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| 1 | The Grid Search Algorithm of Tectonic Stress Tensor Based on Focal Mechanism Data and Its Application in the Boundary Zone of China, Vietnam and Laos显示文摘Stress field plays a key role in geodynamics. In this study, an algorithm to determine the stress tensor and its confidence range from focal mechanism data by using grid search method was proposed. The experiment uses artificial focal mechanism data which were generated by extensional, compression and strike-slip stress regime and different level of noise, shows that the precision of the estimated stress tensor based on this algorithm is greatly improved compared with traditional algorithms. This algorithm has three advantages:(1) The global optimal solution of the stress tensor is determined by fine grid search of 1o×1o×1o×0.01 and local minimum value is avoided;(2) precision of focal mechanism data can be considered, i.e., different weight of the focal mechanism data contributes differently to the process of determining stress tensor;(3) the confidence range of the determined stress tensor can be obtained by using F-test. We apply this algorithm in the boundary zone of China, Vietnam and Laos, and obtain the stress field with SSE-NNW compressive stress direction and NEE-SWW extensional stress direction. The stress ratio is 0.6, which shows that the eigen values of the stress tensor are nearly in arithmetic sequence. The stress field in this region is consistent with the left-lateral strike slip of the Dienbien-Lauangphrabang arc fault. The result will be helpful in studying the geological dynamic process in this region. | Yongge Wan Shuzhong Sheng Jichao Huang Xiang Li Xin Chen | 2016 | Journal of Earth Science2016，27，5： | 48 |
| 2 | Calycosin-7-O-β-D-glucopyranoside stimulates osteoblast differentiation through regulating the BMP/WNT signaling pathways显示文摘The iso fl avone calycosin-7-O-β-D-glucopyranoside(CG) is a principal constituent of Astragalus membranaceus(AR) and has been reported to inhibit osteoclast development in vitro and bone loss in vivo. The aim of this study was to investigate the osteogenic effects of CG and its underlying mechanism in ST2 cells. The results show that exposure of cells to CG in osteogenic differentiation medium increases ALP activity, osteocalcin(Ocal) m RNA expression and the osteoblastic mineralization process. Mechanistically, CG treatment increased the expression of bone morphogenetic protein 2(BMP-2), p-Smad 1/5/8, β-catenin and Runx2, all of which are regulators of the BMP- or wingless-type MMTV integration site family(WNT)/β-catenin-signaling pathways. Moreover, the osteogenic effects of CG were inhibited by Noggin and DKK-1 which are classical inhibitors of the BMP and WNT/β-catenin-signaling pathways, respectively. Taken together, the results indicate that CG promotes the osteoblastic differentiation of ST2 cells through regulating the BMP/WNT signaling pathways. On this basis, CG may be a useful lead compound for improving the treatment of bone-decreasing diseases and enhancing bone regeneration. | Jing Jian Lijuan Sun Xun Cheng Xiaofang Hu Jichao Liang Yong Chen | 2015 | Acta Pharmaceutica Sinica B2015，5，5： | 16 |
| 3 | Surfactant induced reservoir wettability alteration:Recent theoretical and experimental advances in enhanced oil recovery显示文摘Reservoir wettability plays an important role in various oil recovery processes.The origin and evolution of reservoir wettability were critically reviewed to better understand the complexity of wettability due to interactions in crude oil-brine-rock system,with introduction of different wetting states and their influence on fluid distribution in pore spaces.The effect of wettability on oil recovery of waterflooding was then summarized from past and recent research to emphasize the importance of wettability in oil displacement by brine.The mechanism of wettability alteration by different surfactants in both carbonate and sandstone reservoirs was analyzed,concerning their distinct surface chemistry,and different interaction patterns of surfactants with components on rock surface.Other concerns such as the combined effect of wettability alteration and interfacial tension (IFT) reduction on the imbibition process was also taken into account.Generally,surfactant induced wettability alteration for enhanced oil recovery is still in the stage of laboratory investigation.The successful application of this technique relies on a comprehensive survey of target reservoir conditions,and could be expected especially in low permeability fractured reservoirs and forced imbibition process. | Wang Yefei XU Huaimin Yu Weizhao Bai Baojun Song Xinwang Zhang Jichao | 2011 | Petroleum Science2011，8，4： | 14 |
