique is applied, which isn't limited by the operation condition of GIS. Results This paper analyzes propagated electromagnetic (E-M) waves of partial discharge pulse excited by using the finite-difference time-domain (FDTD) method. The signal collected at the outer point is more complex than that of the inner point, and the signals' amplitude of outer is about half of the inner, because it propagates through spacer and insulation slot. Set up UHF PD measuring system. The typical PD in 252kV GIS bus bar was measured using PD detection UHF technique with external sensors. Finally, compare the results of UHF measuring technique using external sensors with the results of FDTD method simulation and the traditional IEC60270 method detection. Conclusion The results of experiment shows that the UHF technique can realize the diagnosis of insulation condition, the results of FDTD method simulation and the result UHF method detection can demonstrate each other, which gives references to further researches and application for UHF PD measuring technique.

Current Research Status of Traditional Chinese Medicine External Treatment for Diarrhea Type Irritable Bowel Syndrome

Irritable bowel syndrome(IBS-D)with diarrhea is a common gastrointestinal functional disease in clinical practice,which seriously affects the quality of life of patients.Cur‐rently,Western medicine has poor therapeutic effects,while traditional Chinese medi‐cine has unique advantages in relieving IBS-D symptoms and preventing recurrence.In recent years,especially with external treatment of traditional Chinese medicine,it has become a new treatment direction in clinical practice and has achieved good therapeutic effects.This article will provide a review of recent research on the treatment of IBS-D using traditional Chinese medicine external treatment methods.

Study on Detection of Negative Corona Discharge Generated in Rod-Plane Air Gap by Using External Electrode Method

A detective method of a negative corona discharge by means of an external electrode is presented. The relationship between an area of the external electrode and a detected voltage waveform is examined experimentally. This experimental study is carried out with the use of a rod-plane air gap. The results obtained will be applicable to problems associated with silos, ducts, and high-voltage equipment.

Nonlinear dynamic analysis of cantilevered piezoelectric energy harvesters under simultaneous parametric and external excitations

The nonlinear dynamics of cantilevered piezoelectric beams is investigated under simultaneous parametric and external excitations. The beam is composed of a substrate and two piezoelectric layers and assumed as an Euler-Bernoulli model with inextensible deformation. A nonlinear distributed parameter model of cantilevered piezoelectric energy harvesters is proposed using the generalized Hamilton＇s principle. The proposed model includes geometric and inertia nonlinearity, but neglects the material nonlinearity. Using the Galerkin decomposition method and harmonic balance method, analytical expressions of the frequency-response curves are presented when the first bending mode of the beam plays a dominant role. Using these expressions, we investigate the effects of the damping, load resistance, electromechanical coupling, and excitation amplitude on the frequency-response curves. We also study the difference between the nonlinear lumped-parameter and distributed- parameter model for predicting the performance of the energy harvesting system. Only in the case of parametric excitation, we demonstrate that the energy harvesting system has an initiation excitation threshold below which no energy can be harvested. We also illustrate that the damping and load resistance affect the initiation excitation threshold.

Manifestation of external field effect in time-resolved photo-dissociation dynamics of LiF

The photo-dissociation dynamics of LiF is investigated with newly constructed accurate ab initio potential energy curves （PECs） using the time-dependent quantum wave packet method. The oscillations and decay of the wave packet on the adiabats as a function of time are given, which can be compared with the femtosecond transition-state （FTS） spectroscopy. The photo-absorption spectra and the kinetic-energy distribution of the dissociation fragments, which can exhibit the vibration-level structure and the dispersion of the wave packet, respectively, are also obtained. The investigation shows a blue shift of the band center for the photo-absorption spectrum and multiple peaks in the kinetic-energy spectrum with increasing laser intensity, which can be attributed to external field effects. By analyzing the oscillations of the wave packet evolving on the upper adiabat, an approximate inversion scheme is devised to roughly deduce its shape.

