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Species’ geographical range, environmental range and traits lead to specimen collection preference of dominant plant species of grasslands in Northern China
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作者 Jingya Zhang Cui Xiao +5 位作者 Xiaoyu Duan Xin Gao Hao Zeng Rong'an Dong Gang Feng Keping Ma 《Plant Diversity》 SCIE CAS CSCD 2024年第3期353-361,共9页
Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection preference.This study aims to determine whether grassland specimen collection... Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection preference.This study aims to determine whether grassland specimen collection in China is preferred by species traits(i.e.,plant height,flowering and fruiting period),environmental range(i.e.,the temperature and precipitation range)and geographical range(i.e.,distribution range and altitudinal range).Ordinary least squares models and phylogenetic generalized linear mixed models were used to analyze the relationships between specimen number and the explanatory variables.Random Forest models were then used to find the most parsimonious multivariate model.The results showed that interannual variation in specimen number between 1900 and 2020 was considerable.Specimen number of these species in southeast China was notably lower than that in northwest China.Environmental range and geographical range of species had significant positive correlations with specimen number.In addition,there were relatively weak but significant associations between specimen number and species trait(i.e.,plant height and flowering and fruiting period).Random Forest models indicated that distribution range was the most important variable,followed by flowering and fruiting period,and altitudinal range.These findings suggest that future floristic surveys should pay more attention to species with small geographical range,narrow environmental range,short plant height,and short flowering and fruiting period.The correction of specimen collection preference will also make the results of species distribution model,species evolution and other works based on specimen data more accurate. 展开更多
关键词 Biological specimen Collection preference Dominant plant species Environmental range Geographical range Species traits
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三维薛定谔方程组的线性Profile分解
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作者 韩依洋 廖梦兰 《湘潭大学学报(自然科学版)》 CAS 2024年第2期44-49,共6页
为了研究线性薛定谔方程组解Strichartz估计的紧性缺失问题,针对H•^(1)(R^(3))×H•^(1)(R^(3))中的三维线性薛定谔方程组的有界解向量序列,使用解序列的Profile分解方法,构造为解向量子列的(1/√h_(n))U(t-t_(n))/h_(n)^(2),(x-x_(n... 为了研究线性薛定谔方程组解Strichartz估计的紧性缺失问题,针对H•^(1)(R^(3))×H•^(1)(R^(3))中的三维线性薛定谔方程组的有界解向量序列,使用解序列的Profile分解方法,构造为解向量子列的(1/√h_(n))U(t-t_(n))/h_(n)^(2),(x-x_(n))/h_(n)类型的Profile分解和.其中,U是线性薛定谔方程组的解向量,在Strichartz范数估计下具有一个很小的余项.首先确定伸缩变换参数序列族,利用傅里叶变换和迭代的思想确定Profile分解族.其次验证了Profile分解和的收敛性,说明了Strichartz范数下余项的收敛性.最后证明了当线性薛定谔方程组的解序列有界时,都可以分解为解向量子列和的形式. 展开更多
关键词 薛定谔方程组 profile分解 STRICHARTZ估计 Sobolev嵌入 傅里叶变换
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Deep learning approaches to recover the plasma current density profile from the safety factor based on Grad–Shafranov solutions across multiple tokamaks
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作者 张瀚予 周利娜 +6 位作者 刘钺强 郝广周 王硕 杨旭 苗雨田 段萍 陈龙 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第5期17-28,共12页
Many magnetohydrodynamic stability analyses require generation of a set of equilibria with a fixed safety factor q-profile while varying other plasma parameters.A neural network(NN)-based approach is investigated that... Many magnetohydrodynamic stability analyses require generation of a set of equilibria with a fixed safety factor q-profile while varying other plasma parameters.A neural network(NN)-based approach is investigated that facilitates such a process.Both multilayer perceptron(MLP)-based NN and convolutional neural network(CNN)models are trained to map the q-profile to the plasma current density J-profile,and vice versa,while satisfying the Grad–Shafranov radial force balance constraint.When the initial target models are trained,using a database of semianalytically constructed numerical equilibria,an initial CNN with one convolutional layer is found to perform better than an initial MLP model.In particular,a trained initial CNN model can also predict the q-or J-profile for experimental tokamak equilibria.The performance of both initial target models is further improved by fine-tuning the training database,i.e.by adding realistic experimental equilibria with Gaussian noise.The fine-tuned target models,referred to as fine-tuned MLP and fine-tuned CNN,well reproduce the target q-or J-profile across multiple tokamak devices.As an important application,these NN-based equilibrium profile convertors can be utilized to provide a good initial guess for iterative equilibrium solvers,where the desired input quantity is the safety factor instead of the plasma current density. 展开更多
关键词 plasma equilibrium deep learning safety factor profile current density profile TOKAMAK
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Three-Channel Interference Interpretation of Fano Profile