| 4 | Effects of Body Size and Environmental Factors on the Acoustic Structure and Temporal Rhythm of Calls in Rhacophorus dennysi显示文摘In anurans, the outcomes of male-male contests and female choice are often associated with body size. In some species, males evaluate an opponent's fighting ability and females evaluate male quality on the basis of male communication signals, which are thought to reflect information concerning male body size. Nevertheless, previous studies reveal that male call structure is not always correlated with body size. In the present study we investigated the relationships between body size and call structure in the large treefrog, Rhacophorus dennysi, as well as the relationship of its calling behavior with air temperature and humidity. The results show that both the dominant and fundamental frequencies are negatively correlated with body size, while inter-note intervals are positively correlated with body size, indicating that call characters could reflect body size in this species.Additionally, calling in this tropical species exhibits a circadian rhythm insofar as relatively high temperature and low humidity during the day is associated with less vocal behavior. Thus, individual variations in call structure are mainly dependent on body size while the temporal rhythm of calling activity is affected by environmental conditions in large treefrogs. | Jichao WANG Jianguo CUI Haitao SHI Steven E.BRAUTH Yezhong TANG | 2012 | Asian Herpetological Research2012，3，3： | 10 |
| 5 | 1,25-Dihydroxyvitamin D3 protects obese rats from metabolic syndrome via promoting regulatory T cell-mediated resolution of inflammation显示文摘Vitamin D_3 has been found to produce therapeutic effects on obesity-associated insulin resistance and dyslipidemia through its potent anti-inflammatory activity, but the precise immunomodulatory mechanism remains poorly understood. In the present study we found that 1,25-dihydroxyvitamin D_3[1,25(OH)_2D_3], the biologically active form of vitamin D_3, significantly attenuated monosodium glutamate(MSG)-induced obesity and insulin resistance as indicated by body weight reduction, oral glucose tolerance improvement, and a glucose infusion rate increase as detected with hyperinsulinemiceuglycemic clamp. Moreover, 1,25(OH)_2D_3 not only restored pancreatic islet functions but also improved lipid metabolism in insulin-targeted tissues. The protective effects of 1,25(OH)_2D_3 on glycolipid metabolism were attributed to its ability to inhibit an obesity-activated inflammatory response in insulin secretory and targeted tissues, as indicated by reduced infiltration of macrophages in pancreas islets and adipose tissue while enhancing the expression of Tgf-β1 in liver tissue, which was accompanied byincreased infiltration of Treg cells in immune organs such as spleen and lymph node as well as in insulintargeted tissues such as liver, adipose, and muscle. Together, our findings suggest that 1,25(OH)_2D_3 serves as a beneficial immunomodulator for the prevention and treatment of obesity or metabolic syndrome through its anti-inflammatory effects. | Wen Jin Bing Cui Pingping Li Fang Hua Xiaoxi Lv Jichao Zhou Zhuowei Hu Xiaowei Zhang | 2018 | Acta Pharmaceutica Sinica B2018，8，2： | 9 |
