Search

In order to obtain the Johnson-Cook（J-C） constitutive parameters that can exactly reflect the plastic flow behavior of the workpiece material under the coupling effect of high temperature, high strain rate and large deformation occurred in high-speed cutting, and make it to suitable for the high-speed cutting simulation. The J-C parameters of Ti-6 Al-4 V was optimized with using the response surface approximation and multi-objective optimization methods to apply it to high-speed cutting simulation. Results show that the optimized constitutive parameters could describe the plastic flow behavior of the workpiece material accurately in a wide range of cutting speeds, and the simulated chip morphologies and the average cutting forces are in good agreement with the experimental results.

In the current e-commerce environment with increasingly fierce competition, paid search advertising has become the most favored form of advertising by advertisers due to its high efficiency and profitability, and effective keyword portfolio strategy is the key to their long-term success. However, previous studies are mostly based on the perspective of a single keyword, assuming that the impact of paid search advertising on search users is single and segmented, which mainly focus on keyword bidding, ad position strategy, search users' behaviors and other aspects. Actually, there are continuous and multiple interactions between search users and keywords. In the face of the increasingly diversified search content and fragmented attention of search users, advertisers need to select a group of keywords that are relevant to products to bid for and focus on the integration effect of keyword portfolio. Therefore, (1) we need to classify keywords semantically based on consumer psychology, and explore the impact of semantic information of different types of keywords portfolio on product advertising; (2) we need to distinguish how the semantic structure of keyword portfolio affects user psychology and advertising performance; (3) we need to understand the rules of the interaction process between search users and search information, so as to develop keyword portfolio strategy to improve user interaction. In order to explore the above issues, this paper focuses on the interaction mechanism between semantic structure of keyword portfolio and user psychology. Based on the dual-system theory, we explore the direct and indirect effects of keyword portfolio on advertising performance and the moderate effect of product characteristics, by using a zero-inflated negative binomial (ZINB) model with robust standard errors. It is found that branded keyword portfolio arouses users' interests through emotional activation mode and produces strong short-time effect, while generic keyword portfolio arouses users' interests through information activation mode and produces strong long-term effect. The concentration strategy of branded keyword portfolio is more effective than its semantic diversity strategy in improving the click-through rates. On the contrary, the semantic diversity strategy of generic keyword portfolio is more effective than its concentration strategy in improving the conversion rates. Product awareness positively moderates the effect of semantic structure of branded keyword portfolio and generic keyword portfolio on advertising performance. However, product demand uncertainty and promotion negatively moderate the effect of semantic structure of branded keyword portfolio and generic keyword portfolio on advertising performance. This paper provides some theoretical contributions and practical implications. Theoretically, first of all, for the research subject, the analysis for advertiser's keyword strategy transfers from bidding for a single keyword and better ad position to keyword portfolio strategy, which is conductive to analyzing the cross-keyword synergy effect from the perspective of search users, and develop new research directions for advertisers' keyword portfolio strategy. Secondly, in terms of research content, in combination with relevant psychological theory, this paper analyzes the types and mechanisms of semantic structure of keyword portfolio from the perspective of consumer behavior and information processing mode, which promotes and develops theories of consumer psychology. Thirdly, from the research perspective, this paper analyzes the direct and indirect effects of keyword portfolio, which enriches relevant research conclusions. Practically, first of all, this paper helps paid search advertisers to reduce their dependence on keyword bidding and ad position strategies. Secondly, product features, such as product awareness, product demand uncertainty and promotion are of different degrees of uncertainty for search users, which will affect users' understanding and cognition for semantic information of keywords. This paper helps paid search advertisers to select the most effective keyword portfolio strategy according to product features. Finally, the systematic analysis of the semantic structure and mechanism of keyword portfolio in this paper can effectively guide advertisers to improve advertising performance. The results of this paper will make reasonable suggestions from a dynamic and comprehensive perspective, which is helpful for advertisers to set performance goals according to product features. From the perspectives of interaction mechanism between semantic structure of keyword portfolio and user psychology, this paper explores the mechanism and effects of semantic structure of different types of keyword portfolio on click-through rate and conversion rate of product advertising, and the moderate effects of product features. The results point out that paid search advertisers should set performance goals according to product features, and then select effective keyword portfolio strategies. [ABSTRACT FROM AUTHOR]