Assessing the externalities of a ski resort in Tzoumerka:willingness to pay in order to promote or to prevent its construction

The present study aims to assess the externalities of a ski resort,that is planned to be built at Tzoumerka mountains,in Greece.The research relies on the Contingent Valuation method,which indirectly estimates the economic value of environmental and other nonmarket assets,based on the expressed preferences of members of a social group.The investigation was based on primary data.The core idea of questionnaire’s design,is subject to the use of a double WTP(willingness to pay)question,aiming at the monetary assessment of the attitude of the residents,regarding the upcoming infrastructure project,taking into account both its positive and its negative externalities.Depending on the attitude of the survey respondents,they were asked to decide if they wish to offer an amount of money either to promote or to prevent the construction of the ski resort.Parametric and non-parametric models were then applied in order to calculate in economic terms the expressed opinion of the respondents.The primary question to be answered is whether the willingness to build the ski resort holds a higher economic value than the desire to prevent it.According to the results of the survey,the vast majority of residents(92.4%)supported the idea of building the ski resort,projecting their apparent desire for the tourist and economic development of the area.The reinforcement of the construction idea of the project was estimated on average at €378,200.The very low proportion of the participants who disagreed with the project(5%),did not allow the economic assessment of its prevention,leaving room for further research into the application of Contingent Valuation method and its contribution in cost-benefit analysis and decision making,regarding upcoming projects.

Mechanical Properties of Moso Bamboo Connections with External Clamp Steel Plates

The Moso bamboo,a renewable green building material used in various new green buildings,have received exten-sive attention with the promotion of the concept of green buildings.To explore the mechanical properties of Moso bamboo connections with external clamp steel plates,the 16 specimens were designed by changing the bolt diameters and the end distances of the bolt holes.Their static tension tests were conducted to investigate bearing capacities and failure modes of different connection configurations.Based on test results,three failure modes of these connections were obtained,including the shear failure of bolt shank,bearing failure of bolt hole and punch-ing shear failure of the Moso bamboo.The influence of bolt diameters and end distances of bolt holes on bearing capacities of the connections was quantitatively analyzed.Based on a simplified mechanical model,the analytical models were deduced for the bolt shear failure and the bearing failure of bolt holes.The results showed that the predictive values are in substantial agreement with the experimental results.Finally,the design and manufacturing suggestions are recommended for this Moso bamboo connections.

Advanced Deterioration Diagnosis Model for Building External Wall Tiles

In 1981 Taiwan entered a period of intense construction, meaning that today many buildings are more than 30 years old. Lack of maintenance has led to frequent safety incidents involving external walls. This study focuses on a deterioration diagnostic model for external wall tiles of aged buildings, using both stage 1 and stage 2 diagnostic methods. The visual test results are categorized based on impact on public safety, and renovation strategies are proposed. Stage 1 diagnosis mainly adopted the DER visual inspection deterioration assessment method. For enhance the accuracy, this research adopted the Infrared Thermal Imaging detection method to double confirm the visual inspection results. After producing an external wall tile Condition Indicator (CI). For stage 1 diagnostic results that fall in a gray area, stage 2 diagnosis was carried out using a tap tone test, followed by fast Fourier transform and pattern recognition to analyze the tapping results. Finally, the study provides a deterioration evaluation criteria for external wall tiles replacement recommendations and a standard operating procedure for deterioration diagnosis. The study also recommends directions for future amendment of regulations, and provides a basis of reference for the government in determining urban renewal, renovation and maintenance strategies.