| 6 | Immobilization of lead in anthropogenic contaminated soils using phosphates with/without oxalic acid显示文摘Understanding the effects of oxalic acid(OA) on the immobilization of Pb(Ⅱ) in contaminated soils by phosphate materials, has considerable benefits for risk assessment and remediation strategies for the soil. A series of phosphate amendments with/without oxalic acid were applied to two anthropogenic contaminated soils. We investigated the immobilization of Pb(Ⅱ) by KH2PO4, phosphate rock(PR), activated phosphate rock(APR) and synthetic hydroxyapatite(HAP) at different phosphate:Pb(P:Pb) molar ratios(0, 0.6, 2.0 and 4.0) in the presence/absence of 50 mmol oxalic acid/kg soil, respectively. The effects of treatments were evaluated using single extraction with deionized water or Ca Cl2, Community Bureau of Reference(BCR) sequential extraction and toxicity characteristic leaching procedure(TCLP)methods. Our results showed that the concentration of water extractable, exchangeable and TCLP-Pb all decreased with incubation time. The concentration of water-extractable Pb after120 days was reduced by 100% when soils were amended with APR, HAP and HAP + OA, and the TCLP-Pb was <5 mg/L for the red soil at P:Pb molar ratio 4.0. Water-soluble Pb could not be detected and the TCLP-Pb was <5 mg/L at all treatments applied to the yellow-brown soil. BCR results indicated that APR was most effective, although a slight enhancement of water-soluble phosphate was detected at the P:Pb molar ratio 4.0 at the beginning of incubation. Oxalic acid activated phosphates, and so mixing insoluble phosphates with oxalic acid may be a useful strategy to improve their effectiveness in reducing Pb bioavailability. | Xiaojuan Su Jun Zhu Qingling Fu Jichao Zuo Yonghong Liu Hongqing Hu | 2015 | Journal of Environmental Sciences2015，27，2： | 9 |
| 7 | Response of Groundwater to Climate Change under Extreme Climate Conditions in North China Plain显示文摘The North China Plain(NCP) is one of the water shortage areas of China. Lack of water resources restricted the economic and social development of North China area and resulted in deterioration of ecosystem and natural environment. Influenced by the climate change and human activities, the water circulation of NCP was largely changed and the crisis of water resources was aggravated. Therefore, it is important to study the features of the extreme climate and the response mechanism of groundwater to climate change. We analyzed the trend of climate change and extreme climate features in the past 60 years based on the monitoring data of meteorological stations. And then the response characteristics of groundwater to climate change were discussed. The average temperature of NCP was in an obviously upward trend. The overall precipitation variation was in a downward trend. The climate change in this area showed a warming-drying trend. The intensity of extreme precipitation displayed a trend of declining and then increasing from north to south as well as declining from eastern coastal plain to the piedmont plain. Grey correlation degree analysis indicated that groundwater depth had a close relationship with precipitation and human activities in NCP. The response of groundwater level to precipitation differed from the piedmont alluvial-pluvial plain to the coastal plain. The response was more obvious in the coastal plain than the piedmont alluvial-pluvial plain and the middle plain. The precipitation influenced the groundwater depth both directly and indirectly. Under the condition of extreme precipitation, the impact would aggravate, in the forms of rapid or lag raise of groundwater levels. | Ying Zhang Jincui Wang Jihong Jing Jichao Sun | 2014 | Journal of Earth Science2014，25，3： | 9 |
| 8 | The validation of HY-2 altimeter measurements of a significant wave height based on buoy data显示文摘HY-2 has been launched by China on August 16,2011 which assembles multi-microwave remote sensing payloads in a body and has the ability of monitoring ocean dynamic environments.The HY-2 satellite data need to be calibrated and validated before being put into use.Based on the in-situ buoys from the National Data Buoy Center(NDBC),Ku-band significant wave heights(SWH,hs)of HY-2 altimeter are validated.Eleven months of HY-2 altimeter Level 2 products data are chose from October 1,2011 to August 29,2012.Using NDBC 60 buoys yield 902 collocations for HY-2 by adopting collocation criteria of 30 min for temporal window and 50 km for a spatial window.An overall RMS difference of the SWH between HY-2 and buoy data is 0.297 m.A correlation coefficient between these is 0.964.An ordinary least squares(OLS)regression is performed with the buoy data as an independent variable and the altimeter data as a dependent variable.The regression equation of hs is hs(HY-2)=0.891×hs(NDBC)+0.022.In addition,2016 collocations are matched with temporal window of 30 min at the crossing points of HY-2 and Jason-2 orbits.RMS difference of Ku-band SWH between the two data sets is 0.452 m. | WANG Jichao ZHANG Jie YANG Jungang | 2013 | Acta Oceanologica Sinica2013，32，11： | 7 |