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作者 李波 李天钧 +3 位作者 马子茹 王希源 黄新朝 朱林繁 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第5期30-34,共5页
Fano resonance is a ubiquitous phenomenon, and it is commonly interpreted as a two-channel interference of the discrete and continuous channels. The present work investigates the Fano profile from a perspective of the... Fano resonance is a ubiquitous phenomenon, and it is commonly interpreted as a two-channel interference of the discrete and continuous channels. The present work investigates the Fano profile from a perspective of the temporal evolution of the wave function. By exciting the atom with a δ pulse and calculating the evolution of the wave function, the Fano formula is deduced. The results clearly show that the Fano resonance is of a three-channel interference, which is different from the traditional understanding. The three channels are revealed as the groundcontinuum, ground-discrete-continuum, and a previously unmentioned third channel, i.e., ground-continuumdiscrete-continuum. The present three-channel interpretation can be easily generalized to other physical systems,contributing to a deeper understanding of the Fano profile. 展开更多
关键词 FUNCTION profile CONTINUUM
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Genomic Profile of SARS-COV-2 Associated with COVID-19 Outbreaks in N’Djamena, Chad
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作者 Mathieu Hota Henry Yandai Fissou +2 位作者 Dezoumbe Koutaya Djallaye Djimtoïbaye Mahamat Moussa Ali 《Advances in Bioscience and Biotechnology》 CAS 2024年第7期432-442,共11页
Background: SARS-CoV-2 has circulated worldwide with dramatic consequences. In Chad, we have no data reported of variants. The aim of this study was to identify the SARS-CoV-2 variants that circulated during the epide... Background: SARS-CoV-2 has circulated worldwide with dramatic consequences. In Chad, we have no data reported of variants. The aim of this study was to identify the SARS-CoV-2 variants that circulated during the epidemic from 2020 to 2021. Methods: This is a cross-sectional, descriptive study carried out between 2020 and 2021. Samples from patients with suspected COVID-19 were tested in five laboratories in N’Djamena. One hundred quality samples of the positives were sequenced in Kinshasa using Oxford nanopore technologies minion and the Protocol Midnight SARS-CoV2. Data were processed using Excel version 16 software. Results: Of the 100 samples sequenced, 77 (77%) produced sequences, 23 (23%) did not. The genomic profiles were wild-type Wuhan and minor mutations (19A, 19B (A), 20A (B.1, B.2), 20B (AV.1), 20D (B.1.1.1 /C.36), 20C), variant of concern Alpha (20I), variant of concern Delta (21A/J), variant of interest Eta (21D), variant of concern Omicron (21K) and unclassified variant under surveillance (B.1.640). Of these variants, the maximums were detected in patients aged 26 - 35 with 30.26% and 25.26% in 36 - 45. However, 24.67% were in travelers and 75.32% in residents, 35.06% in those vaccinated against COVID-19 and 62.33% in non-vaccinates. The estimated case-fatality rate was 2.44% (107/4374). Conclusion: This work has provided preliminary data on COVID-19 and SARS-CoV-2 variants circulating during the 2020-2021 epidemics in Chad. 展开更多
关键词 COVID-19 SARS-CoV-2 Genomic profile VARIANT CHAD
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Baseline design of the KunLun Turbulence Profiler instrument
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作者 Xiaohui Guo Yi Hu +2 位作者 Jing Li Xu Yang Zhengzhou Yan 《Astronomical Techniques and Instruments》 CSCD 2024年第4期218-226,共9页
Adaptive optics systems are the most powerful tools to counteract the image blurring caused by atmospheric turbulence,allowing ground-based telescopes to capture high-resolution images.A critical parameter influencing... Adaptive optics systems are the most powerful tools to counteract the image blurring caused by atmospheric turbulence,allowing ground-based telescopes to capture high-resolution images.A critical parameter influencing adaptive optics system performance is the atmospheric refractive index structure constant,C_(n)^(2),which characterizes the intensity of atmospheric optical turbulence as a function of altitude.Given its simplicity,the lunar scintillometer is the preferred method for detecting atmospheric turbulence in challenging environments like Dome A in Antarctica,where sites are still in the developmental stages and local environmental conditions are extremely harsh.However,optimizing the performance of such instruments requires carefully determining the baseline configuration of photon sensors according to each site's specific optical turbulence profile characteristics.This study uses a Monte Carlo method to identify the optimal configuration for the KunLun Turbulence Profiler(KLTP),an instrument comparable to the lunar scintillometer,developed for use at Dome A.Simulations conducted using the obtained optimal baseline configuration recovered three different model optical turbulence profiles,demonstrating the effectiveness of our method in obtaining an optimal baseline configuration.Our approach can be easily applied to baseline design for similar turbulence profilers at other sites. 展开更多
关键词 KunLun Turbulence profiler Monte Carlo Simulation Turbulence profile
