Analysis on the vibration modes of the electric vehicle motor stator

The lightweight design of the electric vehicle motor brought about more serious vibration and noise problem of the motor. An accurate modal calculation was the basis for the study of the vibration and noise characteristics of the electric vehicle motor. The finite element method was used to perform the modal simulation of the PMSM. Through the reasonable simplification and equivalence of the motor stator model, the first 7 orders natural frequencies and corresponding modes of the motor stator under the free state were calculated. After that, the accuracy of the finite element model was verified by the hammering modal experiment of the prototype. Furthermore, the above results will provide the theoretical basis for the electric vehicle motor’s vibration control and NVH improvement

中國金融、生態與合作問題 = Finance, ecology, and cooperation in today’s China

此節由董筱丹 (中國人民大學) 主持，先由講者分享對中國金融、生態與合作問題的思考，點評人隨後作出點評。 演講: - 靳培云 (嶺南大學) - 何志雄 (北京梁漱溟鄉村建設中心) - 黃志友 (北京愛故鄉文化發展中心) - 嚴曉輝 (全球大學、國仁鄉建社企聯盟) 點評 : - 盧麒元 (沃德國際管理顧問有限公司) - 張孝德 (中共中央黨校國家行政學院

Booktalk at Library : 涓流彩園錄 Strolling the Lingnan Garden, 2014-2015

2016年11月22日，嶺南大學圖書館舉辦的讀書活動邀請劉健芝、歐陽麗嫦、嚴曉輝、靳培雲四位老師，談彩園年刊、成效及對未來的設想。服務研究處和參與農耕課程的同學都各自談到對彩園項目看法，其他同學也針對個別問題提出疑問，彩園老師也都一一作答。 On November 22 2016, the Lingnan library invited Professor Lau Kin Chi as well as Ms Auyueng Lai Seung, Mr Yan Xiaohui and Ms Jin Peiyun to discuss the Lingnan Gardeners publication Strolling the Lingnan Garden in terms of its impact and future vision, as well as answer questions from the students. Some students from the Farming class also presented their views on the Lingnan Gardeners project

Experimental research on the sound recognition of the electric vehicle motor

By synthetically applying order tracking method and acoustic holography method, the noise source of the electric vehicle motor was discerned in the bench test. According to profiling of the test data, the motor noise order tracking diagrams and sound holography contour maps were employed to draw the noise map of the electric vehicle motor. It was revealed that the low and medium frequency components of the motor’s noise are mainly related to the rotational passing frequency of the bearing rolling element and cage, as well as the doubling frequencies of the rotational frequencies of the rotor. The medium and high frequency components of motor’s noise are mainly related to motor’s loads and speeds. In the 1000-2500 r/min speed stage of the motor with load, the main order of motor’s noise is the 72nd order and in the speed stage of 3000-5000 r/min, motor’s noise is mainly the 15th, 18th and 26th orders. When the motor speed increases from 5000r/min to 8000r/min, the main order of motor’s noise is the fourth order. When the motor was accelerated in no-load operation, its noise characteristics are different from those of the motor with load. When the motor run at no load and low speed, the 16th and 72nd order are the main order of motor noise, while at high speed, the 2nd order of motor noise and the orders of motor switching frequency noise caused by frequency converter are the main order of motor noise. The above conclusions will give the assistance to further research on the acoustic characteristic of the electric vehicle motor

Experimental research on the sound recognition of the electric vehicle motor

By synthetically applying order tracking method and acoustic holography method, the noise source of the electric vehicle motor was discerned in the bench test. According to profiling of the test data, the motor noise order tracking diagrams and sound holography contour maps were employed to draw the noise map of the electric vehicle motor. It was revealed that the low and medium frequency components of the motor’s noise are mainly related to the rotational passing frequency of the bearing rolling element and cage, as well as the doubling frequencies of the rotational frequencies of the rotor. The medium and high frequency components of motor’s noise are mainly related to motor’s loads and speeds. In the 1000-2500 r/min speed stage of the motor with load, the main order of motor’s noise is the 72nd order and in the speed stage of 3000-5000 r/min, motor’s noise is mainly the 15th, 18th and 26th orders. When the motor speed increases from 5000r/min to 8000r/min, the main order of motor’s noise is the fourth order. When the motor was accelerated in no-load operation, its noise characteristics are different from those of the motor with load. When the motor run at no load and low speed, the 16th and 72nd order are the main order of motor noise, while at high speed, the 2nd order of motor noise and the orders of motor switching frequency noise caused by frequency converter are the main order of motor noise. The above conclusions will give the assistance to further research on the acoustic characteristic of the electric vehicle motor