| 9 | Progress on design and related R&D activities for the water-cooled breeder blanket for CFETR显示文摘The water-cooled ceramic breeder (WCCB) blanket is one of the blanket candidates for Chinese fusion engineering testing reactor (CFETR) and is being developed at the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). This paper reviews design and evolution of the WCCB blanket for CFETR, and presents a new WCCB blanket design according to the latest CFETR core parameters (major and minor radii are R = 7.2 m and a = 2.2 m, respectively) and missions. This new design is expected to satisfy multiple CFETR operation modes of 0.2, 0.5, 1.0, and 1.5 GW fusion power and achieve tritium self-sufficiency. The feasibility of the updated blanket design is evaluated from the aspects of neutronics and thermo-hydraulics. Furthermore, the research and development (R&D) activities supporting to the WCCB blanket for CFETR are reported, including the design code, the water loop experiments, the pebble bed modeling and experiments, and the components fabrication technology. | Songlin Liu Xiaoman Cheng Xuebin Ma Lei Chen Kecheng Jiang Xia Li Hui Bao Jichao Wang Wanjing Wang Changhong Peng Peng Lu Min Li Kai Huang | 2019 | Theoretical & Applied Mechanics Letters2019，9，3： | 6 |
| 10 | Dealing with the Spatial Synthetic Heterogeneity of Aquifers in the North China Plain:A Case Study of Luancheng County in Hebei Province显示文摘The complexity of alluvial-pluvial fan depositional systems makes the detailed characterization of their heterogeneity difficult,yet such a detailed characterization is commonly needed for construction of reliable groundwater models.Traditional models mainly focus on using a single aquifer property to qualitatively or semi-quantitatively characterize the heterogeneity of aquifer,so that they are unable to quantitatively reflect the synthetic heterogeneity of all aquifer properties.In this paper,we propose the heterogeneity synthetic index(HSI) for quantitative characterization of synthetic heterogeneity of an aquifer.The proposed calculation process involves four steps:(1) estimation of the hydraulic conductivity of a sediment sample using the cloud-Markov model,(2) establishment of the sedimentary microfacies distribution model through the Markov chain,(3) characterization of the distribution model of hydrogeological parameters using the improved sequential simulation method according to the 'facies-controlled modeling' technique,and(4) application of the entropy weight method to calculate the weight coefficient of the above aquifer properties.The HSI of an aquifer is calculated by superposition of these models according to the corresponding weight coefficient.This approach was applied to the Luancheng aquifer deposit in the southeast Hutuo River alluvial-pluvial fan in the North China Plain(NCP).The results have demonstrated that aquifer 3 which was formed in the middle Pleistocene has the strongest heterogeneity,with an HSI of 0.25-0.75.Aquifer 4 formed in the early Pleistocene shows an intermediate heterogeneity,with the HSI ranging 0.35-0.75.The weakest heterogeneity was found in aquifers 1 and 2 formed in the Holocene and late Pleistocene,with HSI values of 0.40-0.75 and 0.40-0.80,respectively.The heterogeneity of all the four aquifers is relatively strong in the radial direction of the Huai River alluvial-pluvial fan due to the abrupt change of microfacies.In contrast,in the radial direction of the Hutuo River alluvial-pluvial fan,the microfacies change mildly,and the continuity of hydrogeological parameters is better,which has resulted in weaker heterogeneity of the four aquifers in this direction.Findings suggest that the sedimentary environment has significant effects on the aquifer heterogeneity.Considering that there are many aquifer properties,HSI can quantitatively characterize the synthetic heterogeneity of the aquifer and describe the influence of each aquifer property on the synthetic heterogeneity of the aquifer according to its weight coefficient.Thus the HSI approach can be successfully used to deal with the spatial heterogeneity of aquifer and provide a foundation for studies on contaminant transport. | MA Rong SHI Jiansheng LIU Jichao | 2012 | Acta Geologica Sinica(English Edition)2012，86，1： | 6 |