Concrete 3D printing is a typical representative of modern digital manufacturing, which has attracted wide attention due to its technological advantages of intelligence, personalize and green construction. As a new construction method, concrete 3 D printing has had a disruptive effect on the construction industry and has challenged traditional concrete materials. Improving the adaptability of concrete materials and 3D printing technology and realizing the wide application of 3D printing technology in buildings are the focus of general attention. In this paper, the development process of concrete 3D printing technology was summarized and the performance requirements of concrete materials for 3D printing were discussed, including the rheological properties, printability, buildability and mechanical properties. The typical application of 3D printing formwork technology in decoration and special-shaped structures was also introduced, which was expected to provide some reference for the research and engineering development of concrete 3D printing. [ABSTRACT FROM AUTHOR]

There will exist great pressure for sustaining employment in China when GDP growth is under 8% in the context of the adjustment in economic structure which can cause social instability. How can this outcome be avoided? In a review of the literature, this paper supposes that tourism development is one of the most effective ways for solving the problem of structural unemployment during this period of economic transition. However, most researches pay attention to employment in the formal tourism sector and its pull effects and neglect the informal employment of tourism. In fact, the informal sectors have absorbed a large number of laid-off workers and migrant workers since China's reform and opening - up policies were launched which has been ignored and discriminated against by many Chinese local governments. In order to discover true power of informal sectors, the employment of the tourism informal sector was selected as a representative of the service industry. First, the paper presents many categories of informal employment of tourism showing the evidence of informal employment spreading over most industries. Second, the paper reveals the different tourism multipliers between domestic scholars and WTTC(Word Travel & Tourism Council) reports and explains why the different multipliers come out, pointing out that WTTC underestimates the employment effects of tourism since 2001. Thirdly, based on the above analysis, the paper takes advantage of statistical data and re-estimates the population of informal employment in the nation. Fourthly, using the stable weights of employment in the service industry to total employment, the paper measures and calculates with different methods, the scale of informal employment of tourism and its structural pull effects which demonstrate that the tourism informal sectors supply 20.4 million jobs and its multiplier was 9.98 in 2011. Grounding on the research conclusion, we argue that the pull effects of informal employment of tourism is much bigger than that of indirect employment by domestic scholars and WTTC in terms of sector structure, which suggests that the government should attach much more importance to the informal tourism sector during the period of industrial restructuring in China. At the end of the paper, some suggestions for governments are put forward. [ABSTRACT FROM AUTHOR]

