Development Status and Application Research of Rare Earth Permanent Magnet Motor

Since entering the new century, the efficient use of energy has become the key to the development of every country in the world, so it is an inevitable trend to create a resource-saving society. So many fields are also actively exploring new environmental protection technology, and in the development process of China's industrial industry, the further use of rare earth permanent magnet motor can better realize the full use of energy. Therefore, this paper will analyze the development of rare earth permanent magnet motor and the overall application trend

Smart Cities are Big Cities - Comparative Advantage in Chinese Cities

The literature on China indicates that the concentration of economic activities in China is less than in other industrialized countries. Institutional limits are largely held responsible for this finding (e.g. the Hukou system); firms and workers are not able to take full advantage of the benefits from agglomeration economies. China is changing rapidly, however, also in this respect. We show that, by using the methodology developed by Davis and Dingel (2013), high-skilled workers in high-skill intensive sectors sort into larger locations. We demonstrate this for regions, agglomerations, cities, and for skills, occupations, and sectors. The results are strongest for cities and skills, followed by agglomerations and occupations, respectively. Between 2000 and 2010 this sorting process has become stronger, which we interpret as an indication that institutional limitations in China against further agglomeration weaken, and that the consensus in the literature that Chinese cities are too small' needs some qualification

Urban development in China:On the sorting of skills

For advanced economies, it is a well-established stylized fact that large cities are relatively skill abundant. For emerging markets, like China, this relationship is less well established. We show, using recently developed tests, that also in China higher skills sort into larger locations. This sorting process is consistent with the comparative advantage of cities. We identify two types of spatial units (Core-Cities and Extended-Cities) and analyse sorting for three types of skills (education skills, sector skills, and occupation skills). The sorting process across cities is stronger for Core-Cities than for Extended-Cities, stronger for education skills than for sector- and occupation skills, and stronger for 2010 than for 2000. We interpret these results as an indication that investments in, for example, infrastructure and institutional liberalization (such as the relaxation of the Hukou system), stimulates sorting of higher skills in larger cities

Degradation Characteristics of Aniline with Ozonation and Subsequent Treatment Analysis

Owing to the toxicity and low biodegradability of aniline in water, its removal usually needs high cost processes such as adsorption and advanced oxidation. The degradation characteristics of aniline during ozonation were studied. The influence of operation parameters such as contact time, initial concentration, ozone dosage, temperature, and pH was also investigated. With ozone dosage of 22 mg/L, neutral pH, and room temperature, the ozonation removed aniline efficiently. After two hours’ ozonation, aniline removal reached 93.57%, and the corresponding COD removal was 31.03%, which indicated most of aniline was transformed into intermediates. At alkaline conditions, the aniline was more susceptible to being removed by ozonation owing to more hydroxyl radicals’ production. The results of GC-MS indicated many intermediates appeared during the process of ozonation such as butane diacid, oxalic acid, and formic acid. The intermediates produced during ozonation were more biodegradable than aniline; thus the ozonation of such organic compounds as aniline could be integrated with biological processes for further removal

Fan-Shaped Model for Generating the Anisotropic Catchment Area of Subway Stations based on Feeder Taxi Trips

The catchment areas of subway stations have always been considered as a circular shape in previous research. Although some studies show the catchment area may be affected by road conditions, public transportation, land use, and other factors, few studies have discussed the shape of the catchment area. This study focuses on analyzing the anisotropy of catchment areas and developing a sound methodology to generate them. Based on taxi global positioning system (GPS) data, this paper first proposes a data mining method to identify feeder taxi trips around subway stations. Then, a fan-shaped model is proposed and applied to Xi\u27an Metro Line 1 to generate catchment areas. The number and angle of fan areas are determined according to the spatial distribution characteristics of GPS points. Results show that the acceptable distance of the catchment area has significant differences in different directions. The average maximum acceptable distance of one station is 2.31 times the minimum. Furthermore, for feeder taxis, the overlap ratio of the catchment area is very high. Travelers in several places could choose several different stations during the travel. A multiple linear regression model was introduced to find the influencing factors, and the result shows the anisotropy of the catchment area is affected not only by neighboring subway stations, but also by the road network, distance from the city center, and so on