| 11 | Impairment of the autophagy-lysosomal pathway in Alzheimer’s diseases: Pathogenic mechanisms and therapeutic potential显示文摘Alzheimer’s disease(AD),the most common neurodegenerative disorder,is characterized by memory loss and cognitive dysfunction.The accumulation of misfolded protein aggregates including amyloid beta(Aβ)peptides and microtubule associated protein tau(MAPT/tau)in neuronal cells are hallmarks of AD.So far,the exact underlying mechanisms for the aetiologies of AD have not been fully understood and the effective treatment for AD is limited.Autophagy is an evolutionarily conserved cellular catabolic process by which damaged cellular organelles and protein aggregates are degraded via lysosomes.Recently,there is accumulating evidence linking the impairment of the autophagy-lysosomal pathway with AD pathogenesis.Interestingly,the enhancement of autophagy to remove protein aggregates has been proposed as a promising therapeutic strategy for AD.Here,we first summarize the recent genetic,pathological and experimental studies regarding the impairment of the autophagy-lysosomal pathway in AD.We then describe the interplay between the autophagy-lysosomal pathway and two pathological proteins,Aβand MAPT/tau,in AD.Finally,we discuss potential therapeutic strategies and small molecules that target the autophagy-lysosomal pathway for AD treatment both in animal models and in clinical trials.Overall,this article highlights the pivotal functions of the autophagy-lysosomal pathway in AD pathogenesis and potential druggable targets in the autophagy-lysosomal pathway for AD treatment. | Wei Zhang Chengchao Xu Jichao Sun Han-Ming Shen Jigang Wang Chuanbin Yang | 2022 | Acta Pharmaceutica Sinica B2022，12，3： | 6 |
| 12 | Grain-filling characteristics and yield differences of maize cultivars with contrasting nitrogen efficiencies显示文摘To investigate the effect of nitrogen management on the grain-filling characteristics and yield formation of maize cultivars with contrasting nitrogen efficiencies,and to identify differences in grain-filling characteristics and yield of maize cultivars in response to nitrogen management,a two-year field experiment was conducted in southwest China in2015–2016.The grain-filling rate and duration of the N-inefficient cultivar XY 508 were higher than those of the N-efficient cultivar ZH 311.The 100-kernel weight of XY 508 was significantly higher than that of ZH 311.The kernel number per ear of ZH 311 was significantly higher than that of XY 508,making the population filling rate of ZH 311 significantly higher than that of XY 508.The higher population filling rate of the N-efficient maize cultivar led to a significant yield advantage over the N-inefficient maize cultivar.Nitrogen management effectively improved maize grain yield,but the response of maize cultivars with contrasting nitrogen efficiencies to nitrogen management was inconsistent.A basal fertilizer ratio 60.43%with a topdressing ratio 39.57%effectively increased grainfilling rate,delayed the time to maximum filling rate,prolonged the active filling period and effective grain-filling time,increased the 100-kernel weight,and maintained higher kernels per ear,thereby improving the population filling rate and maximizing the yield advantage of the N-efficient cultivar.A 100%basal fertilizer ratio not only increased the number of kernels per ear,but also maintained high grain filling characteristics to obtain a higher 100-kernel weight and increased the population filling rate,leading to a high grain yield in the N-inefficient cultivar.Thus,the 100%basal fertilizer ratio partially compensated for the deficient grain yield of the N-inefficient cultivar. | Qiang Li Lunjing Du Dongju Feng Yun Ren Zhexin Li Fanlei Kong Jichao Yuan | 2020 | The Crop Journal2020，8，6： | 5 |
