Political selection is central to the survival of all regimes. This article evaluates the relative importance of performance and political connection for the advancement of local politicians under ...authoritarianism. We hypothesize that in a large-scale multilevel polity, economic performance plays a greater role in promotion at lower administrative levels of government than at higher ones, even after controlling for political connections. This dualist strategy allows the ruling elites to achieve economic performance while minimizing the advancement of potentially disloyal challengers. Thus, balancing between loyalty and competence among subordinates enhances regime survival. Our empirical evidence draws on a comprehensive panel dataset of provincial, prefectural, and county-level Communist party secretaries and government executives appointed between 1999 and 2007. We find consistent evidence for our argument under various model specifications. We also explore the heterogeneous effects of performance on promotion given the Chinese Communist Party’s (CCP) age ineligibility rule for cadre promotion and jurisdiction characteristics.
Abnormalities of navigation buoys include tilting, rusting, breaking, etc. Realizing automatic extraction and evaluation of rust on buoys is of great significance for maritime supervision. Severe ...rust may cause damage to the buoy itself. Therefore, a lightweight method based on machine vision is proposed for extracting and evaluating the rust of the buoy. The method integrates image segmentation and processing. Firstly, image segmentation technology is used to extract the metal part of the buoy based on an improved U-Net. Secondly, the RGB image is converted into an HSV image by preprocessing, and the transformation law of HSV channel color value is analyzed to obtain the best segmentation threshold and then the pixels of the rusted and the metal parts can be extracted. Finally, the rust ratio of the buoy is calculated to evaluate the rust level of the buoy. Results show that both the segmentation precision and recall are above 0.95, and the accuracy is nearly 1.00. Compared with the rust evaluation algorithm directly using the image processing method, the accuracy and processing speed of rust grade evaluation are greatly improved.
The design of adsorbents for rapid, selective extraction of ultra-trace amounts of gold from complex liquids is desirable from both an environmental and economical point of view. However, the ...development of such materials remains challenging. Herein, we report the fabrication of two vinylene-linked two-dimensional silver(I)-organic frameworks prepared via Knoevenagel condensation. This material enables selective sensing of gold with a low limit of detection of 60 ppb, as well as selective uptake of ultra-trace gold from complex aqueous mixtures including distilled water with 15 competing metal ions, leaching solution of electronic waste (e-waste), wastewater, and seawater. The present adsorbent delivers a gold adsorption capacity of 954 mg g
, excellent selectivity and reusability, and can rapidly and selectively extract ultra-trace gold from seawater down to ~20 ppb (94% removal in 10 minutes). In addition, the purity of recovered gold from e-waste reaches 23.8 Karat (99.17% pure).
Pollutants and water consumption in agriculture are essential factors in terms of water environment resource conservation. Calculating the water resource use efficiency of crops is crucial to reduce ...water consumption and pollution to alleviate the conflict between water use and food. Herein, we presented an integrated research framework that coupled the water footprint with data envelope analysis (DEA) to calculate the water resource use efficiency. Based on the calculation of the water footprint of three crop species (rice, corn, and soybean) in nine cities of Jilin Province from 2009 to 2016, we measured the resource use efficiency of crop water consumption through a superefficient slack-based measure. The driving force of variation in the resource use efficiency was determined by using the Malmquist–Luenberger index at a spatiotemporal scale and breaking down the driving force into an efficiency change and a technical change based on the evaluation results. Siping ranked first in the resource use efficiency of crop water consumption, whereas Yanbian ranked ninth. The technical change value based on the Malmquist–Luenberger index was less than 1, suggesting that it is essential that resource use efficiency in Jilin Province be improved. Moreover, the resource use efficiency in eastern cities with abundant water resources, such as Baishan and Yanbian, needs to be improved. The proposed water footprint can be coupled with the data envelopment analysis framework to provide a more reasonable evaluation that can be used by managers and regulators.
The path of crack propagation in a graphene sheet is significant for graphene patterning via the tearing approach. In this study, we evaluate the fracture properties of pre-cracked graphene during ...the tearing process, with consideration of the effects of the aspect ratio, loading speed, loading direction, and ambient temperatures on the crack propagation in the monolayer sheet. Some remarkable conclusions are drawn based on the molecular dynamic simulation results, i.e., a higher loading speed may result in a complicated path of crack propagation, and the propagation of an armchair crack may be accompanied by sp carbon links at high temperatures. The reason for this is that the stronger thermal vibration reduces the load stress difference near the crack tip and, therefore, the crack tip can pass through the sp link. A crack propagates more easily along the zigzag direction than along the armchair direction. The out-of-plane tearing is more suitable than the in-plane tearing for graphene patterning. The path of crack propagation can be adjusted by changing the loading direction, e.g., a rectangular graphene ribbon can be produced by oblique tearing. This new understanding will benefit the application of graphene patterning via the tearing approach.
This paper takes the real estate development enterprise as the research object, based on the characteristics of land VALUE-ADDED tax, carries out tax planning on the land value-added tax of the real ...estate development enterprise from four aspects, including the deduction of interest expense, reasonable pricing, collection cost and whether to combine the real estate with different value-added rates. The conclusion shows that the real estate development enterprises can calculate the tax threshold and choose different tax payment schemes to reduce the tax burden.
By bending a straight carbon nanotube and bonding both ends of the nanotube, a nanoring (or nano-wheel) is produced. The nanoring system can be driven to rotate by fixed outer nanotubes at room ...temperature. When placing some atoms at the edge of each outer tube (the stator here) with inwardly radial deviation (IRD), the IRD atoms will repulse the nanoring in their thermally vibration-induced collision and drive the nanoring to rotate when the repulsion due to IRD and the friction with stators induce a non-zero moment about the axis of rotational symmetry of the ring. As such, the nanoring can act as a wheel in a nanovehicle. When the repulsion is balanced with the intertubular friction, a stable rotational frequency (SRF) of the rotor is achieved. The results from the molecular dynamics simulation demonstrate that the nanowheel can work at extremely low temperature and its rotational speed can be adjusted by tuning temperature.
Unrest in the Xinjiang region of China currently poses the most imminent threat to the internal security of China and to central government control over peripheral regions. Instability in Xinjiang, ...furthermore, has ramifications for the wider security environment in Central Asia as the conflict becomes linked with jihadist groups in other security hotspots, like Pakistan and Syria. However, our understanding of important potential factors affecting political instability in Xinjiang is limited by the lack of systematically collected event data of ethnic violence. In this article, we introduce the first effort to fill this gap in data collection, that is, the Ethnic Violence in China (EVC) Database: the Xinjiang Region. This is a geocoded database of yearly incidents of ethnic violence at the county level in Xinjiang from 1990 to 2005. Using the EVC database, we demonstrate some initial results modeling ethnic violence in Xinjiang. We find that ethnic violence is positively associated with interethnic inequality; resources such as oil and cotton, on the other hand, are unrelated to the likelihood of ethnic violence.
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