检索结果-南通市图书馆

china & World Economy 2024年第3期32卷 98-129页

作者： Jia Wang Huan Liu Mei Li Han Li School of Economics Xiamen UniversityChina School of Economics and Management Nanjing Agricultural UniversityChina School of Economics and Management Wuhan UniversityChina

To analyze the efect of the state-owned capital transfer policy on the sustainability of china's urban employee basic pension insurance fund(CUEBPIF),this study develops an actuarial model for pension *** results reveal the following:(i)Without policy intervention,the CUEBPIF would face a deficit in 2027 and a cumulative shortfall of RMB207.44 trillion by 2050,and the proportion of fiscal subsidies for the CUEBPIF in the total fiscal expenditure would increase to 12.86 percent in 2050.(i)Based on a delayed retirement policy,the transfer of 10 percent of state-owned capital can delay the onset of the fund deficit by 6 years,and the accumulated shortfall in 2050 would fall to RMB39.42 trillion,and the proportion of fiscal subsidies would decrease by I1.77 percentage points.(ii)The state-owned capital transfer policy can improve the sustainability of the CUEBPIF and reduce the burden of enterprise social security contributions when the transfer ratio increases to 20 percent.

关键词： burden of enterprise social security contributions delayed retirement policy state-owned capital transfer policy sustainability of basic pension insurance fund

The tail risk safe haven property of china's energy futures against US market implied volatility

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Management Science and Engineering 2024年第2期9卷 271-291页

作者： Xingyu Dai Peng-Fei Dai Qunwei Wang Zhi-Yi Ouyang College of Economics and Management Nanjing University of Aeronautics and AstronauticsNanjing211106China Research Center for Soft Energy Science Nanjing University of Aeronautics and AstronauticsNanjing211106China School of Management Wuhan University of TechnologyWuhan430070China Research Institute of Digital Governance and Management Decision Innovation Wuhan University of TechnologyWuhan430070China Huafu Fund Management Co. Ltd.ShanghaiChina

This paper analyses the tail risk contagion of US market implied volatility(USIV)on china's energy futures(CEF)markets,exploring how to utilize operations in the CEF to achieve a safe *** CEF characteristics to simultaneously take both long-/short-positions and engage in long-/short-run investment horizons,this paper defines eight different CEF safe haven attributes to counteract the tail risk of extreme increases in *** trading data from March 27,2018,to October 30,2023,the empirical results show that,first,in the analysis of the entire sample period,china's coking coal futures can serve as a weak safe haven,aiding long-position investors in mitigating the tail risks associated with US gold and stock market implied *** coal futures also assist short-position investors in countering US stock market implied volatility tail ***,in the sub-period analysis,the safe haven attributes of CEF exhibit strong heterogeneity and asymmetry across different ***,the time span during which CEF exhibits a particular safe haven attribute does not persist for an extended period.

关键词： china's energy futures Safe havenImplied volatility Multi-timescale analysis Cross-quantilogram model

Digital Revolution and Job Quality of Lower Class Workers: Quasi-experimental Evidence from the Broadband china Program

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

china & World Economy 2024年第4期32卷 146-178页

作者： Xiumei Wang Ye Jiang Famin Yi School of Business Fuyang Normal UniversityChina Department of Economics Dickinson CollegeUSA School of Economics and Management South China Agricultural UniversityChina

This study examines the impact of the digital revolution on the job quality of workers with a specific focus on those at the lowest end of the spectrum in china's domestic labor market. Leveraging exogenous timing variations that result from the implementation of the Broadband china Program across different cities, it provides quasi-experimental evidence concerning the effects of the digital revolution on the job quality of lower class workers, particularly rural–urban migrant workers. Using data from china Migrants Dynamic Survey, this study reveals that migrants' comprehensive job quality index increased by 0.0138 (5.33 percent), and its component indices experienced positive effects after the Broadband china Program was implemented. This study also investigates heterogeneous policy treatment effects among workers with diverse demographic and occupational characteristics. Underlying mechanisms are considered, including positive macroeconomic shocks, increased social interactions, and Internet use. In particular, migrants' attitudes toward local settlement became more positive, suggesting that the positive effects of the digital revolution on livelihood lasted for some time. Taking china as an example, this study contributes valuable empirical evidence of how the digital revolution can affect lower class workers' employment or living conditions in a developing country. Related policy implications are also considered.

