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| 1 | Controlled attenuation parameter for non-invasive assessment of hepatic steatosis in Chinese patients显示文摘AIM:To evaluate the performance of a novel non-invasive controlled attenuation parameter(CAP)to assess liver steatosis.METHODS:This was a multi-center prospective cohort study.Consecutive patients(aged≥18 years)who had undergone percutaneous liver biopsy and CAP measurement were recruited from three Chinese liver centers.Steatosis was categorized as S0:<5%;S1:5%-33%;S2:34%-66%;or S3:≥67%,according to the nonalcoholic fatty liver disease(NAFLD)activity score.The FibroScan?502 equipped with the M probe(Echosens,Paris,France)was used to capture both CAP and liver stiffness measurement values simultaneously.Receiver operating characteristic curves were plotted,and the areas under the curves were calculated to determine the diagnostic efficacy.The accuracy of the CAP values at the optimal thresholds was defined by maximizing the sum of sensitivity and specificity(maximum Youden index).RESULTS:A total of 152 patients were recruited,including 52(34.2%)patients with NAFLD and 100(65.8%)with chronic hepatitis B(CHB)virus infection.After adjustment,the steatosis grade(OR=37.12;95%CI:21.63-52.60,P<0.001)and body mass index(BMI,OR=6.20;95%CI:2.92-9.48,P<0.001)were found independently associated with CAP by multivariate linear regression analysis.CAP was not influenced by inflammation,fibrosis or aetiology.The median CAP values and interquartile ranges among patients with S0,S1,S2 and S3 steatosis were 211(181-240)dB/m,270(253-305)dB/m,330(302-360)dB/m,and 346(313-363)dB/m,respectively.The cut-offs for the CAP values in all patients with steatosis≥5%,≥34%and≥67%were 253 dB/m,285 dB/m and 310 dB/m,respectively.The areas under the curves were 0.92,0.92and 0.88 for steatosis≥5%,≥34%and≥67%,respectively.No significant differences were found in the CAP values between the NAFLD group and the CHB group in each steatosis grade.CONCLUSION:CAP appears to be a promising tool for the non-invasive detection and quantification of hepatic steatosis,but is limited by BMI. | Feng Shen Rui-Dan Zheng Yu-Qiang Mi Xiao-Ying Wang Qin Pan Guang-Yu Chen Hai-Xia Cao Ming-Li Chen Liang Xu Jian-Neng Chen Yi Cao Rui-Nan Zhang Lei-Ming Xu Jian-Gao Fan | 2014 | World Journal of Gastroenterology2014，20，16： | 55 |
| 2 | Effects of the Biot and the squirt-flow coupling interaction on anisotropic elastic waves显示文摘Considering the velocity anisotropy of the solid/fluid relative motion and employment of the BISQ theory based on the one-dimensional porous isotropic case, we establish a two-phase anisotropic elastic wave equation to simultaneously include the Biot and the squirt mechanisms in terms of both the basic principles of the fluid’s mass conservation and the elastic-wave dynamical equations in the two-phase anisotropic rock. Numerical results, while the Biot-flow and the squirt-flow effects are simultaneously considered in the transversely isotropic (Tl) poroelastic medium, show that the attenuation of the quasi P-wave and the quasi SV-wave strongly depend on the permeability anisotropy, and the attenuation behavior at low and high frequencies is contrary. Meanwhile, the attenuation and dispersion of the quasi P-wave are also affected seriously by the anisotropic solid/fluid coupling additional density. | YANG Dinghui & ZHANG Zhongjie Department of Mathematical Sciences, Tsinghua University, Beijing 100084, China Institute of Geophysics, Chinese Academy of Sciences, Beijing 100101, China | 2000 | Chinese Science Bulletin2000，45，23： | 33 |
| 3 | Transient elastography(Fibro Scan~?) with controlled attenuation parameter in the assessment of liver steatosis and fibrosis in patients with nonalcoholic fatty liver disease- Where do we stand?