查询词典 particle physics

The main research work of this paper are focused on following areas:(1) Based on review of the theory and methods on measurements of particle fields, a new idea for obtaining particle size and velocity distribution within a spray through imaging the particle field with a laser light sheet was put forward;(2) A DPIV (Digital Particle Image Velocimetry) system, is fit for velocity measurements of low speed flows, was developed and expended to particle size distribution measurement;(3) An arithmetic for particle velocity field reconstruction was developed, and the velocity distribution of water mist was also obtained;(4) A software system for particle analysis, which based on image geometry emend, de-noise and image partition was developed, the parameters such as particle size distribution, mean diameter, number of particles, minimum and maximum diameter can be got with this system;(5) A water mist system was developed and its characteristics, such as droplet velocity, size distribution, number of droplets and spray cone angle under different conditions were obtained from experiments with PIVS;(6) The measurement results of water mist characteristics with PIVS were compared and analyzed with the simply simulated results, and in addition, in order to verify the accuracy of PIVS, some experiments were conducted with the standard particles, such as glass-ball with known mean diameter of 50μm and 115μm, metallic coated tracing particle with mean diameter of 12μm;(7) Some experimental studies on interaction of water mist with liquid pool fires were conducted.

本论文的主要工作包括以下几个方面：（1）在对粒子场测量的相关理论和具体方法进行综述分析的基础上，提出了通过采用激光片光对粒子场进行成像以获取其粒径和速度等参数分布的新思路；（2）研制了适宜于低速流动速度场测量的DPIV(Digital Particle Image Velocimetry)系统，并使其实现了对粒子场粒径分布的测量功能；（3）研制了基于粒子运动轨迹的速度场重建算法，获取了细水雾雾场的速度分布；（4）研制了基于几何校正、去噪、图象分割等图象处理方法的"粒度分析软件系统"，该系统既可分析给出粒子场的粒径分布直方图和平均粒径，还可给出粒子的数目以及最大、最小粒径等信息；（5）建立了一细水雾发生系统，并应用上述方法对不同压力条件下细水雾系统的雾场特性（如速度分布、雾滴粒径分布、雾滴的数目、喷雾张角以及雾化长度等）进行了实验测量研究；（6）对细水雾特性参数的PIVS测量结果与计算机简单模拟计算结果进行了定性比较分析，并利用平均粒径为50μm和115μm的玻璃球以及12μm的标准示踪粒子对PIVS系统的粒径和速度测量结果进行了实验验证，同时对其局限性进行了分析讨论；（7）对不同工况条件下细水雾与油池火相互作用的过程进行了模拟实验研究。

The BEijing Spectrometer is an only large general purpose solenoidal detector at the BEPC, on which the physics is to study e+e- collide physics in 2-5GeV region , the emphasis is in the τ-charm physics and the topics include J/ψ physics,ψ(2S) physics, T physics, Ds physics, D physics and hadrons generation mechanism as well as the test of QCD in 2-5GeV.

经过中外科学家的共同努力，在北京谱仪上已作出了包括"τ轻子质量的精密测量"、"2-5GeV能区的R值测量"，以及在J／ψ、ψ(2S)、Ds介子等物理研究中的多项国际领先水平的重要科研成果，引起了国际高能物理界的普遍重视和广泛关注。

The mainly conclusions in our research are as flowing: tungsten trioxide powders with 100 nm primary particle are obtained by spray drying,calcination and wet milling process, and an average size of quadric particle composed of agglomerated particles is 0.64 μm; tungtsen powders with 39 nm grain size and 60 -100 nm primary particle are produced directly from previous tungsten trioxide using one step reduction in hydrogen at 700℃, and an average size of quadric particle of tungsten powder is 2.91 μm; tungsten trioxide and copper tungstate compound powders with 100 nm - 200 nm primary particle are produced using ammonia metatungsten and copper nitrate as raw materials by spray drying,calcination and wet milling process;the compound powders are transformed completely into tungsten and copper compound powders by reduction in hydrogen at 700℃,in which tungsten grain size is 59 nm and copper grain size is 51 nm; primary particle size of compound powders is 80 - 120 nm,and an average size of agglomerated quadric particle is 1.86 μm; tungsten nitride powders with 35 nm grain size are prepared from tungsten trioxide powders by nitrogen treatment thoroughly in pure ammonia at 650℃, and an average size of agglomerated quadric particle is 0.64 μm in normal temperature.

研究结果表明：采用喷雾干燥—焙烧—球磨工艺可以制备出粒度约为100nm的WO_3粉体，它们在团聚后形成的二次颗粒平均粒度为0.64μm；采用一步直接氢还原方法可在700℃下从上述WO_3粉体制备出晶粒尺寸为39nm的、一次颗粒粒度为60-100nm的W粉体，其二次颗粒的平均粒度为2.91μm；以偏钨酸铵、硝酸铜为原料，采用喷雾干燥—焙烧—球磨工艺可制备出一次粒度为100-200nm的WO_3和CuWO_4混合粉体；采用氢还原工艺可在700℃下将这种粉体完全转变为W、Cu复合粉体，其中W的平均晶粒粒尺寸为59nm，Cu的平均晶粒尺寸为51nm；复合粉体的一次颗粒尺寸为80-120nm，在常温下团聚后形成的二次平均粒度为1.86μm；采用纯氨氮化工艺可以在650℃下由WO_3粉体制得WN，其晶粒尺度为35nm，在常温下团聚后的二次平均粒度为6.4μm。

Modem medical physics should include 4 parts, medical imaging physics, nuclear medicine physics, radiation oncology physics, and health physics.

