Search

High-voltage pillar-type porcelain insulators are important components of power plants and substations, and are widely used in power grids. In recent years, various kinds of accidents caused by breakage of pillar insulators have occurred frequently during the operation of the power grid, posing a serious threat to the safe operation of the power grid. Aiming at the problem of the deterioration detection of porcelain strut insulators in transmission lines, this paper introduces the detection principle of vibro-acoustic method and the vibro-acoustic detection process of porcelain strut insulators. A set of vibro-acoustic-based porcelain strut insulator detection equipment is studied and designed, and its design principle is expounded. And hardware components, the effectiveness of the detection function is verified through the actual measurement analysis, which provides support for the follow-up research and promotion of this detection technology.

The development of the Internet era has brought about a globally integrated economic and trade system, which has enabled the economies of many countries to develop by leaps and bounds. Of course, under such an economic system, China’s economy has also benefited a lot. However, compared with other countries, China’s has many shortcomings in brand building. Although China’s is the world’s largest country in terms of exports, most of these exports are based on cheap labor costs and low-tech content, while the exports of branded products only account for a small part. This paper analyzes the current problems and deficiencies of China’s exports in brand and brand strategy by studying the competitiveness of Chinese export brands in the international market, and analyzes the solutions to these existing or possible problems.

The ancient road cultural route is an important part of Huizhou cultural heritage, which is closely related to Huizhou tradition. Huizhou ancient villages are important historical and cultural heritage. The important features of their locations and layouts are the high integration with nature, forming a traditional residential environment pattern of “backing mountain, surrounding water and facing screen”. From the perspective of Huizhou Ancient Road, this paper selects Chengkan ancient village, which is an important cultural route of “Shuyuan Lingshan Chengkan ancient road”, as the research object, and takes the construction of human settlements as the main research content. From the natural environment and cultural background, and the formed human environment as the starting point, the paper focuses on the village agglomeration spatial pattern, the village water system, the street space environment, the architectural environment and the Shuikou landscape environment to analyze the characteristics and concepts of traditional residential environment construction in Huizhou ancient villages represented by Chengkan village, so as to make a beneficial discussion on the regional rural revitalization, the protection and development of traditional village human settlement environment.

In the construction plan of China (Hubei) pilot free trade zone issued by China (Hubei) pilot free trade zone in 2018, it is pointed out that industrial transfer should be orderly undertaken, which undoubtedly provides a strong institutional guarantee for Hubei to undertake industrial transfer. This paper analyzes the mechanism of industrial transfer on industrial structure upgrading: capital accumulation mechanism, technology progress mechanism, industry aggregation mechanism. At the same time through empirical analysis it is concluded that: build the double logarithm model of Hubei province to undertake industry shift after the provincial labor resources, science and technology innovation ability, industrial concentration degree of ascension for the upgrading of industrial structure in Hubei province has a certain role in promoting, especially the size of the capital and the increase of the number of high-tech talent to upgrade the industrial structure to promote the most significant effect. Therefore, the government should intensify efforts to introduce domestic and foreign capital, cultivate and attract more high-tech talents, focus on improving the quality of workers, expand the scale of industrial agglomeration within the province, and enhance the ability of scientific and technological innovation.

Exhaled contaminants transported in the air can result in the transmission of many airborne infectious diseases in indoor environments. When the exhaled air from the infected person directly enters the breathing zone of another person, direct exposure occurs. When the exhaled contaminants disperse in the room and then are inhaled by another person, indirect exposure occurs. This investigation developed a method for differentiating the direct and indirect exposure to exhaled contaminants in indoor environments with mechanical ventilation. A literature review was conducted to collect experimental data for 191 person-to-person contaminant transport cases. With the analysis of the database, a mathematical method was developed to differentiate direct and indirect exposure in rooms with mixing and displacement ventilation systems. The proposed method correctly differentiated direct and indirect exposure for 120 out of the 133 mixing ventilation cases and 47 out of the 58 displacement ventilation cases. It can be used at the early design stage to quickly assess whether there will be direct exposure to exhaled contaminants in a room with mechanical ventilation systems.

Fast simulation tools for the prediction of transient particle transport are critical in designing the air distribution indoors to reduce the exposure to indoor particles and associated health risks. This investigation proposed a combined fast fluid dynamics (FFD) and Markov chain model for fast predicting transient particle transport indoors. The solver for FFD-Markov-chain model was programmed in OpenFOAM, an open-source CFD toolbox. This study used a case from the literature to validate the developed model and found well agreement between the transient particle concentrations predicted by the FFD-Markov-chain model and the experimental data. This investigation further compared the FFD-Markovchain model with the CFD-Eulerian model and CFD-Lagrangian model in terms of accuracy and efficiency. The accuracy of the FFD-Markov-chain model was similar to that of the other two models. For the studied case, the FFD-Markov-chain model was 4.7 times faster than the CFD-Eulerian model, and it was 137.4 times faster than the CFD-Lagrangian model in predicting the steady-state airflow and transient particle transport. Therefore, the FFD-Markov-chain model is able to greatly reduce the computing cost for predicting transient particle transport in indoor environments.

The working principle and measurement of ultrasonic machining gap is analyzed in this paper. A stable machining gap between the tool and workpiece must be maintained for improving processing accuracy and efficiency. Therefore, a fuzzy self-tuning PID parameters controller for ultrasonic machining tool feed system is designed, by means of using Matlab /Simulink simulation experiment, in this paper.

