In recent years, detecting anomalies in networks has attracted much attention in the literature. Researchers have developed various statistical process control (SPC) techniques to monitor the communication level within the networks. It is quite common to see the nodes belonging to some densely connected communities or subgroups and the nodes within a community communicate with each other more frequently than with nodes from other communities. However, we can find scarce SPC techniques that consider the multiple community labels and heterogeneity of nodes simultaneously. It is necessary to overcome this drawback to improve the change detection efficiency. This article establishes a new mixed-membership stochastic block model to characterize the multiple community labels and heterogeneity of nodes simultaneously. Then a new control chart is developed based on generalized likelihood ratio test (GLRT). The proposed control chart can be easily implemented in practice and avoids constant parameter estimation in Phase II monitoring. Numerous simulation studies and a real example show the advantages of proposed chart over existing ones.

Research and development (R&D) investment is very important for firms to gain competitive advantages and sustainable development. Due to the uncertainty of the market and competitors, R&D investment is usually costly and high risk. In such circumstances, firms not only have to figure out the optimal investment timing, but also consider whether to cooperate with competitors to share the risks and costs. In this paper, a two-stage dynamic exchange option game model is proposed for two symmetric competing firms to analyze their R&D investment decision and cooperation. The results show that under uncertainty, the R&D investment timing and cooperation strategy of the two firms depend on the market fluctuation, R&D cost, opportunity benefit of free riding, and the externality of cooperation. If the opportunity benefit of free riding is less than or equal to half of the cooperative research cost, the two firms will invest as early as possible and cooperate. The technology spillover and profits of new products will positively affect the willingness of the competing firms to invest and cooperate in R&D. Moreover, we also calculate the market value thresholds of the investment strategies for the two firms. When the market value is small, the two firms wait for the R&D investment; when the value increases, the firm with a high successful R&D probability will lead the investment, and the other firm follows the investment; when the value is large enough, the two firms will invest at the beginning of the period.

With the cyclical development of emerging technologies, in reality, the evolution dynamics of their innovation networks will inevitably show obvious time attributes. Numerous network analyses of real complex systems usually focus on static networks; however, it is difficult to describe that most real networks undergo topological evolutions over time. Temporal networks, which incorporate time attributes into traditional static network models, can more accurately depict the temporal features of network evolution. Here, we introduced the time attribute of the life cycle of emerging technology into the evolution dynamics of its innovation network, constructed an emerging technology temporal innovation network from a temporal network perspective, and established its evolution model in combination with the life cycle and key attributes of emerging technology. Based on this model, we took 5G technology as an example to conduct network evolution simulation, verified the rationality of the above model building, and analyzed the cyclical evolution dynamics of this network in various topological structures. The results show that the life cycle of emerging technology, as well as multiple knowledge attributes based on the key attributes of emerging technology, are important factors that affect network evolution by acting on node behaviors. Within this study, we provide a more realistic framework to describe the internal mechanism of the cyclical evolution of emerging technology innovation network, which can extend the research on innovation network evolution from the single topological dynamics to the topological–temporal dynamics containing time attributes and enrich the research dimensions of innovation network evolution from the perspective of temporal evolution.

AlON ceramics with high transmittance and strength are essential for transparent armor application. However, high-temperature sintering for long time would result in large grain sizes associated with low strength. In this paper, a low + high temperature two-step sintering method with ultrafine AlON powders was reported for the preparation of high-strength and high-transmittance AlON ceramics. Firstly, the high-purity AlON powders with high specific surface area of 29.77 m2/g was synthesized by solution combustion synthesis-nitridation method and subsequently ball-milling process. Thereafter a sample with 97% density and small grain size (less than 4 mu m) can be obtained after sintered at 1750 degrees C for 3 h, in which the difference of kinetics between grain-boundary diffusion and grain-boundary migration was used to suppress the final stage of grain growth. Further increasing sintering temperature to 1850 degrees C resulted in the elimination of the residual porosity, and realizing transparent AlON ceramics with high optical transmission (85.4%) and high flexural strength (375.1 MPa) could be achieved.