显示文摘Non-alcoholic fatty liver disease(NAFLD) is the most common cause of chronic liver disease worldwide. Currently, the routinely used modalities are unable to adequately determine the levels of steatosis and fibrosis(laboratory tests and ultrasonography) or cannot be applied as a screening procedure(liver biopsy). Among the non-invasive tests, transient elastography(Fibro Scan?, TE) with controlled attenuation parameter(CAP) has demonstrated good accuracy in quantifying the levels of liver steatosis and fibrosis in patients with NAFLD, the factors associated with the diagnosis and NAFLD progression. The method is fast, reliable and reproducible, with good intra- and interobserver levels of agreement, thus allowing for population-wide screening and disease follow-up. The initial inability of the procedure to accurately determine fibrosis and steatosis in obese patients has been addressed with the development of the obese-specific XL probe. TE with CAP is a viable alternative to ultrasonography, both as an initial assessment and during follow-up of patients with NAFLD. Its ability to exclude patients with advanced fibrosis may be used to identify low-risk NAFLD patients in whom liver biopsy is not needed, therefore reducing the risk of complications and the financial costs. | Ivana Mikolasevic Lidija Orlic Neven Franjic Goran Hauser Davor Stimac Sandra Milic | 2016 | World Journal of Gastroenterology2016，22，32： | 33 |
| 4 | Microvesicle-delivery miR-150 promotes tumorigenesis by up-regulating VEGF,and the neutralization of miR-150 attenuate tumor development显示文摘Tumor-associated macrophages(TAMs)mostly exhibit M2-like(alternatively activated)properties and play posi-tive roles in angiogenesis and tumorigenesis.Vascular en-dothelial growth factor(VEGF)is a key angiogenic factor.During tumor development,TAMs secrete VEGF and other factors to promote angiogenesis;thus,anti-treatment against TAMs and VEGF can repress cancer development,which has been demonstrated in clinical trials and on an experimental level.In the present work,we show that miR-150 is an oncomir because of its promotional effect on VEGF.MiR-150 targets TAMs to up-regulate their secre-tion of VEGF in vitro.With the utilization of cell-derived vesicles,named microvesicles(MVs),we transferred an-tisense RNA targeted to miR-150 into mice and found that the neutralization of miR-150 down-regulates miR-150 and VEGF levels in vivo and attenuates angiogenesis.There-fore,we proposed the therapeutic potential of neutralizing miR-150 to treat cancer and demonstrated a novel,natu-ral,microvesicle-based method for the transfer of nucleic acids. | Yuchen Liu Luming Zhao Dameng Li Yuan Yin Chen-Yu Zhang Jing Li Yujing Zhang | 2013 | Protein & Cell2013，4，12： | 18 |
| 5 | Temporal-spatial variations of euphotic depth of typical lake regions in Lake Taihu and its ecological environmental significance显示文摘By using the data of underwater irradiance measured in the different lake regions of Lake Taihu during 1998-2004 and total suspended solids (TSS), wind speeds of the total 13 stations in typical lake regions during 1993-2003, this paper analyzes the factors of influencing on PAR (pho- tosynthetically available radiation) attenuation, euphotic depth, and presents the temporal and spatial variations of euphotic depth of typical lake regions in Lake Taihu, and the spectral distributions of euphotic depth at station 2. The results show that the concentration of TSS is the most important factor impacting PAR attenuation, followed by chlorophyll a; chromophoric dissolved organic matter (CDOM) has little impact on the PAR euphotic depth. During 1993-2003, the mean yearly PAR eu- photic depths of the typical lake regions ranged from 1.04 to 1.95 m with a mean value of 1.35±0.23 m. The PAR euphotic depth fell into 3 spatial zone types: Type I, the lowest, including the lake center and the inflows of rivers; Type II, intermediate, including Meiliang Bay, Wulihu Lake and Gonghu Bay; Type III, the greatest, including the East Lake Taihu; corresponding mean depths were approximately 1.1, 1.4, 2.0 m, respectively. The seasonal variations of euphotic depths were not quite the same in different lake regions. In the lake center, the mean values of PAR euphotic depth in summer and au- tumn were significantly greater than those in winter and spring; in the Meiliang Bay, winter means were significantly greater than in the other three seasons; in the East Lake Taihu, winter means were significantly less than in the other three seasons. However, no distinct seasonal change was recorded in the Wulihu Lake, Gonghu Bay and the inflows of rivers. The spectral distributions of euphotic depth present a minimal value at the blue light wave band of 400 nm, and a peak at the green light wave band of around 580 nm. In 1998 and 1999, based on the seasonal many-day continuous measure- ments, the PAR euphotic depths at station 2 were recorded 2.00±0.21, 2.52±0.45, 1.58±0.24, 2.00 ±0.15 m in spring, summer, autumn and winter, respectively. The peak value of 440 nm absorbed by phytoplankton corresponded to a euphotic depth of only 0.81-1.47 m (mean 1.07±0.29 m), which was much lower than the mean PAR euphotic depth of 1.98±0.41 m. | ZHANG Yunlin1, 2, QIN Boqiang1, HU Weiping1, WANG Sumin1, CHEN Yuwei1 & CHEN Weimin1 1. Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China 2. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China | 2006 | Science China Earth Sciences2006，49，4： | 16 |