Hemodynamics of Enhanced External Counterpulsation with Different Coronary Stenosis

Enhanced external counterpulsation(EECP)is able to treat myocardial ischemia,which is usually caused by coronary artery stenosis.However,the underlying mechanisms regarding why this technique is effective in treating myocardial ischemia remains unclear and there is no patient-specific counterpulsation mode for different rates of coronary artery stenosis in clinic.This study sought to investigate the hemodynamic effect of varied coronary artery stenosis rates when using EECP and the necessity of adopting targeted counterpulsation mode to consider different rates of coronary artery stenosis.Three 3-dimensional(3D)coronary models with different stenosis rates,including 55%(Model 1),65%(Model 2),and 75%(Model 3),were generated,then coupled with a 0-dimensional(0D)lumped parametric model of the blood circulatory system.EECP was applied to the 0D/3D coupled models to study the hemodynamic response of the coronary artery.Under the same counterpulsation mode,the ratio of diastolic blood pressure to systolic blood pressure of 3 models during counterpulsation was 1.4,and the cardiac output and coronary artery flow rate increased significantly.The low wall shear stress(WSS)and high oscillatory shear index(OSI)areas were mainly located at the posterior end of the stenosis and coronary artery bifurcation.Moreover,with an increase in the rate of coronary artery stenosis,the increased percentage of flow rate through the coronary artery stenosis and area-averaged WSS decreased.The geometric multiscale model in this study can be used to effectively simulate the hemodynamic characteristics of cardiovascular system following the application of EECP.Local precise hemodynamic effect of the coronary artery stenosis can be observed.It was found from the hemodynamic factors that the coronary artery with lower stenosis rate more likely led to better vascular endothelial remodeling.Thus,it is necessary to adopt patient-specific counterpulsation mode accounting for different condition of coronary artery stenosis.

Mechanism of biaxial pre-stress method on welding residual stress and hot cracks controlling

Based on the conventional uniaxial pre-tensile stress method during welding, this study presents a new method of welding with biaxial pre-stress. With the help of numerical simulation, experiments were carried out on the self-designed device. Except for the control on residual stress and distortion us-welded, the experimental results also show its effect on the prevention of hot cracks, thus this method can make up for the disadvantage of the conventional pre-stress method. Hot cracks disappear when the value of pre-stress surpasses 0. 2 σs（yield limit）. Welded thin plates with low-level residual stress, little distortion and no hot cracks are obtained with longitudinal pre-tensile stress level between 0. 6σsand 0. 7σs and precompressive stress between 0. 2 σs and 0. 3 σs in transverse direction.

Static Model Classification Status： Taking Into Account Emerging External Factors

Analysis of the problem of predicting bankruptcy shows that foreign and domestic models included only internal factors of enterprises. But the same indicators of internal factors in the rapidly changing external environment can lead to bankruptcy, and not in others. External factors are the most dangerous, because the possible influence on them is minimal and the impact of their implementation can be devastating. This paper focuses on the same factors to assess the impact of the macroeconomic indicators （extemal factors） on the parameters of static models predicting a local approximation of the crisis at the plant. To accomplish the purpose, a Spark set of 100 companies was compiled, including 50 companies which officially declared bankruptcy in the period of 2000-2009 and 50 stable operating companies with a random sample of the same time period. External factors were extracted from the Joint Economic and Social Data Archive1 The author compared two data sets： （1） microeconomic indicators--money to the total liabilities, retained earnings to total assets, net profit to revenue, Earnings Before Interest and Taxes （EBIT） to assets, net income to equity, net profit to total liabilities, current liabilities to total assets, the totality of short-term and long-term loans to total assets, current assets to current liabilities, assets to revenue, equity to total assets, and current assets to revenue; and （2） external factors--index of real gross domestic product （GDP）, industrial production index, the index of real cash incomes, an index of real investments, consumer price index, the refinancing rate, unemployment rate, the price of electricity, gas prices, oil price, gas price, dollar to ruble, ruble euro Standard ＆ Poor （S＆P） index, the Russian Trading System （RTS） index, and region. The aim of the comparison results paging classes ＂insolvent＂ and ＂non-bankrupt＂ is achieved using two methods： classification and discrimination. In both methods, computational procedures are realized with the use of algorithms linear regression, artificial neural network, and genetic algorithm. In the 2-m model, data set includes both internal and external factors. The results showed that the inclusion of only the microeconomic indicators, excluding external factors, impedes models about two times.

