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Efficient In SAR phase noise reduction via total variation regularization

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Science China(Information Sciences) 2015年第8期58卷 64-76页

作者： LUO xiaomei WANG XiangFeng SUO zhiYong LI zhenFang State Key Laboratory of Integrated Services Networks Xidian University Department of Electronic Information engineering Nanchang University Shanghai Key Laboratory of Trustworthy Computing Software Engineering InstituteEast China Normal University National Laboratory of Radar Signal Processing Xidian University

We consider the phase noise filtering problem for Interferometric Synthetic Aperture Radar(In SAR)using a total variation regularized complex linear least squares formulation. Although the original formulation is convex, solving it directly with the standard CVX package is time consuming due to the large problem size. In this paper, we introduce the effective and efficient alternating direction method of multipliers(ADMM) to solve the equivalent well-defined complex formulation for the real and imaginary parts of the optimization *** the iteration complexity and the computational complexity of the ADMM are established in the forms of theorems for our In SAR phase noise problem. Simulation results based on simulated and measured data show that this new In SAR phase noise reduction method not only is 3 orders of magnitude faster than the standard CVX solver, but also has a much better performance than the several existing phase filtering methods.

关键词： interferometric synthetic aperture radar phase noise reduction total variation regularization least squares formulation alternat

Mating patterns and pollen dispersal in a Japanese larch(Larix kaempferi) clonal seed orchard： a case study

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Science China(Life Sciences) 2018年第9期61卷 1011-1023页

作者： Xingbin Chen xiaomei Sun Leiming Dong Shougong zhang State Key Laboratory of Tree Genetics and Breeding Chinese Academy of ForestryBeijing100091China Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration Research Institute of Forestry Chinese Academy of ForestryBeijing 100091China Jiangxi Provincial Key Lab for Plant Biotechnology Jiangxi Academy of ForestryBeijing 100091 China

Pollination dynamics highly determines the genetic quality of seed orchard crops. However, there is less research about the effect of mating patterns on seed productivity of orchard crops. So far, clonal seed orchards have been producing genetically improved seedlings used for most Japanese larch(Larix kaempferi(Lamb.) Carr.) plantations in China. In the present study, a total of 17 highly variable simple sequence repeat(SSR) markers were used for genotyping a progeny trial population consisting of 647 open-pollinated progenies germinated from seeds which were collected from 63 maternal clones with 140 potential paternal clones in a Japanese larch clonal seed orchard in China. Paternity analysis was used in the present case study in order to evaluate the level of paternal gametic contribution, estimate pollen contamination and selfing rates, and investigate pollination patterns,pollen dispersal patterns and the impact of mating patterns on seed productivity of orchard crops. We observed 93.7% of the success rate of the parental assignment, unequal paternal gametic contribution(0–12.4%) with 6.3% of the progenies derived from pollen contamination or unsampled pollen donors, and absence of evidence for selfing. We also found that pollination rate highly depended on the distance between pollen donors and maternal parents, the majority of the identified crossing(65.7%)occurred between clones within a 150-m radius, and large variations in growth performance existed among the paternal halfsiblings. Progeny growth performance(diameter at breast(DBH) and height(HGT)) was measured at Age-20 in order to investigate the impact of mating patterns on timber production of orchard crops. As either the paternal or maternal, two clones(i.e., clones z38 and z62) were identified to have produced progenies with higher average stem volume breeding values than that of all of the progenies. Specifically, the genetic gains for volume were 3.53% for the two clones as paternal parents, and 8

关键词： Larix kaempferi simple sequence repeats(SSRs) paternity analysis pollen contamination pollen dispersal growth performance

Dynamic response of debris flows impacting curved joint check dams

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International Journal of Sediment Research 2022年第5期37卷 589-600页

作者： Dongpo Wang xiaomei zhang Wei Shen Aronne Armanini State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Sichuan Province Geological engineering Co. Ltd. Department of Biological Geological and Environmental Science University of Bologna Department of Civil Environmental and Mechanical Engineering University of Trento

The dynamic impact force of debris flow on dams with a curved upstream face curved was investigated using laboratory experiments and a theoretical approach. Equations describing the impact force and maximum run-up height were derived. The experiments and theoretical considerations reveal that the impact force and maximum run-up height are mainly controlled by the Froude number(Fr) reduced by the cosine of the channel slope angle(cosa). Both the impact force and the maximum run-up height have a quadratic relation with the modified Froude number(Fr/(cosa)0.5).The experimental data and the results of the theoretical approach are in good agreement, indicating that the theoretical approach can be used in practical applications. It is concluded that the comparison between the curved-joint dam and the more conventional sharp-joint dam shows no differences in the maximum impact force and run-up height for the same modified Froude *** the sharp-joint dam, the peak values of the impact force are reached more quickly than with the curved-joint dam.