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Profile of Full-Term Births in Maternity Wards of Public Hospitals in Douala Cameroon
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作者 Henri Essome Merlin Boten Bounyom +14 位作者 Astrid Ndolo Kondo Ingrid Doriane Ofakem Ilick Fulbert Mangala Nkwele Irène Cyrielle Edjoa Mboe Michel Roger Ekono Alphonse Ngalame Nyong Robert Tchounzou Moustapha Bilkissou Junie Ngaha Yaneu Marga Vanina Ngono Akam Gervais Mounchikpou Ngouhouo Grâce Tocki Toutou Théophile Nana Njamen Valère Mve Koh Pascal Foumane 《Open Journal of Obstetrics and Gynecology》 2024年第5期705-720,共16页
Introduction: Pregnancy as much as childbirth constitutes a risky situation, potentially fraught with sometimes dramatic complications: maternal death. Objective: We conducted this study with the aim of establishing t... Introduction: Pregnancy as much as childbirth constitutes a risky situation, potentially fraught with sometimes dramatic complications: maternal death. Objective: We conducted this study with the aim of establishing the profile of those giving birth in our context with the aim to anticipate operationally in the future on morbidity but more on maternal deaths. Methodology: We conducted, using a structured questionnaire, a prospective descriptive study in representative maternity wards in the city of Douala;the study variables were socio-economic, anthropometric, obstetrical and clinical. Statistical analyses were carried out with CS Pro 7.3 and SPSS version 25.0 software. The Student, Chi-square and Fischer tests were used to compare the means of the variables and the percentages. Results: We recruited 305 births for our study. The average age of our births was 28.7 years ± 6.1 with an average height of 161.6 cm ± 5.06;an average body mass index at the start of pregnancy of 28.0 kilograms/square meter and 31.3 kilograms/square meter at delivery;the average weight gain was 8.4 g ± 5.37;an average gestation of 2.84±1.90;an average parity of 2.2 ± 2.1 with an average birth interval of 27.7 months ± 23.7. The average gestational age was 39.2 weeks ± 1.21 with pregnancy pathology dominated by malaria;85.9% began their prenatal follow-up before the 14th week of amenorrhea. Conclusion: The profile of childbirth in urban Cameroon does not seem potentially dystocic compared to that of the same regional and racial area. 展开更多
关键词 profile Delivery TERM MALARIA Douala
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Extraction of Acoustic Normal Mode Depth Functions Using Range-Difference Method with Vertical Linear Array Data
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作者 GAO Siyu LI Weilu +2 位作者 ZHANG Yinquan LI Xiaolei WANG Ning 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第4期871-882,共12页
Data-derived normal mode extraction is an effective method for extracting normal mode depth functions in the absence of marine environmental data.However,when the corresponding singular vectors become nonunique when t... Data-derived normal mode extraction is an effective method for extracting normal mode depth functions in the absence of marine environmental data.However,when the corresponding singular vectors become nonunique when two or more singular values obtained from the cross-spectral density matrix diagonalization are nearly equal,this results in unsatisfactory extraction outcomes for the normal mode depth functions.To address this issue,we introduced in this paper a range-difference singular value decomposition method for the extraction of normal mode depth functions.We performed the mode extraction by conducting singular value decomposition on the individual frequency components of the signal's cross-spectral density matrix.This was achieved by using pressure and its range-difference matrices constructed from vertical line array data.The proposed method was validated using simulated data.In addition,modes were successfully extracted from ambient noise. 展开更多
关键词 range difference depth function extraction normal mode
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Immunovirological Profile of HIV1 Infection in Children and Adolescents Followed at the Bangui Pediatric University Hospital
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作者 Simplice Cyriaque Kango Synthia Ningatoloum Nazita +3 位作者 Marie Colette Nganda-Bangue Michaël Dan-Houron Alexandre Manirakiza Jean Chrysostome Gody 《Open Journal of Pediatrics》 2024年第3期585-597,共13页