Externalities as Compensatory Criteria of Compulsory Expropriation Actions

Ownership/private property and property inheritance are concepts well-established and constitutionally protected in our modern societies.Nevertheless,numerous provisions in the national legal framework enable the states to expropriate individual private goods under certain severe circumstances through compensation prerequisites.The present manuscript presents a short comparative study of the constitutional articles of many countries,regarding expropriation actions,examines the compensation techniques employed,and interrelates expropriation implementation with economic analysis methods and experimental economics.Furthermore,this paper states that the current Greek expropriate methods consist of an economic disturbance and externality in economic terms.

"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.

高铁开通对工业技术效率的影响研究——基于市场可达性与集聚经济效应的分析

中国高铁的快速发展降低了运输和交易成本,加速了要素流动,从而影响了地级及以上城市(以下简称地级市)的工业技术效率。基于2006—2020年259个地级市的面板数据,将市场可达性以及三种不同类型集聚外部性纳入同一框架,考察高铁开通对地级市工业技术效率的直接、空间影响效应及其内在机制。研究发现:整体而言,尽管存在一定滞后效应,但地级市高铁开通可以显著提高其工业技术效率,且存在正向的空间溢出效应;高铁开通可以有效提高非区域中心城市工业技术效率,但对区域中心城市的提升效应不显著;机制分析结果表明,高铁开通能够有效提升地级市市场可达性、工业集聚专业化和竞争外部性,促进其技术效率的提升,但对多样化外部性具有显著负向影响,且结果具有较强的稳健性;与非区域中心城市相比,高铁开通对区域中心城市多样化外部性的影响不再显著。因此,各地应通过体制机制创新,优化要素配置,优化工业空间布局,引导、支持企业向工业园区等优势产地和市场区集聚,因地制宜地制定差异化的工业发展战略,放大高铁开通对地区工业技术效率的改善作用。

A HPLC Method for the Determination of Salmon Calcitonin in Injection by Gradient Elution

It was concluded that the described HPLC method could be used for the assayof salmon calcitonin in injection, as it offers qualified selectivity, accuracy and precision ofanalysis.

“劳淋病”古代中医药文献记载及现代治疗现状

“劳淋病”常因劳倦而发,迁延不愈,是临床常见难治性疾病,其现代医学病名对应的是复发性尿路感染。现代医学的主流治疗劳淋的抗生素疗法仍存在诸多局限性,中医药疗法历史悠久、潜力巨大、优势显著。本文通过整理中国古代关于淋证的记载以及近年来中医药治疗劳淋的相关文献,从历代文献记载、现代医家对于劳淋的认识、中医验方、中医外治法等方面进行概括总结,对未来研究进行展望,以期为劳淋的临床治疗提供些许参考。

中医治疗糖尿病皮肤瘙痒症研究进展

糖尿病皮肤瘙痒症是糖尿病最常见的皮肤并发症,对糖尿病患者日常生活质量和身心健康都产生了极大影响。通过对中医治疗糖尿病皮肤瘙痒症近5年的研究文献进行综述,从不同的角度探讨中医在治疗糖尿病皮肤瘙痒症方面的方法和临床效果,包括古代及现代医家对该病病因病机的认识、中医内治法、外治法、内外结合法和中西医结合法等。通过总结归纳,发现中医药治疗糖尿病皮肤瘙痒症有良好临床疗效,通过总结研究中的进展与不足,以期为该病相关研究的开展及治疗提供更好的科研思路和临床治疗方法。

Rolling Force and Rolling Moment in Spline Cold Rolling Using Slip-line Field Method

