Intergenerational Occupational Mobility, Labor Migration and Sustained Demographic Dividends

Based on the 1% sample survey of the National Population Census (2015), this paper empirically analyzes the impact of intergenerational occupational mobility levels on labor migration in terms of push and pull factors. We found that increasing the degree of intergenerational occupational mobility has a significant “agglomeration effect” on registered and mobile labor: reducing the emigration willingness of household registered labor and increasing the immigration probability of labor from cities with a lower degree of intergenerational occupational mobility. Labor migration generally occurs from cities with lower intergenerational occupational mobility to cities with a higher degree of intergenerational occupational mobility. The heterogeneity analysis reveals that the agglomeration effect of a city on native labor is insignificant in east, northwest and northeast China. Rural laborers, highly educated laborers and rural laborers with high education levels are more likely to move from their registered cities. The mechanism analysis finds that improving the city’s comprehensive economic incremental competitiveness will enhance the city’s agglomeration effect on native labor, while increasing the degree of educational returns will strengthen the city’s agglomeration effect on mobile labor from cities with a lower degree of intergenerational mobility. Moreover, after using IV-probit, IV-2SLS and heteroscedasticity-based IVs to deal with endogenous problems, the above conclusions are still robust. Our findings may contribute to realizing sustained demographic dividends through internal migration

Preparation and Properties of a Novel Cross-Linked Network Waterborne Polyurethane for Wood Lacquer

Waterborne polyurethane (WPU) is a waterborne coating with excellent physicochemical properties. Its deficiencies of water resistance, chemical resistance, staining, and hardness have limited the wide application of polyurethane in the wood lacquer market. In this study, polycarbonate diols (PCDL) were used as soft segments and WPCU was modified by cross-linking using Trimethylolpropane (TMP) to prepare polycarbonate type WPU (WPCU) with cross-linked network structure. The new wood lacquer was prepared by adding various additives and tested by applying it on wood board. The successful synthesis of WPCU was determined by FTIR testing, and the cross-linking degree of WPCU was probed by low-field NMR. The viscosity of the cross-linked WPCU emulsion showed a decreasing trend compared to the uncross-linked WPCU emulsion, and WPCU-2 had the smallest particle size. Compared with the uncrosslinked WPCU film, the crosslinked WPCU film had lower water absorption (2.2%), higher water contact angle (72.7°), excellent tensile strength (44.02 MPa), higher thermomechanical, and better water and alcohol resistance. The effect of crosslinker content on the microphase separation of WPCU chain segments on the surface roughness of the film was investigated by SEM. The wood paint prepared by WPCU emulsion has good dry heat resistance, chemical resistance, and adhesion, and the hardness of the wood paint when the TMP content is 3% reaches H. It also has good resistance to sticky stains, which can be used to develop new wood lacquer

Optimized Planning of Power Source Capacity in Microgrid, Considering Combinations of Energy Storage Devices

Since renewable energy resource is universally accepted as a promising method to solve the global energy problem, optimal planning and utilization of various distributed generators (DG) and energy storage (ES) devices deserve special concern. ES devices possess various characteristics in power density, energy density, response speed (switching speed) and lifetime. Besides, as different load types have various requirements on power supply reliability according to their importance, coordinated planning with consideration of reasonable matching between power source and load can efficiently improve power supply reliability and economic efficiency via a customized power supply and compensation strategy. This paper focuses on optimization of power source capacity in microgrid and a coordinated planning strategy is proposed with integrated consideration of characteristics of DG, ES and load. An index named additional compensation ratio (ACR) for balancing economic efficiency and reliability is proposed and considered in the strategy. The objective function which aims to minimize life cycle cost (LCC) is established considering economic efficiency, reliability and environmental conservation. The proposed planning strategy and optimizing model is calculated and verified through case study of an autonomy microgrid