关键词： Broadband china Program digital revolution job quality lower clas workers rural-urban migrants

Learning from Neighbors and Differentiating Export Quality

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

china & World Economy 2024年第4期32卷 1-32页

作者： Qiming Liu Bin Qiu Huw Edwards Bo Gao School of Economics and Management Southeast UniversityChina Business school Loughborough UniversityUK

This paper explores how learning from neighboring firms affects new exporters' product quality. It builds a Bayesian learning model to study how new exporters revise their prior beliefs about foreign customers' preferences for product quality from neighboring pioneering exporters. The model shows that a new exporter improves its product quality when it receives a positive quality-preference signal from its neighbors. The learning process of a firm depends on the number of neighbors, the level and heterogeneity of their export quality, and its own prior knowledge of the market. Highly disaggregated firm–product–country level transaction data provide robust evidence for this. The results also suggest that the impact of neighboring signals on a new exporter's quality can be channeled through the importation of high-quality intermediate inputs and more fixed investment. Learning effects are heterogeneous across firms and learning can influence other aspects of export performance.

关键词： Bayesian learning export quality information spillovers uncertainty

Dynamic Response of A Group of Cylindrical Storage Tanks with Baffles Considering the Effect of Soil Foundation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

china Ocean Engineering 2024年第1期38卷 129-143页

作者： SUN Ying WANG Jia-dong HUO Rui-li ZHOU Ding GU Zhen-yuan QIAN Wang-ping School of Transportation and Civil Engineering Nantong UniversityNantong 226019China Faculty of Civil Engineering and Mechanics Jiangsu UniversityZhenjiang 212013China College of Civil Engineering Nanjing Tech UniversityNanjing 211816China

The sloshing in a group of rigid cylindrical tanks with baffles and on soil foundation under horizontal excitation is studied *** solutions for the velocity potential are derived out by the liquid subdomain *** models with mass-spring oscillators are established to replace continuous *** with the least square technique,Chebyshev polynomials are employed to fit horizontal,rocking and horizontal-rocking coupling impedances of soil,respectively.A lumped parameter model for impedance is presented to describe the effects of soil on tank structures.A mechanical model for the soil-foundation-tank-liquid-baffle system with small amount of calculation and high accuracy is proposed using the substructure *** analytical solutions are in comparison with data from reported literature and numerical codes to validate the effectiveness and correctness of the *** dynamic properties and seismic responses of the soil-tank system are given for the baffle number,size and location as well as soil parameter.

关键词： cylindrical tanks multiple annular baffles equivalent analytical model soil−structure interaction subdomain method dynamic response

A novel responsive stabilizing Janus nanosilica as a nanoplugging agent in water-based drilling fluids for exploiting hostile shale environments

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 1190-1210页

作者： Alain Pierre Tchameni Lv-Yan Zhuo Lesly Dasilva Wandji Djouonkep Robert Dery Nagre Lu-Xin Chen Lin Zhao Chao Ma Bin-Qiang Xie College of Petroleum Engineering Yangtze UniversityWuhan430100HubeiChina Key Laboratory of Drilling and Production Engineering for Oil and Gas HubeiChina Lost Circulation Control Laboratory National Engineering Laboratory for Petroleum Drilling EngineeringYangtze UniversityWuhan430100HubeiChina College of Petroleum Engineering Shandong Institute of Petroleum and Chemical TechnologyDongying257061ShandongChina Petroleum Engineer Research Institute of Petrochina Dagang Oilfield Tianjin300280China Department of Chemical Engineering Kumasi Technical UniversityP.O.Box 854KumasiGhana

