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This study aims to simulate and test the performance of a transmitting and receiving capacitive micro-machined ultrasonic transducer (CMUT). Aimed at detecting demand of the CMUT, a matched integrated adjustment circuit was designed through analyzing processing methods of transducer’s weak echo signal.

Based on the analysis of CMUT array structure and work principle, the CMUT units are designed and the dynamic performance analysis of SIMULINK is given according to the demand of underwater detecting. A transceiver isolation circuit is used to make transmission mode and receiving mode separate. A detection circuit is designed based on the transimpedance amplifier to achieve extraction of high-frequency and weak signal.

Through experimentation, the effectiveness of the CMUT performance simulation and the transceiver integrated adjustment circuit were verified. In addition, the test showed that CMUT with 400 kHz frequency has wider bandwidth and better dynamic characteristics than other similar transducers.

This paper provides a theoretical basis and design reference for the development and application of CMUT technology.

The purpose of this paper is to obtain high-solids-content and low-viscosity starch adhesive, and improve bonding strength of the pure starch adhesive.

Maize starch was treated by hydrochloric acid solution with different concentrations, and acid-thinned starch adhesive was prepared. Polyisocyanate as a crosslinking agent was added to improve water resistance of the pure starch adhesive.

The physical and chemical properties of the acid-thinned starch adhesive were characterised. Acid hydrolysis did not change structure of starch granules, but increased its crystallinity. After acid modification, starch granules became less smooth and some fragments appeared. Acid treatment had little influence on thermal stability of starch, when acid hydrolysis was not strong. High concentration of HCl solution led to starch granules being destroyed, resulting in decrease in bonding strength. The optimal HCl concentration was 0.5 mol/L. Polyisocyanate addition was beneficial to improve the bonding strength of the acid-thinned starch adhesive.

Acid hydrolysis changed the properties of the starch adhesive.

Acid hydrolysis decreased viscosity of the starch adhesive and improved its solids content, which had a positive effect on the application of the starch adhesive.

It was helpful to develop an environment-friendly, natural polymer-based wood adhesive.

The properties of acid-thinned starch and acid-thinned starch adhesive were studied.

The purpose of the study was to prepare melamine-urea-formaldehyde (MUF) resin that would be resistant to boiling water and high temperature and exhibit low formaldehyde emission.

The authors prepared MUF resin with different F/(M + U) and changed the amount of melamine added, through the analysis of MUF resin properties to get the best reaction parameters, and used different amino acid cure systems including NH₄Cl cured the resin.

Resin’s heat resistance and water resistance are mainly determined by the amount of melamine added, and formaldehyde emission of the plywood can be changed by adjusting F/(M + U). The peak temperature of the curing agent-cured resin increases as compared with the self-curing resin. Stronger the acidity of curing agent, faster the viscosity increased in probation period and lower the bonding strength and heat resistance of the resin.

Melamine improves the heat resistance and water resistance of the resin. When the amount of melamine is more than a certain value, water resistance of the resin decreased.

MUF resin that is resistant to boiling water and exhibits low formaldehyde emission can be used in high temperature, high humidity and strict formaldehyde emission environment and can also be combined with other materials.

It was helpful to reduce the effect of formaldehyde emission on people’s health and environmental pollution and is also beneficial for the expansion of the application range of aldehyde resin.

The originality is twofold: the influence of the acid strength of curing agent on the bonding strength of the resin adhesive and the method for preparing high performance MUF resin by following the traditional process.

This paper aims to implement quality of service(QoS) dynamic optimization for the integrated satellite-terrestrial network(STN) of the fifth-generation Inmarsat system(Inmarsat-5).

The structure and operational logic of Inmarsat-5 STN are introduced to build the graphic evaluation and review technique(GERT) model. Thus, the equivalent network QoS metrics can be derived from the analytical algorithm of GERT. The center–point mixed possibility functions of average delay and delay variation are constructed considering users' experiences. Then, the grey clustering evaluation of link QoS is obtained combined with the two-stage decision model to give suitable rewards for the agent of GERT-Q-learning, which realizes the intelligent optimization mechanism under real-time monitoring data.

