Contribution of factor structure change to China’s economic growth: evidence from the time-varying elastic production function model

The time-varying factor share runs through the entire process of the Chinese economic miracle, unlike the ‘Kaldor Facts’ in developed countries. Following the new structural economics theory, we construct a time-varying elastic production function model that characterises the structural changes of China’s economic element, and decompose the driving force of economic growth to measure the contribution of factor structure. We found that, from 1978–2017, the average contribution of capital, labour, technological progress, and factor structure change to the GDP was 67.01%, 10.38%, 23.08%, and 0.47%, respectively. The measurement results can aptly portray the impact of policy changes in China’s unique gradual reform process, such as the economic market reforms in 1992, the global financial crisis in 2008, and the policy changes of the new economic normal in 2014. Meanwhile, the results reveal that improving factor allocation can accelerate the total factor productivity and promote high-quality development of China’s economy

Building3D: An Urban-Scale Dataset and Benchmarks for Learning Roof Structures from Point Clouds

Urban modeling from LiDAR point clouds is an important topic in computer vision, computer graphics, photogrammetry and remote sensing. 3D city models have found a wide range of applications in smart cities, autonomous navigation, urban planning and mapping etc. However, existing datasets for 3D modeling mainly focus on common objects such as furniture or cars. Lack of building datasets has become a major obstacle for applying deep learning technology to specific domains such as urban modeling. In this paper, we present a urban-scale dataset consisting of more than 160 thousands buildings along with corresponding point clouds, mesh and wire-frame models, covering 16 cities in Estonia about 998 Km2. We extensively evaluate performance of state-of-the-art algorithms including handcrafted and deep feature based methods. Experimental results indicate that Building3D has challenges of high intra-class variance, data imbalance and large-scale noises. The Building3D is the first and largest urban-scale building modeling benchmark, allowing a comparison of supervised and self-supervised learning methods. We believe that our Building3D will facilitate future research on urban modeling, aerial path planning, mesh simplification, and semantic/part segmentation etc

Sulfurization of bimetallic (Co and Fe) oxide and alloy decorated on multi-walled carbon nanotubes as efficient bifunctional electrocatalyst for water splitting

The advancement in electrocatalysis, particularly in the development of efficient catalysts for hydrogen and oxygen evolution reactions (HER and OER), is crucial for sustainable energy generation through processes like overall water splitting. A notable bifunctional electrocatalyst, CoFe2O4/Co7Fe3, has been engineered to facilitate both OER and HER concurrently, aiming to reduce overpotentials. In the pursuit of further enhancing catalytic efficiency, a morphological transformation has been achieved by introducing a sulphur source and multi-walled carbon nanotubes (MWCNTs) into the catalyst system, resulting in S–CoFe2O4/Co7Fe3/MWCNTs. This modification has significantly improved the activity for both OER and HER. An onset overpotential of 250 mV@10 mAcm−2 for the OER and 270 mV@50 mAcm−2 for the HER, indicating efficient catalytic activity at relatively low overpotentials. S–CoFe2O4/Co7Fe3/MWCNTs display an outstanding long-term stability in alkaline electrolytes, with minimal Tafel slopes of 77 mV/dec for the OER and 70 mV/dec for the HER, suggesting sustained catalytic performance over extended periods. Furthermore, when employed as both the cathode and anode in the context of complete water splitting, S–CoFe2O4/Co7Fe3/MWCNTs demonstrate an impressive cell voltage of 1.52 V at a current density of 10 mA cm−2 in a 1 M KOH solution, showcasing its viability for practical applications. Given its cost-effectiveness and superior activity, S–CoFe2O4/Co7Fe3MWCNTs hold significant promise for widespread applications in overall water splitting electrocatalysis, contributing to the advancement of cleaner and sustainable fuel generation technologies

Synthesis of a magnetic π-extended carbon nanosolenoid with Riemann surfaces

Riemann surfaces are deformed versions of the complex plane in mathematics. Locally they look like patches of the complex plane, but globally, the topology may deviate from a plane. Nanostructured graphitic carbon materials resembling a Riemann surface with helicoid topology are predicted to have interesting electronic and photonic properties. However, fabrication of such processable and large π-extended nanographene systems has remained a major challenge. Here, we report a bottom-up synthesis of a metal-free carbon nanosolenoid (CNS) material with a low optical bandgap of 1.97 eV. The synthesis procedure is rapid and possible on the gram scale. The helical molecular structure of CNS can be observed by direct low-dose high-resolution imaging, using integrated differential phase contrast scanning transmission electron microscopy. Magnetic susceptibility measurements show paramagnetism with a high spin density for CNS. Such a π-conjugated CNS allows for the detailed study of its physical properties and may form the base of the development of electronic and spintronic devices containing CNS species

