检索结果-南通市图书馆

Note on a new fundamental length scale l instead of the Newtonian constant G

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2011年第10期54卷 1771-1774页

作者： SHAO LiJing ma boqiang School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China Center for High Energy Physics Peking UniversityBeijing 100871China Center for History and Philosophy of Science Peking UniversityBeijing 100871China

The newly proposed entropic gravity suggests gravity as an emergent force rather than a fundamental one. In this approach,the Newtonian constant G does not play a fundamental role any more, and a new fundamental constant is required to replace itsposition. This request also arises from some philosophical considerations to contemplate the physical foundations for the unificationof theories. We here consider the suggestion to derive G from more fundamental quantities in the presence of a new fundamentallength scale l, which is suspected to originate from the structure of quantum space-time, and can be measured directly from Lorentz-violating observations. Our results are relevant to the fundamental understanding of physics, and more practically, of natural units,as well as explanations of experimental constraints in searching for Lorentz violation.

关键词： physical constants entropic gravity Lorentz violation

Sewage sludge disintegration by high-pressure homogenization: A sludge disintegration model

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2012年第5期24卷 814-820页

作者： Yuxuan Zhang Panyue Zhang panyue_zhang@*** boqiang ma Hao Wu Sheng Zhang Xin Xu Beijing Key Laboratory for Source Control Technology of Water Pollution Beijing Forestry University Beijing 100083 China

High-pressure homogenization （HPH） technology was applied as a pretreatment to disintegrate sewage sludge. The effects of homogenization pressure, homogenization cycle number, and total solid content on sludge disintegration were investigated. The sludge disintegration degree （DDCOD）, protein concentration, and polysaccharide concentration increased with the increase of homogenization pressure and homogenization cycle number, and decreased with the increase of sludge total solid （TS） content. The maximum DDCOD of 43.94% was achieved at 80 MPa with four homogenization cycles for a 9.58 g/L TS sludge sample. A HPH sludge disintegration model of DDCOD= kNaPb was established by multivariable linear regression to quantify the effects of homogenization parameters. The homogenization cycle exponent a and homogenization pressure exponent b were 0.4763 and 0.7324 respectively, showing that the effect of homogenization pressure （P） was more significant than that of homogenization cycle number （N）. The value of the rate constant k decreased with the increase of sludge total solid content. The specific energy consumption increased with the increment of sludge disintegration efficiency. Lower specific energy consumption was required for higher total solid content sludge.

关键词： high-pressure homogenization sludge disintegration homogenization pressure homogenization cycle number total solid content

Numerical simulation of granular silicon growth and silicon fines formation process in polysilicon fluidized bed

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第4期87卷 74-86页

作者： Guangkai Gu Guoqiang Lv Wenhui ma Shanlin Du boqiang Fu Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China State Key Laboratory of Complex Nonferrous Metal Resources Cleaning Utilization in Yunnan Province Kunming 650093China

Operating conditions strongly affect the yield and quality of polysilicon in a polysilicon fluidized *** this study,a new model of polysilicon fluidized bed was established using the Euler-Euler model coupled with population balance model(PBM),which was combined with fluid flow,heat,and mass transfer models,while considering the scavenging effect of silicon *** effects of different operating conditions on the deposition and formation rates of silicon fines were *** show that the model can correctly describe the particle growth process in the fluidized bed of *** silicon fines and the interphase velocity difference show"N"-and"M"-shaped distributions along the axial direction,*** particle temperature and concentration near the wall are higher than those in the central *** decomposition of silane in the bottom region of the bed is dominated by het-erogeneous *** scavenging of silicon fines occurs in the dilute-phase *** effects of operating conditions,*** gas temperature,silane composition,and gas velocity,on the reactor performance were also explored *** the inlet gas composition and velocity enhances the formation rates of solid silicon and *** the inlet gas temperature promotes the growth of solid silicon and inhibits the formation of silicon *** fluidization ratio,low inlet silane concentration,and high inlet gas temperature enhance the selectivity of silicon growth.