With the expanding trade deficit of Chinese tourism services, more attention is being paid to strengthening the transnational/cross-border business of Chinese tourism enterprises to reduce the negative impacts. Based on a brief analysis and sorting of the development status of the Chinese outbound travel market and tourism transnational/cross-border operations, the paper argues that the transnational/cross-border operation of Chinese tourism enterprises is far from keeping up with the rise of Chinese outbound travel. There is a problem in finding good locations to promote Chinese tourism transnational/cross-border operations and in developing them rapidly and healthily. On the basis of relevant research about the influencing factors when selecting the best locations for servince studies on selecting transnational/cross-border operation locations and few studies on selecting tourism transnational/cross-border business locations. Additionally, the study of transnational/cross-border business service is still mainly concentrated on producer services such as financing, advertising and consulting. Considering the importance and urgency of selecting transnational/cross-border operation locations for Chinese tourism enterprises, the paper analyzes the main potential locations according to market scale and tourism economy competitiveness through integrating Chinese outbound tourism destination distribution data between the years 2008 ~ 2010 from the UN World Tourism Organization (UNWTO) and the tourism competitiveness data of 2011 from the World Economic Forum. It notes that Hong Kong, Korea, Japan, Singapore, Malaysia, Taiwan and France are the preferred locations for tourism enterprise transnational/cross-border investment. Entering into the mature stage of development, tourism enterprise transnational/cross-border operations should carefully consider the overall size of the inbound, outbound and domestic tourism market of the host country and not entirely depend on tourists from the home country. Analyzing tourism GDP data from World Travel & Tourism Council (WTTC) from the period 2006 ~ 2011 and tourism competitiveness data from the World Economic Forum in 2011, the paper argues that the United States, Japan, France and Germany are the preferred locations of travel agency transnational/cross-border investment and the first three countries are the preferred locations of hotel transnational/cross-border investment. Using the latest data of the Hofstede cultural distance report, and purchasing power parity data of GDP between 2002 ~ 2011 from the WTTC and the relevant countries and regions, the paper constructs a foreign direct investment gravity model for tourism, calculating the tourism investment gravity coefficient and the host country investment gravity coefficient of the main potential locations, and analyzing the transnational/cross-border investment potential of Chinese tourism enterprises in the main potential locations. It concludes that Hong Kong, the United States, India and Taiwan are the preferred locations of tourism enterprise transnational/cross-border investment. According to the data of host country investment gravity coefficiency, tourism investment gravity and host country tourism competitiveness, the research undertook K cluster analysis and found that in addition to Hong Kong, the United States, Japan, Korea, Singapore, Malaysia and Thailand are the preferred locations of Chinese tourism enterprise transnational/cross-border operations. With the SPSS scatter diagram and the K cluster analysis, the paper classifies the investment value of the potential investment locations, taking Hong Kong, the United States, Singapore, Japan, Korea, Malaysia and Taiwan as the locus areas of tourism enterprise transnational/cross-border investment. [ABSTRACT FROM AUTHOR]

Objective: To observe the effects of cross electro-nape-acupuncture on reflex remodeling of airway protective reflex cough in patients with tracheotomy after cerebral hemorrhage., Methods: With the method of completely random design, according to treatment order, 60 patients who received tracheotomy after cerebral hemorrhage accompanied with cough reflex difficulty were randomly divided into a cross electro-nape-acupuncture group and an acupuncture group, 30 cases in each group. Both groups were treated with basic treatment, including anti-inflammation, eliminating phlegm, improving cerebral metabolism and so on. The acupuncture group was treated with acupuncture at Yifeng (TE 17), Fengchi (GB 20), Lianquan (CV 23), Baihui (GV 20), Touwei (ST 8), Dicang (ST 4) through Jiache (ST 6), Hegu (LI 4), Quchi (LI 11), and motor area on the affected side, and the needles were retained for 30 min. Based on the treatment of acupuncture group, the cross electro-nape-acupuncture group was additionally treated with cross electro-nape-acupuncture (continuous wave) for 30 min per treatment. The treatment was both given twice a day from Monday to Friday and once a day on Saturday and Sun day for 4 weeks. Tracheostomy cough reflex grading score (TCRGS) and clinical pulmonary infection score (CPIS) were observed before and after treatment in the two groups, and the clinical efficacy of two groups was evaluated., Results: Compared before the treatment, TCRGS and CPIS were both reduced in two groups (both P < 0.01); after treatment, there were significant differences of TCRGS and CPIS between two groups (both P < 0.01), indicating cross electro-nape-acupuncture group was superior to acupuncture group. Regarding the effects of cough reflex remodeling, the cured and markedly effective rate was 96.7% (29/30) in the cross electro-nape-acupuncture group, which was significantly different from 55.2% (16/29) in the acupuncture group (P < 0.01)., Conclusion: Cross electro-nape-acupuncture could effectively improve the remodeling of cough reflex and promote the recovery of lung infection in patients with tracheotomy after cerebral hemorrhage, leading to an increased quality of life.