A review on fundamentals for designing hydrogen evolution electrocatalyst

As a clean, efficient, and renewable energy source, hydrogen has always been recognized as a favourable replacement of fossil fuel. A primary challenge is an efficient generation of hydrogen to fulfil the requirements of hydrogen on a commercial scale. The electrocatalytic process of HER (hydrogen evolution reaction), as primary phase in water electrolytic process for H2 production, has undergone comprehensive observation from recent decades. Electrolytic water splitting presents a promised route to attain efficient hydrogen generation concerning energy conversion and storage, with electrolysis or catalysis playing a pivotal role. The advancement of catalyst or electrocatalysts that are effective, enduring and economical is necessary prerequisite for realizing the intended electrolytic hydrogen generation from water splitting for applicable considerations, embodying the primary emphasis of this article. In this extensive review, we initially summarize the basics of the Hydrogen evolution reaction and examine the latest cutting-edge progress in economical and highly efficiency catalysts utilizing both non-noble and noble metals. Moreover, the recent breakthroughs over the preceding years in electrolytic HER employing more affordable and widely available nanoparticles with a specific center of attention on economical and non-platinum electrocatalysts rooted in metal free (MF) and transition metal composite catalysts are deliberated here

Flexible decapyrrylcorannulene hosts

球形笼状的富勒烯是上个世纪末最重要的科学发现之一，但对富勒烯的精确几何结构的认识却困难重重，原因是单晶中球形分子的取向往往是无序的，需通过笼外衍生或通过八乙基金属卟啉-富勒烯超分子主客体组装来固定富勒烯的取向，然后利用常用的单晶衍射分析技术来精确表征富勒烯的几何结构。然而许多富勒烯新结构因无法与卟啉主体形成高质量的单晶至今仍无法利用X射线衍射技术进行结构分析，直接制约了对富勒烯形成机理及结构-性能关系的深入认识。功能团簇材料创新研究群体的谢素原、张前炎课题组另辟蹊径地从曲面结构的十氯碗烯C20Cl10出发，合成了十吡咯取代的碗烯分子C20(C4H4N)10。结构分析表明该分子的结构特征是碗烯的碳框架与十个吡咯基团通过单键相连。实验还证明，用甲基去取代吡咯3, 4-位置的氢并不利于富勒烯与碗烯衍生物形成有序的超分子组装体，理论研究进一步诠释了十个吡咯‘手指’的集体贡献比单个碗烯‘手掌’更大的原因。该研究工作是功能团簇材料创新研究群体长期积累，并由校内外十多位研究人员共同努力完成。徐云彦（2014级硕士生）、田寒蕊（2014级博士生）和李姝慧（2016年进站博士后）为该论文共同第一作者。【Abstract】The assembly of spherical fullerenes, or buckyballs, into single crystals for crystallographic identification often suffers from disordered arrangement. Here we show a chiral configuration of decapyrrylcorannulene that has a concave ‘palm’ of corannulene and ten flexible electron-rich pyrryl group ‘fingers’ to mimic the smart molecular ‘hands’ for self-adaptably cradling various buckyballs in a (+)hand-ball-hand(−) mode. As exemplified by crystallographic identification of 15 buckyball structures representing pristine, exohedral, endohedral, dimeric and hetero-derivatization, the pyrryl groups twist with varying dihedral angles to adjust the interaction between decapyrrylcorannulene and fullerene. The self-adaptable electron-rich pyrryl groups, susceptible to methylation, are theoretically revealed to contribute more than the bowl-shaped palm of the corannulene in holding buckyball structures. The generality of the present decapyrrylcorannulene host with flexible pyrryl groups facilitates the visualization of numerous unknown/unsolved fullerenes by crystallography and the assembly of the otherwise close-packed spherical fullerenes into two-dimensional layered structures by intercalation.This research was supported by the National Natural Science Foundation of China (21771152, 21721001, 21827801, 51572231, 51572254, 21571151, 2170010228), the 973 Program of China (2014CB845601 and 2015CB932301), the China Postdoctoral Science Foundation (2016M602067), the National Key Research and Development Program of China (2017YFA0402800), and the Fundamental Research Funds for the Central Uni- versities (20720170028, 20720160084). Q.Y.Z. is particularly grateful to 21771152, 2015CB932301, 20720170028, 20720160084; S.F.Y. is particularly grateful to 51572254 and 2017YFA0402800; S.Y.X. is particularly grateful to 21721001 and 51572231; L.S.Z. is particularly grateful to 21827801; S.L.D. is particularly grateful to 21571151; S.H.L. is particularly grateful to 2170010228 and 2016M602067. 研究工作得到国家自然科学基金（21771152、21721001、21827801、51572231、51572254, 21571151、2170010228）、科技部973计划（2014CB845601、2015CB932301）和重点研发计划（2017YFA0402800）、国家博士后科学基金、中央高校基本科研业务费等的资助

