|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | RESOlution激光剥蚀系统在微量元素原位微区分析中的应用显示文摘采用美国Resonetics公司生产的RESOlution M-50激光剥蚀系统和Agilent 7500a型的ICP-MS联机,对7个不同岩性的地质样品经过熔融制备的MPI-DING玻璃标样的37种微量元素进行了分析。RESOlution M-50激光剥蚀系统包括一个193 nm ArF准分子(excimer)激光器,一个双室(two-volume cell)样品室,一个平滑激光剥蚀脉冲的Squid系统和电脑控制高精度X-Y样品台移动、定位系统。双室样品室的好处是降低样品交叉污染,减少样品室吹洗所需时间。平滑激光剥蚀脉冲的Squid系统可以降低因激光脉冲带来的统计误差。样品定位系统的定位精度优于0.1μm。本次实验使用的激光束斑直径为31μm和69μm。分析结果表明,对于用地质样品制备的MPI-DING玻璃标样,微量元素分析的相对标准偏差RSD一般优于5%,分析值与不同参考值之间的相对偏差(RD)一般优于10%,少数RSD和RD较大的元素主要出现在含量很低或不均匀样品中。稀土元素的RSD和RD均优于5%。本研究证明,RESOlution M-50激光剥蚀系统与Agilent 7500a型ICP-MS联机,可准确测定从超基性岩到酸性岩的不同类型地质样品的微量元素,其新式的双室样品室和平滑Squid系统对于测定含量在0.1μg/g以上的元素具有更好的分析精度和准确度。 | 涂湘林 张红 邓文峰 凌明星 梁华英 刘颖 孙卫东 | 2011 | 地球化学2011，40，1： | 94 |
| 2 | Stable classi?cation with limited sample: transferring a 30-m resolution sample set collected in 2015 to mapping 10-m resolution global land cover in 2017显示文摘As the world strives to reduce the impact of population growth, urbanization, agricultural expansion, and climate change on food security, energy and water shortage, resource over-exploration, biodiversity loss, environmental pollution, and ultimately human health, timely and higher resolution land cover information is urgently needed to achieve the sustainable development goals of the United Nations. | Peng Gong Han Liu Meinan Zhang Congcong Li Jie Wang Huabing Huang Nicholas Clinton Luyan Ji Wenyu Li Yuqi Bai Bin Chen Bing Xu Zhiliang Zhu Cui Yuan Hoi Ping Suen Jing Guo Nan Xu Weijia Li Yuanyuan Zhao Jun Yang Chaoqing Yu Xi Wang Haohuan Fu Le Yu Iryna Dronova Fengming Hui Xiao Cheng Xueli Shi Fengjin Xiao Qiufeng Liu Lianchun Song | 2019 | Science Bulletin2019，64，6： | 166 |
| 3 | Supersonic flow imaging via nanoparticles显示文摘Due to influence of compressibility,shock wave,instabilities,and turbulence on supersonic flows, current flow visualization and imaging techniques encounter some problems in high spatiotemporal resolution and high signal-to-noise ratio(SNR)measurements.Therefore,nanoparticle based planar laser scattering method(NPLS)is developed here.The nanoparticles are used as tracer,and pulse planar laser is used as light source in NPLS;by recording images of particles in flow field with CCD, high spatiotemporal resolution supersonic flow imaging is realized.The flow-following ability of nanoparticles in supersonic flows is studied according to multiphase flow theory and calibrating experiment of oblique shock wave.The laser scattering characteristics of nanoparticles are analyzed with light scattering theory.The results of theoretical and experimental studies show that the dynamic behavior and light scattering characteristics of nanoparticles highly enhance the spatiotemporal resolution and SNR of NPLS,with which the flow field involving shock wave,expansion,Mach disk,boundary layer,sliding-line,and mixing layer can be imaged clearly at high spatiotemporal resolution. | ZHAO YuXin YI ShiHe TIAN LiFeng CHENG ZhongYu | 2009 | Science China(Technological Sciences)2009，52，12： | 31 |
| 4 | 应用MODIS数据反演青藏高原地区地表反照率显示文摘应用RossThick-LiTransit核驱动BRDF(bidirectional reflectance distribution function)模型,选择2004年Terra MODIS(moderate resolution imaging spectraradiometer)500 m分辨率数据,对青藏高原地区的地表反照率进行了反演研究,并以平均气溶胶光学厚度值0.11计算了正午时(北京时间12:00)实际的地表反照率,反演结果与当地的地表覆盖类型和地形具有较好的一致性。此外,藏北高原4个辐射观测站点观测资料与反演结果的比较表明,500 m分辨率反演结果不仅可以满足气候和陆面过程模式的精度要求,而且精度高于美国1 km分辨率反照率反演结果。 | 陈爱军 卞林根 刘玉洁 朱小祥 | 2009 | 南京气象学院学报2009，32，2： | 20 |
| 5 | 石油组分高分辨质谱的数据处理显示文摘A data processing combination of manual and automatic steps for mass peaks identification of a coking gas oil was illustrated.Some representative compounds were identified by manual process.A program was performed to search the various types with the same hetero-atoms(familes-class,NnSsOo)but different rings plus double bonds(R+DB)value(Z in CcH2c+ZNnOoSs),then,alkylation series of each types were revealed by multiplying each mass by 14.00000 in Kendrick mass scale.Finally,isotope groups of each identified peaks were picked up respectively.The method is appropriate to the data analysis of FT-ICR MS spectra with a poor mass accuracy. | 史权 董智勇 张亚和 赵锁奇 徐春明 | 2008 | 分析测试学报2008，27，S1： | 17 |