关键词： Polysilicon fluidized bed Particle growth Fines CFD Population balance model(PBM)

Mutual feedback between algal blooming and global warming

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2024年第3期42卷 787-801页

作者： Jianrong ma Guijun YANG Xianfu ZHAO boqiang QIN Kun SHAN Botian ZHOU Yan ZENG Jingfu WANG Jingan CHEN Chongqing Institute of Green and Intelligent Technology Chinese Academy of SciencesChongqing 400714China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550002China School of Environment and Ecology Jiangnan UniversityWuxi 214122China Key Laboratory of Ministry of Water Resources for Ecological Impacts of Hydraulic-projects and Restoration of Aquatic Ecosystem Institute of HydroecologyMinistry of Water Resources&Chinese Academy of SciencesWuhan 430079China State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China

Global warming and algal blooms have been two of the most pressing problems faced by the world *** recent decades,numerous studies indicated that global warming promoted the expansion of algal ***,research on how algal blooms respond to global warming is *** warming coupled with eutrophication promoted the rapid growth of phytoplankton,which resulted in an expansion of algal *** blooms are affected by the combined effects of global warming,including increases in temperatures,CO_(2)concentration,and nutrient input to aquatic systems by extreme weather *** the growth of phytoplankton requires CO_(2),they appear to act as a carbon ***,algal blooms will release CH4,CO_(2),and inorganic nitrogen when they die and *** substrate nitrogen increases from decompose algal biomass,more N2O will be released by nitrification and *** comparison to CO_(2),CH4has 28-fold and N2O has 265-fold greenhouse ***,algal blooms in the polar regions may contribute to melting glaciers and sea ice(will release greenhouse gas,which contribute to global warming)by reducing surface albedo,which consequently would accelerate global ***,algal blooms and global warming could form feedback loops which prevent human survival and *** researches shall examine the mechanism,trend,strength,and control strategies involved in this mutual ***,it will promote global projects of environmental protection combining governance greenhouse gas emissions and algal blooms,to form a geoengineering for regulating the cycles of carbon,nitrogen,and phosphorus.

关键词： climate change carbon neutrality eutrophication greenhouse gas glaciers melting geoengineering

TWO-LEVEL CONVOLUTlON FORMULA FOR NUCLEAR STRUCTURE FUNCTION

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1990年第5期7卷 208-211页

作者： ma boqiang Institute of High Energy Physics Academia SinicaBeijing 100039

A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons *** results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions.

关键词： quark Fermi meson

Preparation of(Lu,Y)_(3)(Al,Sc,Cr)_(2)Al_(3)O_(12)phosphor ceramics with high thermal stability for near-infrared LED/LD

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第3期13卷 354-363页

作者： Yuelong ma Xingcan Li Lan Wu Chenyang Shao boqiang Zhang Tao Pang Lili Lu Hui Qiu Ye Tian Guilu Wang Yanbo Hui Qianwen Guo Daqin Chen School of Mechanical and Electrical Engineering Henan University of TechnologyZhengzhou 450001China Huzhou Key Laboratory of materials for Energy Conversion and Storage College of ScienceHuzhou UniversityHuzhou 313000China College of Physics and Energy Fujian Normal UniversityFuzhou 350117China SongShan Laboratory Zhengzhou 450046China College of Food Science and Engineering Henan University of TechnologyZhengzhou 450046China School of Mechanical Engineering Zhengzhou University of Science and TechnologyZhengzhou 450064China

Near-infrared(NIR)phosphor-converted light-emitting diodes/laser diodes(LEDs/LDs)are prospective lighting sources for NIR ***,developing NIR phosphor materials with desired thermal robustness and high photoelectric efficiency is a crucial challenge for their *** this work,based on the cationic radius matching effect,a series of(Lu,Y)_(3)(Al,Sc,Cr)_(2)Al_(3)O_(12)NIR phosphor ceramics(LuYScCr NIR-PCs)were fabricated by vacuum *** thermal stability(95%@150℃)was obtained in the prepared NIR-PCs,owing to their weak electron-phonon coupling effect(small Huang-Rhys factor).Being excited at 460 nm,NIR-PCs realized a broadband emission(650-850 nm)with internal quantum efficiency(IQE)of 60.68%.Combining NIR-PCs with LED/LD chips,the maximum output power of the encapsulated LED prototype was 447 mW@300 ma with photoelectric efficiency of as high as 18.6%@180 ma,and the maximum output power of the LD prototype was 814 mW@2.5 *** working temperatures of NIR-PCs were 70.8℃@300 ma(LED)and 102.8℃@3 A(LD).Finally,the prepared NIR-PCs applied in food detection were verified in this study,demonstrating their anticipated application prospects in the future.

