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Patterns of Cytosine Methylation in Parental Lines and Their Hybrids of Large White and Meishan Reciprocal Crosses 被引量:6
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作者 JIANGCao-de DENGChang-yan XIONGYuan-zhu 《Agricultural Sciences in China》 CAS CSCD 2004年第1期57-63,共7页
The extent and patterns of cytosine methylation in blood DNA were assessed, using thetechnique of methylation-sensitive amplified polymorphism(MSAP),in Meishan, Large White pigsand hybrids of their reciprocal crosses.... The extent and patterns of cytosine methylation in blood DNA were assessed, using thetechnique of methylation-sensitive amplified polymorphism(MSAP),in Meishan, Large White pigsand hybrids of their reciprocal crosses. In all, 1 508 fragments, each representing a reco-gnition site cleaved by either or both of the isoschizomers, MspI and HpaII, were amplifiedusing 20 pairs of selective primers. 10.3% of CCGG sites were methylated in Meishan pigs, 10.5%in Large White pigs, and 10.2% in the hybrids. Cytosine methylation was not significantlydifferent among parental lines and hybrids of reciprocal crosses. Four classes of patternswere identified in a comparative assay of cytosine methylation in the parents and hybrids: (1)the same level of methylation in both parental lines and the hybrids; (2) the same level ofmethylation in either parent or hybrid; (3) an increased level of methylation in the hybridscompared to the parents, and (4) a decreased level of methylation in the hybrids. 11 cross-specific methylation sites were detected in F1 hybrids of Large White ×Meishan, and 10 cross-specific methylation sites in the hybrid of Meishan ×Large White. In conclusion, (1) the wholemethylation status between parental lines and hybrids was not different, but specific siteswere differentially methylated; (2) specific sites were differentially methylated betweenreciprocal crosses; (3) demethylation and hypermethylation of many sites accounted for mostly(more than 50%) methylated sites in the hybrids compared to parental lines. 展开更多
关键词 MSAP DNA 甲基化作用 杂交特异性 胞核嘧啶 亲本 大白猪 梅山猪
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Comparison of Muscle Fiber Growth from F1Generations of Large Yorkshire Pig andErhualian Pig by Reciprocal Cross
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作者 DING Ren-bo SU Hao +4 位作者 HU Yao-dong SHI Rui XIE Fei WANG Li-juan GAO Shu-wen 《Animal Husbandry and Feed Science》 CAS 2010年第10期1-3,10,共4页
[Objective] To compare the muscle fiber growth between F1 generations of large Yorkshire pig and Erhualian pig by reciprocal cross, and provide a theoretical basis for the integrated breeding of meat quality traits an... [Objective] To compare the muscle fiber growth between F1 generations of large Yorkshire pig and Erhualian pig by reciprocal cross, and provide a theoretical basis for the integrated breeding of meat quality traits and growth performances by rational utilization of hybrid combination. [Method] The hybrid pigs of large Yorkshire pig and Erhualian pig were fed and managed in the same conditions. The reciprocal combinations were Erhualian pig ♀× Yorkshire pig ♂ and Yorkshire pig ♀× Erhualian pig ♂, respectively. At the age of 20, 70, 120 and 180 d, the longissimus dorsi muscle and thigh muscle were collected and made into frozen sections for hematoxylin and eosin (HE) staining, and then the muscle fiber area was determined. [Result] The muscle fiber was thickened gradually with increasing age; and the absolute growth curve of muscle fiber area was presented as "S" shape. The diameter, perimeter and area of longissimus dorsi muscle and thigh muscle fibers in the reciprocal combination of Yorkshire pig ♀× Erhualian pig ♂ were higher than those in the reciprocal combination of Erhualian pig ♀× Yorkshire pig ♂(P < 0.01). The thigh muscle grew faster than longissimus dorsi muscle at the age of 20-120 d; but at the age of 120-180 d, the growth rate of longissimus dorsi muscle was higher than that of thigh muscle; and at the age of 180 d, the muscle fiber area had no significant difference between the longissimus dorsi muscle and the thigh muscle. The muscle fiber area had extremely significant difference between the reciprocal combinations at the age of 20 d; but no significant difference was found at the age of 180 d. [Conclusion] The reciprocal combinations can affect the muscle fiber growth of hybrid pigs of Yorkshire pig and Erhualian pig, but the affect degree reduces with the increasing age. 展开更多
关键词 肌肉纤维 二花脸猪 生长比较 大白猪 F1代 正反交 肌纤维面积 生长年龄
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Genome-wide recombination variation in biparental segregating and reciprocal backcross populations provides information for introgression breeding in Brassica napus
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作者 Meng Wang Graham J.King +6 位作者 Lei Shi Ruiyuan Li Yi Zhang Xiaohua Wang Jinling Meng Jinxing Tu Jun Zou 《The Crop Journal》 SCIE CSCD 2023年第1期208-219,共12页
Variation in patterns of recombination in plant genomes provides information about species evolution,genetic diversity and crop improvement. We investigated meiotic crossovers generated in biparental segregating and r... Variation in patterns of recombination in plant genomes provides information about species evolution,genetic diversity and crop improvement. We investigated meiotic crossovers generated in biparental segregating and reciprocal backcross populations of the allopolyploid genome of rapeseed(Brassica napus)(AACC, 2n = 38). A structured set of 1445 intercrossed lines was derived from two homozygous de novo genome-assembled parents that represented the major genetic clusters of semi-winter Chinese and winter European rapeseeds, and was used to increase QTL resolution and achieve genomic reciprocal introgression. A high-density genetic map constructed with 6161 genetic bins and anchored centromere regions was used to establish the pattern of recombination variation in each chromosome. Around 93%of the genome contained crossovers at a mean rate of 3.8 c M Mb^(-1), with the remaining 7% attributed to centromeres or low marker density. Recombination hotspots predominated in the A genome, including two-thirds of those associated with breeding introgression from B. rapa. Genetic background might affect recombination variation. Introgression of genetic diversity from European winter to Chinese semi-winter rapeseed showed an increase in crossover rate under the semi-winter environment. Evidence for an elevated recombination rate having historically contributed to selective trait improvement includes accumulation of favorable alleles for seed oil content on hotspots of chromosome A10. Conversely, strong artificial selection may affect recombination rate variation, as appears to be the case with a coldspot resulting from strong selection for glucosinolate alleles on A09. But the cold region would be promptly reactivated by crossing design indicated by the pedigree analysis. Knowledge of recombination hotspots and coldspots associated with QTL for 22 traits can guide selection strategies for introgression breeding between the two gene pools. These results and rich genomic resources broaden our understanding of recombination behavior in allopolyploids and may advance rapeseed genetic improvement. 展开更多