The Alteration of Subtelomeric DNA Methylation in Aging-Related Diseases

The telomere is located at the end of the chromosome and consists of a non-coding, repetitive DNA sequence. As the cell divides, the length of telomere gradually decreases. A very short telomere can terminate mitosis, and thus telomere length becomes a hallmark of cellular aging. The 500 kb region of each autosomal arm terminal is the so-called subtelomeric region. Both telomere and subtelomere have high-density DNA repeats. Telomeres do not contain genes or CpG sequences, while subtelomeres contain small amounts of genes and high-density CpG sequences, and DNA methylation often occurs in subtelomeres. Previous studies have shown that aberrant methylation of subtelomeric DNA exists in many diseases, and it has a certain effect on the regulation of telomere length. In this review, we focus on the correlation between subtelomeric DNA methylation and aging-related diseases. We also summarize the relationship between subtelomeric methylation and telomere length in different diseases

FFN-SkipLLM: A Hidden Gem for Autoregressive Decoding with Adaptive Feed Forward Skipping

Autoregressive Large Language Models (e.g., LLaMa, GPTs) are omnipresent achieving remarkable success in language understanding and generation. However, such impressive capability typically comes with a substantial model size, which presents significant challenges for autoregressive token-by-token generation. To mitigate computation overload incurred during generation, several early-exit and layer-dropping strategies have been proposed. Despite some promising success due to the redundancy across LLMs layers on metrics like Rough-L/BLUE, our careful knowledge-intensive evaluation unveils issues such as generation collapse, hallucination of wrong facts, and noticeable performance drop even at the trivial exit ratio of 10-15% of layers. We attribute these errors primarily to ineffective handling of the KV cache through state copying during early-exit. In this work, we observed the saturation of computationally expensive feed-forward blocks of LLM layers and proposed FFN-SkipLLM, which is a novel fine-grained skip strategy of autoregressive LLMs. More specifically, FFN-SkipLLM is an input-adaptive feed-forward skipping strategy that can skip 25-30% of FFN blocks of LLMs with marginal change in performance on knowledge-intensive generation tasks without any requirement to handle KV cache. Our extensive experiments and ablation across benchmarks like MT-Bench, Factoid-QA, and variable-length text summarization illustrate how our simple and ease-at-use method can facilitate faster autoregressive decoding.Comment: arXiv admin note: text overlap with arXiv:2310.0138

Unveiling microstructural damage for leakage current degradation in SiC Schottky diode after heavy ions irradiation under 200 V

Single-event burnout and single-event leakage current (SELC) in SiC power devices induced by heavy ions severely limit their space application, and the underlying mechanism is still unclear. One fundamental problem is lack of high-resolution characterization of radiation damage in the irradiated SiC power devices, which is a crucial indicator of the related mechanism. In this letter, high-resolution transmission electron microscopy (TEM) was used to characterize the radiation damage in the 1437.6 MeV 181Ta-irradiated SiC junction barrier Schottky diode under 200 V. The amorphous radiation damage with about 52 nm in diameter and 121 nm in length at the Schottky metal (Ti)-semiconductor (SiC) interface was observed. More importantly, in the damage site the atomic mixing of Ti, Si, and C was identified by electron energy loss spectroscopy and high-angle annular dark-field scanning TEM. It indicates that the melting of the Ti-SiC interface induced by localized Joule heating is responsible for the amorphization and the formation of titanium silicide, titanium carbide, or ternary phases. These modifications at nanoscale in turn cause the localized degradation of the Schottky contact into Ohmic contact, resulting in the permanent increase in leakage current. This experimental study provides some valuable clues to thorough understanding of the SELC mechanism in SiC diode.Comment: 4 pages,4 figure