[Review on Analytical Methods of Doping Elements in Synthetic Crystals].

During the synthesis of crystal material, specific dopant can enhance the qualities and performance of crystals, while the types, concentrations and distributions of doping elements also have significant influence on the structures and properties of artificial crystals. Hence, it is very important to determine the concentrations of doping elements for further improving the crystal material formulas, crystal growth process, andits quality control. Currently, the analysis techniques for doping elements' characterization include atomic spectrometry, X-ray fluorescence spectrometry, inorganic mass spectrometry, electron probe microanalysis, etc. The principles, advantages and disadvantages of these techniques are discussed in this paper. Considering the specialties and scope of application, it is necessary to choose the suitable methods to improve the efficiency and accuracy. Meanwhile, the developing trends of analysis methods for doping elements are also prospected.

[Quantitative surface analysis of Pt-Co, Cu-Au and Cu-Ag alloy films by XPS and AES].

In order to improve the quantitative analysis accuracy of AES, We associated XPS with AES and studied the method to reduce the error of AES quantitative analysis, selected Pt-Co, Cu-Au and Cu-Ag binary alloy thin-films as the samples, used XPS to correct AES quantitative analysis results by changing the auger sensitivity factors to make their quantitative analysis results more similar. Then we verified the accuracy of the quantitative analysis of AES when using the revised sensitivity factors by other samples with different composition ratio, and the results showed that the corrected relative sensitivity factors can reduce the error in quantitative analysis of AES to less than 10%. Peak defining is difficult in the form of the integral spectrum of AES analysis since choosing the starting point and ending point when determining the characteristic auger peak intensity area with great uncertainty, and to make analysis easier, we also processed data in the form of the differential spectrum, made quantitative analysis on the basis of peak to peak height instead of peak area, corrected the relative sensitivity factors, and verified the accuracy of quantitative analysis by the other samples with different composition ratio. The result showed that the analytical error in quantitative analysis of AES reduced to less than 9%. It showed that the accuracy of AES quantitative analysis can be highly improved by the way of associating XPS with AES to correct the auger sensitivity factors since the matrix effects are taken into account. Good consistency was presented, proving the feasibility of this method.

[Analytical figures of merit of Hildebrand grid and ultrasonic nebulizations in inductively coupled plasma atomic emission].

Hildebrand grid nebulizer is a kind of improved Babington nebulizer, which can nebulize solutions with high total dissolved solids. And the ultrasonic nebulizer (USN) possesses advantage of high nebulization efficiency and fine droplets. In the present paper, the detection limits, matrix effects, ICP robustness and memory effects of Hildebrand grid and ultrasonic nebulizers for ICP-AES were studied. The results show that the detection limits using USN are improved by a factor of 6-23 in comparison to Hildebrand grid nebulizer for Cu, Pb, Zn, Cr, Cd and Ni. With the USN the matrix effects were heavier, and the degree of intensity enhancement and lowering depends on the element line, the composition and concentrations of matrices. Moreover, matrix effects induced by Ca and Mg are more significant than those caused by Na and Mg, and intensities of ionic lines are affected more easily than those of atomic lines. At the same time, with the USN ICP has less robustness. In addition, memory effect of the USN is also heavier than that of Hildebrand grid nebulizer.

[Effect of cultivation for snail control on schistosomiasis in Changsha urban section of Xiangjiang River].

OBJECTIVE: To study a reliable, friendly environmental and sustainable Oncomelania snail control method in marshlands of the Xiangjiang River. METHODS: According to the special characteristics of the marshlands of the Xiangjiang River, smoothing and cultivating in beaches were applied for snail control. In sections with scarce distribution of snails, lowering parts of 4.4 beaches and raising other parts were added. RESULTS: Since 2003, the project has been practiced for 8 years. The average snail density declined by 99.83% with the simple smoothing beaches and then cultivation there. The average snail density declined by 100% with lowering parts of beaches and raising other parts and then cultivation. The schistosome infection rate was 0.31% with a declined rate of 93.84% in residents in 2006. The schistosome infection rate was 1.03% in 2010. The test result of water contamination was negative. CONCLUSIONS: The method of simple smoothing beaches and then cultivation can control the density of snails in marshlands and the method of lowering parts of beaches and raising other parts and then cultivation is more effective.