Social Participation as a Predictor of Morbid Thoughts and Suicidal Ideation among the Elderly Population: A Cross-Sectional Study on Four Low-Middle-Income Countries

Social wellbeing constitutes a critical aspect of one’s health, quality of life, and overall psychosocial wellbeing. Social isolation and perceived loneliness are growing public health concerns as they are considered to be important risk factor for poor physical and mental health outcomes. Not much is known about how the level of one’s social participation is associated with morbid thought and suicidal ideation. In the present study, we aimed to investigate whether social participation shows any significant correlation with morbid thought and suicidal ideation among the elderly population. Methods: Cross-sectional data were collected from Wave 1 of the Study of Global AGEing and Adult Health (SAGE). The sample population consisted 2018 men and women aged 65 years and above from the following countries: China (n = 787), Ghana (n = 278), India (n = 560), and Russia (n = 396). Outcome variables of self-reported occurrence of morbid thoughts and suicide ideation during the past 12 months were reported. Results: A great majority of the participants reported not participating in activities such as public meetings (84.6%), club meeting (49.6%), neighborhood activities (46%), and religious activities (57.2%). Those who reported attending public meetings several times a year had a higher likelihood of reporting having morbid thoughts (predicted probability = 1.24, 95% CI = 1.02, 1.52). However, the association was no longer significant after stratifying by sex. Attending clubs (marginal effect = 0.61, 95% CI = 0.49, 0.76) and neighborhood activities (predicted probability = 0.71, 95% CI = 0.58, 0.88) several times a year showed protective effects against morbid thoughts. Being visited by friends several times a month (predicted probability = 0.52, 95% CI = 0.40, 0.67) and visiting friends (predicted probability = 0.61, 95% CI = 0.50, 0.75) several times a year also showed lower likelihood of morbid thoughts. Similar effects were observed for attending social gatherings with colleagues and social events as well. Conclusions: The present findings suggest that there exist significantly positive associations between participation in social activities and morbid thoughts and suicidal ideation among the elderly population in the sample countries. More in-depth studies are necessary to investigate the barriers to participation in social activities as well as the role of the quality of social relationships with experiencing suicidal thoughts

Do Mothers with Lower Socioeconomic Status Contribute to the Rate of All-Cause Child Mortality in Kazakhstan?

Background. This study aimed to explore whether or not mothers with higher educational and wealth status report lower rate of child mortality compared to those with less advantageous socioeconomic situation. Methods. Data used were cross-sectional and collected from Multiple Indicator Cluster Survey in Kazakhstan conducted in 2015. Subjects experiencing childbirth were 9278 women aging between 15 and 49 years. The associations between maternal education and household wealth status with child mortality were examined by multivariate analytical methods. Results. The overall prevalence of child mortality was 6.7%, with noticeable variations across the different regions. Compared with women who had the highest educational status, those with upper and lower secondary were 1.47 and 1.89 times more likely to experience child death. Women in the lowest and second lowest wealth quintile had 2.74 and 2.68 times higher odds of experiencing child death compared with those in the richest wealth status households. Conclusions. Policy makers pay special attention to improving socioeconomic status of the mothers in an effort to reduce child mortality in the country. Women living in the disadvantaged regions with poor access to quality health care services should be regarded as a top priority

A theoretical study of spin-polarized transport properties of planar four-coordinate Fe complexes

We present a first-principles study of the spin-polarized transport properties of three planar four-coordinate Fe complexes with different noninnocent ligands sandwiched between two armchair (5,5) single-walled carbon nanotube (SWCNT) electrodes. Theoretical results clearly reveal that the current of the spin-up electrons through three examined molecular junctions is significant larger than that of the spin-down electrons. The low bias conductance is determined by the tail of transmission peak coming from the perturbed lowest unoccupied molecular orbital of the spin-up electrons. The high spin-filter efficiencies (up to 99.0%) are predicted for three planar four-coordinate Fe complexes coupled to SWCNTs