关键词： Debris flow Curved-joint check-dam Impact force Maximum run-up height Impact response

Research on wind erosion processes and controlling factors based on wind tunnel test and 3D laser scanning technology

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Journal of Arid Land 2022年第9期14卷 1009-1021页

作者： YAN Ping WANG Xiaoxu z.eng Shucheng WANG Yong LI xiaomei Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China zhuhai Branch of State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityZhuhai 519087China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China MOE engineering Research Centre of Desertification and Blown-sand Control Beijing 100875China Institute of Geographical Sciences Henan Academy of SciencesZhengzhou 450052China School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China

The study of wind erosion processes is of great importance to the prevention and control of soil wind *** this study,three structurally intact soil samples were collected from the steppe of Inner Mongolia Autonomous Region,China and placed in a wind tunnel where they were subjected to six different wind speeds(10,15,17,20,25,and 30 m/s)to simulate wind erosion in the wind *** each test,the soil surfaces were scanned by a 3D laser scanner to create a high-resolution Digital Elevation Model(DEM),and the changes in wind erosion mass and microtopography were *** on this,we performed further analysis of wind erosion-controlling *** study results showed that the average measurement error between the 3D laser scanning method and weighing method was 6.23%for the three undisturbed soil *** increasing wind speed,the microtopography on the undisturbed soil surface first became smooth,and then fine stripes and pits gradually *** the initial stage of wind erosion processes,the ability of the soil to resist wind erosion was mainly affected by the soil *** the late stage of wind erosion processes,the degree of soil erosion was mainly affected by soil organic matter and CaCO_(3)*** results of this study are expected to provide a theoretical basis for soil wind erosion control and promote the application of 3D laser scanners in wind erosion monitoring.

关键词： 3D laser scanning technology wind erosion wind tunnel test wind erosion depth microtopography soil hardness

Efficient collision attacks on smart card implementations of masked AES

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Science China(Information Sciences) 2015年第5期58卷 97-111页

作者： WANG An WANG zongYue z.eng XueXin WANG xiaomei CHEN Man zHANG GuoShuang WU LiJi Institute of Microelectronics Tsinghua University Key Laboratory of Cryptologic Technology and Information Security Ministry of EducationShandong University China Academy of Electronics and Information Technology School of Computer and Communication engineering University of Science and TechnologyBeijing Science and Technology on Communication Security Laboratory

Collision attack is often employed against some cryptographic algorithms such as AES and *** a usual countermeasure, masking can resist such attacks to some extent. In CHES 2011, Clavier et *** a collision-correlation attack based on Pearson correlation coefficient against masking. In this paper, a collision distinguisher based on least absolute deviation against masking is proposed. Subsequently, we suggest three other distinguishers based on least square method, least exponent method, and central moment product,respectively. Our experiments and simulations show that in practice, our distinguishers based on least absolute deviation and least square method perform much better than collision-correlation attack and other proposed distinguishers in this paper. We also give four application examples, which show that even if the masks are not reused, new distinguishers are competent to collision attacks.

关键词： power analysis attack collision attack least absolute deviation least square method masking

Redox-triggered dearomative[5+1]annulation of indoles with O-alkyl ortho-oxybenzaldehydes for the synthesis of spirochromanes

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Organic Chemistry Frontiers 2022年第6期9卷 1668-1674页

作者： Lianyi Cao Fangzhi Hu Hongmei Sun xiaomei zhang Shuai-Shuai Li Asymmetric Synthesis and Chiraltechnology Key Laboratory of Sichuan Province Chengdu Institute of Organic ChemistryChinese Academy of SciencesChengduChina University of Chinese Academy of Sciences BeijingChina College of Chemistry and Pharmaceutical Sciences Qingdao Agricultural UniversityQingdao 266109China

The dearomative[5+1]annulation of 2-methylindoles with new five-membered synthons O-alkyl orthooxybenzaldehydes was developed unprecedentedly through cascade[1,5]-hydride transfer/dearomativecyclization in HFIP for the synthesis of spirochromanes bearing the 2-methylindolenine ***,the dual alkylation of the methyl group of 2-methylindolenines was achieved by sequential operation through the redox neutral[5+1]annulation with the second five-membered synthon N-alkylortho-aminobenzaldehyde,providing the chromane and tetrahydroquinoline fused spiroindolenines ingood ***,the auxiliary group that facilitates the hydride transfer process could be simplyremoved.