Rolling force and rolling moment are prime process parameter of external spline cold rolling. However, the precise theoretical formulae of rolling force and rolling moment are still very fewer, and the determination of them depends on experience. In the present study, the mathematical models of rolling force and rolling moment are established based on stress field theory of slip-line. And the isotropic hardening is used to improve the yield criterion. Based on MATLAB program language environment, calculation program is developed according to mathematical models established. The rolling force and rolling moment could be predicted quickly via the calculation program, and then the reliability of the models is validated by FEM. Within the range of module of spline m=0.5-1.5 mm, pressure angle of reference circle α=30.0°-45.0°, and number of spline teeth Z=19-54, the rolling force and rolling moment in rolling process （finishing rolling is excluded） are researched by means of virtualizing orthogonal experiment design. The results of the present study indicate that： the influences of module and number of spline teeth on the maximum rolling force and rolling moment in the process are remarkable; in the case of pressure angle of reference circle is little, module of spline is great, and number of spline teeth is little, the peak value of rolling force in rolling process may appear in the midst of the process; the peak value of rolling moment in rolling process appears in the midst of the process, and then oscillator weaken to a stable value. The results of the present study may provide guidelines for the determination of power of the motor and the design of hydraulic system of special machine, and provide basis for the farther researches on the precise forming process of external spline cold rolling.

Numerical simulation on the seismic performance of retrofitted masonry walls based on the combined finite-discrete element method

Due to the long construction life,improper design methods,brittle material properties and poor construction techniques,most existing masonry structures do not perform well during earthquakes.The retrofitting method using an external steel-meshed mortar layer is widely used to retrofit existing masonry buildings.Assessing the seismic performance of masonry walls reinforced by an external steel-meshed mortar layer reasonably and effectively is a difficult subject in the research field of masonry structures.Based on the combined finite-discrete elements method,the numerical models of retrofitted brick walls with four different masonry mortar strengths by an external mortar layer are established.The shear strength of mortar and the contact between the retrofitted mortar layer and the brick blocks are discussed in detail.The failure patterns and load-displacement curves of the retrofitted brick walls were obtained by applying low cycle reciprocating loads to the numerical model,and the bearing capacity and the failure mechanism of the retrofitted walls were obtained by comparing the failure patterns,ultimate bearing capacity,deformability and other aspects with the tests.This study provides a basis for improving the seismic strengthening design method of masonry structures and helps to better assess the seismic performance of masonry structures after retrofitting.

Modified surgical method of supra-and infratentorial epidural hematoma and the related anatomical study of the squamous part of the occipital bone

BACKGROUND Supra-and infratentorial acute epidural hematoma(SIEDH)is a common posterior cranial fossa epidural hematoma located at the inner surface of the squamous part of the occipital bone(SOB).Traditionally,surgical treatment of the SIEDH requires a combined supra-infratentorial craniotomy.AIM To analyze the morphological characteristics of the SOB and introduce a single supratentorial craniotomy for SIEDH.METHODS Skull computed tomography(CT)scan data from 32 adult patients were collected from January 1,2019 to January 31,2020.On the median sagittal plane of the CT scan,the angle of the SOB(ASOB)was defined by two lines:Line A was defined from the lambdoid suture(LambS)to the external occipital protuberance(EOP),while line B was defined from the EOP to the posterior edge of the foramen magnum(poFM).The operative angle for the SIEDH(OAS)from the supra-to infratentorial epidural space was determined by two lines:The first line passes from the midpoint between the EOP and the LambS to the poFM,while the second line passes from the EOP to the poFM.The ASOB and OAS were measured and analyzed.RESULTS Based on the anatomical study,a single supratentorial craniotomy was performed in 8 patients with SIEDH.The procedure and the results of the modified surgical method were demonstrated in detail.For males,the ASOB was 118.4±4.7 and the OAS was 15.1±1.8;for females,the ASOB was 130.4±5.1 and the OAS was 12.8±2.0.There were significant differences between males and females both in ASOB and OAS.The smaller the ASOB was,the larger the OAS was.The bone flaps in 8 patients were designed above the transverse sinus intraoperatively,and the SIEDH was completely removed without suboccipital craniotomy.The SOB does not present as a single straight plane but bends at an angle around the EOP and the superior nuchal lines.The OAS was negatively correlated with the ASOB.CONCLUSION The single supratentorial craniotomy for SIEDH is reliable and effective.