Influence of

In order to evaluate the influence of Daphnia magna and Ceratophyllum demersum on the control of algae under different phosphorus concentrations, Cyclotella sp., Microcystis aeruginosa, and Chlorella vulgaris were selected to establish an aquatic microcosmic model. When the phosphorus concentration ranged from 0.05 to 2 mg L−1, D. magna significantly inhibited the three species of algae from different phylum, particularly M. aeruginosa, and the total growth rates of the three species of algae decreased with the increase of phosphorus concentration. When the phosphorus concentration ranged from 0.05 to 2 mg L−1, C. demersum imparted a significant inhibition of the three species of algae, particularly M. aeruginosa. The total growth rates of the three species of algae were reduced with higher phosphorus concentrations; however, the effect was lower than that of D. magna, with C. vulgaris as the dominant species. When the phosphorus concentration ranged from 0.05 to 2 mg L−1, D. magna combined with C. demersum inhibited the growth of the three species of algae to a considerable degree, which was an improvement over that of other experimental groups using only D. magna or C. demersum by themselves. The total growth rates of algae were reduced with higher phosphorus concentrations. When the phosphorus concentration ranged from 0.05 to 0.1 mg L−1, the removal rates of phosphorus exceeded 90%, and the phosphorus concentration became the limiting factor in the culture system. We observed that under higher initial phosphorus concentrations, the nitrogen removal rate increased, whereas the phosphorus removal rate decreased.Three species of water blooms algae from different phylum (Cyclotella sp., Microcystis aeruginosa, Chlorella vulgaris), zooplankton (Daphnia magna), and aquatic macrophyte (Ceratophyllum demersum) were selected to establish an aquatic microcosmic model, which was to facilitate quantitative study of the relationships between the concentrations of nitrogen or phosphorus and the three types of organism. The results of the study will provide an important reference for the control of water blooms

Use of Lasers in Laryngeal Surgery

NIH National Institute oil Deafness and Other Communication Disorders [R01 DC008850]Lasers are a relatively recent addition to laryngeal surgery. Since their invention, laser use and applications have expanded rapidly. In this article, we discuss the benefits and disadvantages of lasers for different procedures, as well as ways to overcome commonly faced clinical problems. The use of lasers in Surgery has offered a time- and cost-efficient alternative to cold Surgical techniques, and has been used in the treatment of numerous laryngeal pathologies, including stenoses, recurrent respiratory papillomatosis, leukoplakia, nodules, malignant laryngeal disease, and polypoid degeneration (Reinke's edema). However, lasers can incur adjacent tissue damage and vocal fold scarring These problems can be minimized through understanding the mechanisms by which lasers function and correctly manipulating the parameters under a surgeon's control. By varying fluence, power density, and pulsation, tissue damage can be decreased and lasers can be used with greater confidence. The various types of lasers and their applications to the treatment of specific pathologies are reviewed with the intention of helping surgeons select the best tool for a given procedure. Recent applications of lasers to treat benign laryngeal lesions and severe laryngomalacia demonstrate that additional research must be conducted to realize the full potential of this surgical tool

The Main Anthocyanin Monomer from <i>Lycium ruthenicum</i> Murray Fruit Mediates Obesity via Modulating the Gut Microbiota and Improving the Intestinal Barrier

Anthocyanins have been shown to exert certain antiobesity properties, but the specific relationship between anthocyanin-induced beneficial effects and the gut microbiota remains unclear. Petunidin-3-O-[rhamnopyranosyl-(trans-p-coumaroyl)]-5-O-(β-D-glucopyranoside) (P3G) is the main anthocyanin monomer from the fruit of Lycium ruthenicum Murray. Therefore, in this study, we investigated the antiobesity and remodeling effects of P3G on gut microbiota through a high-fat diet (HFD)-induced obesity mouse model and a fecal microbiota transplantation experiment. P3G was found to reduce body weight gain, fat accumulation, and liver steatosis in HFD-induced obese mice. Moreover, supplementation with P3G alleviated the HFD-induced imbalance in gut microbiota composition, and transferring the P3G-regulated gut microbiota to recipient mice provided comparable protection against obesity. This is the first time evidence is provided that P3G has an antiobesity effect by changing the intestinal microbiota. Our present data highlight a link between P3G intervention and enhancement in gut barrier integrity. This may be a promising option for obesity prevention

A Comparative Study on the Vertical Structures and Microphysical Properties of a Mixed Precipitation Process over Different Topographic Positions of the Liupan Mountains in Northwest China

A field campaign in Liupan Mountains was carried out by the Weather Modification Center of the China Meteorological Administration to study the impact of terrain on precipitation in Northwest China. The vertical structures and microphysical characteristics of a mixed cloud and precipitation process, which means stratiform clouds with embedded convection, over three topographic positions of the Liupan Mountains, namely, the Longde (LD, located on the windward slope), Liupan (LP, located on the mountain top), and Dawan sites (DW, located on the leeward slope), are compared using measurements from ground-based cloud radar (CR), micro rain radar (MRR), and disdrometer (OTT). The 17 h process is classified into cumulus mixed (1149 min), shallow (528 min), and stratiform (570 min) cloud and precipitation stages. Among them, the vertical structures over the three sites are relatively similar in the third stage, while the differences, mainly in cloud-top heights (CTHs) and rain rates (Rs), are significant in the second stage due to the strong instability. Overall, the characteristics of higher concentrations and smaller diameters of raindrops are found in this study, especially at the LP site. Topographic forcing makes the microphysical and dynamic processes of mountaintop clouds and precipitation more intense. The updrafts are the strongest at the LP, caused by orographic uplifting, and the DW is dominated by the downdrafts due to the topography impact on the dynamic structure. Meanwhile, particle falling velocities (Vts) and downdrafts rapidly increase within 0.6 km near the ground over the LP, forming positive feedback, and the collision–coalescence process is dominant