| 6 | 地质样品Sr同位素激光原位等离子体质谱(LA-MC-ICP-MS)测定显示文摘Sr同位素在研究岩浆演化及其源区具有重要的示踪作用。MC-ICP-MS的出现为具有高Sr含量地质样品的激光原位Sr同位素测定变成了现实。本文利用Netpune MC-ICP-MS和193nm准分子激光联机,通过滨珊瑚、斜长石、磷灰石和钙钛矿等系列实验,建立了激光原位Sr同位素测定方法。实验结果表明,激光Sr同位素测定中Kr、Rb和稀土元素二价离子的干扰能够有效扣除,而钙聚合物的干扰在Neptune型MC-ICP-MS并不显著。不同激光参数的实验表明,大激光束斑产生更高信号强度,因而Sr同位素精度更高,同一激光束斑大小,激光脉冲频率对Sr同位素精度无明显影响。 | 杨岳衡 吴福元 谢烈文 杨进辉 张艳斌 | 2009 | 岩石学报2009，25，12： | 16 |
| 7 | Study of density field measurement based on NPLS technique in supersonic flow显示文摘Due to the influence of shock wave and turbulence, supersonic density field exhibits strongly inhomogeneous and unsteady characteristics. Applying traditional density field measurement techniques to supersonic flows yields three problems: low spatiotemporal resolution, limitation of measuring 3D density field, and low signal to noise ratio (SNR). A new method based on Nano-based Planar Laser Scattering (NPLS) technique is proposed in this paper to measure supersonic density field. This method measures planar transient density field in 3D supersonic flow by calibrating the relationship between density and concentration of tracer particles, which would display the density fluctuation due to the influence of shock waves and vortexes. The application of this new method to density field measurement of supersonic optical bow cap is introduced in this paper, and the results reveal shock wave, turbulent boundary layer in the flow with the spatial resolution of 93.2 μm/pixel. By analyzing the results at interval of 5 μs, temporal evolution of density field can be observed. | TIAN LiFeng YI ShiHe ZHAO YuXin HE Lin CHENG ZhongYu | 2009 | Science China(Physics,Mechanics & Astronomy)2009，52，9： | 15 |
| 8 | 在过敏 bronchopulmonary 麴菌病的胸 X 光线照相术、计算的 tomographic 表明显示文摘 AIM:To investigate the chest radiographic and high resolution computed tomography(HRCT)chest manifestations in glucocorticoid-naive allergic bronchopulmonary aspergillosis(ABPA)patients.METHODS:This is a prospective observational study and includes 60 consecutive glucocorticoid-naive patients with ABPA who underwent chest radiography and HRCT of the chest(1.25 mm every 10 mm)in the routine diagnostic workup for ABPA.RESULTS:Chest radiographs were normal in 50%of cases.Of the remainder,most patients demonstrated permanent findings in the form of parallel line and ring shadows suggesting bronchiectasis.Consolidation was detected in 17 cases but in the majority,the corresponding HRCT chest scan showed mucus-filled bronchiectatic cavities.Chest HRCT was normal in 22 patients,while central bronchiectasis(CB)was demonstrated in the remaining 38 patients.Bronchiectasis extended to the periphery in 33%-43%depending on the criteria used for defining CB.The other findings observed on HRCT were mucoid impaction,centrilobular nodules and high-attenuation mucus in decreasing order of frequency.CONCLUSION:Patients with ABPA can present with normal HRCT chest scans.Central bronchiectasis cannot be considered a characteristic feature of ABPA as peripheral bronchiectasis is commonly observed.Consolidation is an uncommon finding in ABPA. | Ritesh Agarwal Ajmal Khan Mandeep Garg Ashutosh N Aggarwal Dheeraj Gupta | 2012 | World Journal of Radiology2012，4，4： | 14 |
| 9 | SPOT5卫星影像测绘能力分析显示文摘HRS同轨立体影像获取能力是SPOT5卫星最突出的一个关于测绘制图的新特性,它确定了SPOT5卫星在测绘中的重要应用前景。本文从SPOT5HRS的立体成像方式,SPOTImage公司最新推出的Reference3D产品及陕西宝鸡地区的HRS立体影像测量试验等方面对SPOT5HRS影像测绘能力进行了分析和评价,说明了SPOT5卫星影像测绘将是解决我国西部困难地区基础测绘的一种重要手段。 | 燕琴 张继贤 邱志成 高武俊 | 2005 | 测绘科学2005，30，4： | 14 |
