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For heat sinks with high fins used in outdoor high-power electronic equipment, this paper proposes a natural convection heat transfer calculation method based on the chimney effect and uses this method and numerical simulation to analyze the heat transfer performance of the heat sinks with interrupted fins. Results show that the interrupted fins effectively improve the convective heat transfer coefficient of the fins by breaking the thermal boundary layer of the fins, and have a significant effect on the air flow between the fins. When the fin interruption length is 1mm and the number of interrupts is 15, the natural convection heat transfer performance of the heat sink is the best. Compared to heat sinks of the same size without interrupted fins, the thermal performance has been improved by 80% while reducing weight by 7%.

In the context of a high proportion of renewable energy integrated to the power grid, the net load may has significant fluctuations, and it is necessary to quantify peak regulation demand of power system. This paper stablishes a peak regulation demand prediction model based on long short-term memory (LSTM) method by training historical data. The typical data such as load and renewable energy output are selected as the input vector, and correlation coefficients are used to process and simplify the input vector. The historical prediction errors are used to set margins for peak regulation demand prediction. The case study shows that the proposed model can effectively predict the peak regulation demand of the power system.

Tourists’ good brand sensory image for Traditional Chinese Medicine health tourism (TCMHT) can improve the brand building of tourism destinations. This paper takes some tourists who enter the scenic spots of integrated TCMHT as the research object to investigate the sensory perception of the brand of the TCMHT destination of this group, aiming to further analyze the matching degree between the existing brand building of TCMHT destination and Tourists’ Brand Sensory Impression (TBSI). This paper uses Matlab software to carry out a visual word cloud analysis on the TCMHT keywords that tourists pay more attention to. Based on the word cloud data, the binary Logistic regression model is constructed by using Python and SPSS software, and the influencing factors of TBSI’s selection of TCM are analyzed from six dimensions. The results show that the richness of natural landscape, the quantity and type of cultural resources, ecological environment, professional service ability, healthy diet and supporting facilities, and market position have a significant positive impact on the choice of TCMHT destination. Meanwhile, the marketing publicity, forms and features of TCMHT destinations have a significant positive impact on tourists’ impression intention. Based on the research conclusions and the characteristics of TBSI, this paper proposes the development positioning of tourist destinations, and provides theoretical guidance for the brand building of tourist destinations by using tourists’ unique, specific and direct sensory experience.

Offering reference for sustainable researches of psychological warning field by analyzing hotspots in it in the latest decade. 589 literatures relevant to psychological warning conformed to standard, were extracted keywords. Cooccurrence matrix and lexical matrix were exported by using python software, and the correlations among high frequency keywords were received by analyzing the combination between social network and semantic network which also drew the semantic network graph. The hierarchical clustering function was used to draw the high frequency keywords clustering analysis diagram, and the Eucidean range model was used to draw the two-dimensional scale analysis graph. The combination between co-word analysis and knowledge graph revealed, explored, and summarized the current research hotspots and their relationships in the field of psychological warning. Hotspots research showed the necessity of researches in the psychological warning field. The construction of psychological warning evaluation system and the analysis of key elements of psychological warning should be attached importance.

This study aims to investigate the binding properties of co-fired fly ash (CFFA) in paste and mortar specimens. Paste specimens containing various CFFA proportions (25%, 50%, 75%, 100% by weight of cement) were conducted and evaluated using setting time tests, water demand tests and compressive strength tests. Mortar specimens containing various CFFA and Pulverised coal fly ash (PCFA) proportions (10%, 20%, 30% by weight of cement) were also conducted and compared with regard to flowability and compressive strength. The test results indicated that the water demand increased as the amount of CFFA replacement increased on the flow level at 110±3%; this is due to the higher ignition loss (L.O.I.). Higher L.O.I. values mean that there are more unburned carbon particles in the CFFA and that most of these carbon particles are porous. The compressive strength of mortar specimens decreased as the amount of CFFA replacement increased. Compared to the chemical compositions of cement (C3S, C2S), the main components of CFFA (Ca(OH)2, CaCO3, CaO) have lower crystalline strength and compactness. Therefore, the higher amount of CFFA replacement would inevitably cause a reduction of the cement contents of specimens, thereby reducing the compressive strength of the mortar specimens. Thus, an appropriate amount of superplasticiser and CFFA replacement in the mixture is useful with regard to the binding properties of cementitious materials.