| 13 | Application of Fast Wavelet Analysis on Early Stall Warning in Axial Compressors显示文摘The timely detection of stall inception is of great significance for safe operation and stability control of axial compressor. In the current study, a fast wavelet tool was selected to predict stall precursor in axial compressors with spike-type and modal-wave stall inception. Dynamic pressure was measured in the casing wall by using a collection of time-resolved pressure transducers with circumferential and chord-wise spatial resolution. Fast wavelet analysis with low frequency reconstruction results demonstrate that the initial inception can be detected 110 rotor revolutions prior to stall for modal-wave stall inception in a 1.5 stage axial compressor. For spike-type stall inception, despite the failure of early stall warning via low frequency reconstruction, an increase amplitude frequency band of 0.2–0.8 blade passing frequency was identified using high frequency reconstruction in an isolated-rotor axial compressor. Fast wavelet method can predict two kinds of stall inceptions simultaneously in advance and realize the early stall warning in axial compressors through a reasonable selection of reconstructed frequency. | LIU Yang LI Jichao DU Juan LI Fan ZHANG Hongwu | 2019 | Journal of Thermal Science2019，28，5： | 5 |
| 14 | Entropy Generation Analysis in a Mixed-Flow Compressor with Casing Treatment显示文摘Casing treatments(CT) can effectively extend compressors flow ranges with the expense of efficiency penalty. Compressor efficiency is closely linked to loss. Only revealing the mechanisms of loss generation can design a CT with high aerodynamic performance. In the paper, a highly-loaded mixed-flow compressor with tip clearance of 0.4 mm was numerically studied at a rotational speed of 30,000 r/min to reveal the effects of axial slot casing treatment(ASCT) on the loss mechanisms in the compressor. The results showed that both isentropic efficiency and stall margin were improved significantly by the ASCT. The local entropy generation method was used to analyze the loss mechanisms and to quantify the loss distributions in the blade passage. Based on the axial distributions of entropy generation rate, for both the cases with and without ASCT, the peak entropy generation rate increased in the rotor domain and decreased in the stator domain during throttling the compressor. The peak entropy generation in rotor was mainly caused by the tip leakage flow and flow separations near the rotor leading edge for the mixed-flow compressor no matter which casing was applied. The radial distributions of entropy generation rate showed that the reduction of loss in the rotor domain from 0.4 span to the rotor casing was the major reason for the efficiency improved by ASCT. The addition of ASCT exerted two opposite effects on the losses generated in the compressor. On the one hand, the intensity of tip leakage flow was weakened by the suction effect of slots, which alleviated the mixing effect between the tip leakage flow and main flow, and thus reduced the flow losses;On the other hand, the extra losses upstream the rotor leading edge were produced due to the shear effect and to the heat transfer. The aforementioned shear effect was caused by the different velocity magnitudes and directions, and the heat transfer was caused by temperature gradient between the injected flow and the incoming flow. For case with smooth casing(SC), 61.61% of the overall loss arose from tip leakage flow and casing boundary layer. When the ASCT was applied, that decreased to 55.34%. The loss generated by tip leakage flow and casing boundary layer decreased 20.54% relatively by ASCT. | ZHANG Qianfeng DU Juan LI Zhihui LI Jichao ZHANG Hongwu | 2019 | Journal of Thermal Science2019，28，5： | 5 |