| 6 | Effect of sediment resuspension on underwater light field in shallow lakes in the middle and lower reaches of the Yangtze River:A case study in Longgan Lake and Taihu Lake显示文摘Based on three continuous in situ underwater light field measurement under different wind waves conditions in Longgan Lake, Meiliang Bay of Taihu Lake in July 2003 and littoral zone near TLLER in July 2004, respectively, the effects of sediment resuspension caused by wind waves on PAR diffuse attenuation, absorption coefficients and euphotic depths are analyzed. In Longgan Lake, PAR diffuse attenuation coefficients during small, middle and large wind waves were 1.74, 2.02 and 2.45 m-1, respectively, and the corresponding PAR spectral diffuse attenuations ranged from 0.98 to 2.97, 1.34 to 3.95 and 1.80 to 5.40 m-1, respectively. In Meiliang Bay, PAR diffuse attenuation coefficients were 2.63, 3.72, 4.37 m-1 during small, middle and large wind waves. PAR diffuse attenuation coefficients increased by 41% and 66% from small to middle, large wind waves, respectively.Absorption coefficients integrated over the range of PAR of CDOM, phytoplankton were 0.26, 0.28 m-1;0.76, 0.49 m-1, respectively during middle and large wind waves. Absorption coefficients integrated over the range of PAR of non-algal particulate matter and total suspended particulate matter increased from 0.94 to 1.73 m-1, and from 1.70 to 2.22 m-1, respectively during middle and large wind waves. Relative contributions of absorption coefficients of non-algal particulate matter to total absorption coefficient integrated over the range of PAR were 44.14%, 65.05%, respectively, during middle and large wind waves. PAR euphotic depths decreased by 0.40, 0.19, 0.20 m from middle to large wind waves in Longganhu Lake, Meliang Bay and littoral zone near TLLER. Significant correlations were found between transparency, PAR diffuse attenuation coefficients, euphotic depths and total suspended particulate matter, wind velocity, wave height. Most significant correlations were found between transparency, PAR diffuse attenuation coefficients, euphotic depths and inorganic suspended particulate matter but low correlations for chlorophyll a, dissolved organic carbon. Increase of total suspended particulate matter, especially inorganic suspended particulate matter caused by wind waves was the dominant factor affecting underwater light field in shallow lakes in the middle and lower reaches of the Yangtze River based on observations at three stations. | ZHANG Yunlin, QIN Boqiang, ZHU Guangwei, GAO Guang, LUO Liancong & CHEN Weimin Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China Graduate School of Chinese Academy of Sciences, Beijing 100039, China | 2006 | Science China Earth Sciences2006，49，z1： | 14 |
| 7 | Ultrasound-based techniques for the diagnosis of liver steatosis显示文摘Non-alcoholic fatty liver disease(NAFLD)is the leading cause of diffuse liver disease.An accurate estimate of the fat in the liver is important in the diagnostic work-up of patients with NAFLD because the degree of liver steatosis is linked to the metabolic syndrome and the cardiovascular risk.Ultrasound(US)B-mode imaging allows to subjectively estimate the fatty infiltration in the liver;however,it has a low performance for the detection of mild steatosis.Quantitative US is based on the analysis of the radiofrequency echoes detected by an US system,and it allows to calculate a backscatter coefficient or an attenuation coefficient or the sound speed.The estimation of the backscatter coefficient is rather cumbersome and requires the use of a phantom for addressing all sources of variability.Controlled attenuation parameter(CAP)available on the FibroScan system(Echosens,France)measures the attenuation of the US