| 10 | Weak minimum aberration and maximum number of clear two-factor interactions in 2_(IV)^(m-p)designs显示文摘 | YANG Guijun,LIU Minqian & ZHANG Runchu Department of Statistics, Tianjin University of Finance and Economics, Tianjin 300222, China Department of Statistics, School of Mathematical Sciences and LPMC, Nankai University, Tianjin 300071, China | 2005 | Science China Mathematics2005，48，11： | 12 |
| 11 | New Families in the Stable Homotopy of Spheres Revisited | LIN Jin Kun Department of Mathematics. Nankai University. Tianjin 300071. P. R. China | 2002 | Acta Mathematica Sinica,English Series2002，18，1： | 12 |
| 12 | Large field of view computed laminography with the asymmetric rotational scanning geometry显示文摘X-ray computed laminography(CL)is used in the fields of industrial inspection and medical imaging.It can provide the internal structure three-dimensional(3D)information of a region of the objects nondestructively.It is important to the clinical diagnosis and the quality control of flat objects like printed circuit boards,aircraft wings and satellite solar panels.With the restriction that the imaging region must be within the X-ray beam formed by the X-ray source and the detector,the imaging field of view of CL is limited by the size of detector.A new CL method with an asymmetric rotational cone-beam scanning geometry,called large field of view CL,is presented to overcome the existing disadvantage.It can extend the imaging region when the imaging spatial resolution keeps the same as that of the conventional CL.It can also improve the imaging spatial resolution when the imaging region keeps the same as that of the conventional CL.The asymmetric configuration can be achieved by offsetting the detector from the conventional symmetric configuration.It does not,however,require new detectors and X-ray source nor alter the scanning mechanical system.The filtered back-projection(FBP)reconstruction algorithm and the data truncation smoothing functions have been deduced to reconstruct the images directly from the data acquired with this asymmetric configuration.We performed numerical studies and experiments to demonstrate and validate the proposed approach. Results in these studies and experiments confirm that the proposed method can enlarge the imaging region and improve the spatial resolution.The proposed approach may find applications in the CL system with the rotational scanning geometry. | FU Jian 1,2 ,JIANG BaiHong&LI Bin 1 School of Mechanical Engineering and Automation,Beihang University,Beijing 100191,China 2 Research Center of Digital Radiation Imaging and Biomedical Imaging,Beihang University,Beijing 100191,China | 2010 | Science China(Technological Sciences)2010，53，8： | 12 |
| 13 | Improvement of GPS ambiguity resolution using prior height information. Part Ⅱ: The method of using quasi observation显示文摘This paper deals with the method of using quasi observation. In the paper a simple algorithm is developed for the adjustment computation with quasi observation at first. And then the ability of quasi observation to improve ambiguity search technique is studied in detail. The robustness of the method is also discussed. A method to determine the weight of quasi observation is proposed. The results show that a prior height can be taken as a quasi observation and used together with GPS observations. It can strengthen residual tests, especially in situation where there are fewer satellites in the sky. It also can change structure of incorrect solutions, which will theoretically make less incorrect solutions left in search space. At last the field tests are carried out to show that the proposed method is effective. The success rate of ambiguity resolution in the four field tests is improved significantly. | 朱建军 Rock Santerre | 2002 | Journal of Central South University of Technology2002，9，4： | 12 |