Currently, objects and people can communicate to formulate various networks such as computer networks, social networks, and protein networks. Anomalies may cause abrupt increases or decreases in the frequency of communications within networks. Many researchers have developed change detection methods to monitor interaction levels based on statistical process control (SPC), a prevalent tool in quality control. However, existing SPC techniques have seldom incorporated the overlapping communities of networks and have shown limited efficiency in detecting shifts at the community level. In addition, it is not convenient to utilize traditional mixed membership stochastic block model (MSBM) for network monitoring due to the complicated parameter estimation. To bridge this research gap, we propose a latent MSBM, which can be expressed in matrix form to enable easy parameter estimation with maximum likelihood estimation (MLE). This model also benefits two monitoring statistics derived from the generalized likelihood ratio test (GLRT). The two finalized change detection methods show higher efficiency than competing approaches in nearly all cases of simulation studies and a real application.

Financial inclusion is an effective way to eliminate poverty and narrow the income gap. Digital financial inclusion developed by digital technology has further improved its accessibility and affordability. However, it has also sparked discussions on whether digital financial inclusion can contribute to narrowing the urban-rural income gap due to technical barriers. To explore the relationship between digital financial inclusion and urban-rural income gap, using the data of China's prefecture-level cities from 2011 to 2020 and the fixed-effects model, the influence mechanisms of digital financial inclusion on the urban-rural income gap were analyzed. Results show that: (1) Digital financial inclusion directly narrows the urban-rural income gap by improving the coverage breadth of financial digital financial inclusion and the degree of digitization. It indirectly narrows the gap by promoting rural industrial development and farmers' employment and entrepreneurship. (2) The influence of different digital financial services on the urban-rural income gap is heterogeneous. Online insurance and online money fund narrow the gap, whereas online credit and online investment widen it. (3) The influence of digital financial inclusion on the urban-rural income gap is heterogeneous among different regions. In high-income regions, it has no significant impact on the gap; in middle-income regions, it contributes to narrowing the gap; in low-income regions, it widens the gap. Conclusions can provide policy implications for developing digital financial inclusion to narrow the urban-rural income gap.

Nowadays it is common to see information exchange among certain nodes in various network systems such as Internet of Things (IoT) and social networks. Once anomalies occur in a network system, the interaction frequency will increase or decrease abruptly. Detecting such changes has attracted much attention in the field of statistical process control (SPC). However, limited number of research incorporate the heterogeneity and community information of nodes simultaneously. The loss of information refrains the control chart from detecting network anomalies in a timely manner. In this regard, we propose a logit model with latent factors of nodes and communities to describe the variation of communications within unweighted networks, where the presence and absence of communication between each pair of nodes is regarded as a Bernoulli variable. Then the proposed model is expressed in a matrix form to enable easy parameter estimation and derivation of monitoring statistic. A new control chart is established based on generalized likelihood ratio test (GLRT). The simulation results and two real examples demonstrate the effectiveness and advantages of proposed control chart in comparison with two alternative methods.

China agricultural development has been facing the problem of resource constraints because its resources per capita such as land and energy are relatively lower than the global average. By applying the provincial agricultural panel data from 2000 to 2015 and fixed effect model based on the translog production function, this paper estimates both output elasticities and substitution elasticities of agricultural inputs, which may provide insights into sustainable agricultural development. The results show that, except for capital, the output elasticities of other production factors are all positive. Energy has always played an important role in agricultural production, whose elasticity in agriculture increased from 0.0203 in 2000 to 0.1694 in 2015. We also find a severe scarcity of land, and the high intensity of energy in the field of agriculture. Moreover, there exists a substitute relationship between all factors, which means that in the short term, one production factor can be employed to replace another to maintain agricultural development. From the empirical results of this paper, some policy suggestions are proposed as follows: it is crucial that more attention should be placed on land and to plan energy use wisely. In addition, on account of the current situation in China, the input of labor force should be stepped up and energy should be used more efficiently to make up for the shortage of land resources. The empirical results and policy suggestions in this paper may benefit the sustainable development of China’s agricultural economy.