History: Pediatric management of HIV infection in children in the Central African Republic began in 2004 with the use of fractionated adult antiretrovirals and Cotrimoxazole. It has evolved over the years with the use... History: Pediatric management of HIV infection in children in the Central African Republic began in 2004 with the use of fractionated adult antiretrovirals and Cotrimoxazole. It has evolved over the years with the use of pediatric forms, oral suspensions and dispersible tablets. The transition to Dolutegravir took place in 2020. The active file of our patients will grow from 78 to over 1900 today. Follow-up examinations are carried out to assess adherence to treatment. Objective: To determine the immunovirological profile and factors associated with treatment failure during follow-up of children on ART at the Bangui pediatric university hospital. Patients and Method: This was a cross-sectional, analytical study from May 30 to December 02, 2022. The study sample was drawn from a cohort of HIV-1-infected children followed up at the Bangui pediatric university hospital and on ART for three semesters who met the selection criteria. Results: The prevalence of treatment failure varied from one semester to the next. Thus, the prevalence of therapeutic failure was 20% in the first semester, 10% in the second semester and 7% in the third semester. The prevalence of virological failure was 10.28% in the first half of the year, 6.91% in the second half and 4.98% in the third. Secondly, immunological failure was 0.48% in the first half of the year, 0.32% in the second 0.64% in the third half. Finally, clinical failure was 8.82% in the first half, 4.82% in the second half, 1.92% in the third half. Socio-demographic and clinical factors associated with treatment failure were male gender (p 1000 copies/ml (p Conclusion: The occurrence of treatment failures in children is a major problem, especially in our resource-limited countries, given the challenges facing antiretroviral therapy. It is therefore necessary to carry out a study on resistance genotyping in order to propose correct management protocols, as the future of treatment programs depends on it. 展开更多
关键词 profile Immunovirological HIV/AIDS CHILDREN Bangui
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TP-PROFILE: Monitoring the Thermodynamic Structure of the Troposphere over the Third Pole
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作者 Xuelong CHEN Yajing LIU +6 位作者 Yaoming MA Weiqiang MA Xiangde XU Xinghong CHENG Luhan LI Xin XU Binbin WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第6期1264-1277,共14页
Ground-based microwave radiometers(MWRs)operating in the K-and V-bands(20–60 GHz)can help us obtain temperature and humidity profiles in the troposphere.Aside from some soundings from local meteorological observatori... Ground-based microwave radiometers(MWRs)operating in the K-and V-bands(20–60 GHz)can help us obtain temperature and humidity profiles in the troposphere.Aside from some soundings from local meteorological observatories,the tropospheric atmosphere over the Tibetan Plateau(TP)has never been continuously observed.As part of the Chinese Second Tibetan Plateau Scientific Expedition and Research Program(STEP),the Tibetan Plateau Atmospheric Profile(TPPROFILE)project aims to construct a comprehensive MWR troposphere observation network to study the synoptic processes and environmental changes on the TP.This initiative has collected three years of data from the MWR network.This paper introduces the data information,the data quality,and data downloading.Some applications of the data obtained from these MWRs were also demonstrated.Our comparisons of MWR against the nearest radiosonde observation demonstrate that the TP-PROFILE MWR system is adequate for monitoring the thermal and moisture variability of the troposphere over the TP.The continuous temperature and moisture profiles derived from the MWR data provide a unique perspective on the evolution of the thermodynamic structure associated with the heating of the TP.The TP-PROFILE project reveals that the low-temporal resolution instruments are prone to large uncertainties in their vapor estimation in the mountain valleys on the TP. 展开更多
关键词 microwave radiometer thermodynamic structure vertical profile Tibetan Plateau
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Neurocognitive Profile of People Living with Human Immunodeficiency Virus Initiating Treatment in Kinshasa in the Dolutegravir Era, Democratic Republic of Congo
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作者 Candide About Kabamba Berry Ikolango Bongenya +10 位作者 Jocelyn Ewuti Nonga Lambert Omombo Losenga Noëlla Maketi Dikati Thérèse Kasaka Ntumba Grace Ipaya Booto Rosalie Djamba Dembo Stéphanie Mauwa Selenge Benoit Obel Kabengele Guy Makila Mabe Bumoko Marie-Thérèse Ayane Safi Sombo Erick Ntambwe Kamangu 《Neuroscience & Medicine》 2024年第1期1-22,共22页
Context: Antiretroviral therapies improve the prognosis of NeuroAIDS contrasting with a high frequency of Minor Neurocognitive Disorders (MND) even in aviremic subjects. Objective: The objective of this study is to pr... Context: Antiretroviral therapies improve the prognosis of NeuroAIDS contrasting with a high frequency of Minor Neurocognitive Disorders (MND) even in aviremic subjects. Objective: The objective of this study is to present the neurological and cognitive profile of People Living with HIV (PLHIV) initiating antiretroviral treatment in Kinshasa in the era of Dolutegravir (DTG). Methods: This is a multicenter, cross-sectional study with a descriptive aim carried out in 16 HIV Outpatient Treatment Centers (OTC) in Kinshasa from October 4, 2021 to February 15, 2022. The International HIV Dementia Scale (IHDS) correlated with the Activities of Daily Living (IADL) scale facilitated the categorization of NeuroCognitive Disorders (NCD) of PLHIV evaluated after carrying out a summary neurological examination. Results: Of the 96 patients recruited, 56.3% were women with a sex ratio of 0.68. The average age was 40.1 ± 12.1 years. The secondary education level was the majority at 64.6%. Malaria (44.8%) and tuberculosis (32.3%) were more common as opportunistic infections. They were alcoholics in (30.2%). Their history was heart disease (15.6%), high blood pressure (18.8%);drug abuse (10.4%). The IHDS score was light in 55.2% of cases. The correlation between IHDS/IADL watches asymptomatic neurocognitive impairments (ANI) in 77.1%, almost all of subjects are found with normal overall functioning (94.8%) and a disturbed neurological examination in 53.1% of cases with a predominance of motor impairments in 79.1%. Conclusion: In view of these results, early and systematic screening of NCD and associated factors remains necessary in our context. . 展开更多