| 14 | Wide area real time kinematic decimetre positioning with multiple carrier GNSS signals显示文摘This paper presents the technical basis for wide area real time decimetre positioning services using multiple carrier signals transmitted by future GNSS such as modernized GPS and Compass systems. The first step is to form two ionosphere-reduced extra-widelanes (EWL) that have the minimal total noise levels in cycles, considering the effects of the ionospheric and tropospheric delays, orbital error, and phase noise terms in various observational environments. The proposed three carrier ambiguity resolution approach can determine the integer ambiguities of the selected EWL signals with geometry-free and geometry- based estimations respectively over the distances of typically hundreds of kilometres. With two ambiguity-fixed EWL signals, the kinematic positioning solutions can be achieved in decimetre level accuracy. A semi-simulation method is employed to generate three frequency Compass data to demonstrate the above expected performance for decimetre positioning services. Both theoretical and experimental results have demonstrated the overall 3D root mean square accuracy of better than 15 cm obtained through with a phase smoothing process over 120 epochs. The dominating error factor in this positioning result is the residual tropospheric biases, which would become less correlated as the baselines grow beyond hundreds of kilometres. With respect to dual-frequency based precise point positioning and wide area differential positioning solutions, a major advantage of using the third frequency signals is the convergence time being shorten from tens of minutes to a few minutes. In addition, due to the instant ambiguity resolution capability, phase breaks or cycle slips no longer affect the continuity of the solutions. This reliable decimetre positioning capability introduces a significant improvement to safety-of-life, liability-critical and professional applications. | FENG YanMing1 & LI BoFeng1,2 1 Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, QLD 4001, Australia 2 Department of Surveying and Geo-informatics Engineering, Tongji University, Shanghai 200092, China | 2010 | Science China Earth Sciences2010，53，5： | 11 |
| 15 | All-optical forward-viewing photoacoustic probe for high-resolution 3D endoscopy显示文摘A miniature forward-viewing endoscopic probe that provides high-resolution 3D photoacoustic images is demonstrated.The probe is of outer diameter 3.2mm and comprised of a transparent Fabry-Pérot(FP)polymer-film ultrasound sensor that is located at the distal end of a rigid optical fiber bundle.Excitation laser pulses are coupled simultaneously into all cores of the bundle and are transmitted through the FP sensor to provide wide-field tissue illumination at the distal end.The resulting photoacoustic waves are mapped in 2D by sequentially scanning the input end of the bundle with an interrogation laser beam in order to individually address different points on the FP sensor.In this way,the sensor acts as a high-density ultrasound array that is comprised of 50,000 individual elements,each of which is 12μm in diameter,within the 3.2mm diameter footprint of the probe.The fine spatial sampling that this affords,along with the wide bandwidth(f_(-3dB)=34 MHz)of the sensor,enables a high-resolution photoacoustic image to be reconstructed.The measured on-axis lateral resolution of the probe was depth-dependent and ranged from 45-170μm for depths between 1 and 7 mm,and the vertical resolution was 31μm over the same depth range.The system was evaluated by acquiring 3D images of absorbing phantoms and the microvascular anatomies of a duck embryo and mouse skin.Excellent image fidelity was demonstrated.It is anticipated that this type of probe could find application as a tool for guiding laparoscopic procedures,fetal surgery and other minimally invasive interventions that require a millimeter-scale forward-viewing 3D photoacoustic imaging probe. | Rehman Ansari Edward Z.Zhang Adrien E.Desjardins Paul C.Beard | 2018 | Light(Science & Applications)2018，7，1： | 11 |
