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Liulin Type Instruments
Liulin-type is a class of spectrometry-dosimetry instruments. History The first Liulin device was developed in 1986–1988 time period for the scientific program of the second Bulgarian cosmonaut for the flight on MIR space station. All Liulin type dosimetric instruments use one or more silicon detectors and measure the deposited energy and number of particles into the detector(s) when charged particles hit the device, that allowing it to calculate the dose rate and particle flux. The measurements in the LIULIN instrument were based on a single silicon detector followed by a charge-sensitive shaping amplifier (CSA). The number of the pulses at the output of CSA above a given threshold was proportional to the particle flux hitting the detector; the amplitude of the pulses at the output of CSA was proportional to the particles deposited energy. Further the integral In mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LIULIN
Liulin ( is a county of western Shanxi province, China, bordering Shaanxi province and the Yellow River to the west. It is under the administration of Lüliang city. The county is the site of the Xiangyan Temple ( zh). Liulin has been inhabited since the Neolithic era. During the Han dynasty the county seat was in Mengmen town. It is the birthplace of Lin Xiangru and Red Army general He Chang ( 贺昌). It has historically been a trade town between the Central Plains and the Silk Road. It is a center of coal industry, jujube Jujube (), sometimes jujuba, known by the scientific name ''Ziziphus jujuba'' and also called red date, Chinese date, and Chinese jujube, is a species in the genus ''Ziziphus'' in the buckthorn family Rhamnaceae. Description It is a smal ... and walnut cultivation. Its regional cuisines include Liulin Wantuan, a steamed buckwheat noodle, and sesame cakes. Administrative divisions Climate Referenceswww.xzqh.org See also * Wang Ning, coun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Spectrometry
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures. A mass spectrum is a type of plot of the ion signal as a function of the mass-to-charge ratio. These spectra are used to determine the elemental or isotopic signature of a sample, the masses of particles and of molecules, and to elucidate the chemical identity or structure of molecules and other chemical compounds. In a typical MS procedure, a sample, which may be solid, liquid, or gaseous, is ionized, for example by bombarding it with a beam of electrons. This may cause some of the sample's molecules to break up into positively charged fragments or simply become positively charged without fragmenting. These ions (fragments) are then separated accordin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dosimetry
Radiation dosimetry in the fields of health physics and radiation protection is the measurement, calculation and assessment of the ionizing radiation dose absorbed by an object, usually the human body. This applies both internally, due to ingested or inhaled radioactive substances, or externally due to irradiation by sources of radiation. Internal dosimetry assessment relies on a variety of monitoring, bio-assay or radiation imaging techniques, whilst external dosimetry is based on measurements with a dosimeter, or inferred from measurements made by other radiological protection instruments. Dosimetry is used extensively for radiation protection and is routinely applied to monitor occupational radiation workers, where irradiation is expected, or where radiation is unexpected, such as in the aftermath of the Three Mile Island, Chernobyl or Fukushima radiological release incidents. The public dose take-up is measured and calculated from a variety of indicators such as ambient measure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulgarian Cosmonaut Program
The Bulgarian cosmonaut program refers to human spaceflight efforts by the People's Republic of Bulgaria. The idea of a Bulgarian manned space mission predated the launch of ''Sputnik 1'', the first artificial satellite. An informal proposal for the Soviet Union to send a Bulgarian cosmonaut in space was issued in 1964, but it was not seriously considered by the Soviets. Official space cooperation began in 1966 with the establishment of the Interkosmos programme which allowed Communist Bloc countries to access Soviet space technology and assets. Under Interkosmos, Bulgaria sent its first cosmonaut, Georgi Ivanov, to the Salyut 6 space station in 1979 and became the sixth country in the world to have a citizen in space. However, a malfunction in his Soyuz 33 spacecraft prevented the crew from docking, and Ivanov only spent 31 orbits around Earth before safely descending back to Earth. A second Bulgarian cosmonaut, Aleksandar Aleksandrov, spent ten days on the Mir Space Station in 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIR Space Station
''Mir'' (russian: Мир, ; ) was a space station that operated in low Earth orbit from 1986 to 2001, operated by the Soviet Union and later by Russia. ''Mir'' was the first modular space station and was assembled in orbit from 1986 to 1996. It had a greater mass than any previous spacecraft. At the time it was the largest artificial satellite in orbit, succeeded by the International Space Station (ISS) after ''Mir'''s orbital decay, orbit decayed. The station served as a microgravity research laboratory in which crews conducted experiments in biology, human biology, physics, astronomy, meteorology, and spacecraft systems with a goal of developing technologies required for permanent occupation of Outer space, space. ''Mir'' was the first continuously inhabited long-term research station in orbit and held the record for the longest continuous human presence in space at 3,644 days, until it was surpassed by the ISS on 23 October 2010. It holds the record for the longes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Detector
