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To achieve on-site calibration of dose instruments, a calibration transmission system about ‘National standard metering station-Secondary standards laboratory-Position y monitor calibration’ aiming at environmental dose monitoring instrument is established using filtered X-rays. In order to obtain X-ray filtered spectrum of different dose rates, properties of original spectrum with 95 kV high voltage is simulated in Geant4, and the attenuation characteristics of signal material is analyzed, on this basis, multi-objective optimization model is established for various materials, the optimum filtering condition is gotten through solving model. Finally the results of the model are verified through experiment, and it meets the national standard requirement for filtered X-ray resource. This method has significant practical value for obtaining specific doses of X-ray filtered spectrum quickly and accurately.

In order to measure the surface contamination level effectively, the large area surface contamination measuring instrument is widely used. This research designs a thin-window flow gas proportional counter with 1000cm2 detecting area. When to achieve simultaneous measurement of α and β rays in using pulse-height discrimination technology, the selection of high voltage operation point for this detector can't follow the traditional method. As the voltage increases, β pulse-height increases, string to α channel, making the result more inaccuracy. Based on experiments, considered the limitation of the interference ratio in α+β count aerodromes, the operation point of detector was located near the head of plateau. Experimental results proved that the selection methods of the working point meet the regulation of national standard.

Gamma spectra is the fingerprint of uranium materials in the arms control verification technology. To calculate and analyse delayed gamma spectra of fission products, we simplified the decay chain into basic state linear chain and excitation state linear chain. We deduced formulas of the changing rule for nuclide number before and after zero-time. We made the C program to calculate the delayed gamma ray spectra data, and carried on related experiments to check our theory. By analysing some nuclides' delayed gamma counts, the calculated results are well consistent with the experiment values.

Generally, people use Monte Carlo and Geant4 methods to simulate the interactions of gamma photons with the detectors (NaI(Tl), Ge(Li), HPGe and so on), to calculate the response function of detecting system. But when they make separate lines of the measured spectra, energy peaks are hard to simulate for noise signals. In order to including noise signals from the statistical fluctuation of the detector, we designed some special differential functions to measure the gamma energy change for scattering effects, and to better record the accumulated counts in a constant energy region. We interpolated the ideal spectra with the use of designed differential functions. We presented some simulation results, which show that differential functions are effective even in energy spectra with low counts.

The total isotropic sensitivity (TIS) is one of important parameters of the mobile phone, and should be measured by developers and manufacturers. But measuring TIS would take a long time based on the stepping test technique of the Cellular Telecommunications & Internet Association (CTIA). The paper proposed an efficiency measurement method for TIS based on data predication. As the relationship between BER and Cell power is nonlinear, using exponential function, a math model is set up to describe this relationship. The unknown coefficients in the model can be determined by several sets of measurement data and the least square method. Then the TIS can be predicted using above math model. Finally, fast automatic measuring software is designed and the measurement results show that the proposed method keeps the precision but the measurement time is only 1/3 of the stepping test technique.

The simplified equivalent circuit models are set up for coupled microstrip lines without/with the defected ground structure(DGS) in this paper. Then using the equivalent circuit models, the effect of the DGS on even-and odd-mode impedances of coupled lines is analysed and the band broadening method for balun is summarized. Based on this theory, an improved DGS is presented to broaden the bandwidth of the planar balun. Finally, a sample of planar balun with the proposed DGS is designed, fabricated and measured. The measured return loss is better than -10dB from 1.3GHz to 4.5GHz, or 145% bandwidth, and shows good agreements with the simulated result. The results show that the balun with the DGS proposed here has a wider bandwidth and is smaller in size.

Nowadays, the bioelectromagnetic field has been accepted, and more and more scientists are concerned about the bioelectromagnetic effect from external electromagnetic field. But few scientists study the bioelectromagnetic spectrum, which features may be used to identify the living beings. In this paper, we give a method to measure the bioelectromagnetic field. At first, we study the theory of measuring the bioelectromagnetic signal. Furthermore, we designed an automatic test system (ATS) based on the theory. The automatic test software, an important part of the ATS, which can control the instruments such as spectrum analyzer, poisoning controllers, etc, is introduced by the diagram. Finally, the measurement data are calculated and recorded to a text file, which can be used to analyze the bioelectro-magnetic spectrum. We also display the 3D graph of the bioelec-tromagnetic field vs. each frequency, to study and view the direction of bioelectromagnetic field. The automatic system has been applied in our research about mice's bioelectromegnetic field test, and works well.