关键词 IHDS Dolutegravir Initiation KINSHASA Neurological profile PLHIV
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Bacteriological Profile of Effusion Fluids Infections at Charles De Gaulle University Pediatric Hospital from 2017 to 2020
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作者 Kambiré Dinanibè Ouédraogo Oumarou +14 位作者 Tiendrebéogo Salam Tondé Issa Tamboura Mamadou Zida Sylvie Kpoda Dissinviel Sagna Tani Compaoré T. Rebeca Zouré Abdou-Azaque Soubeiga R. Serge Théophile Sawadogo Stanislas Ilboudo Maïmouna Rouamba Hortense Ouédraogo Wenkouni Henri Gautier Ouédraogo-Traoré Rasmata Sanou Mahamoudou 《Open Journal of Medical Microbiology》 2024年第2期146-163,共18页
Introduction: Microbiology of effusion fluids in children in Burkina Faso is characterized by the scarcity of data. This work aimed to study the bacteriological and antibiotics susceptibility profile of bacteria invol... Introduction: Microbiology of effusion fluids in children in Burkina Faso is characterized by the scarcity of data. This work aimed to study the bacteriological and antibiotics susceptibility profile of bacteria involved in effusion fluid infections in paediatrics in order to improve the choice of probabilistic antibiotics therapy. Methods: A cross-sectional, descriptive study was used in children aged 0 to 15 years from 2017 to 2020 at the Charles De Gaulle Pediatric University Hospital Center (CHUP-CDG) in Ouagadougou. Classical bacteriology methods such as macroscopy, Gram staining, identification galleries and antibiotics susceptibility testing were used. Results: Of 231 samples, 64 bacteria were isolated. The most common bacterial strains of pleural fluid were Staphylococcus aureus (25%) and 40% for Enterobacteriaceae. Of the peritoneal fluid, 77% were Enterobacteriaceae with 57% Escherichia coli;and from joint fluid, 33% were S. aureus and 22% for P. aeruginosa. The overall susceptibility profile showed 29% extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL), 10% methicillin-resistant S. aureus (MRSA), and 8% carbapenemases. Conclusion: Bacteriological profile is characterized by ESBL-producing Enterobacteriaceae and MRSA. The most active antibiotics were macrolides, aminoglycosides, and cefoxitin (methicillin) for Gram-positive cocci, carbapenems, and aminoglycosides for Gram-negative bacilli. Then, the monitoring of antibiotics resistance must be permanent. 展开更多
关键词 Bacteriological profile Effusion Fluid INFECTIONS
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An efficient physics-guided Bayesian framework for predicting ground settlement profile during excavations in clay
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作者 Cong Tang Shuyu He Wanhuan Zhou 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1411-1424,共14页
Recently,the application of Bayesian updating to predict excavation-induced deformation has proven successful and improved prediction accuracy significantly.However,updating the ground settlement profile,which is cruc... Recently,the application of Bayesian updating to predict excavation-induced deformation has proven successful and improved prediction accuracy significantly.However,updating the ground settlement profile,which is crucial for determining potential damage to nearby infrastructures,has received limited attention.To address this,this paper proposes a physics-guided simplified model combined with a Bayesian updating framework to accurately predict the ground settlement profile.The advantage of this model is that it eliminates the need for complex finite element modeling and makes the updating framework user-friendly.Furthermore,the model is physically interpretable,which can provide valuable references for construction adjustments.The effectiveness of the proposed method is demonstrated through two field case studies,showing that it can yield satisfactory predictions for the settlement profile. 展开更多
关键词 Bayesian updating EXCAVATIONS Ground settlement profile Simplified model UNCERTAINTY
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Image Steganography by Pixel-Value Differencing Using General Quantization Ranges
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作者 Da-Chun Wu Zong-Nan Shih 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期353-383,共31页