| 15 | Lessons from the seismic behavior of a steel grid roof structure heavily damaged in Lushan earthquake显示文摘The seismic behavior of a school gymnasium, whose steel grid roof was heavily damaged during the Mw6.6 Lushan earthquake in 2013, is simulated through nonlinear dynamic analysis. The simulated damage is compared with field observations to validate the numerical model, based on which a parametric study was performed to provide insight into the failure process and damage patterns of steel grids. The results suggest that the grid damage is strongly related to roofsubstructure interactions. These include not only the substructure's amplification of the vibration, but the uncoordinated displacement of the substructure's columns which support the grid also play an equally important role. In particular, the latter effect may significantly alter the internal force distribution in the steel grid and lead to unexpected buckling of members that are proportioned as tension-only members. While such interactions are generally not accounted for in the design practice for grid structures in China, similar seismic damage may be expected for other existing grid roofs in future earthquakes. As is also demonstrated in this study, seismic isolation of the roof is a promising solution to protect grid roof structures by mitigating the detrimental effects of roof-substructure interactions. | Li Jichao Qu Zhe Wang Tao | 2019 | Earthquake Engineering and Engineering Vibration2019，18，1： | 5 |
| 16 | An enhanced hybrid and adaptive meta-model based global optimization algorithm for engineering optimization problems显示文摘由于在高效率和精确性之间的好平衡,元模型基于优化算法是一个重要全球优化范畴并且广泛地被使用了。更好解决高度非线性并且集中的工程优化问题,一个提高的混血儿和适应元模型基于的计算全球优化(电子火腿) 首先在这个工作被建议。重要区域更改方法(IRU ) 和不同采样尺寸策略在优化方法被建议提高表演。由使用自动、可伸缩的策略,重要区域将根据搜索结果适应地被更新改进产生精确和集中率。不平的采样策略和集中的采样策略在优化的不同阶段被使用高效地改进搜索并且避免过早地在一个小设计空格聚在一起的结果。新优化算法的有效性被与不同变量凳子标记优化问题作比较到六个优化方法验证。电子火腿优化方法然后被使用优化实际否定泊松比率(NPR ) 的设计参数在这个工作的碰撞盒子。结果显示建议电子火腿在优化计算有高精确性和效率集中的问题和罐头广泛地在设计工业被使用。 | ZHOU Guan DUAN LiBin ZHAO WanZhong WANG ChunYan MA ZhengDong GU JiChao | 2016 | Science China(Technological Sciences)2016，59，8： | 4 |
| 17 | Quaternion based joint DOA and polarization parameters estimation with stretched three-component electromagnetic vector sensor array显示文摘The three-component electromagnetic vector sensor(EMVS) consisting of co-centered orthogonally oriented x-dipole,z-dipole and z-loop is considered. In order to make full use of the spatial aperture of each component, the original uniform linear three-component EMVS array(ULTEA) is stretched into one halfwavelength spaced uniform linear loop subarray(ULLSA) along the z axis, and one sparse uniform linear co-centered orthogonally oriented dual-dipole(CODD) subarray(SULCSA) along the x axis. Then, a generalized rotation invariance based quaternion multiple signal classification(GRIQ-MUSIC) algorithm is presented for direction of arrival(DOA) and polarization parameters estimation. According to the proposed algorithm, the elevation angles are firstly estimated based on the half-wavelength spaced ULLSA.Then the polarization phase differences and azimuth angles are obtained based on the coupling relationship between the angle domain and polarization domain, but the azimuth angles are in coarse-resolution since the array aperture is not utilized. Next,the SULCSA is used to re-estimate the azimuth angles in fineresolution, and the ambiguity problem can be resolved by the least square method. Finally, based on the estimated elevation angles, azimuth angles and polarization phase differences, the corresponding auxiliary polarization angles can be estimated by N times one-dimensional parameter search, where N is the sources number, and the parameters are matched automatically. Based on the GRIQ-MUSIC algorithm, the high dimensional parameters search problem of the conventional Q-MUSIC algorithm is simplified to a one-dimensional parameter search problem, thus the proposed algorithm not only reduces the computation complexity considerably, but also avoids the performance degradation caused by the failure in parameters pairing. The simulation examples demonstrate the effectiveness and feasibility of the proposed algorithm. | Jichao Zhao Haihong Tao | 2017 | Journal of Systems Engineering and Electronics2017，28，1： | 4 |