Underground excavations often pass through underground retaining structures on one side or between the structures. In most cases, ground loss will be caused. At present, there are more and more collapses caused by excavation. When the ground loss occurs, the development of earth pressure and ground settlement is the decision basis for structural reinforcement or treatment. To obtain the preliminary rules of disturbance influences of the ground loss, the model test setup and the steel rod analogical soil technology are developed. A trapdoor is used to simulate the stratum loss caused by underground excavation and collapse, and the foundation pit excavation is simplified as the translation of the retaining wall. Considering the ratios of trapdoor depth to width, trapdoor depth to distance and trapdoor depth to side limit width, 15 groups of two-dimensional model tests are carried out. The earth pressure of retaining structures is measured by 18 cantilevered loaders on the retaining plate, and the surface settlement curve is obtained by the particle image velocimetry. The results show that ground loss increases the earth pressure at the upper part of the retaining wall and decreases the earth pressure at the lower part of the retaining wall. After the occurrence of the ground loss, if the adjacent foundation pit continues being excavated, due to the disturbance of the soil, there is no "bin effect" of the decrease of the earth pressure at the bottom of the retaining structures, and the earth pressure distribution when the retaining wall translation reaches the active limit state is in good agreement with the Coulomb’s active earth pressure. Under the influences of the superposition effect of the translation of the retaining wall after the ground loss caused by the adjacent underground excavation, the maximum value of surface settlement and the curvature of curve increase with the increase of trapdoor width, and increase with the decrease of trapdoor distance and side limit width. Due to the use of steel rod analogical soil, the test results mainly reflect the earth pressure and deformation characteristics of the sandy soil.

To study the influences on the earth pressure and ground settlement when the shield tunnel passes through the adjacent underground retaining structures, a self-designed test device is developed, and 15 model tests are carried out taking into account the ratios of tunnel depth to width, side limit width and excavation distance. In the tests, the stratum loss is simulated using the trapdoor settlement. The earth pressures of retaining structures are measured using 18 cantilever load gauges. The particle image velocimetry technique is used to measure the surface settlement. The variations of earth pressure and distribution of surface settlement during excavation under lateral confinement conditions are analyzed. The results show that the earth pressure at the bottom of retaining wall decreases sharply and then increases at a turning point with a certain height when the shield tunnel passes through the adjacent underground retaining structures. The smaller the ratio of depth to width of tunnel, the larger the decrement of the earth pressure at the bottom and the higher the turning point, and the larger the maximum displacement of surface settlement. The larger the ratio of tunnel depth to lateral limit width, the larger the reduction range of earth pressure, and the larger the maximum ground settlement. The greater the ratio of tunnel depth to distance, the greater the influences on earth pressure of retaining structures, and the greater the maximum ground settlement. Two correction coefficients, the maximum surface subsidence C1and the correction coefficient of settlement trough C2, are introduced, and the Peck’s settlement prediction equation is modified. The predictions show good agreement with the measured values of model tests.

Statistical process control (SPC) has been widely used to control and improve the quality of products in manufacturing processes. Currently, a limited number of schemes is available for change-point detection in multivariate categorical processes (MCPs), where each quality characteristic of products is measured by several attribute levels. Furthermore, existing few methods neglect the dependence structure among quality characteristics so as to provide low efficiency in detecting change points. This paper develops one change-point detection scheme based on the hierarchical log-linear model, which integrates a variable selection procedure to focus only on significant interaction effects, or equivalently dependent relationships among the factors. Therefore, the scheme can achieve higher efficiency than its competing method. The simulation study demonstrates the superiority of the proposed scheme and a real application shows the implementation of the scheme.

中国人口转型之势已不可逆转,经济活动人口持续数年下降,改善人力资本配置效率、释放人力资本潜力将成为维持中国经济持续增长的核心途径.本文构建了一个行业间人力资本错配的数理模型,以探讨其对行业产出及经济总产出的影响机制,并利用CHIP数据进行实证检验,考察中国各行业人力资本错配程度.研究发现:第一产业人力资本供给过多且呈恶化趋势;第二产业人力资本供给总体不足的状况逐渐缓解,但制造业人力资本供给不足呈加重态势;第三产业中边际产品价值较低的生活性服务业和公共服务业人力资本供给相对过剩,而边际产品价值较高的生产性服务业却面临着人力资本供给不足的问题.进一步地,本文测算了人力资本错配对行业产出和经济总产出的影响,发现人力资本错配会导致行业实际产出偏离最优配置状态下的产出,特别是在规模较大的行业中,人力资本供给过剩容易导致产出的过剩,但人力资本供给不足将造成相对更大的产出损失;从总产出层面估算,人力资本错配可能使得2007年和2013年中国实际总产出分别损失1.79％和1.63％.本文的研究结论为提升人力资本使用效率、实现经济高质量发展提供了有益的启示.