A new steganographic method by pixel-value differencing(PVD)using general quantization ranges of pixel pairs’difference values is proposed.The objective of this method is to provide a data embedding technique with a ... A new steganographic method by pixel-value differencing(PVD)using general quantization ranges of pixel pairs’difference values is proposed.The objective of this method is to provide a data embedding technique with a range table with range widths not limited to powers of 2,extending PVD-based methods to enhance their flexibility and data-embedding rates without changing their capabilities to resist security attacks.Specifically,the conventional PVD technique partitions a grayscale image into 1×2 non-overlapping blocks.The entire range[0,255]of all possible absolute values of the pixel pairs’grayscale differences in the blocks is divided into multiple quantization ranges.The width of each quantization range is a power of two to facilitate the direct embedding of the bit information with high embedding rates.Without using power-of-two range widths,the embedding rates can drop using conventional embedding techniques.In contrast,the proposed method uses general quantization range widths,and a multiple-based number conversion mechanism is employed skillfully to implement the use of nonpower-of-two range widths,with each pixel pair being employed to embed a digit in the multiple-based number.All the message bits are converted into a big multiple-based number whose digits can be embedded into the pixel pairs with a higher embedding rate.Good experimental results showed the feasibility of the proposed method and its resistance to security attacks.In addition,implementation examples are provided,where the proposed method adopts non-power-of-two range widths and employsmultiple-based number conversion to expand the data-hiding and steganalysis-resisting capabilities of other PVD methods. 展开更多
关键词 STEGANOGRAPHY pixel-value differencing multiple-based number conversion general quantization range
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Multi-circular formation control with reinforced transient profiles for nonholonomic vehicles:A path-following framework
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作者 Jintao Zhang Xingling Shao +1 位作者 Wendong Zhang Zongyu Zuo 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期278-287,共10页
This article investigates a multi-circular path-following formation control with reinforced transient profiles for nonholonomic vehicles connected by a digraph.A multi-circular formation controller endowed with the fe... This article investigates a multi-circular path-following formation control with reinforced transient profiles for nonholonomic vehicles connected by a digraph.A multi-circular formation controller endowed with the feature of spatial-temporal decoupling is devised for a group of vehicles guided by a virtual leader evolving along an implicit path,which allows for a circumnavigation on multiple circles with an anticipant angular spacing.In addition,notice that it typically imposes a stringent time constraint on time-sensitive enclosing scenarios,hence an improved prescribed performance control(IPPC)using novel tighter behavior boundaries is presented to enhance transient capabilities with an ensured appointed-time convergence free from any overshoots.The significant merits are that coordinated circumnavigation along different circles can be realized via executing geometric and dynamic assignments independently with modified transient profiles.Furthermore,all variables existing in the entire system are analyzed to be convergent.Simulation and experimental results are provided to validate the utility of suggested solution. 展开更多
关键词 Multi-circular formation Reinforced transient profiles Nonholonomic vehicles Path following
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LFM Radar Source Passive Localization Algorithm Based on Range Migration
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作者 Dandan Li Deyi Wang Hao Huan 《Journal of Beijing Institute of Technology》 EI CAS 2024年第2期130-140,共11页
Traditional single-satellite passive localization algorithms are influenced by frequency and angle measurement accuracies,resulting in error estimation of emitter position on the order of kilometers.Subsequently,a sin... Traditional single-satellite passive localization algorithms are influenced by frequency and angle measurement accuracies,resulting in error estimation of emitter position on the order of kilometers.Subsequently,a single-satellite localization algorithm based on passive synthetic aper-ture(PSA)was introduced,enabling high-precision positioning.However,its estimation of azimuth and range distance is considerably affected by the residual frequency offset(RFO)of uncoopera-tive system transceivers.Furthermore,it requires data containing a satellite flying over the radia-tion source for RFO search.After estimating the RFO,an accurate estimation of azimuth and range distance can be carried out,which is difficult to achieve in practical situations.An LFM radar source passive localization algorithm based on range migration is proposed to address the dif-ficulty in estimating frequency offset.The algorithm first provides a rough estimate of the pulse repetition time(PRT).It processes intercepted signals through range compression,range interpola-tion,and polynomial fitting to obtain range migration observations.Subsequently,it uses the changing information of range migration and an accurate PRT to formulate a system of nonlinear equations,obtaining the emitter position and a more accurate PRT through a two-step localization algorithm.Frequency offset only induces a fixed offset in range migration,which does not affect the changing information.This algorithm can also achieve high-precision localization in squint scenar-ios.Finally,the effectiveness of this algorithm is verified through simulations. 展开更多