beam.CAP is accurate in grading fatty infiltration-even though there is an overlap between consecutive grade of liver steatosis-and the values are not influenced by liver fibrosis.Several US manufacturers are developing or have already developed software for quantifying the attenuation of the US beam.Preliminary results show that proprietary technologies implemented in US systems seem more accurate than CAP for grading liver steatosis.Another available method for quantifying liver steatosis is based on the computation of the sound speed and the initial results appear promising. | Giovanna Ferraioli Livia Beatriz Soares Monteiro | 2019 | World Journal of Gastroenterology2019，25，40： | 12 |
| 8 | 胸部CT扫描吸气相和呼气相与肺小气道病变的相关性研究显示文摘目的探讨无症状长期吸烟者肺小气道损害的患者进行吸气相CT扫描,结合呼气相HRCT扫描,评价呼气相HRCT影像表现及相关参数在诊断小气道疾病方面应用价值。方法采用70例作为吸烟试验组,采用30例不吸烟对照组,均使用螺旋CT进行胸部深吸气末CT扫描,结合深呼气末HRCT扫描,重点观察呼气末的空气潴留影像,测量及计算相关参数,统计其与小气道病变的相关性。结果本研究从性别构成上显示男性吸烟者明显高于女性比例,吸烟组与对照组肺容积参数间差异均有统计学意义(P<0.05),分别包括吸气相肺容积、呼气相肺容积、吸气相低衰减区比例、呼气相低衰减区比例、吸气相平均肺野密度、呼气相平均肺野密度、呼气-吸气肺容积比、呼气-吸气平均肺野密度比率、呼气-吸气肺容积差和呼气-吸气平均肺野密度差;轻度与重度吸烟组的肺容积参数比较显示除Ins-LV在2组间差异有统计学意义(P<0.05),其余参数差异均无统计学意义(P>0.05)。结论胸部呼气相HRCT扫描能够清晰的观察到空气潴留的特征表现,结合吸气相CT扫描,测量和计算相关参数等指标,对临床小气道病变的临床早期诊断具有重要意义,敏感性较高,是一种方便快捷,具有临床推广意义的的一种检查手段。 | 刘树芳 张若曦 王立强 李雯 贾建雷 章志华 | 2016 | 河北医药2016，38，16： | 11 |
| 9 | Underwater image enhancement based on red channel weighted compensation and gamma correction model显示文摘Due to the special characteristics of light in water,the information of the red channel is seriously attenuated in collected image.This causes other colors to dominate the image.This paper proposes an underwater image enhancement algorithm based on red channel weighted compensation and gamma correction model.Firstly,by analyzing the attenuation characteristics of RGB channels,the intensity and the edge information of red channel are compensated by weighting the attenuation coefficient ratio between different channels to correct the chromaticity.Then the gamma correction model is employed to stretch the intensity range to enhance the contrast which makes the image look clearer.The experimental results show that the proposed algorithm can correct the color cast effect and improve the contrast by nearly 2 times for the underwater images with too much red component attenuation. | Wending Xiang Ping Yang Shuai Wang Bing Xu Hui Liu | 2018 | Opto-Electronic Advances2018，1，10： | 10 |
| 10 | Estimating steatosis and fibrosis: Comparison of acoustic structure quantification with established techniques显示文摘AIM:To compare ultrasound-based acoustic structure quantification(ASQ) with established non-invasive techniques for grading and staging fatty liver disease.METHODS:Type 2 diabetic patients at risk of nonalcoholic fatty liver disease(n = 50) and healthy volunteers(n = 20) were evaluated using laboratory analysis and anthropometric measurements, transient elastography(TE), controlled attenuation parameter(CAP), proton magnetic resonance spectroscopy(1H-MRS; only available for the diabetic cohort), and ASQ.ASQ parameters mode, average and focal disturbance(FD) ratio were compared with:(1) the extent of liver fibrosis estimated from TE and nonalcoholic fatty liver disease(NAFLD) fibrosis scores; and(2) the amount of steatosis, which was classified according to CAP values.RESULTS:Forty-seven diabetic patients(age 67.0±8.6 years;body mass index 29.4±4.5 kg/m2)with reliable CAP measurements and all controls(age 26.5±3.2 years;body mass index 22.0±2.7 kg/m2)were included in the analysis.All ASQ parameters showed differences between healthy controls and diabetic patients(P<0.001,respectively).The ASQ FD ratio(logarithmic)correlated with the CAP(r=-0.81,P<0.001)and 1H-MRS(r=-0.43,P=0.004)results.The FD ratio[CAP<250 d B/m:107(102-109),CAP between 250 and 300 d B/m:106(102-114);CAP between 300 and 350 d B/m:105(100-112),CAP≥350 d B/m:102(99-108)]as well as mode and average parameters,were reduced in cases with advanced steatosis(ANOVA P<0.05).However,none of the ASQ parameters showed a significant difference in patients with advanced fibrosis,as determined by TE and the NAFLD fibrosis score(P>0.08,respectively).CONCLUSION:ASQ parameters correlate with steatosis,but not with fibrosis in fatty liver disease.Steatosis estimation with ASQ should be further evaluated in biopsy-controlled studies. | Thomas Karlas Joachim Berger Nikita Garnov Franziska Lindner Harald Busse Nicolas Linder Alexander Schaudinn Bettina Relke Rima Chakaroun Michael Trltzsch Johannes Wiegand Volker Keim | 2015 | World Journal of Gastroenterology2015，21，16： | 9 |