Concrete production unfavourably affects the environment due to high energy demands of cement production and consumption of limited natural resources. Therefore, waste utilization in fabrication of cementitious material is beneficial and legitimate. Significant reduction of environmental impact can be secured by utilization of various types of wastes or byproducts used for a partial substitution of cement binder or aggregates. However, the use of waste materials usually leads to deterioration of material properties of the designed composites. Therefore, it is very important to thoroughly investigate important materials properties to verify performance and practical usability of the newly designed materials. In this paper, three types of concrete mixes were designed. The reference concrete involved fine and coarse natural riverbed aggregates and two other mixes were designed using both, natural and recycled aggregates represented by crushed concrete paving cobbles. Concretes were tested in terms of basic physical properties (bulk density), mechanical properties (compressive strength), thermal properties (thermal conductivity, specific heat capacity, thermal diffusivity), and hygric properties (water vapour diffusion resistance factor, water vapour sorption at 97% RH, water absorption coefficient, moisture diffusivity) and experimentally determined data were compared and discussed. It was observed that materials properties of concretes with recycled aggregates are comparable with those of the reference concrete which is a promising fact from the environmental point of view.

The additive manufacturing technologies are fast-developing industrial sector and, potentially, a ground-breaking technology. They have many advantages such as the saving of resources and energy efficiency. However, the full exploitation of 3D printing technology for ceramic materials is currently limited; a lot of research is being conducted in this area. A promising solution seems to be geopolymers, but its application requires a better understanding of the behaviour this group of materials. This article analyses the influence of microstructure on mechanical properties whilst taking the production method into consideration. The paper is based on comparative analysis – the investigation is focused on the influence of material structure on the mechanical properties and fracture mechanism of these kinds of composites, including those reinforced with different kind of fibres. As a raw material for the matrix, fly ash from the Skawina coal power plant (located in: Skawina, Lesser Poland, Poland) was used. The investigation was made by SEM analysis. The results show that the microstructural analysis did not sufficiently explain the underlying reasons for the observed differences in the mechanical properties of the composites.

This study investigated the mechanical properties and durability of mortar specimens containing various quantities of waste limestone powder (0%, 10%, 20%, and 30% of the weight of cement). The mechanical properties were evaluated in terms of flowability, compressive strength, and splitting tensile strength. Permeability was evaluated in terms of resistivity, absorption, and rapid chloride penetration (total charge- passed). Test results revealed that replacing 10% of the cement with limestone powder improves both mechanical performance and durability. However, reducing the cement content reduced the availability of hydration products to fill the pores in the microstructure. The hydration product of limestone powder was mainly calcium hydroxide, which undermines the development of strength in the paste. Nonetheless, our results indicate that waste limestone powder is suitable for the partial replacement of cement.

Conventional cementitious materials as tunnel supporting materials are utilised in the construction of the final repository for spent nuclear fuel. However, the use of cementitious material releases alkaline ions from pH12 to pH13 plumed into groundwater. Such a high pH is detrimental to the performance of the bentonite functioning, which may possibly enhance the dissolution and alteration of the fracture buffer and filling materials. Instead, low-pH cementitious materials are being developed for use in geological repositories. This study is aimed at evaluating the usability of low-pH cementitious materials containing 40% silica fume or composites blended with 20% silica fume and 40% fly ash. Engineering properties were analysed and verified through experimental research using the flow, compressive strength, pH measurement and hydraulic conductivity. Test results show that the replacement level with 40% of silica fume or 20% of silica fume and 40% of fly ash was suitable for the mixture of low-pH cementitious. Compared to the compressive strength and water permeability of ordinary cementitious, those of low-pH cementitious enhanced better engineered performances at the age of 91 days. The information is contributed us to establish the long-term durability and environmental requirements of disposal repositories in Taiwan.