| 16 | Unfolding analysis of LaBr3:Ce gamma spectrum with a detector response matrix constructing algorithm based on energy resolution calibration显示文摘With respect to the gamma spectrum, the energy resolution improves with increase in energy. The counts of full energy peak change with energy, and this approximately complies with the Gaussian distribution. This study mainly examines a method to deconvolve the LaBr_3:Ce gamma spectrum with a detector response matrix constructing algorithm based on energy resolution calibration.In the algorithm, the full width at half maximum(FWHM)of full energy peak was calculated by the cubic spline interpolation algorithm and calibrated by a square root of a quadratic function that changes with the energy. Additionally, the detector response matrix was constructed to deconvolve the gamma spectrum. Furthermore, an improved SNIP algorithm was proposed to eliminate the background. In the experiment, several independent peaks of ^(152)Eu,^(137)Cs, and ^(60)Co sources were detected by a LaBr_3:Ce scintillator that were selected to calibrate the energy resolution. The Boosted Gold algorithm was applied to deconvolve the gamma spectrum. The results showed that the peak position difference between the experiment and the deconvolution was within ± 2 channels and the relative error of peak area was approximately within 0.96–6.74%. Finally, a ^(133) Ba spectrum was deconvolved to verify the efficiency and accuracy of the algorithm in unfolding the overlapped peaks. | Rui Shi Xian-Guo Tuo Huai-Liang Li Yang-Yang Xu Fan-Rong Shi Jian-Bo Yang Yong Luo | 2018 | Nuclear Science and Techniques2018，29，1： | 11 |
| 17 | High time resolution observation and statistical analysis of atmospheric light extinction properties and the chemical speciation of fine particulates显示文摘In recent years,the visibility deterioration caused by regional fine particulate pollution becomes one of the crucial air pollution problems in the urban areas of our country.The rapid variation of visibility and fine particulates make it difficult to estimate the relationship between them precisely and accurately unless high time resolution observation data can be accessed.This study aims to fill this gap in the field of atmospheric science by establishing a formula using multiple linear regressions.Excellent fitting goodness (R2=0.913,n=3167) was obtained using 10 min average of high-resolution real-time light scattering coefficients,light absorption coefficients,main chemical speciation concentration in PM1 and some meteorological parameters from 17 Jan to 16 Feb,2009.It shows that the average light extinction coefficient during the observation in the winter of Shenzhen was measured to be 290 ± 183 Mm?1,consisting of 72% of light scattering and 21% of absorption.In terms of the percentage contribution of PM1 chemical species to the total light extinction,the organic matter was estimated to be most with an average of 45%,followed by ammonium sulfate with an average of 24%.The contributions of black carbon and ammonium nitrate were 17% and 12%,respectively.Besides,the diurnal variation of light extinction was investigated as well in this study. | YAO TingTing1,HUANG XiaoFeng1,HE LingYan1,HU Min2,SUN TianLe1,XUE Lian1,LIN Yun1,ZENG LiWu1 & ZHANG YuanHang2 1Key Laboratory for Urban Habitat Environmental Science and Technology,School of Environment and Energy,Peking University Shenzhen Graduate School,Shenzhen 518055,China 2State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China | 2010 | Science China Chemistry2010，53，8： | 10 |