In the present study, we design a novel hot stamping steel containing high amounts of C and Si and micro-alloying element (i.e. Nb). The steel was subjected to quenching and partitioning (Q&P) process. The new Q&P treated hot stamping steel exhibits a significantly improved mechanical property in terms of strength, ductility and impact toughness compared with the traditional 22MnB5 hot stamping steel. The influence of partitioning time on the microstructure and mechanical properties was investigated. The retained austenite (RA) fraction and the carbon content of RA significantly increased with higher partitioning times. With increasing partitioning time, the uniform elongation, total elongation, strength-ductility balance and impact energy was also remarkably enhanced. The maximum strength-ductility balance achieves around 23 GPa %.

Sheet-like Fe/C nanocomposites have been successfully synthesized by a facile combustion-based method with two simple steps. First, a sheet-like precursor consisting of evenly mixed amorphous iron oxide and carbon was prepared through solution combustion synthesis by using ferric nitrate as an iron source and an oxidizer, glycine as a fuel and glucose as a carbon source. Subsequently, sheet-like Fe/C nanocomposites were synthesized via hydrogen reduction of the as-prepared precursor at 400 degrees C. The obtained Fe/C nanocomposites are composed of iron nanoparticles and amorphous carbon and the iron nanoparticles are homogenously embedded into the sheet-like carbon support. With the reduction time increasing from 2 h to 4 h, the saturation magnetization of the Fe/C nanocomposites reduced at 400 degrees C increases from 145.7 emu/g to 188.4 emu/g, whereas the coercivity decreases from 428.1 Oe to 90.4 Oe. The Fe/C nanocomposites reduced at 400 degrees C for 2 h have homogenous nanocomposite structure, well-dispersed iron nanoparticles with the size of similar to 20 nm and high specific surface area of 274.9 m(2)/g, which make this low-cost material a highly promising candidate for potential applications in water treatment, environmental remediation, absorption and catalysis. (C) 2016 Elsevier B.V. All rights reserved.

基于中国资本密集型和技术密集型产业的面板数据,实证分析了人力资本投入对我国资本和技术密集型产业的技术创新产出的影响.静态分析结果表明,从资本和技术密集型产业的平均技术创新水平来看,人力资本投入显著地促进了资本和技术密集型产业的技术创新产出.分位数回归结果表明,人力资本投入对资本和技术密集型产业中相关行业的技术创新水平的影响呈现显著差异:对资本和技术密集型产业中处于中低端技术创新水平的行业来说,人力资本投入对提升技术创新水平的贡献更加明显;而对资本和技术密集型产业中处于高端技术创新水平的行业来说,人力资本投入的促进作用较弱一些.

Macrophage phenotype and function varies according to their polarized state, which in turn is dependent on microenvironmental stimuli. Under normal physiological conditions, lung interstitial macrophages that express interleukin (IL)-10 are considered to serve regulatory roles in the prevention of allergic reactions in the airways. However, the phenotypic profile of lung interstitial macrophages during the pathophysiology of asthma remains unknown. In the current study, the phenotypic characteristics of lung interstitial macrophages were investigated in an ovalbumin (OVA)-induced mouse model of asthma. The patterns of surface markers chemokine ligand and interleukin, and the metabolic enzyme activity of lung interstitial macrophages were investigated using flow cytometry analysis, reverse transcription-quantitative polymerase chain reaction, western blot analysis, and ELISA. It was observed that lung interstitial macrophages derived from OVA-induced asthmatic mice expressed phenotypic markers associated with alternatively activated macrophages (M2), including cluster of differentiation-206, transglutaminase 2, arginase (Arg) 1 and chemokine ligand (CCL)17/CCL22/CCL24 secretion. The M2 macrophages also exhibited increased levels of Arg1 activity and reduced levels of IL-10 expression, relative to macrophages derived from control mice. However, when evaluating the expression of markers associated with classically activated (M1) macrophages, namely inducible nitric oxide synthase and IL-12, it was observed that levels of M1 markers in the interstitial macrophages from asthmatic mice did not differ significantly to those in controls. Collectively, these data suggest that lung interstitial macrophages undergo a phenotypic switch from a regulatory macrophage phenotype under normal conditions to an alternative activation state in OVA-induced asthmatic mice.