Home blood pressure measurement in prehypertension and untreated hypertension: comparison with ambulatory blood pressure monitoring and office blood pressure.

OBJECTIVES: (i) To explore blood pressure (BP) baseline characteristics in prehypertension (PH) and untreated essential hypertension (HT), and (ii) to evaluate whether simple home blood pressure (HBP) measurement can provide more reliable BP information than office blood pressure (OBP) in PH and untreated essential HT, and (iii) to investigate whether HBP measurement can also satisfactorily screen out masked hypertension (MH) and white-coat hypertension (WCH) by comparing with ambulatory blood pressure (ABP) monitoring. METHODS: We recruited 122 Beijing community volunteers. According to OBP measurement, they were divided into three groups, including PH group (n=51), stage 1 HT group (HT-1, n=51) and stage 2 HT group (HT-2, n=20). We calculated average OBP, HBP, and ABP, detection rate of MH, WCH, and nondipper status percentage in each group. RESULTS: Nondipper status percentage of PH, HT-1, and HT-2 was 54.9, 45.1, and 75%, respectively. Except for diastolic blood pressure difference between HBP and ABP, the others did not reach statistical significance. ABP correlated more strongly with HBP than OBP. Detection rate of MH in PH participants by HBP and ABP was 49.0 and 52.9% (P=0.56), respectively, and MH diagnostic agreement between ABP and HBP was moderate (kappa=0.53, 95% confidence interval: 0.30-0.76). Detection rate of WCH in stage 1 HT participants by HBP and ABP was 9.8 and 11.8% (P=0. 65), respectively, and WCH diagnostic agreement between ABP and HBP was moderate (kappa=0.49, 95% confidence interval: 0.10-0.87). CONCLUSION: Nondipper status percentage was higher in PH and untreated HT, and detection rate of MH in PH participants was also higher. The simple HBP measurement can provide more reliable and actual BP information and may be a feasibility of screening out MH and WCH for the clinical practice.

[Mineralogical effect correction for pressed iron ore samples in wavelength dispersive X-ray fluorescence analysis].

The possibility of correcting mineralogical effect for pressed powder pellets of iron ore samples was studied in wavelength dispersive X-ray fluorescence analysis of major and minor elements with 10 Chinese iron ore CRMs. Two methods were applied to reduce the influence of mineralogical effect. The first one is to check 20 angles for every sample before measurement to correct peak shift; another method is replacing peak intensity with peak area of the analytical line to correct the shape distortion of the spectrum. The K factors of the two methods for each element were compared to those from regular measurements. The results show that the calibration for most of the elements was improved, although to different degrees. The improvement in the calibration for sulfur is evident. The calibration for other elements can meet the general requirements except for total iron.

[Calculation of the contributions of scattering effects to the X-ray fluorescence intensities].

The contribution of scattering effects to the X-ray fluorescence intensity was studied for pure element samples, BaB binary samples and fused disk samples by theoretic calculation and experiment. Three scattering effects were considered in the present study, i. e. coherent scattering effect, incoherent scattering effect, and primary fluorescence that was scattered into the direction of detector. The study shows that the contribution of scattering effects to the intensity of fluorescence is related to the energy of the atomic absorption edge, and the sample's matrix. The higher the energy of the atomic absorption edge, the more the contribution of scattering effects to the intensity of fluorescence. The contribution of scattering effects to the fluorescence intensity is larger for light matrix samples than heavy matrix samples. The results of experiment show that the accuracy of theoretic calculation was evidently improved when the scattering effects were considered in the theoretic calculation for the intensity of fluorescence.

[Study on the influence of excitation voltage and anode on the contribution of scattering effects to the intensity of X-ray fluorescence].