| 18 | Paleoproductivity records for the past 30 ka in the southern Nansha area, the South China Sea显示文摘This note presents productivity variations for the past 30 ka in the southern Nansha area, the South China Sea, from the gravity core 17962 (7°11 ′N, 112°5′E, core length: 8 m, water depth: 1 968 m). Estimated surface productivity demonstrates that at the last glacial maximum the productivity was about 1.6 times as much as that in the Holocene, and the change may be ascribed to an increase of terrestrial nutrients as sea level lowered in the glacial time. | Dianyong Fang Zhimin Jian Pinxian Wang | 2000 | Chinese Science Bulletin2000，45，13： | 10 |
| 19 | Direction synthesis in DOA estimation for monostatic multiple input multiple output (MIMO) radar based on synthetic impulse and aperture radar (SIAR) and its performance analysis显示文摘A new direction synthetic method for monostatic multiple input multiple output (MIMO) radar is presented based on synthetic impulse and aperture radar (SIAR) system. Concerned with the monostatic MIMO radar which simultaneously emits orthogonal signals with multi-carrier-frequency and possesses sparsely distributed transmitting and receiving arrays with respective location, as well as the situation for the presence of multipath propagation in the low flying target’s echo, the method integrates the aperture of the transmitting arrays with the receiving arrays to form the digital beam-forming (DBF) in azimuth and elevation dimensions. And a study has been made of planar general MUSIC algorithm based on decorrelating the multipath signals of multi-carrier-frequency MIMO radar. Through compensat-ing the phase delay of both the transmitting and the receiving arrays and synthe-sizing the transmitting beam in two dimensions at the receiver, the angular resolu-tion and measurement accuracy are improved and the computational complexity is reduced after transforming the three-dimensional (3D) parameter estimation prob-lem into a two-dimensional (2D) one. Finally, the Cramer-Rao Bounds (CRBs) of DOA estimation for azimuth and elevation is put forward with the exsiting multipath propagation. Results of computer simulation demonstrate the validity of the new method. | ZHAO GuangHui CHEN BaiXiao ZHU ShouPing | 2008 | Science China(Technological Sciences)2008，51，6： | 9 |
| 20 | High resolution temperature measurement technique for measuring marine heat flow显示文摘High resolution temperature measurement technique is one of the key techniques for measuring marine heat flow. Basing on Pt1000 platinum resistance which has the characteristics of high accuracy and good stability, we designed a bridge reversal excitation circuit for high resolution temperature measurement. And the deep ocean floor in-situ test results show that: (1) temperature deviation and peak-to-peak resolution of the first version circuit board (V1) are 1.960-1.990 mK and 0.980-0.995 m Kat 1.2-2.7°C, respectively; and temperature deviation and peak-to-peak resolution of the second circuit board (V2) are 2.260mK and 1.130 mK at 1.2-1.3°C, respectively; (2) During the 2012NSFC-IndOcean cruise, seafloor geothermal gradient at Ind2012HF03,-07 and-12 stations (water depth ranges from 3841 to 4541 m) were successfully measured, the values are 59.1,75.1 and 71.6°C/km, respectively. And the measurement errors of geothermal gradient at these three stations are less than 3.0% in terms of the peak-to-peak resolution. These indicate that the high resolution temperature measurement technique based on Pt1000 platinum resistance in this paper can be applied to marine heat flow measurement to obtain high precision geothermal parameters. | QIN YangYang YANG XiaoQiu WU BaoZhen SUN ZhaoHua SHI XiaoBin | 2013 | Science China(Technological Sciences)2013，56，7： | 9 |
您所在的机构暂未开通此部分的功能，请联系管理员