A semiconductor detector in ionizing radiation detection physics is a device that uses a semiconductor (usually silicon or germanium) to measure the effect of incident charged particles or photons. Semiconductor detectors find broad application for radiation protection, gamma and X-ray spectrometry, and as particle detectors. Detection mechanism In semiconductor detectors, ionizing radiation is measured by the number of charge carriers set free in the detector material which is arranged between two electrodes, by the radiation. Ionizing radiation produces free electrons and electron holes. The number of electron-hole pairs is proportional to the energy of the radiation to the semiconductor. As a result, a number of electrons are transferred from the valence band to the conduction band, and an equal number of holes are created in the valence band. Under the influence of an electric field, electrons and holes travel to the electrodes, where they result in a pulse that can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charged Particle
In physics, a charged particle is a particle with an electric charge. It may be an ion, such as a molecule or atom with a surplus or deficit of electrons relative to protons. It can also be an electron or a proton, or another elementary particle, which are all believed to have the same charge (except antimatter). Another charged particle may be an atomic nucleus devoid of electrons, such as an alpha particle. A plasma is a collection of charged particles, atomic nuclei and separated electrons, but can also be a gas containing a significant proportion of charged particles. Charges are arbitrarily labeled as ''positive''(+) or ''negative''(-). Only the existence of two 'types' of charges is known, there isn't anything inherent about positive charges that makes them positive, and the same goes for the negative charge. Examples Positively charged particles * protons and atomic nuclei * positrons (antielectrons) * alpha particles * positive charged pions * cations Negatively c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dose Rate
A dose rate is quantity of radiation absorbed or delivered per unit time. It is often indicated in micrograys per hour (µGy/h) or as an equivalent dose rate ḢT in rems per hour (rem/hr) or sievert The sievert (symbol: SvNot be confused with the sverdrup or the svedberg, two non-SI units that sometimes use the same symbol.) is a unit in the International System of Units (SI) intended to represent the stochastic health risk of ionizing radi ...s per hour (Sv/h). Dose and dose rate are used to measure different quantities in the same way that distance and speed are used to measure different quantities. When considering stochastic radiation effects, only the total dose is relevant; each incremental unit of dose increases the probability that the stochastic effect happens. When considering deterministic effects, the dose rate also matters. The total dose can be above the threshold for a deterministic effect, but if the dose is spread out over a long period of time, the effect i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplifier
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It may increase the power significantly, or its main effect may be to boost the voltage or current (power, voltage or current amplifier). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals, producing a greater amplitude signal at its output. The ratio of output to input voltage, current, or power is termed gain (voltage, current, or power gain). An amplifier, by definition has gain greater than unity (if the gain is less than unity, the device is an attenuator). An amplifier can either be a separate piece of equipment or an electrical circuit contained within another device. Amplification is fundamental to modern electronics, and amplifiers are widely used in almost all electronic equipment. Amplifiers can be categorize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplitude
The amplitude of a periodic variable is a measure of its change in a single period (such as time or spatial period). The amplitude of a non-periodic signal is its magnitude compared with a reference value. There are various definitions of amplitude (see below), which are all functions of the magnitude of the differences between the variable's extreme values. In older texts, the phase of a periodic function is sometimes called the amplitude. Definitions Peak amplitude & semi-amplitude For symmetric periodic waves, like sine waves, square waves or triangle waves ''peak amplitude'' and ''semi amplitude'' are the same. Peak amplitude In audio system measurements, telecommunications and others where the measurand is a signal that swings above and below a reference value but is not sinusoidal, peak amplitude is often used. If the reference is zero, this is the maximum absolute value of the signal; if the reference is a mean value (DC component), the peak amplitude is the maximu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integral
In mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ..., an integral assigns numbers to functions in a way that describes Displacement (geometry), displacement, area, volume, and other concepts that arise by combining infinitesimal data. The process of finding integrals is called integration. Along with Derivative, differentiation, integration is a fundamental, essential operation of calculus,Integral calculus is a very well established mathematical discipline for which there are many sources. See and , for example. and serves as a tool to solve problems in mathematics and physics involving the area of an arbitrary shape, the length of a curve, and the volume of a solid, among others. The integrals enumerated here are those termed definite integrals, which can be int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific Instruments
A scientific instrument is a device or tool used for scientific purposes, including the study of both natural phenomena and theoretical research. History Historically, the definition of a scientific instrument has varied, based on usage, laws, and historical time period. Before the mid-nineteentcenturysuch tools were referred to as "natural philosophical" or "philosophical" apparatus and instruments, and older tools from antiquity to the Middle Ages (such as the astrolabe and pendulum clock) defy a more modern definition of "a tool developed to investigate nature qualitatively or quantitatively." Scientific instruments were made by instrument makers living near a center of learning or research, such as a university or research laboratory. Instrument makers designed, constructed, and refined instruments for purposes, but if demand was sufficient, an instrument would go into production as a commercial product. In a description of the use of the eudiometer by Jan Ingenhousz to show ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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