The influence of X-ray tube spectral distribution related to the X-ray tube voltage and target anode on the contribution of scattering effects to the intensity of fluorescence was studied by using some fused disk samples. Three scattering effects were considered. They are coherent scattering effect, incoherent scattering effect and primary fluorescence scattered into the direction of detector respectively. For the fused beads under investigation, the results show that the contributions of coherent scattering effect and the primary fluorescence scattered into the direction of detector decreased with increasing the tube voltage, and the contribution was larger when excited by the X-ray from Cr target than that from Rh target. On the contrary, the contribution of incoherent scattering effect to the intensity of fluorescence increased with increasing the voltage, and was larger when excited by the X-ray from Rh target than that from Cr target. The sum of the contribution of scattering effects to the intensity of fluorescence increased with increasing the voltage, and was larger when excited by the X-ray from Rh target than that from Cr target.

[Analysis of films by X-ray fluorescence spectrometry].

As a quantitative method of film sample, the X-ray fluorescence (XRF) technique has been used extensively because it is non-destructive, fast and accurate. Moreover it could determine the concentration and thickness of film sample simultaneously. A review was given of the study on the quantitative method of films by X-ray fluorescence spectrometry, in which the theoretical calculation of fluorescence intensity, the matrix effects and the methods for their correction, the sources of errors, the software for quantitative analysis, and the application of the method were summarized and discussed. New development and application of films characterization by X-ray fluorescence spectrometry were also expected. Because the similar calibration specimen for film sample is difficult to prepare and the fundamental parameter method could quantitatively analyze film samples even if only the pure element specimen is employed, the fundamental parameter method is studied extensively. The fundamental parameter method was introduced mainly in the present article, including the fundamental parameter equations to calculate the theoretical intensity of fluorescence, the source of error in calculation, and the software for analysis.

[Study of enhancement effects in X-ray fluorescence analysis for multi-layer samples].

The enhancement effects in X-ray fluorescence analysis for multi-layer samples were studied. A computer program was developed based on the theoretical equations for X-ray fluorescence intensity calculation and used to calculate the intensities of primary fluorescence and secondary fluorescence, the ratios of intensities of secondary fluorescence to primary fluorescence, and the portions of intensities of secondary fluorescence in total fluorescence for Fe Kalpha line in Zn/Fe and Fe/Zn film samples. It was found that the intensities of a characteristic line of an element in primary fluorescence and secondary fluorescence, the ratios of intensities of secondary fluorescence to primary fluorescence, and the portions of intensities of secondary fluorescence in total fluorescence were dependent not only on the thickness of the films but also on the position of the films in case of constant excitation conditions when multi-layer samples were tested by X-ray fluorescence analysis. When the thickness of Zn layer is the same as that of Fe layer, the calculated ratio of intensity of secondary fluorescence to total fluorescence of Fe Kalpha varies with the thickness, and reaches up to 9% for Fe/Zn sample while up to 35% for Zn/Fe sample.

[Epidemiologic research on the clinical features of patients with cervical spondylosis].

OBJECTIVE: To investigate the clinical features of patients with cervical spondylosis. METHODS: Questionnaires were provided and X rays were examined in 1 009 people with different occupations, ages, and sexes. RESULTS: All the patients were diagnozed as cervical spondylosis. Of them, cadres occupied 78.83%, technologists made up 74.21%, and accountants 58.70%; nervous and long-time working people accounted for 59.75%; high and middle pillow-lovers occupied 80.03%. Imaging features: most of the degenerative changes of cervical spine were located between C5-6 (40.79%), C4-5 (26.29%), and C6-7 (18.20%). Patients with vertebral osteophyte were 65.75%, intervertebral space narrow 36.87%, intervertebral foramen narrow 29.19%, and physiological curve change 31.03%. CONCLUSION: This epidemiologic investigation is important, which can further understand the cause of cervical spondyiosis, and strengthen its prevention and treatment.