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Due to the advantages of small deformation, high energy density and welding efficiency, the high-energy beam welding technology has played an important role in aerospace, rail transportation and other advanced manufacturing fields. The existing study shows that the high-energy beam welding could realize high-quality joining of similar/dissimilar materials, such as superalloy, titanium alloy, high-entropy alloy, aluminum alloy and others. The development and physical process of two representative technologies, electron beam welding and laser welding, are briefly introduced. The study on the microstructure feature and mechanical property as well as the effect of the post-weld heat treatment for the two processes are mainly discussed.

旨在验证改进型糠粞分离器的分离效果和为米糠制粒浸出工艺提供一定的技术参考,采用风选分离糠粞、制粒烘干、平转浸出、负压蒸发、DTDC湿粕脱溶的米糠制粒浸出工艺制取米糠原油，通过总结生产中的一些问题和操作经验,改进了风选式糠粞分离器，确定了颗粒化处理方式及米糠制粒浸出工艺关键点的参数。结果表明：采用改进的糠粞分离器，糠粞分离效果良好，处理量大；以低温制粒烘干代替膨化进行米糠的颗粒化处理，米糠制粒浸出工艺关键点的工艺参数为制粒温度60 ℃，颗粒直径3.7 mm，烘干机出料温度60 ℃，烘干后颗粒水分5%，浸出温度55 ℃，蒸发系统真空度70 kPa，第一蒸发器出油浓度85%、温度65 ℃，第二蒸发器出油浓度95%、温度98 ℃，汽提塔出油温度102 ℃，蒸脱机气相温度76 ℃。采用优化的米糠制粒浸出工艺可改善米糠原油及糠粕品质，并可降低能耗。Aiming to verify the separation effect of improved rice bran and fine broken rice separator and provide certain technical reference for rice bran granulation and extraction process, rice bran granulation and solvent extraction process was used to extract crude rice bran oil,including air separation for rice bran and fine broken rice, granulation drying, rotary leaching, negative pressure evaporation,DTDC wet meal desolventizing. By summarizing some problems and operation experience in production, the rice bran and fine broken rice separator was improved,the granulation treatment was determined, and the key process parameters of rice bran granulation and extraction process were determined.The results showed that rice bran and fine broken rice were separated very well by using the improved rice bran and fine broken rice separator, and the system had a larger capacity. Rice bran particle was prepared using low temperature granulation drying instead of expansion. The key technical parameters of rice bran granulation and solvent extraction process were confirmed as follows: granulation temperature 60 ℃, particle diameter 3.7 mm, discharge temperature of drying machine 60 ℃, particle moisture after drying 5%, solvent extraction temperature 55 ℃, vacuum of evaporation system 70 kPa, oil concentration and temperature of the first evaporator 85% and 65 ℃, oil concentration and temperature of the second evaporator 95% and 98 ℃, oil temperature of stripper 102 ℃, and DTDC vapor phase temperature 76 ℃. The optimized rice bran granulation and solvent extraction process can improve the quality of crude rice bran oil and meal, and reduce energy consumption.

ObjectiveIn the context of COVID-19 prevention and control， to summarize the current situation of the public health personnel team development against the pandemic at a county-level center for disease control and prevention （CDC） in Shanghai’s extra-large urban area， to analyze and summarize the current situation and existing problems of the public health personnel team of the district and county-level CDCs， and to propose measures to strengthen and improve the development.MethodsTaking the Shanghai Pudong New Area Center for Disease Control and Prevention， which serves a population of 5.68 millions， as an example， through information access， individual interviews， questionnaires， holding symposiums， etc.， combined with the deployment of personnel in the handling of the COVID-19， we described the Pudong New Area CDC’s talent team characteristics， personnel recruitment and loss， and investigated the factors affecting the construction of talent team.ResultsFrom 2014 to 2020， Pudong CDC recruited 115 people， and 65.71% of them chose to work there. 68 people resigned， with an average of 6.8 people leaving every year， with a fluctuating upward trend in resignation rate （χ2=0.158，P

A roof?rib pillar support system is often formed in the metal mines that applied to the backfill mining method. In order to ensure the safe mining, it is of great significance to explore the failure mechanism of the roof?rib pillar support system under backfill mining. On the basis of considering the side pressure effect of the backfill on the rib pillar, a mechanical model of the roof?rib pillar support system under backfill mining was established. Furthermore, the catastrophe theory was used to explore the failure mechanism of the supporting system under the action of the filling body, and the influence of the structural parameters of the support system before and after filling on the stability of the stope was analyzed. The research results show that under the condition of certain mechanical properties of the rock mass, the stability of the roof?rib pillar support system under backfill mining is controlled by the stope structure parameters (roof thickness, stope span, rib pillar width, rib pillar height), the overburden load and the side pressure of the backfill. The addition of the filling body will reduce the stiffness ratio of the support system, thereby improving the stability of the stope. When the stope is at an unfilled state, the optimization sequence of the structural parameters of the support system should be roof thickness, stope span, rib pillar width and rib pillar height. When the stope is at the state of filling, the optimization sequence should be roof thickness, rib pillar width, stope span, and rib pillar height. The combination of theoretical derivation and numerical simulation is applied in the supporting project to verify the correctness of theoretical derivation.

Yellow tea (YT), a slightly-fermented tea originated from Ming Dynasty with distinctive "Three yellows," mild-sweet smell, and mellow taste attributed to the unique yellowing process. Based on current literature and our previous work, we aim to comprehensively illustrate the key processing procedures, characteristic chemical compounds, health benefits and applications, as well as the interlocking relationships among them. Yellowing is the most vital procedure anchored on the organoleptic quality, characteristic chemical components, and bioactivities of YT, which is influenced by temperature, moisture content, duration, and ventilation conditions. Pheophorbides, carotenoids, thearubigins and theabrownins are the major pigments contributing to the "three yellows" appearance. Alcohols, such as terpinol and nerol, are attributed to the refreshing and sweet aroma of bud and small-leaf YT, while heterocyclics and aromatics forming during roasting result in the crispy rice-like large-leaf YT. Hygrothermal effects and enzymatic reactions during yellowing result in the decline of astringent substances. Meanwhile, multiple bioactive compounds such as catechins, ellagitannins, and vitexin, endow YT with antioxidant, anti-metabolic syndrome, anti-cancer, gut microbiota regulation, and organ injury protection effects. Future studies focusing on the standard yellowing process technology, quality evaluation system, and functional factors and mechanisms, possible orientations, and perspectives are guaranteed. [ABSTRACT FROM AUTHOR]