| 11 | High value of controlled attenuation parameter predicts a poor antiviral response in patients with chronic hepatits B显示文摘BACKGROUND:Controlled attenuation parameter(CAP) is a non-invasive method for diagnosing hepatic steatosis based on vibration-controlled transient elastography.The objective of this study was to investigate the effect of high value of CAP on antiviral therapy in patients with chronic hepatitis B(CHB).METHODS:Patients with CHB receiving enticavir for initial antiviral therapy were studied;they were divided into the high CAP group and normal CAP group at baseline according to the CAP values.The effect of the antiviral therapy between the two groups were compared at week 12,24 and 48.Patients with high CAP value at baseline were divided into three subgroups,mild,moderate and severe elevation;the therapeutic response were compared among patients with normal CAP and subgroups of patients with elevated CAP.RESULTS:A total of 153 patients were enrolled.Among them,63 were in the high CAP group and 90 in the normal CAP group.Patients with high CAP had lower rates of ALT normalization and HBV DNA clearance in response to antiviral therapy compared with those with normal CAP at week 12,24 and 48.Further analysis showed that the rate of ALT normalization in patients with mildly and moderately elevated CAP were significant lower than those with normal CAP at week 12 and 24;while the difference was not significant between the patients with normal CAP and those with severely elevated CAP.The rate of HBV DNA clearance was significantly lower in patients with severely elevated CAP compared with those with normal CAP at week 12,24 and 48.CONCLUSION:CHB patients with high CAP had poor response to antiviral therapy. | Jing Chen Meng-Lan Wang Qin Long Lang Bai Hong Tang | 2017 | Hepatobiliary & Pancreatic Diseases International2017，16，4： | 9 |
| 12 | High attenuation mucoid impaction in allergic bronchopulmonary aspergillosis显示文摘Allergic bronchopulmonary aspergillosis(ABPA) is a complex hypersensitivity syndrome triggered against antigens of Aspergillus fumigatus,a fungus that most commonly colonizes the airways of patients with bronchial asthma and cystic fibrosis.It presents clinically with refractory asthma,hemoptysis and systemic manifestations including fever,malaise and weight loss.Radiologically,it presents with central bronchiectasis and recurrent episodes of mucus plugging.The mucus plugs in ABPA are generally hypodense but in up to 20% of patients the mucus can be hyperdense on computed tomography.This paper reviews the literature on the clinical significance of hyperattenuated mucus in patients with ABPA. | Ritesh Agarwal | 2010 | World Journal of Radiology2010，2，1： | 9 |
| 13 | An analysis of seismic attenuation in random porous media显示文摘The attenuation of seismic wave in rocks has been one of the interesting research topics, but till now no poroelasticity models can thoroughly explain the strong attenuation of wave in rocks. In this paper, a random porous medium model is designed to study the law of wave propagation in complex rocks based on the theory of Biot poroelasticity and the general theory of stochastic process. This model sets the density of grain, porosity, permeability and modulus of frame as random parameters in space, and only one fluid infiltrates in rocks for the sake of better simulation effect in line with real rocks in earth strata. Numerical simulations are implemented. Two different inverse quality factors of fast P-wave are obtained by different methods to assess attenuation through records of virtual detectors in wave field (One is amplitude decay method in time domain and the other is spectral ratio method in frequency domain). Comparing the attenuation results of random porous medium with those of homogeneous porous medium, we conclude that the attenuation of seismic wave of homogeneous porous medium is far weaker than that of random porous medium. In random porous media, the higher heterogeneous level is, the stronger the attenuation becomes, and when heterogeneity σ = 0.15 in simulation, the attenuation result is consistent with that by actual observation. Since the central frequency (50 Hz) of source in numerical simulation is in earthquake band, the numerical results prove that heterogeneous porous structure is one of the important factors causing strong attenuation in real stratum at intermediate and low frequency. | LIU Jiong1, BA Jing2, MA JianWei1 & YANG HuiZhu1 1 Institute of Seismic Exploration, School of Aerospace, Tsinghua University, Beijing 100084, China 2 Research Institute of Petroleum Exploration & Development, PetroChina, Beijing 100083, China | 2010 | Science China(Physics,Mechanics & Astronomy)2010，53，4： | 7 |