This study aims at proposing the mix proportions of low energy super-sulfated cement (SSC) concrete from industrial waste anhydrite from circulating fluidized bed combustion (CFBC) fly ash (CFA) as an alternative sulfate activator of ground granulated blast furnace slag (GGBFS/slag). The optimized mix proportion of the SSC was carried out by using mixture of different amounts of CFA in range of 25—45 wt.% and various quantities of ordinary Portland cement (OPC) in range of 0 — 10 wt.% to trigger the hydration of slag. Experimental results showed that with the expected slump at values of 190 — 220 mm, the 28-day compressive strengths of the concrete with low energy SSC reached 43.69 MPa which can be feasibly applied for widely advanced construction materials. The OPC in range of 3 — 5 wt.% and 25 wt.% of CFA were considered as the optimum ingredients of the activator and was suggested to be used for fabricating the low energy SSC concrete with the good performance on compressive strength, dynamic Young’s modulus, UPV measurement, and stabilized change of length. The OPC additive up to 10 wt.% was encouraged to be used for producing the SSC concrete with significant reduction on creep.

We experimentally investigate the acoustic characteristic of micro plasma shock wave obtained by femtosecond laser ablation of silicon wafer surface using F-P optical fiber acoustic sensor with anti electromagnetic interference. The experimental results show that each of the femtosecond laser pulse can only produce a plasma shock wave. Under the different femtosecond laser energy, the acoustic attenuation signal of single shock wave has been analyzed by using wavelet transform, the results indicated that the energy change of femtosecond laser has no effect on the frequency of the acoustic signal of the micro plasma shock wave and have only influence on the amplitude, meanwhile, the main frequency of the acoustic attenuation signal are distributed within range of 0-100KHz, According to these frequency components, we can conclude that the decay process of micro plasma shock wave is the fast transduction of the ultrasonic signal into the acoustic signal. This study can provide the experimental basis for femtosecond laser ablation mechanism and femtosecond laser plasma control application research.

“Trinity System”, which is consisted of “110,122,119” three police command stations merging into a police command center, the system is to achieve a unified alarm, unified command, joint action and to provide emergency services and urban public security. Multi-living Agent Method is a new method to analysis the complex system. This paper proposes to use a new method of multi-living agent to design “Trinity System”based on analyzing the traditional “Trinity System”, according to the guiding theory of the system. The paper designs the whole framework and system software architecture of “Trinity System”. It provides a good research direction to enhance the capabilities of emergency response for “Trinity System”.

With the rapid development of computer telecommunications integration (CTI) technology, the development of application system for small and medium CTI are updated constantly, but the study of application system for small and medium CTI, we are lack of a stability and unified model. In this paper, the author analyzes the unified structure platform of application system for small and medium CTI based on voice card. Meanwhile, the author introduces a suitable software architecture model and general procedural framework for application system for small and medium CTI based on voice card by using the idea of hierarchical design, which shows the versatility of the architecture. It provided an efficient channel for the development of small and medium CTI.

After building some structures of partial tubular flat knitting fabric composite preform, the influencing factor on tubular section was analyzed and the fabric was knitted selectively. The partial tubular flat knitting fabric composite preform were Knitted by changing different yarn, row number and two-sided partial tubular flat knitting fabric. Multilayer sheet would be got after hot pressing and it has big market prospects and good application value.

Use Woodland camouflage paint Oxford fabric as base cloth, first the light pressure processing was used on the fabric, and then use polyurethane which has high water vapor permeability performance and other various additives as face glue and Bottom glue, the fabric was compounded a thin macromolecule hydrophilic polymer PU film, the fabric was water allocation processed after stripping, At last the fabric will have high performance of the windproof, waterproof and moisture permeability. After testing, the performance index of the fabric are: the smoothness appearance of fabrics after cleaning≥grade4.0; hydrostatic pressure≥10000mmH2O, after 20 times washing≥5000mmH2O, The surface water repellency level≥grade 4.0,after 20 times washing≥grade3.0, water vapor permeability≥3500g/(m2·24h); Electrostatic charge density≥2.5uc/m2; humid air accelerated aging grade≥4.0.Test data shows that the designed functional fabric meet the technology requirement of the standards, meet the demand of the customer’s use requirements.

Background: Patients with a very low probability of infective endocarditis (IE) do not benefit from transthoracic echocardiography (TTE). Because the term 'very low probability' has not yet been defined, the present prospective study sought to identify the population with a 'very low probability'., Methods: TTE was performed between July 2005 and October 2006 in consecutive patients clinically suspected of having IE. Clinical parameters suggestive of IE and presence of infectious focus were recorded., Results: Twenty-four (15.5%) of 155 patients studied had positive findings on TTE. Significant positive predictors were embolic events, intravenous drug use, the presence of a prosthetic valve, positive blood cultures and immunological phenomena. The significant negative predictor was confirmed infection sites other than endocardium. Sixty-three (40.6%) of 155 patients without positive predictors were found to have no vegetation. Thus, the collective absence of these predictors indicated a zero probability of TTE showing evidence of IE. A significant negative predictor was a definite etiology of infection other than IE. Only one in 76 patients was diagnosed with both IE and infection at another site., Conclusions: The absence of positive predictors or the presence of a negative predictor indicate a near-zero probability of IE being detected by TTE. Use of clinical parameters may avoid up to 41% of unnecessary TTE examinations, increasing the likelihood that such a diagnosis will be correct.