Asbestos is widely known as a hazardous material and can contribute to many diseases. Its removal and neutralization are complicated, it requires proper preparation and the use of appropriate technology. Immobilization of asbestos materials in geopolymers seems to be one of the alternatives to its storage in landfills. However, this requires several studies confirming the possibility of asbestos immobilization in geopolymers. Also, asbestos dust contains silicon and aluminum, which may prove useful in the production of geopolymers. The paper presents research results regarding the possibility of using geopolymers based on fly ashes for neutralizing asbestos. An up-to-date literature review on the technology of managing asbestos-containing products is presented. As a result of the research, partial usefulness of geopolymerization technology for binding and neutralizing waste with asbestos was found. The research was carried out using waste asbestos-cement composites. Mixtures based on geopolymers were made in which ground asbestos material was introduced in an amount of 30, 50 and 70% by weight. Compressive strength tests have shown that geopolymers with the addition of asbestos have compressive strength: over 34 MPa for a composition containing 30% of asbestos material and about 14 MPa for a composition containing 70% of asbestos material. SEM observations have shown that asbestos fibers do not dissolve in the geopolymer production process and they can still be a threat if the geopolymer matrix is damaged.

In this study, the different proportions of co-fired fly ash and ground granulated blast-furnace slag were used to fully replace the cement as non-cement blended materials in a fixed water-cement ratio. The recycled fine aggregates were replaced with natural fine aggregates as 10%, 20%, 30%, 40% and 50%. The flowability, compressive strength, water absorption and scanning electron microscope observations were used as the engineered indices by adding different proportions of recycled fine aggregates. The test results indicated that the fluidity cannot be measured normally due to the increase in the proportion of recycled fine aggregates due to its higher absorbability. In the compressive strength test, the compressive strength decreased accordingly as the recycled fine aggregates increased due to the interface structure and the performance of recycled aggregates. The fine aggregates and other blended materials had poor cementation properties, resulting in a tendency for their compressive strength to decrease. However, the compressive strength can be controlled above 35 MPa of the green non-cement blended materials containing 20% recycled aggregates.

Ecological operation of cascade hydropower stations is one of the most important methods for the ecological restoration of a river system. In order to balance the benefits between power generation and ecology of Qingjiang cascade hydropower station, an optimal equilibrium operation method is proposed in this paper. Firstly, the range of ecological flow of the Qingjiang cascade is calculated by using ten-day frequency calculation method. Secondly, an optimal equilibrium operation model by considering the balance between power generation and ecology is established. And then, in order to solve this complex model, a particle swarm optimization based model solution method is proposed, and the evaluation index system of operation schemes is established. Finally, through operation calculation in 2008-2010 years, the results show that compared with the operation scheme considering only power generation benefit, the optimal equilibrium operation scheme increases the runoff ecological dispersion coefficient by 6.90%，reduces the cascade ecological overflow by 7.739 billion m3 and the cascade ecological water shortage by 130 million m3, while the cascade power generation decreases slightly by 1.83%. This study provides an effective scientific method for the optimal operation of Qingjiang cascade under the background of Yangtze River protection.

Stick-slip oscillation in drill-string is a universal phenomenon in oil and gas drilling. It could lead to the wear of drill bit, even cause catastrophic failure of drill-strings and measurement equipment. Therefore, it is crucial to study drilling parameters and develop appropriate control method to suppress such oscillation. This paper studies a discrete model of the drill-string system taking into account torsional degree-of-freedom, drill-string damping, and highly nonlinear friction of rock-bit interaction. In order to suppress the stick-slip oscillation, a new proportional-derivative controller, which can maintain drill bit’s rotation at a constant speed, is developed. Numerical results are given to demonstrate its efficacy and robustness.

