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The purpose of this paper is to investigate the influence of sprue distributions on the flow field and temperature field of the cladding casting process and verify the simulation results by experiments.

A steady-state mathematic model for the coupling of fluid flow, heat transfer and solidification to describe the process of cladding casting was present. The effect of sprue distributions on melt flow and temperature field was discussed. Based on the numerical simulation results, the cladding billet was prepared successfully. Moreover, the model has been verified against by temperature measurements during the cladding casting process.

There is a good agreement between the measured and calculated results. The homogeneity of melt flow determines the formability of cladding billets and circular temperature difference affects the bonding of the two alloys. The AA4045/AA3003 cladding billet with no defects in size of f140/f110 mm was fabricated successfully. The alloy elements diffused across the interface and formed diffusion layer with a thickness of 15 µm. The interface bonding strength is higher than the tensile strength of AA3003, indicating the metallurgical bonding between two alloys.

The casting parameters are limited to the aluminum alloy cladding billet in size of f140/f110 mm in this paper.

There are few reports of cladding billet, which are used to prepare condense pipes of automotive engines. The effect of distribution schemes on the cladding casting process is rarely studied.

Aiming at the high temperature, high speed, high precision and high surface quality of the copper belt cold rolling, the purpose of this paper is to develop a new type of lubricant for cold rolled copper belt.

The component of the developed oil was determined based on the physical and chemical properties of the base oil and the tribological properties, the oxidation resistance properties, the rust resistance properties, the anti-foam properties, the demulsibility and the other properties of the additives. The orthogonal experiment method was used to determine the optimum adding amount of the additives; finally, the developed oil formulation was determined.

The physical and chemical experiment results show that the developed oil has a good performance of oil film bearing capacity and oxidation resistance. The simulation of rolling experiment found that the developed oil can significantly reduce rolling pressure and effectively reduce the friction in the process of rolling.

The experimental results show that the developed oil has excellent performance and can meet the requirement of lubrication in the process of cold rolling copper belt.

The purpose of this paper is to study the effect of feeding scheme on melt flow and temperature field during the steady-state of level-pour direct-chill (DC) casting of A390 alloy hollow billet and optimize the design of feeding scheme.

Melt flow and temperature field are investigated by numerical simulation, which is based on a three-dimensional mathematical model and well verified by experiments.

The numerical results reveal that both melt flow and temperature field are obviously affected by the feeding scheme. The homogeneity of melt flow and temperature field in hollow billet with the feeding scheme of modified four inlets are better than the other feeding schemes. Experimental results show that crack can be eliminated by increasing the number of feeding inlets. The primary Si size appears unaffected while the distribution of primary Si particles is highly affected by the change of feeding scheme. Only with the feeding scheme of modified four inlets can fine and uniformly distributed primary Si particles be achieved.

The paper includes implications for the design of feeding scheme in level-pour DC casting of hollow billet for practical use.

This paper develops different feeding schemes for level-pour DC casting of hollow billet and optimizes the design of feeding scheme.

This rejoinder aims to critique some of the perspectives in Chen’s (2018) study on hospitality and host–guest paradigm in China.

In this preliminary probe into Chen’s study, critical analysis is performed on Chen’s approaches, whereas document analysis is applied to the relevant ancient Chinese writings. Translations are the author’s own unless indicated otherwise.

Chen’s views are problematic and supported by patchy evidence. “Hierarchy principle” and “host-centric foundation” do not hold up. In a series of asymmetrical comparisons, Chen goes a bit too far in arguing for uniqueness.

This rejoinder presents valid critiques of Chen’s study, thus directing future research in the right direction. It is of some significance to clarify Chen’s misrepresentations and offer a truer and fuller account of Chinese hospitality, given the difficulty for international scholars to validate Chen’s views because of language barrier and cultural unfamiliarity.

The literature review aims to facilitate a broader understanding of on-demand service platform operations management and proposes potential research directions for scholars.

This study searches four databases for relevant literature on on-demand service platform operations management and selects 72 papers for this review. According to the research context, the literature can be divided into research on “a single platform” and research on “multiple platforms”. According to the research methods, the literature can be classified into “Mathematical Models”, “Empirical Studies”, “Multiple Methods” and “Literature Review”. Through comparative analysis, we identify research gaps and propose five future research agendas.

This paper proposes five research agendas for future research on on-demand service platform operations management. First, research can be done to combine classic research problems in the field of operations management with platform characteristics. Second, both the dynamic and steady-state issues of on-demand service platforms can be further explored. Third, research employing mathematical models and empirical analysis simultaneously can be more fruitful. Fourth, more research efforts on the various interactions among two or more platforms can be pursued. Last but not least, it is worthwhile to examine new models and paths that have emerged during the latest development of the platform economy.

Through categorizing the literature into two research contexts as well as classifying it according to four research methods, this article clearly shows the research progresses made so far in on-demand service platform operations management and provides future research directions.

