A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL...A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.展开更多
Centrifugal atomization technique is internationally recognized as one of the most appropriate methods for obtaining uniform fine droplets, and also an advanced technology to get a narrower range of droplet particle s...Centrifugal atomization technique is internationally recognized as one of the most appropriate methods for obtaining uniform fine droplets, and also an advanced technology to get a narrower range of droplet particle spectrum. The importance and related mechanism of centrifugal atomization technique in the field of plant protection are expounded, and the overview of centrifugal atomization technique at home and abroad is introduced. Moreover, the direction of future research in this field is prospected.展开更多
The inception of radioisotope and its application in China are introduced. The research,development, production, application progress and the future development prospect of radioisotope and its products are described.
Sustainability is the ability to nurture or support a process for a long time without compromising the needs of future generations. Rather, sustainable chemistry is a term that refers to the production of chemical pro...Sustainability is the ability to nurture or support a process for a long time without compromising the needs of future generations. Rather, sustainable chemistry is a term that refers to the production of chemical products and processes that reduce or eliminate the use and production of hazardous substances. Green chemistry creates alternative technologies that are safer for human health and the environment to prevent further damage to human health and the environment, such as reducing the release of hazardous chemicals into the air, leading to reduced lung damage. Although sustainable and environmentally friendly technologies have evolved in other areas of science, their use in redox reactions and industry is still in its early stages. The current review aims to highlight the need for green chemistry as a sustainable chemistry and its principles and its application to produce environmentally friendly industrial products and to reduce or stop the production of harmful intermediates and products during its synthesis process.展开更多
Firstly,this paper introduced the special requirements of pesticide application technical equipment for the facility agriculture. Secondly,it analyzed domestic situation of pesticide application technical equipment fo...Firstly,this paper introduced the special requirements of pesticide application technical equipment for the facility agriculture. Secondly,it analyzed domestic situation of pesticide application technical equipment for the facility agriculture. Then,it discussed existing controlled droplet pesticide sprayer from operating principle,structural characteristics,and innovation points,and pointed out existing research findings and future research modules of the controlled droplet pesticide sprayer. Finally,in line with main research points and development direction of controlled droplet pesticide sprayer for the facility agriculture,it came up with pertinent recommendations and measures. It is intended to provide references for the application and development of pesticide application technical equipment for the facility agriculture in China.展开更多
研究采用真空感应气雾化(Vacuum Induction Gas Atomization,VIGA)技术制备GH4169合金粉末,系统探究气体温度对粉末特性的影响规律。结果表明,随着气体温度从100℃升高到600℃,粉末的粒度分布明显向左移动,D50由75μm减小到42μm。扫描...研究采用真空感应气雾化(Vacuum Induction Gas Atomization,VIGA)技术制备GH4169合金粉末,系统探究气体温度对粉末特性的影响规律。结果表明,随着气体温度从100℃升高到600℃,粉末的粒度分布明显向左移动,D50由75μm减小到42μm。扫描电子显微镜(Scanning Electron Microscope,SEM)分析表明,较高气体温度有助于提高粉末的球形度,减少卫星粉的生成。X射线衍射(X-Ray Diffraction,XRD)分析揭示,气体温度对粉末的物相组成影响不大,但是较高温度下粉末具有更高的结晶度和更大的晶粒尺寸。此外,粉末的流动性随气体温度的升高而显著改善。展开更多
基金supported by the National Natural Science Foundation of China under Grant 62034002 and 62374026.
文摘A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.
基金Supported by National Natural Science Foundation of China(31401296)Key Research and Development Plan of Jiangsu Province(Modern Agriculture)(BE2016303)Science and Technology Innovation Fund Project of Jiangsu Province[CX(14)2101]
文摘Centrifugal atomization technique is internationally recognized as one of the most appropriate methods for obtaining uniform fine droplets, and also an advanced technology to get a narrower range of droplet particle spectrum. The importance and related mechanism of centrifugal atomization technique in the field of plant protection are expounded, and the overview of centrifugal atomization technique at home and abroad is introduced. Moreover, the direction of future research in this field is prospected.
文摘The inception of radioisotope and its application in China are introduced. The research,development, production, application progress and the future development prospect of radioisotope and its products are described.
文摘Sustainability is the ability to nurture or support a process for a long time without compromising the needs of future generations. Rather, sustainable chemistry is a term that refers to the production of chemical products and processes that reduce or eliminate the use and production of hazardous substances. Green chemistry creates alternative technologies that are safer for human health and the environment to prevent further damage to human health and the environment, such as reducing the release of hazardous chemicals into the air, leading to reduced lung damage. Although sustainable and environmentally friendly technologies have evolved in other areas of science, their use in redox reactions and industry is still in its early stages. The current review aims to highlight the need for green chemistry as a sustainable chemistry and its principles and its application to produce environmentally friendly industrial products and to reduce or stop the production of harmful intermediates and products during its synthesis process.
基金Supported by State Key Research and Development Program of Ministry of Science and Technology(2017YFD0200303)China Agriculture Research System of Watermelon and Melon(CARS-25)Key Research and Development Program(Modern Agriculture)of Jiangsu Province(BE2016303)
文摘Firstly,this paper introduced the special requirements of pesticide application technical equipment for the facility agriculture. Secondly,it analyzed domestic situation of pesticide application technical equipment for the facility agriculture. Then,it discussed existing controlled droplet pesticide sprayer from operating principle,structural characteristics,and innovation points,and pointed out existing research findings and future research modules of the controlled droplet pesticide sprayer. Finally,in line with main research points and development direction of controlled droplet pesticide sprayer for the facility agriculture,it came up with pertinent recommendations and measures. It is intended to provide references for the application and development of pesticide application technical equipment for the facility agriculture in China.
文摘研究采用真空感应气雾化(Vacuum Induction Gas Atomization,VIGA)技术制备GH4169合金粉末,系统探究气体温度对粉末特性的影响规律。结果表明,随着气体温度从100℃升高到600℃,粉末的粒度分布明显向左移动,D50由75μm减小到42μm。扫描电子显微镜(Scanning Electron Microscope,SEM)分析表明,较高气体温度有助于提高粉末的球形度,减少卫星粉的生成。X射线衍射(X-Ray Diffraction,XRD)分析揭示,气体温度对粉末的物相组成影响不大,但是较高温度下粉末具有更高的结晶度和更大的晶粒尺寸。此外,粉末的流动性随气体温度的升高而显著改善。