关键词 passive localization range migration residual frequency offset
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The interaction between temperature and precipitation on the potential distribution range of Betula ermanii in the alpine treeline ecotone on the Changbai Mountain
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作者 Yu Cong Yongfeng Gu +8 位作者 Wen J.Wang Lei Wang Zhenshan Xue Yingyi Chen Yinghua Jin Jiawei Xu Mai-He Li Hong S.He Ming Jiang 《Forest Ecosystems》 SCIE CSCD 2024年第1期42-51,共10页
Alpine treeline ecotones are highly sensitive to climate warming.The low temperature-determined alpine treeline is expected to shift upwards in response to global warming.However,little is known about how temperature ... Alpine treeline ecotones are highly sensitive to climate warming.The low temperature-determined alpine treeline is expected to shift upwards in response to global warming.However,little is known about how temperature interacts with other important factors to influence the distribution range of tree species within and beyond the alpine treeline ecotone.Hence,we used a GF-2 satellite image,along with bioclimatic and topographic variables,to develop an ensemble suitable habitat model based on the species distribution modeling algorithms in Biomod2.We investigated the distribution of suitable habitats for B.ermanii under three climate change scenarios(i.e.,low(SSP126),moderate(SSP370)and extreme(SSP585)future emission trajectories)between two consecutive time periods(i.e.,current-2055,and 2055-2085).By 2055,the potential distribution range of B.ermanii will expand under all three climate scenarios.The medium and high suitable areas will decline under SSP370 and SSP585scenarios from 2055 to 2085.Moreover,under the three climate scenarios,the uppermost altitudes of low suitable habitat will rise to 2,329 m a.s.l.,while the altitudes of medium and high suitable habitats will fall to 2,201 and2,051 m a.s.l.by 2085,respectively.Warming promotes the expansion of B.ermanii distribution range in Changbai Mountain,and this expansion will be modified by precipitation as climate warming continues.This interaction between temperature and precipitation plays a significant role in shaping the potential distribution range of B.ermanii in the alpine treeline ecotone.This study reveals the link between environmental factors,habitat distribution,and species distribution in the alpine treeline ecotone,providing valuable insights into the impacts of climate change on high-elevation vegetation,and contributing to mountain biodiversity conservation and sustainable development. 展开更多
关键词 Biomod2 BIRCH Climate change Climate scenarios Habitat suitability range shift Treeline species
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Kinetic equilibrium reconstruction with internal safety factor profile constraints on EAST tokamak
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作者 樊皓尘 李国强 +10 位作者 钱金平 张学习 邬潇河 储宇奇 朱翔 连辉 刘海庆 吕波 金仡飞 臧庆 黄佳 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第4期61-67,共7页
Reconstruction of plasma equilibrium plays an important role in the analysis and simulation of plasma experiments. The kinetic equilibrium reconstruction with pressure and edge current constraints has been employed on... Reconstruction of plasma equilibrium plays an important role in the analysis and simulation of plasma experiments. The kinetic equilibrium reconstruction with pressure and edge current constraints has been employed on EAST tokamak. However, the internal safety factor(q) profile is not accurate. This paper proposes a new way of incorporating q profile constraints into kinetic equilibrium reconstruction. The q profile is yielded from the Polarimeter Interferometer(POINT)reconstruction. Virtual probes containing information on q profile constraints are added to inputs of the kinetic equilibrium reconstruction program to obtain the final equilibrium. The new equilibrium produces a more accurate internal q profile. This improved method would help analyze EAST experiments. 展开更多
关键词 equilibrium reconstruction tokamak data analysis kinetic equilibrium q profile polarimeter-interferometer
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Radical Hysterectomy in Cervical Cancer: Patients’ Epidemiological and Clinical Profiles and Perioperative Outcome in Two Referral Hospitals in Cameroon
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作者 Théophile Njamen Nana Robert Tchounzou +16 位作者 Fulbert Nkwele Mangala Alphonse Ngalame Henri Essome Sedrick Tiokeng Sidonie Noa Ananga Andrew Tassang Humphry Tatah Neng Isaac Mboh Eyong Gaetan Andre Wambo Simo Felix Adolphe Elong Fidelia Kobenge Mbi Junior Cédric Nana Njamen Charlotte Tchente Nguefack Thomas Obinchemti Egbe Gregory Ekane Halle Emile Telesphore Mboudou Marcellin Ngowe Ngowe 《Open Journal of Obstetrics and Gynecology》 2024年第3期466-479,共14页