This paper introduces an audio encryption algorithm based on permutation of audio samples using discrete modified Henon map followed by substitution operation with keystream generated from the modified Lorenz-Hyperchaotic system. In this work, the audio file is initially compressed by Fast Walsh Hadamard Transform (FWHT) for removing the residual intelligibility in the transform domain. The resulting file is then encrypted in two phases. In the first phase permutation operation is carried out using modified discrete Henon map to weaken the correlation between adjacent samples. In the second phase it utilizes modified-Lorenz hyperchaotic system for substitution operation to fill the silent periods within the speech conversation. Dynamic keystream generation mechanism is also introduced to enhance the correlation between plaintext and encrypted text. Various quality metrics analysis such as correlation, signal to noise ratio (SNR), differential attacks, spectral entropy, histogram analysis, keyspace and key sensitivity are carried out to evaluate the quality of the proposed algorithm. The simulation results and numerical analyses demonstrate that the proposed algorithm has excellent security performance and robust against various cryptographic attacks.

The purpose of this paper is to analyze long-term institutional causes and consequences of preference falsification by studying the evolution of China’s patriarchal clan system.

The historic study shows that although the clan system was abolished in the Qin dynasty, it re-emerged among high-standing families in the Han dynasty and spread to common people after the Tang dynasty.

The author submits that the clan system was an institutional response to the preference falsification problem that arose due to the dictatorial political institutions first established in the Qin dynasty. It helped people to take collective action by themselves and also opened a back door to influence government decisions. A piece of clear evidence is the co-evolution of the clan system and government personnel system.

In this sense, the clan system probably also helped to prolong the political institutions for 2,000 years.

This is the first institutional study on the clan system in China.

The purpose of this paper is to identify the causal effect of high-speed railways (HSRs) and investigate the affecting channels; the second purpose is to examine how HSRs change the distribution of economic activity across cities and sectors.

A difference-in-difference strategy is implemented to estimate the impact of recently built HSRs on local economic performance in China, exploiting the geography and time variations in HSR operations.

Using panel data from China’s City Statistical Yearbook 2001–2019, the authors find that HSRs lead to a significant increase in cities’ gross domestic product (GDP) and GDP per capita, but the authors do not find any significant change in GDP growth. This conclusion still holds true after the authors address the endogeneity problems. A mechanism analysis shows that HSRs improve local economic performance mainly by increasing fixed asset investment. The authors also find that the HSR investment is a policy that favors metropolitan areas due to the larger increase in the GDP for larger cities and with HSRs, the industrial and service sectors will further agglomerate in larger cities.

The authors contribute to the literature in several ways. First, this paper improves the estimation strategy in identifying the HSR impact on the local economic performance. Second, this paper investigates the affecting channels of HSRs. This paper proves that HSRs in China promote the cities’ economic performance mainly by increasing the fixed asset investment. Third, this study provides evidence for the new economic geography models pioneered by Krugman (1991).

The purpose of this paper is to conceptualize the indigenous concept of suzhi at individual and organizational levels, and identify its dimensions for human resource management (HRM) research and practice in China.

Based on a comprehensive review of suzhi literature, Chinese cultural and historical literature, as well as Western mainstream HRM research, a multidimensional suzhi framework is conceptualized.

As an indigenous expression, suzhi can be and has been adopted for Chinese HRM research and practice. As a multidimensional construct, one’s cognitive suzhi is jointly determined by corresponding moral suzhi, wenhua (knowledge-based) suzhi and zhuanye (professional) suzhi. Cognitive suzhi, in turn, determines one’s behavioral suzhi that drives employees to enhance organizational performance, and this relationship is moderated by psychological suzhi.

The proposed framework provides new insight for Chinese indigenous management research, particularly in developing suzhi measurement for different dimensions. It also informs HRM practices in recruiting, selection, performance analysis and employee career development.

The complexity of suzhi dimensions from an organizational HRM perspective is analyzed. The resulting suzhi framework offers new insight for HRM research and practices in China.

Pre-construction of a project comprises stages that are pivotal for the procurement performance. It is defined as the duration from the project's initiation to construction. However, Private Public Partnerships (PPPs) have been subjected to a long pre-construction, thereby leading to an inefficient development process. Therefore, the purpose of this paper is to pay attention to the influencing factors elongating the pre-construction duration.

Based on data of 5,677 PPP projects between 2009 and 2021 in China, the authors adopt the Accelerated Failure Time (AFT) model in duration analysis to empirically analyze the following underlying dynamics determining the duration of PPP pre-construction stages: (1) policy uncertainty; (2) corruption; and (3) procurement method selection. To observe the influencing paths more specifically, the authors divided the pre-construction duration into the pre-tendering period and tendering period and regressed them separately.

The results indicate that the pre-construction duration is significantly prolonged with increased policy uncertainty and corruption degree as well as the use of tendering methods. Meanwhile, the above factors have a greater impact on the pre-tendering period than the tendering period.

The contribution of this study is twofold: (1) theoretically, this paper provides new evidence on the impact of PPP policy uncertainty, corruption and procurement method selection on the pre-construction duration. It complements empirical studies on the factors elongating the time efficiency of PPPs projects. (2) In practice, it provides a specific path for the government to improve the time efficiency of PPPs.