Traditional charge mode based on terminal voltage of batteries results in serious overcharge since status of battery cell is not known, it seriously shortens batteriespsila cycle life, even results in hidden trouble of safety. A new type of charge mode combining BMS (Battery Management Systems) and charger is presented in this paper. By data sharing between BMS and charger, the charger can known very well information about each batterypsilas voltage, temperature and failures, according to this, charger can adjust charging current. Therefore, it ensures no overcharge of any battery occurs and reduces influences that charging have on batteries, and increases safety of charging process. In this paper, principles of model parameter identification under the charge mode and an even more scientific consistency evaluation based on capacity and internal resistance are also elaborated.

In this paper the determination of radon concentration at fifteen sites of the air of underground establishment was measured by the SSTD. A distribution of radon concentration in the air of underground establishment between alpha particles and environment is plotted primarily. The measurements with the SSTD indicates that radon concentration in the air of underground establishment ranges from 66.4 to 1356 Bq/m3 with an average of 556.42Bqldrm-3. The experiment indicates that the kind of the new-style detector can detect radon level in the air of underground establishment exactly and effectively.

The electrical parameter deviation of GPS antenna patch base material is caused by the productive processes, and it influences on the performance of GPS antenna. A rapid test method for the electrical parameter deviation of GPS antenna patches is proposed in this paper. The design principle and the test apparatus are given in detail based on the stripline model. The test result shows the proposed method is efficiency and the test method is also convenient for large-scale manufacture.

During the design of GPS microtrip antenna, the axial ratio of antenna is a vital parameter, so it should be measured and assure it less than 2dB. In order to promoting the efficiency of testing, it's necessary to design an automatic test system for axial ratio. In this paper, an automatic test system based on GPIB and NI Labwindows/CVI for GPS microtrip antennas is discussed. With the automatic test system, we can measure the axial ratios automatically in the microwave anechoic chamber, which can reduce the electromagnetic interface outdoor. The tested axial ratio varied with measuring frequencies is displayed with the diagram of curve and tables. By the diagram we can judge intuitively if the frequency of the best axial ratio is on the GPS working frequency or not. If there is frequency shift, the shift direction can be a guidance to modify the GPS patch. The automatic test system has been used in our research center and works well.

In order to have a comprehensive understanding of the application and radioactivity level of fly ash in Xi'an DaTang thermoelectricity group, five samples were collected from fly ash stack of the group by quincunx collecting method. Natural radioactivity nuclide contents in the samples were measured by a low background anti-Compton HPGe Gamma spectrometer. The result was that the contents of 238U, 226Ra, 232Th 40K respectively were 67.6Bq/kg, 79.5Bq/kg, 72.7Bq/kg, 190Bq/kg. According to national standard GB6566-2001,the result indicates the radioactivity level of all the samples is at the common background level and the fly ash can be used as the A kind building materials. Finally, the future application of the fly ash in Xi'an DaTang thermoelectricity group was analyzed.

In order to know long-life radioactive aerosol's concentration in the atmosphere in three places of the area and evaluate radioactive environment's quality and the radioactive aerosol's infection to the teachers and students, we investigate radioactive aerosol's concentration in the working place, living place and teaching place of the area. The result shows that the radioactive aerosol's concentration of the area is under the country's control criterion.

The minimum energy consumption principle (MECP) is a general rule holding true for all systems such as life system, non-life system and linear balance or unbalance mechanics system, which is widely applied in the material mechanical science, biological science, even in society science. This paper is aimed to introduce this principle into the field of electromagnetics, and obtain a constraint condition for arbitrary non-dispersive loss medium parameters using MECP, which provide a new way to investigate the constraint relationship of complex electromagnetic medium

The constraint condition of the gyrotropic-like anisotropic media is obtained in this paper, based on the constraint relationship of arbitrary media parameters. Designing proper optimum functions, five complex constitutive parameters are reconstructed from the reflection and transmission coefficients of a plat model in free space for the normally and oblique incidence plane wave of two polarizations, in simulation, moreover, the noise has been considered. The results show that the longitudinal parameters are reconstructed correctly by using the free-space method. This provides a new way for reconstruction of arbitrary complex electromagnetic media.

A dual-layers measurement model of the same biaxial anisotropic medium is presented in this paper for the reconstruction of biaxial anisotropic medium parameters. The transmission and reflection formula are derived for this model. Some calculation results are obtained which are compared with the single-layer model. The results show that the double-layers model has more choices for measurement and some parameters are more sensitive to transmission and reflection than single layer model. These provided a measurement method to reconstruct the biaxial anisotropic medium parameters.

In this paper, the solution of moment method is to calculate KCS of arbitrarily partially coated conducting objects by using triangle-roof function as base function from the electromagnetic field integral equations. Some special numerical treatments have been proposed to improve the accuracy of calculation. The asymptotic waveform evaluation (AWE) technique is combined with the method of moment (MOM) is to realize the fast evaluation of RCS of arbitrarily partially coated conducting objects in a wide band. The theory is verified by numerical results.