A case study based on five time periods of monitoring data verifies the adaptability of the proposed method. On the one hand, grey clustering based on possibility function enables a more effective measurement of link QoS from the users' perspective. On the other hand, the method comparison intuitively shows that the proposed method performs better.

With the development trend of integrated communication, STN has become an important research object in satellite communications. This paper establishes a modular and extensible optimization framework whose loose coupling structure and flexibility facilitate management and development. The grey-clustering-based GERT-Q-Learning model has the potential to maximize design and application benefits of STN throughout its life cycle.

Scholars have examined the relationship between sports and urban development and proposed to use sport programs and events as a catalyst to revitalize communities, upgrade urban infrastructure, promote city image, shift economic structure, nurture an active lifestyle, and enhance societal harmony and solidarity. Yet, previous studies were usually focused on mega sport events and were typically conceptual, theoretical and lack of practical applications. This study was designed to attain in-depth understanding on how a specific sport, table tennis, can be systematically organized and utilized to influence urban development through a qualitative research injury.

This investigation was carried by conducting in-depth interviews of the executive director of the Shanghai Table Tennis Association, on-site observations and comprehensive review of literature. Development of interview questions took into consideration the conceptual framework postulated by Preuss (2007) that contains six structures of urban development through sports. Triangulation analyses were conducted to cross validate the three information sources to generate themes and assertions.

While the identified practices were consistent with Preuss' (2007) framework, specific management activities earnestly practiced in Shanghai are centered on utilizing cultural and historical heritage, star power, branding strategies, staging tournaments, hallmark events, technical innovation and government relations to achieve the objectives of table tennis as a sport and the objectives of urban development through table tennis.

The findings of this study help fill the void that a theory usually cannot specify, namely, detailed, unambiguous practices. While table tennis may be a viewed as a small sport in many parts of the world, it has a strong, unprecedented historical heritage in Shanghai. This city has made a prudent choice and investment in this sport, which has proved to be effective. Other cities in the world should look into their own social, cultural and historical heritage and develop sport strategies, operations and programs accordingly.

The purpose of this paper is to study the effective procedure for blocking and deblocking isocyanate by sodium bisulphite with special cosolvent and dropwise method.

A number of analytical techniques, including Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and Thermo gravimetric analyser (TGA) were employed to assess the reactions between isocyanates and sodium bisulphite, water, cosolvent, also the deblocking temperature of blocked isocyanates.

The blocked isocyanates reacted with sodium bisulphite, water and cosolvent via a special procedure. It was found that the − NCO functional groups of the isocyanates were completely blocked by sodium bisulphite and a new method for determining the lowest deblocking temperature of the blocked isocyanates was described. It was revealed that the deblocking temperature of blocked isocyanates by sodium bisulphite was lower than others.

The paper provides some useful information about the blocking and deblocking of isocyanate, which would be helpful for the preparation of blocking and deblocking isocyanate, and guiding the practical applications of blocked isocyanate.

The investigation found that the sodium bisulphite was a very efficient blocking agent for isocyanates at the room temperature via the special procedure developed. On the basis of emulsion polymerisation theory, polymer isocyanates were blocked by sodium bisulphite, which realised the new breakthrough effectively by means of controlled temperature, stirring speed and optimum dropwise speed in the whole reaction system. Meanwhile, the special cosolvent could improve the intermiscibility of isocyanate in sodium bisulphite aqueous solution, reduce the side reaction of isocyanate with water and accelerate reaction rate of isocyanate with sodium bisulphite. If no cosolvent was present, the blocked system would not be homogeneous.

The mechanisms of the deblocking reaction of the polyurethane with blocking agent were investigated in detail relatively using thermogravimetric analysis (TGA), Fourier transform infrared spectrometry (FTIR) and X-ray photoelectron spectroscopy (XPS). This kind of method for polyurethane as the application of wood adhesives can provide the conditions of application and the main theoretical basis.

The blocking rate and latex particle size distribution were determined using the titrimetric analysis and the laser particle analysis, respectively. TGA, FTIR, XPS and differential scanning calorimetry were used to investigate the deblocking temperature and time of the blocked isocyanate in detail.