关键词： benzaldehyde alkyl indole

Longitudinal investigation of mineral composition in human milk and its correlation with infant anthropometric outcomes among Tibetan mother-infant dyads during the first 6 months postpartum

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Food Science and Human Wellness 2024年第5期13卷 2857-2865页

作者： xiaomei zhang Yaling Wang Junying zhao Weicang Qiao Yanpin Liu Lijun Chen National engineering Research Center of Dairy Health for Maternal and Child Beijing Sanyuan Foods Co.Ltd.Beijing 100163China Beijing engineering Research Center of Dairy Beijing Technical Innovation Center of Human Milk ResearchBeijing Sanyuan Foods Co.Ltd.Beijing 100163China

Nutrients in human milk,including minerals,relate growth and development of breast-fed *** mother-infant dyads possess unique characteristics on early nutrition due to their featured long-lasting *** study longitudinally investigated the relationship between the mineral composition in human milk and the z-scores of infants among Tibetan mother-infant dyads during their first 6 months postpartum through a prospective cohort *** results show that the minerals of Na,Mg,K,Ca,Cu,zn,and Se were of higher levels in colostrum than other lactation *** minerals were below the recommended values for infants according to Chinese dietary ***,a large proportion of infant z-scores were below-2 as lactation period *** statistical analysis revealed that classifications and correlations in varying degrees were observed between minerals in human milk and infant *** findings will be advantageous for research upon Chinese early nutrition and progress of tailor-made infant formula.

关键词： Tibetan mother-infant dyads Minerals z-scores Classification and correlation Breastfeeding

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Asian Herpetological Research 2014年第2期5卷 119-127页

作者： Ying HE Jianfang GAO Longhui LIN xiaomei MA Xiang JI Hangzhou Key Laboratory for Animal Adaptation and Evolution School of Life Sciences Hangzhou Normal University Jiangsu Key Laboratory for Biodiversity and Biotechnology College of Life Sciences Nanjing Normal University

In this study we explored electrophoretic profiles, enzymatic activities and immunoreactivity of neonate and adult venoms from two snakes （Naja atra and Deinagkistrodon acutus） coexisting in southeastern China. Age-related variation in electrophoretic profiles was found in both species and proteolytic and fibrinogenolytic activity was higher in neonate than adult venoms. Neonate D. acutus venom had higher 5＇ nucleotidase, PLA2, hyaluronidase and gelatinolytie activity, but lower esterolytic activity, than adult venom. Neonate and adult D. acutus venoms showed identical phosphomonoesterase, LAO and fibrinolytic activities. Neonate N. atra venom had higher phosphomonoesterase and LAO activity, but lower 5＇ nucleotidase, PLA2, hyaluronidase and Ache activities than adult venom. Neonate and adult N. atra venoms showed similar gelatinolytic activity. Further, age-dependent immunoreactivity was found in both species, and cross-reactions between homologous venoms and antiserums were closely related to venom composition. We speculate that age-related variation in venom characteristics is possibly driven by evolutionary forces associated with ontogenetic shifts in dietary habits, competition and predation pressure.

关键词： Naja atra Deinagkistrodon acutus Age-related variation Electrophoretic profile Enzymatic activity,Immunoreactivity

Aquaculture area extraction and vulnerability assessment in Sanduao based on richer convolutional features network model

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Journal of Oceanology and Limnology 2019年第6期37卷 1941-1954页

作者： LIU Yueming YANG xiaomei WANG zhihua LU Chen LI zhi YANG Fengshuo State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing 210023China

Sanduao is an important sea-breeding bay in Fujian,South China and holds a high economic status in *** and accurately obtaining information including the distribution area,quantity,and aquaculture area is important for breeding area planning,production value estimation,ecological survey,and storm surge ***,as the aquaculture area expands,the seawater background becomes increasingly complex and spectral characteristics differ dramatically,making it difficult to determine the aquaculture *** this study,we used a high-resolution remote-sensing satellite GF-2 image to introduce a deep-learning Richer Convolutional Features(RCF)network model to extract the aquaculture *** we used the density of aquaculture as an assessment index to assess the vulnerability of aquaculture areas in *** results demonstrate that this method does not require land and water separation of the area in advance,and good extraction can be achieved in the areas with more sediment and waves,with an extraction accuracy>93%,which is suitable for large-scale aquaculture area *** assessment results indicate that the density of aquaculture in the eastern part of Sanduao is considerably high,reaching a higher vulnerability level than other parts.

关键词： aquaculture area vulnerability assessment Richer Convolutional Features(RCF)network model deep learning high-resolution remote sensing