| 18 | A universal elliptical disc(UED)model to represent natural rock fractures显示文摘Since natural fractures are often non-equidimensional,the circular disc model still has great limitations.By contrast,the elliptical disc model is more applicable to representing natural fractures,especially for slender ones.This paper developed a universal elliptical disc(UED)model by incorporating the center point,size,and azimuth of fractures as variables.Specifically,with respect to the azimuth of elliptical fractures in three-dimensional(3D)space,we proposed a paradigm to construct its probability density function(PDF)by coupling the orientation and rotation angle of long axis based on three coordinate transformations.To illustrate the construction process of the PDF of the fracture azimuth,we took the orientation following the Fisher distribution and the rotation angle following Von Mises distribution as an example.A rock slope is used to show the use of the developed UED model,and the 3D DFNs for the slope rock mass are generated by Monte Carlo simulation.In addition,the DFNs for the rock mass are also generated based on the existing circular disc model and non-universal elliptical disc model.The comparison results from the three models clearly illustrate the superiority of the UED model over the existing circular and non-universal elliptical disc models. | Jun Zheng Jichao Guo Jiongchao Wang Honglei Sun Jianhui Deng Qing Lv | 2022 | International Journal of Mining Science and Technology2022，32，2： | 4 |
| 19 | Seismic fragility of flexible pipeline connections in a base isolated medical building显示文摘Flexible pipelines are often used to connect hard pipes from a foundation to a superstructure to accommodate large deformation in the base isolation layer during an earthquake. Although Chinese seismic design guidelines suggest several confi gurations, they are diff erent from the designs that have been proven in practice, e.g., Japanese styles, and extensive experimental investigation into their seismic performance is required. Three types of seals, rubber-, metal- and asbestinebased, were tested quasi-statically with infi lled pressurized water at 2.5 MPa. The asbestine-based seal leaked at a smaller deformation than the other two types of seals. Based on the test results, three damage states were defi ned and the deformation capacity was estimated. To evaluate their performance, a three-dimensional model of a base-isolated medical building was developed using OpenSees, with the fl exible pipelines simulated by a mechanical model calibrated from the experimental data. A probabilistic seismic demand model and the fragility function of the fl exible pipelines were then developed to evaluate the seismic performance. | Shang Qingxue Wang Tao Li Jichao | 2019 | Earthquake Engineering and Engineering Vibration2019，18，4： | 4 |
| 20 | Combined Use of Multivariate Statistical Analysis and Hydrochemical Analysis for Groundwater Quality Evolution: A Case Study in North Chain Plain显示文摘Understanding the controlling factor of groundwater quality can enhance promoting sustainable development of groundwater resources. To this end, multivariate statistical analysis(MA) and hydrochemical analysis were introduced in this work. The results indicate that the canonical discriminant function with 7 parameters was established using the discriminant analysis(DA) method, which can afford 100% correct assignation according to the 3 different clusters(good water(GW), poor water(PW), and very poor water(VPW)) obtained from cluster analysis(CA). According to factor analysis(FA), 8 factors were extracted from 25 hydrochemical elements and account for 80.897% of the total data variance, suggesting that groundwater with higher concentrations of sodium, calcium, magnesium, chloride, and sulfate in southeastern study area are mainly affected by the natural process; the higher level of arsenic and chromium in groundwater extracted from northwestern part of study area are derived by industrial activities; domestic and agriculture sewage have important contribution to copper, iron, iodine, and phosphate in the northern study area. Therefore, this work can help identify the main controlling factor of groundwater quality in North China plain so as to make better and more informed decisions about how to achieve groundwater resources sustainable development. | Rong Ma Jiansheng Shi Jichao Liu Chunlei Gui | 2014 | Journal of Earth Science2014，25，3： | 4 |
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