Our previous study showed that invariant natural killer T (iNKT) cells might act as an adjuvant to promote Th2 inflammatory responses in an OVA-induced mouse model of allergic asthma, but the mechanism remains unknown. To clarify the underlying mechanism through which iNKT cells promote Th2 inflammatory responses, we investigated the modulatory influence of iNKT cells on phenotypic and functional maturation of lung dendritic cells (LDCs) using iNKT cell-knockout mice, specific iNKT cell activation, coculture experiments, and adoptive transfer of iNKT cells in mouse models of asthma. Our data showed that iNKT cell deficiency could downregulate surface maturation markers and proinflammatory cytokine secretion of LDCs from a mouse model of asthma. However, elevated activation of iNKT cells by α-galactosylceramide and adoptive transfer of iNKT cells could upregulate surface maturation markers and proinflammatory cytokine secretion of LDCs from mouse models of asthma. Meanwhile, iNKT cells significantly influenced the function of LDCs, markedly enhancing Th2 responses in vivo and in vitro. In addition, iNKT cell can induce LDCs expression of CD206 and RELM-α, reflecting alternative activation of LDCs in a mouse model of asthma. α-Galactosylceramide treatment significantly enhanced expression of CD40L of lung iNKT cells from a mouse model of asthma, and the coculture experiment of LDCs with iNKT cells showed that the blockade of CD40L strongly suppressed surface maturation markers and proinflammatory cytokine production by LDCs. Our data suggest that iNKT cells can promote immunogenic maturation of LDCs to enhance Th2 responses in mouse models of asthma.

Magnesia-spinel composite refractories were prepared from high purity magnesia and pre-synthesized spinel with hercynite addition. The magnesia-spinel specimens were characterized using X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Laserflash thermal analyer. The effect of hercynite addition on the properties of magnesia-spinel composite refractories sintered in different atmospheres was investigated. The results showed that adding 2–3 wt% FeAl2O4 can enhance the sintering and increase the coefficient of thermal conductivity. The specimen with 2 wt% FeAl2O4 added and sintered in Ar atmosphere shows higher thermal conductivity and the best combination of properties. Fe2+ is more effective than Fe3+ in enhancing sintering of MgO-MgAl2O4.

Tungsten carbide/carbon (WCx/C) composite was synthesized by combustion-carbothermal reduction method. Systematic experiments that vary the ratio of the carbon atom of glucose to the tungsten atom of ammonium tungstate (C/W ratio), temperature and holding time used generated to investigate the synthesis process. The morphology of the as-prepared powders is flake-like and the WCx nanoparticles are embedded in the carbon matrix. This method is facile and easy to scale up. Electrochemical measurements demonstrate that the WCx/C composite exhibits good hydrogen evolution reaction (HER) catalytic activity, giving a eta(10) (the overpotential for driving a current of 10 mA cm(-2)) of -264 mV and Tafel slope of 85 mV dec(-1) in acid solution (0.5 M H2SO4). (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

BACKGROUND:Invariant natural killer T cells (iNKT cells) are a unique subset of T lymphocytes and are considered to play an important role in the development of allergic bronchial asthma. Recently, iNKT cells were shown to play an immunoregulatory role in CD4+ and CD8+ T cell-mediated adaptive immune response. Allergen-specific Th2 inflammatory responses are an important part of the adaptive immune response in asthma. However, the regulatory functions of the Th2 inflammatory response in asthma have not been studied in detail.METHOD:In this study, we have investigated the regulatory functions of iNKT cells on the Th2 inflammatory response in an ovalbumin (OVA)-induced murine model of asthma.RESULTS:Our results demonstrate that α-Galactosylceramide (α-GalCer) administration activated iNKT cells but could not induce the Th2 inflammatory response in wild-type (WT) mice. In the OVA-induced asthma model, α-GalCer administration and adoptive transfer of iNKT cells significantly augmented the Th2 inflammatory responses, including elevated inflammatory cell infiltration in the lung and bronchoalveolar lavage fluid (BALF); increased levels of IL-4, IL-5, and IL-13 in the BALF and splenocyte culture supernatant; and increased serum levels of OVA-specific IgE and IgG1. In addition, the Th2 inflammatory response was reduced, but not completely abrogated in CD1d-/- mice immunized and challenged with OVA, compared with WT mice.CONCLUSION:These results suggest that iNKT cells may serve as an adjuvant to enhance Th2 inflammatory response in an OVA-induced murine model of asthma.