| 14 | Seismic attenuation tomography in frequency domain and its application to engineering显示文摘Seismic tomography is a new geophysical technique being developed to meet the needs of mining and engineering projects. Attenuation tomography, as one kind of seismic tomography technique, is a powerful prospecting tool for determining structure defaults such as fault, broken zone, and hidden voids, but it has been little discussed up to now. Its principle and applications are presented in detail. Attenuation tomography technology includes the following main points. First, on the basis of spectrum analysis to each seismic record, geometric correction is conducted, then common source parameters are introduced into common shot records in order to keep absorption effect of the geological media separate from source spectrum influence. Finally, an equation set is obtained which consists of absorption coefficients, common source parameters and energy field data observed. This technique can be employed together with velocity tomography to provide more evidence for engineering and geological diagnosis. Its | 赵永贵 李勤 郭鸿 靳洪晓 王超凡 | 2000 | Science China Earth Sciences2000，43，4： | 7 |
| 15 | Modeling and prediction of ultrasonic attenuations in liquid-solid dispersions containing mixed particles with Monte Carlo method显示文摘We develop a theoretical model for predicting the ultrasonic attenuation in the liquid-solid system containing mixed particles. The ultrasonic attenuation coefficient is obtained by counting the number of phonons that reach the receiver. Using the Monte Carlo method (MCM), numerical simulations were performed to predict the ultrasonic attenuations with not only a single particle type but also monodisperse and polydisperse mixed particles. The simulation results for the systems with a single particle type were compared with various standard models. The results show that they agree well at relatively low particle volume concentrations (within 10%). For systems with mixed particles, the particle volume concentrati on was found to in crease to around 10%, and the variation of the ultrasonic attenuation agai nst the mixing ratio yields a nonlinear trend. Moreover, the ultrasonic attenuation is significantly affected by particle properties. The numerical results also show that both the particle type and particle size distribution should be carefully taken into account in the dispersions with polydisperse mixed particles, where the MCM can give a more direct description of the physics of sound propagation compared with the conventional models. | Jianfei Gu Fengxian Fan Yunsi Li Huinan Yang Mingxu Su Xiaoshu Cai | 2019 | Particuology2019，17，2： | 7 |
| 16 | Quantitative energy-dispersive X-ray fluorescence analysis for unknown samples using full-spectrum least-squares regression显示文摘The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements. | Yong-Li Liu Qing-Xian Zhang Jian Zhang Hai-Tao Bai Liang-Quan Ge | 2019 | Nuclear Science and Techniques2019，30，3： | 6 |
| 17 | Safety of engineered structures against blast vibrations: A case study显示文摘Blasting used for rock excavation is associated with ground vibrations having potential damage to surrounding structures.The extent of damage produced in a structure depends largely on ground motion characteristics,dynamic characteristics of structure and the type of geological strata on which it is founded.The safety of surrounding structures against blast vibrations is a cause of concern.However,use of a systematic approach to rock blasting helps to complete the excavation safely in time without endangering the safety of surrounding structures.Various steps are commonly adopted at construction sites to ensure safety of engineered structures against blast vibrations,e.g.adopting