国际相关业界公认，现代医学物理学必须涵盖医学影像物理、肿瘤放射治疗物理、核医学物理和保健物理等重要内容。

In this paper, we mainly study the two problems of teaching and learning physics conception in basic physics, which is relate to Physics of middle school as well as the physics knowledge in the Course Nature of elementary school and General Physics of college.

本文主要研究基础物理中的物理概念的教与学两个方面的问题。本文所指基础物理主要是指中学物理，也泛指小学自然课中的物理知识和中专物理以及大学普通物理。

Secondly, relations between the structuralism and physics teaching illustrate that the physics history can play the role of "advanced organizer" in improving the transfer ability. Moreover, the theory of recapitulation of physics announces the inherent similarity between the process of physics research and the process of physics conception learning. According to constructivist learning theories, the dissertation explains the process of students' learning the scientific concepts.

首先论文通过分析比较皮亚杰认知发展论和库恩科学发展论得出教育实践应与科学发展规律保持一致，应重视物理学史在物理教学中的应用，对于不同认知水平的学生和不同类型的知识应采用不同的教学方法：其次从结构主义与物理教学的关系说明物理学史在提高迁移能力上可以扮演"先行组织者"的角色；再次，通过物理文化重演理论揭示人类研究物理学的过程与学生学习物理概念的过程的内在相似性，并根据建构主义学习理论解释学生学习科学概念的过程。

Phys. The science of matter and energy and of interactions between the two, grouped in traditional fields such as acoustics, optics, mechanics, thermodynamics, and electromagnetism, as well as in modern extensions including atomic and nuclear physics, cryogenics, solid-state physics, particle physics, and plasma physics.

物理，物理学：有关物质和能量及两者之间相互作用的科学，传统上分为声学、光学、机械学、热力学和电磁学，现今又扩展到包括原子物理、核物理、低温学、固体物理学、微粒物理学和等离子体物理学

Since 1957 Lee's "weak interaction in the parity nonconservation" concept was experimental and that shared the Nobel Prize in Physics; its 1954 proposed standard field theory, in the 1970s developed into integration and understanding elementary particle strong and weak, and electromagnetic interactions of the three foundation are also in the statistical physics, condensed matter physics, quantum field theory, mathematical physics in a number of outstanding major contribution.

著名美籍华裔科学家、物理学大师、诺贝尔物理学奖获得者。1957年由于与李政道提出的&弱相互作用中宇称不守恒&观念被实验证明而共同获得诺贝尔物理学奖；其于1954年提出的规范场理论，则于70年代发展成为统合与了解基本粒子强、弱、电磁等三种相互作用力的基础；此外并曾在统计物理、凝聚态物理、量子场论、数学物理等领域作出多项卓越的重大贡献。

People through nuclear reactions, have been synthesized 17 kinds of atomic number greater than 92 of the transuranic elements, and thousands of The new kinds of radioactive nuclides, and by high-energy and ultra-high energy-ray beam and the interaction of atomic nuclei and found hundreds of kinds of short-lived particles, namely, baryon, meson, lepton, and particle resonance states of these particles has led to a new field of study - the birth of particle physics since the age of .70, nuclear physics has entered a deep development and wide application of new, more mature stage, on the one hand the development of particle acceleration and detection techniques, expanding people's research in nuclear means, the other hand, nuclear technology to serve the national economy, for example, for the development and utilization of nuclear energy to provide more accurate nuclear data; the use of isotope tracer technique diagnosis and treatment of disease; the use of radiation and irradiation preservation of food, irradiation breeding .

人们通过核反应，已经人工合成了17种原子序数大于92的超铀元素和上千种新的放射性核素，并且通过高能和超高能射线束和原子核的相互作用，发现了上百种短寿命粒子、即重子、介子、轻子和共振态粒子，对这些粒子的研究导致了一门新学科——粒子物理学的诞生。70年代以来，核物理进入了纵深发展和广泛应用的新的更成熟的阶段，一方面发展粒子的加速技术和探测技术，扩充人们研究原子核的手段，另一方面将核技术服务于国民经济中，例如，为核能的开发利用提供更为准确的核数据；利用同位素示踪技术诊断和治疗疾病；利用射线及辐照技术保存食品、辐照育种等。

The study shows that in the radial direction the dynamic forces acting on the particle balance on the particle itself; there is not a so-called trajectory of the particle in which the composition of forces acting on the particles is zero, but there is a trajectory of the particle in which the radial slip velocity of particle is zero, the tra...

通过对固体颗粒的运动和受力分析发现固体颗粒在沉降过程中径向合力几乎处处为零，不存在所谓的径向合力为零的一个平衡轨迹面，但存在着一个径向沉降速度为零的轨迹面，这一轨迹面就是平衡轨迹面法所要寻找的；首次推导出了该轨迹面半径与固体颗粒直径、水力旋流器自身几何参数以及操作参数之间的定量表达式。

More direct, directer ; most direct, directest

径直的，笔直的

Do you know how to use a chain saw?

你知道如何使用链锯吗？