关键词： thermal stability electron phonon coupling effect photoelectric efficiency near-infrared phosphor ceramics(NIR-PCs) NIR light-emitting diode/laser diode(LED/LD)prototype

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Λ超子碎裂函数的夸克味分离

高能物理与核物理 2000年第3期24卷 196-202页

作者：马伯强黄新兵 Jacques Soffer 中国科学院高能物理研究所北京100039 Centre de Physique Theorique CNRS Marseille France

利用有非极化和极化的Ａ和Ａ超子产生的中微子和反中微子的深度非弹性散射，可以清晰地测量各种味的夸克变为Ａ超子的各种非极化和极化的碎裂函数，也就是得到了碎裂函数的夸克味分离．这种方法不但适用于轻味夸克。反夸克，也适用于奇... 详细信息

利用有非极化和极化的Ａ和Ａ超子产生的中微子和反中微子的深度非弹性散射，可以清晰地测量各种味的夸克变为Ａ超子的各种非极化和极化的碎裂函数，也就是得到了碎裂函数的夸克味分离．这种方法不但适用于轻味夸克。反夸克，也适用于奇异夸克ｓ和ｓ．和产生Ａ和Ａ的极化电子的深度非弹性散射结合起来，人们就能够系统地测量或核实各种味和各种自旋的夸克的相关碎裂函数．这样的测量给有关强子的自旋结构和核子海的夸克一反夸克不对称性的各种预言提供判决性的实验．

关键词： Λ超子夸克味分离深度非弹性散射碎裂函数

在线全文

学校读者我要写书评

暂无评论

首位数规律在物理学中的应用

科技导报 2010年第18期28卷 98-102页

作者：邵立晶马伯强北京大学物理学院核物理与核技术国家重点实验室北京100871

自然世界数据库中的首位非零数字并不以1～9的等概率出现,而是符合一个对数分布,即Benford定理。在研究该定理在粒子物理与天体物理中的表现时发现,粒子物理中的强子宽度与寿命、脉冲星中的功率与运动等多类物理量均符合Benford分布;统... 详细信息

自然世界数据库中的首位非零数字并不以1～9的等概率出现,而是符合一个对数分布,即Benford定理。在研究该定理在粒子物理与天体物理中的表现时发现,粒子物理中的强子宽度与寿命、脉冲星中的功率与运动等多类物理量均符合Benford分布;统计物理中的三大正则统计——玻尔兹曼-吉布斯统计、费米-狄拉克统计和玻色-爱因斯坦统计均解析满足首位数规律。本文简介了首位数定理,阐述了其在粒子物理、脉冲星中的应用,讨论其标度不变性、整数幂次不变性、基数不变性等性质,最后分析了三大物理统计中的首位数规律。如何更好地理解Benford定理这个"百年难题",探讨首位数分布的自然规律,还需要更多的后续研究。

关键词：统计物理首位数强子宽度脉冲星

在线全文

学校读者我要写书评

暂无评论

圆球型电石渣反应料处理煤矿酸性废水

环境工程学报 2015年第8期9卷 3889-3894页

作者：邵保钧瞿丽雅康媞马博强许璟贵州师范大学地理与环境科学学院贵阳550001 贵州省楚天环境工程技术研究中心贵阳550081 贵州省环境保护厅贵阳550002

采用电石渣制备成圆球型反应料,通过多级处理式实验装置对煤矿酸性废水进行处理.研究了在不曝气和曝气2组实验情况下处理出水的pH变化特征和反应料去除铁、锰的效果.结果表明,在不曝气组,当水力停留时间（HRT）为17.6 h,总出水pH值由进... 详细信息

采用电石渣制备成圆球型反应料,通过多级处理式实验装置对煤矿酸性废水进行处理.研究了在不曝气和曝气2组实验情况下处理出水的pH变化特征和反应料去除铁、锰的效果.结果表明,在不曝气组,当水力停留时间（HRT）为17.6 h,总出水pH值由进水2.84～2.95提高到4.17～11.88,总出水铁平均浓度80.43 mg/L,平均去除率为72.87％,锰平均浓度6.16 mg/L,平均去除率48.21％.在曝气组,当HRT为17.6 h,曝气量为10.50L/min,总出水pH值由进水2.84 ～ 3.00提高到9.10 ～11.87,总出水铁平均浓度0.03 mg/L,平均去除率为99.99％,锰平均浓度0.14 mg/L,平均去除率为98.72％.因此,利用圆球型电石渣反应料去除煤矿酸性废水中的铁、锰以及提高pH有很好的效果.

关键词：圆球型电石渣煤矿酸性废水曝气铁锰