Electroreduction of Holmium Ion on Iron Electrde in Molten Cholorides

用循环状安、恒电位断电、电位阶跃、Ｘ射线衍射和电子探针研究了Ｈｏ（Ⅲ）在氯化物熔体中铁电极上还原的电极过程及表面合金层的物相．Ｈｏ（Ⅲ）在铁电极上还原，首先形成多种钬和铁的金属间化合物，然后才析出金属钬，电荷转移是可逆的．测定了Ｈｏ－Ｆｅ体系四个金属间化合物的生成自由能、Ｈｏ在合金化阴极中的扩散系数及扩散活化能．The cyclic voltammetry,open circuit potential-time curve after poteritiostaticelectrolysis,current-time curve at potential step,x-ray diffraction and electron probe microanalysiswere used to investigate the electrode process of Ho(Ⅲ)reduced on iron electrode in molten chloridesand the phases of surface alloy layer.The Ho-Fe alloys are formed at first,and then the metallicholmium is deposited when Ho(Ⅲ)is reduced on iron electrede. The charge transfer is reversible. Thefree energies of formation for the four intermetallic compounds of Ho-Fe system,the diffusioncoefficients and diffusion activation energy of Ho in alloyed cathode are determined.作者联系地址：中山大学化学系，广州师范学院Author's Address: Department of Chemistry,Zhongshan University Guangzhou 51027

Electrochemical Studies of ZnCl 2 Urea Melts

研究了温度、浓度对ＺｎＣｌ２－尿素熔体电导的影响，ＺｎＣｌ２－ＮａＣｌ－尿素熔体的电导率（１２５℃）可达３０ｍｓ·ｃｍ－１以上．用循环伏安曲线、恒电位电解及断电后的电位－时间曲线，研究尿素熔体中Ｚｎ２＋的电还原和锌在钛、铜电极上的电沉积．Ｚｎ２＋的电还原为一步可逆过程，锌沉积在铜电极上会形成ＣｕＺｎ５合金．Ｚｎ２＋在熔体中扩散系数为１．３×１０－６ｃｍ２·ｓ－１（１２５℃）The electric conductivities of ZnCl 2 Urea melts were determined.The influences of temperature and concentration on the conductance have been studied.The cylic voltammetry,potentiostatic electrolysis and open circuit potential time curve after electrolysis,X ray diffraction were used to investigate the electroreduction of Zn 2+ , electrodeposition of zinc on some electrodes in urea metal chlorides melt. The conductivity of urea NaCl ZnCl 2 melt can reach to over 30 ms·cm -1 (125 ℃), and has a liner relationship with temperature from 108 to 140 ℃. The electroreduction of Zn 2+ to zinc is reversible at one step, and CuZn 5 alloy has been found on copper electrode. The diffusion coefficient of Zn 2+ in urea NaCl ZnCl 2 melt was determined as 1.3×10 -6 cm 2·s -1 (125 ℃).作者联系地址：中山大学化学系Author's Address: Department of Chemistry, Zhongshan Universit

Amplification of RAD54B promotes progression of hepatocellular carcinoma via activating the Wnt/β-catenin signaling

Liver cancer was reported to be the sixth most frequently diagnosed cancer, and hepatocellular carcinoma (HCC) accounts for 75%-85% of primary liver cancer. Nevertheless, the concrete molecular mechanisms of HCC progression remain obscure, which is essential to elucidate. The expression profile of RAD54B in HCC was measured using qPCR and western blotting. Moreover, the levels of RAD54B in paraffin-embedded samples were evaluated using immunohistochemistry (IHC). The effect of RAD54B on HCC progression was testified by in vitro experiments, and in vivo orthotopic xenograft tumor experiments. The mechanisms of RAD54B promoting HCC progression were investigated through molecular and function experiments. Herein, RAD54B are dramatically upregulated in HCC tissues and cell lines both on mRNA and protein levels, and RAD54B can servers as an independent prognostic parameter of 5-year overall survival and 5-year disease-free survival for patients with HCC. Moreover, up-regulation of RAD54B dramatically increases the capacity for in vitro cell viability and motility, and in vivo intrahepatic metastasis of HCC cells. Mechanistically, RAD54B promotes the HCC progression through modulating the wnt/β-catenin signaling. Notably, blocking the wnt/β-catenin signaling axis can counteract the activating effects of RAD54B on motility of HCC cells. Besides, further analysis illustrates that DNA amplification is one of the mechanisms leading to mRNA overexpression of RAD54B in HCC. Our findings indicate that RAD54B might be a promising potential prognostic marker and a candidate therapeutic target to therapy HCC