Thermo-responsive nanocomposites have recently emerged as potential nanoplugging agents for shale stabilization in high-temperature water-based drilling fluids(WBDFs). However, their inhibitory properties have not been very effective in high-temperature drilling operations. Thermo-responsive Janus nanocomposites are expected to strongly interact with clay particles from the inward hemisphere of nanomaterials, which drive the establishment of a tighter hydrophobic membrane over the shale surface at the outward hemisphere under geothermal conditions for shale stabilization. This work combines the synergistic benefits of thermo-responsive and zwitterionic nanomaterials to synchronously enhance the chemical inhibitions and plugging performances in shale under harsh conditions. A novel thermoresponsive Janus nanosilica(TRJS) exhibiting zwitterionic character was synthesized, characterized,and assessed as shale stabilizer for WBDFs at high temperatures. Compared to pristine nanosilica(Si NP)and symmetrical thermo-responsive nanosilica(TRS), TRJS exhibited anti-polyelectrolyte behaviour, in which electrolyte ions screened the electrostatic attraction between the charged particles, potentially stabilizing nanomaterial in hostile shaly environments(i.e., up to saturated brine or API brine). Macroscopically, TRJS exhibited higher chemical inhibition than Si NP and TRS in brine, prompting a better capability to control pressure penetration. TRJS adsorbed onto the clay surface via chemisorption and hydrogen bonding, and the interactions became substantial in brine, according to the results of electrophoretic mobility, surface wettability, and X-ray diffraction. Thus, contributing to the firm trapping of TRJS into the nanopore structure of the shale, triggering the formation of a tight hydrophobic membrane over the shale surface from the outward hemisphere. The addition of TRJS into WBDF had no deleterious effect on fluid properties after hot-treatment at 190℃, implying that TRJ

关键词： Janus nanosilica Thermo-responsive copolymer Anti-polyelectrolyte effect Shale stabilizer Inhibition Plugging Drilling fluid

Nanodiamond/Ti_(3)C_(2) MXene-coated quartz crystal microbalance humidity sensor with high sensitivity and high quality factor

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第6期43卷 2719-2729页

作者： Yao Yao Qiao Chen Yan-Qi Li Xian-He Huang Wei-Wei Ling Zhe-MiaoXie Jia-QiWang Chang-Ming Chen College of Communication Engineering Chengdu University of Information TechnologyChengdu 610225China School of Automation Chongqing University of Posts and TelecommunicationsChongqing 400065China School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Advanced Micro-/Nano-Devices Lab Department of Systems Design EngineeringUniversity of WaterlooWaterlooON N2L 3GlCanada

To address the challenge of achieving both high sensitivity and a high quality factor in quartz crystal microbalance(QCM)humidity sensors,a nanodiamond(ND)/Ti_(3)C_(2)MXene composite-coated QCM humidity sensor was *** material characteristics of ND,Ti_(3)C_(2)MXene,and ND/Ti_(3)C_(2)MXene composite were analyzed by transmission electron microscopy(TEM)and Fourier transform infrared(FTIR)*** experimental results demonstrated that the hydrophilic ND nanoparticles coated on Ti_(3)C_(2) MXene nanosheet prevented the self-stacking of Ti_(3)C_(2)MXene and enhanced the sensitivity of Ti_(3)C_(2) MXene-based QCM humidity ***,the high mechanical modulus of Ti_(3)C_(2) MXene material helped ND/Ti_(3)C_(2)MXene composite-coated QCM humidity sensor to achieve a high quality factor(>20,000).ND/Ti_(3)C_(2)MXene compositecoated QCM humidity sensor exhibited a sensitivity of 82.45 Hz/%RH,a humidity hysteresis of 1.1%RH,fast response/recovery times,acceptable repeatability,and good stability from 11.3%RH to 97.3%*** response mechanism of ND/Ti_(3)C_(2) MXene composite-coated QCM humidity sensor was analyzed in combination with a bi-exponential kinetic adsorption ***,the potential application of ND/Ti_(3)C_(2)MXene composite-coated QCM humidity sensor was demonstrated through its frequency response to wooden blocks with different moisture contents.

关键词： Humidity sensor Quartz crystal microbalance Nanodiamond Ti_(3)C_(2)MXene High quality factor

Optimization design and experiment of the variable differential gear train planting mechanism

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2024年第2期17卷 85-93页

作者： Xiong Zhao Ziwei Liu Yuanwu Jia Xingxiao Ma Pengfei Zhang Jianneng Chen School of Mechanical Engineering Zhejiang Sci-Tech UniversityHangzhou 310018China Xi’an International University Engineering College Xi’an 710077China Hangzhou Vocational&Technical College Hangzhou 310018China