SCR (selective catalytic reduction) system is continuously being analyzed by many researchers worldwide on various concerns due to the stringent nitrogen oxides (NOx) emissions legislation for heavy-duty diesel engines. Urea-SCR includes AdBlue as urea source, which subsequently decomposes to NH3 (ammonia) being the reducing agent. Reaction temperature is a key factor for the performance of urea-SCR system, as urea decomposition rate is sensitive to a specific temperature range. This particular study was directed to investigate the temperature of the SCR system in diesel engine with the objective to confirm that whether the appropriate temperature is attained for occurrence of urea based catalytic reduction or otherwise and how the system performs on the prescribed temperature range. Diesel engine fitted with urea-SCR exhaust system has been operated on European standard cycle for emission testing to monitor the temperature and corresponding nitrogen oxides (NOx) values on specified points. Moreover, mathematical expressions for approximation of reaction temperature are also proposed which are derived by applying energy conservation principal and gas laws. Results of the investigation have shown that during the whole testing cycle system temperature has remained in the range where urea-SCR can take place with best optimum rate and the system performance on account of NOx reduction was exemplary as excellent NOx conversion rate is achieved. It has also been confirmed that selective catalytic reduction (SCR) is the best suitable technology for automotive engine-out NOx control.

CRISPR-Cas systems, consisting of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated proteins (Cas), are the latest generation of gene editing technology and have been widely used in molecular biology research. CRISPR-Cas systems also have unlimited potential in the field of medicine, especially in the treatment of human viral diseases, such as blocking virus invasion, interfering with virus replication, and eliminating viral genome and sequelae of virus infection. In this article, the latest research progress of CRISPR-Cas9 system and other CRISPR systems in treatments of several viral diseases are reviewed. In addition, the advantages and potential problems of CRISPR systems as treatment options are analyzed to provide ideas for subsequent related research.

This paper analyzes the American drama “Modern Family” by using Stuart Hall’s “encoding/decoding” theory. Modern Family uses universal themes and a “modern” plot to attract Chinese viewers, and uses diverse characters to bring a sense of psychology and identity to decoders. The American values embodied in the show mainly focus on values related to diversity and confident low-context culture. The decoders mainly show a hegemonic position on episodes such as the way of education between parents and children, a negotiated position on episodes that go against traditional concepts, and an antagonistic position on the ideological, political, and economic levels of the episodes.

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.

The influencing effect of pressure on structural, elastic and electronic properties of CaMg2 Laves phase is mainly investigated. The optimized structural parameters at zero pressure are a = b = 6.250Å, c = 10.101Å, which has good agreement with the experimental and theoretical values. The elastic constants are calculated, and then the bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio and anisotropy factor are determined. The results show that the applied pressure is beneficial to the elastic properties of CaMg2. The analysis of electronic density of states (DOS) and Mulliken electron population reveal the bonding characteristics in CaMg2 crystal. Finally, the Debye temperatures under different pressures are obtained from the average sound velocity.

In order to solve the problems that test data of the drug control institution is not standardized and low quality, the data exchange and information sharing are realized, the data value is mined and the information level is improved. Method: combined with the business of control institution and information practice, refer to the practice of relevant standard development; carry out the research on standard development work from the content, principle and process. Result and conclusion: this research completes development of the local standard of Guangdong drug test data, which can provide reference for the development of similar standards in future.

This paper describes the chemical, physical property of the pollution source along with its perniciousness. In addition, with the recent treatment or degradation of the hexachlorobenzene (HCB), it talks about the research developments on the HCB. Of the many options available for treatment of municipal and industrial HCB pollution, the anaerobic biological treatment process is unique because of its potential for producing usable energy. It focuses on the biodegradation pathway which is intent to finish the steps of dechlorination. Moreover, the future study on the HCB degradation is prospected in this paper from the author’s angle.