Background: Cervical cancer (CC) is one of the most frequent cancers and the leading cause of death from gynecological cancer in Low and middle income countries, Cameroon inclusive. Surgery is the primary treatment mo... Background: Cervical cancer (CC) is one of the most frequent cancers and the leading cause of death from gynecological cancer in Low and middle income countries, Cameroon inclusive. Surgery is the primary treatment modality when the disease is diagnosed at early stage. Radical hysterectomy in cervical cancer has not been evaluated in recent years in Cameroon. The purpose of this study is thus to evaluate the epidemiological and clinical features and short term outcomes of patients who underwent surgery. Patients and methods: This retrospective study was conducted at the Douala Gynaeco-obstetric and Pediatric Hospital and the Douala General Hospital. Cervical cancer patients who underwent Radical hysterectomy between January 2015 and December 2020 were included. A pre-established data collection tool was used to record socio-demographic, clinical and outcomes information from patients’ files;additional outcome information was obtained from phone calls. Descriptive analysis was done using the SPSS version 26. Bivariate analysis was used to determine associations between disease and patients characteristics and occurrence of adverse postoperative outcome. P value of 0.05 was considered. Results: Sixty one patients were enrolled. Their ages ranged from 33 to 74 years with a mean age of 51.95 ± 10.29 years. Over 85% of women were married, 65.57% were unemployed and 86.88% were multiparous. Only 28% had never done cervical cancer screening. Most patients had stage IB1 to IB2 stage disease (57.1%). Less than 9% underwent radical hysterectomy and 8 of those (13.11%) suffered intraoperative complications. Twenty-five patients (40.98%) presented immediate and short term complications. There was no significant association between the disease or patients’ characteristics and adverse outcomes. Conclusion: Cervical cancer patients are relatively young in our settings and only 9% of them reach the hospital at early stage. Postoperative adverse outcomes rate is higher than that reported in the literature. Sensitization on screening and awareness of early symptoms can reverse the situation. 展开更多
关键词 Cervical Cancer Radical Hysterectomy Epidemiological and Clinical profiles OUTCOMES Cameroon
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Profiles of the Headspace Volatile Organic and Essential Oil Compounds from the Tunisian Cardaria draba (L.) Desv. and Its Leaf and Stem Epidermal Micromorphology
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作者 Wissal Saadellaoui Samiha Kahlaoui +6 位作者 Kheiria Hcini Abir Haddada Noomene Sleimi Roberta Ascrizzi Guido Flamini Fethia Harzallah-Skhiri Sondes Stambouli-Essassi 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第4期725-744,共20页
In this work, we investigated aroma volatiles emanated by dry roots, stems, leaves, flowers, and fruits of Cardariadraba (L.) Desv. growing wild in Tunisia and its aerial part essential oils (EOs) composition. A total... In this work, we investigated aroma volatiles emanated by dry roots, stems, leaves, flowers, and fruits of Cardariadraba (L.) Desv. growing wild in Tunisia and its aerial part essential oils (EOs) composition. A total of 37 volatileorganic compounds (96.7%–98.9%) were identified;4 esters, 4 alcohols, 7 hydrocarbons, 12 aldehydes, 5 ketones,1 lactone, 1 organosulfur compound, 2 organonitrogen compounds, and 1 acid. The hydrocarbons form the maingroup, representing 49.5%–84.6% of the total detected volatiles. The main constituent was 2,2,4,6,6-pentamethylheptane(44.5%–76.2%) reaching the highest relative percentages. Forty-two compounds were determined in thetwo fractions of EOs, representing 98.8% and 97.2% of the total oil composition, respectively. The principal componentswere hexadecanoic acid (34.6%), 6-methyl-5-hepten-2-one (18.3%), decanal (15.0%), 6,10,14-trimethyl-2-pentadecanone (13.2%), and n-pentacosane (13%). Micromorphological details of the leaf and stem epidermisusing light microscopy revealed polygonal cells with sinuous walls in the adaxial and abaxial leaf surfaces andnearly rectangular and long ones with linear and thick walls for the stem epidermis. The stomata complexes wereanisocytic in the leaf epidermis and mainly anisocytic and rarely paracytic in the stem epidermis. Non-glandulartrichomes were unbranched and long with an acute apex or short with a convex apex. The glandular ones wereidentified for the first time in this species. They were short-stalked with a large secretory head. The highest stomatalindex (17.02%) was recorded in the abaxial leaf surface. The identification of headspace volatiles and essentialoil compounds can be used to characterize this species, and the various epidermis micromorphologicalfeatures are very useful for biosystematics taxonomic studies within Brassicaceae. 展开更多
关键词 Cardaria draba aroma profile essential oils EPIDERMIS TRICHOMES
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