The results indicated that the blocking rate was approximately 97 per cent and the average particle size was 360 nm. The results of laser particle analysis have confirmed that the dispersivity of the blocked polyurethane emulsion was good. XPS results showed that the amount of –O = C-N-benzyl groups increased with an increasing deblocking temperature and subsequently reached equilibrium. In summary, the blocked isocyanate was deblocked at temperatures ranging from 50 to 90°C.

An important approach in future wood adhesive work would be to gain access to man-made board application data.

The paper provided some useful information about deblocking mechanisms of blocked polyurethane that would be helpful to guide applied practical applications as wood adhesive.

To promote China’s wood processing technology progress and solve the problem of shortage of the natural quality of wood is of important practical significance.

The paper is the first to use the XPS characterisation method to characterise deblocking polyurethane solution.

This paper aims to describe the corrosion behavior and possibility of inhibition by corrosion inhibitor SA1-3 in acidizing solution (5 per cent hydrochloric acid [HCl] solution). The study aims to explain the mechanism of corrosion and inhibition of N80 steel in 5 per cent HCl solution to provide theoretical basis for expanding the range of application of N80 steel in acidification process.

This paper opted for a laboratory study using simulation of acidizing solution to do the experiments. The results of experiments including weight-loss method, electrochemical method and surface analysis were used to explain the mechanism of corrosion and inhibition so as to predict the dissolution progress of N80 steel in 5 per cent HCl solution with and without inhibitor SA1-3.

This paper provides theoretical insights about how to inhibit the corrosion behavior of N80 steel in 5 per cent HCl solution. It suggests that the corrosion inhibitor which can form a protective film on the steel surface should be used to expand the application of N80 steel in acidizing solution. The inhibitor SA1-3 is a kind of cathodic corrosion-controlling inhibitor which mainly inhibits cathode corrosion; it cannot change the corrosion mechanism of N80 steel.

This paper provides a theoretical basis for the corrosion behavior and inhibition mechanism of N80 steel in acidizing solution.

The purpose of this paper is to model the aircraft-cargo’s coupling dynamics during ultra-low altitude heavy cargo airdrop and to design the aircraft’s robust flight control law counteracting its aerodynamic coefficients perturbation induced by ground effect and the disturbance from the sliding cargo inside.

Aircraft-cargo system coupling dynamics model in vertical plane is derived using the Kane method. Trimmed point is calculated when the cargo fixed in the cabin and then the approximate linearized motion equation of the aircraft upon it is derived. The robust stability and robust H_∞ optimal disturbance restraint flight control law are designed countering the aircraft’s aerodynamic coefficients perturbation and the disturbance moment, respectively.

Numerical simulation shows the effectiveness of the proposed control law with elevator deflection as a unique control input.

The model derived and control law designed in the paper can be applied to heavy cargo airdrop integrated design and relevant parameters choice.

The dynamics model derived is closed, namely, the model can be called in numerical simulation free of assuming the values of parachute’s extraction force or cargo’s relative sliding acceleration or velocity as seen in many literatures. The modeling is simplified using Kane method rather than Newton’s laws. The robust control law proposed is effective in guaranteeing the aircraft’s flight stability and disturbance restraint performance in the presence of aerodynamic coefficients perturbation.

In response to food scares related to high levels of agro-chemical residues sometimes found on foods, consumers in China increasingly demand for organic foods. As little is known on consumer perceptions and attitudes toward organic food products, the purpose of this paper is to gain insight into the purchase of organic food products by consumers and to explore the main factors driving this process.

Mixed (quantitative and qualitative) market survey approaches were used to provide a potentially deeper insight into consumer’s perspective and could help get a better picture of the complex factors involved.

The main trigger for purchasing organic food products is that consumers expect them to be healthier and safer. The respondents who have bought organic food products tend to have a higher education level and disposable incomes, be families with children and be older than those who have not bought them. The main barriers to increasing the market share of organic food products are the consumers’ lack of knowledge, the relatively high price premium and the lack of availability of organic food products. Informing consumers about unique characteristics of organic production methods, the decline in the prices of and increasing the availability of organic food products to its customers might be a promising strategy to develop the market for organic food products.

This paper provides a unique insight into buying behavior and attitudes of organic consumers in China. The results of the research could provide information for the organic food industry to expand its market and improve its profitability and reliability.