a suitable safe vibration level,developing site-specific attenuation relation,estimating safe charges for different distances,designing blasting pattern,and monitoring vibrations during actual blasting.The paper describes the details of studies conducted for ensuring safety of an 85 years old masonry dam and green concrete of varying ages during excavation of about 30,000 m^3 of hard rock in Maharashtra,India.The studies helped to complete the rock excavation safely in time and the safety of the dam was ensured by monitoring blast vibrations during actual rock excavation. | g.r.tripathy r.r.shirke m.d.kudale | 2016 | Journal of Rock Mechanics and Geotechnical Engineering2016，8，2： | 6 |
| 18 | Measurement of mass attenuation coefficients,effective atomic numbers,and electron densities for different parts of medicinal aromatic plants in low-energy region显示文摘The mass attenuation coefficients(l/q) for different parts(root, flower, stem, and leaf) of three medicinal aromatic plants(Teucrium chamaedrys L. subsp. sinuatum,Rheum ribes, and Chrysophthalmum montanum) were measured using an ^(241)Am photon source in a stable geometry and calculated using the Monte Carlo N-Particle Transport Code System-extended(MCNPX) code and the WinXCOM program. The experimental and theoretical MCNPX and WinXCOM values exhibited good agreement.The measured mass attenuation coefficient values were then used to compute the effective atomic number(Z_(eff))and electron density(N_E) of the samples. The results reveal that S1-S(stem of Teucrium chamaedrys L. subsp. sinuatum) has the highest values of l/q and Zeff. | M.I.Sayyed F.Akman I.H.Geccbesler H.O.Tekin | 2018 | Nuclear Science and Techniques2018，29，10： | 5 |
| 19 | Azimuthal anisotropy of seismic velocity, attenuation and Q value in viscous EDA media显示文摘By considering the constitution relationship between stress and strain in viscous EDA media in the domain of frequency, seismic wave equations in the media in the domain of time and space are established. The anelastic effects induced by cracks or fractures are shown by the third derivatives of displacement components with respect to time in the equations. After solving the equations for the seismic propagation of plane waves, seismic velocity, attenuation and quality factor ( Q value) are obtained, and their azimuthal anisotropy in the dry cracked and water saturated cracked EDA media are studied. The results show that, seismic velocity, attenuation, quality factor ( Q value), especially attenuation or quality factor ratio of 2 kinds of qS wave can be used to indicate the existence of oriented cracks and material contents in the crack. Meanwhile, elasticity is predominant at low frequency, and anelasticity is significant at high frequency. | 张中杰 滕吉文 贺振华 | 2000 | Science China(Technological Sciences)2000，43，1： | 5 |
| 20 | Seismic wave propagating in Kelvin-Voigt homogeneous visco-elastic media显示文摘This paper studies, under a small disturbance, the responses of seismic transient wave in the visco-elastic media and the analytic solution of the corresponding third-order partial differential equation. A plane wave solution of Kelvin-Voigt homogeneous visco-elastic third-order partial differ-ential equation with a pulse source is obtained. By the principle of pulse stacking of particle vibration, the result is extended to the solution of Kelvin-Voigt homogeneous visco-elastic third-order partial differential equation with any source. The velocities of seismic wave propagating and the attenuation of seismic wave in Kelvin-Voigt homogeneous visco-elastic media are discussed. The velocities of seismic wave propagating and the coefficient of attenuation of seismic wave in Kelvin-Voigt homogeneous visco-elastic media are derived, expressed as functions of density of the media, elastic modulus and visco-elastic coefficient. These results can be applied in inversing lithology parameters in geophysical prospecting. | YUAN Chunfang1, PENG Suping1, ZHANG Zhongjie2 & LIU Zhenkuan3 1. China University of Mining & Technology, Beijing 100083, China 2. Institute of Geophysics, Chinese Academy of Sciences, Beijing 100101, China 3. Exploration and Development Research Institute of Daqing Oilfield, Daqing 163712, China | 2006 | Science China Earth Sciences2006，49，2： | 5 |
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