In order to improve the adaptability of the planting mechanism for different plant spacings,a variable differential gear train planting mechanism based on precise pose and trajectory control was proposed by combining the open chain 2R rod group and the variable differential gear *** to the pose requirements of receiving seedling point,transporting seedling point and planting point,three precise pose points of constrained planting trajectory were *** the three-position motion generation structural synthesis method,combined with computer-aided optimization design software,a set of mechanism parameters that meet the planting requirements were *** on the optimized mechanism parameters,by only changing the coordinates of two trajectory shape control points,three planting trajectories with key point position information adapted to 300 mm,400 mm and 500 mm plant spacing were obtained by interpolation,and three pairs of total transmission ratio of three groups of variable differential gear trains were *** distributing the total transmission ratio of the mechanism,the fixed axis gear train and the differential gear train are *** fixed axis gear train included a pair of non-circular gear pairs and a pair of positive gear pairs,which were convenient for disassembly and *** former drives the sun gear at variable speed,and the latter drives the planet carrier at uniform *** on this structure,the transmission ratio of the positive gear pair is-1,and the transmission ratio of the differential gear train is *** sub-transmission ratio of the single-stage non-circular gear pair was calculated and the pitch curves of three pairs of noncircular gears were *** pairs of non-circular gear pairs with different transmission ratios were replaced in turn and three sets of planting mechanisms were modeled in three *** virtual prototype motion simulation was completed by ADAMS software,and the p

关键词： plant spacing planting mechanism variable differential gear train precise pose trajectory control parameter optimization

Financial Structure,Technology,and Economic Growth:A Structural Matching Perspective

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

china & World Economy 2023年第1期31卷 119-148页

作者： Dezhu Ye Yunjue Huang Xian Ye School of Economics Jinan UniversityChina Laboratory for Behavioral and Regional Finance Guangdong University of FinanceChina

Different types of capital are better suited to financing technologies with different risk profiles,and structural matching between finance and technology may critically influence economic *** cross-province panel data from china,we estimated the impact of the matching relationship between regions'financial structure and technology level on economic *** show that:(ⅰ)the matching relationship had a statistically significant positive impact on economic growth;(ⅱ)structural mismatching reduced economic growth in comparison with the optimal matching point;(ⅲ)structural matching better facilitated economic growth in more developed regions;and(ⅳ)capital accumulation and technological progress were two of the main channels through which matching influenced economic *** address potential endogeneity concerns and perform robustness checks,and our results remain *** findings provide convincing evidence for the optimalfinancial structure theory and explain china's rapid growth despite its comparatively underdeveloped securities market.

关键词： economic growth optimal financial structure structural matching technology

Abnormal cortical surface-based spontaneous and functional connectivity in the whole brain in lifelong premature ejaculation patients

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2023年第6期25卷 699-703页

作者： Si-Yan Xing Jia-Ming Lu Yue-Hui Jiang Tong Wang Guang-Jun Du Bai-Bing Yang Qing-Qiang Gao Bin Wang Ning Wu Chun-Lu Xu Tao Song Yu-Tian Dai Department of Andrology Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjing 210008China Department of Radiology Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjing 210008China Nanjing Drum Tower Hospital Clinical College of Nanjing University of Chinese Medicine Nanjing 210046China

Recent research has highlighted structural and functional abnormalities in the cerebral cortex of patients with premature ejaculation(PE).These anomalies could play a pivotal role in the physiological mechanisms underlying *** study leveraged functional magnetic resonance imaging(fMRI),a noninvasive technique,to explore these neural *** conducted resting-state fMRI scans on 36 PE patients and 22 healthy controls(HC),and collected data on Premature Ejaculation Diagnostic Tool(PEDT)scores and intravaginal ejaculation latency time(IELT).Employing a surface-based regional homogeneity(ReHo)approach,we analyzed local neural synchronous spontaneous activity,diverging from previous studies that utilized a volume-based ReHo *** with significant ReHo differences between PE and HC groups underwent surface-based functional connectivity(FC)*** discrepancies in ReHo and FC across the cortical surface were observed in the PE ***,PE patients exhibited decreased ReHo in the left triangular inferior frontal gyrus and enhanced ReHo in the right middle frontal *** latter showed heightened connectivity with the left lingual gyrus and the right orbital superior frontal ***,a correlation between ReHo and FC values with PEDT scores and IELT was found in the PE *** findings,derived from surface-based fMRI data,underscore specific brain regions linked to the neurobiological underpinnings of PE.

关键词： functional connectivity functional magnetic resonance imaging lifelong premature ejaculation regional homogeneity surface-based