关键词 ALLOPOLYPLOID Meiotic crossovers Brassica napus Historical introgression reciprocal backcross population
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State-selective charge exchange cross sections in collisions of highly-charged sulfur ions with helium and molecular hydrogen
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作者 朱小龙 崔述成 +9 位作者 邢大地 徐佳伟 B.Najjari 赵冬梅 郭大龙 高永 张瑞田 苏茂根 张少锋 马新文 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期29-33,共5页
The state-selective cross section data are useful for understanding and modeling the x-ray emission in celestial observations.In the present work,using the cold target recoil ion momentum spectroscopy,for the first ti... The state-selective cross section data are useful for understanding and modeling the x-ray emission in celestial observations.In the present work,using the cold target recoil ion momentum spectroscopy,for the first time we investigated the state-selective single electron capture processes for S^(q+)–He and H_(2)(q=11–15)collision systems at an impact energy of q×20 keV and obtained the relative state-selective cross sections.The results indicate that only a few principal quantum states of the projectile energy level are populated in a single electron capture process.In particular,the increase of the projectile charge state leads to the population of the states with higher principal quantum numbers.It is also shown that the experimental averaged n-shell populations are reproduced well by the over-barrier model.The database is openly available in Science Data Bank at 10.57760/sciencedb.j00113.00091. 展开更多
关键词 highly charged sulfur ion charge exchange state-selective cross sections COLTRIMS
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Absolute partial and total ionization cross sections of carbon monoxide with electron collision from 350 eV to 8000 eV
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作者 Taj Wali Khan 黄伟哲 +2 位作者 王恩亮 单旭 陈向军 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期459-464,共6页
The absolute partial and total cross sections for electron impact ionization of carbon monoxide are reported for electron energies from 350 eV to 8000 eV.The product ions(CO^(+),C^(+),O^(+),CO^(2+),C^(2+),and O^(2+))a... The absolute partial and total cross sections for electron impact ionization of carbon monoxide are reported for electron energies from 350 eV to 8000 eV.The product ions(CO^(+),C^(+),O^(+),CO^(2+),C^(2+),and O^(2+))are measured by employing an ion imaging mass spectrometer and two ion-pair dissociation channels(C^(+)+O^(+)and C^(2+)+O^(+))are identified.The absolute cross sections for producing individual ions and their total,as well as for the ion-pair dissociation channels are obtained by normalizing the data of CO^(+)to that of Ar^(+)from CO-Ar mixture target with a fixed 1:1 ratio.The overall errors are evaluated by considering various kinds of uncertainties.A comprehensive comparison is made with the available data,which shows a good agreement with each other over the energy ranges that are overlapped.This work presents new cross-section data with electron energies above 1000 eV. 展开更多
关键词 electron impact ionization cross sections carbon monoxide ion imaging mass spectrometer
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A Simplified Method for the Stress Analysis of Underground Transfer Structures Crossing Multiple Subway Tunnels
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作者 Shen Yan Dajiang Geng +2 位作者 Ning Dai Mingjian Long Zhicheng Bai 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期2893-2915,共23页
According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock layer.To address this challenge,a subterranean transfer str... According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock layer.To address this challenge,a subterranean transfer structure spanning multiple subway tunnels was proposed.Deliberating on the function of piles in the transfer structure as springs with axial and bending stiffness,and taking into account the force balance and deformation coordination conditions of beams and plates within the transfer structure,we established a simplified mechanical model that incorporates soil stratification by combining it with the Winkler elastic foundation beam model.The resolved established simplifiedmechanicalmodel employed finite difference technology and the Newton-Simpsonmethod,elucidating the mechanical mechanism of the transfer structure.The research findings suggest that the load carried by the upper structural columns can be transferred to the pile foundation beneath the beams through the transfer structure,subsequently reaching the deep soil layer and ensuring minimal impact on adjacent tunnels.The established simplified analysis method can be used for stress analysis of the transfer structure,concurrently considering soil stratification,pile foundation behavior,and plate action.The pile length,pile section size,and beam section size within the transfer structure should account for the characteristics of the upper load,ensuring an even distribution of the beam bending moment. 展开更多
关键词 crossing tunnels transfer structure force mechanism simplify analysis layered soil mass
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Using Cross Entropy as a Performance Metric for Quantifying Uncertainty in DNN Image Classifiers: An Application to Classification of Lung Cancer on CT Images
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作者 Eri Matsuyama Masayuki Nishiki +1 位作者 Noriyuki Takahashi Haruyuki Watanabe 《Journal of Biomedical Science and Engineering》 2024年第1期1-12,共12页
Cross entropy is a measure in machine learning and deep learning that assesses the difference between predicted and actual probability distributions. In this study, we propose cross entropy as a performance evaluation... Cross entropy is a measure in machine learning and deep learning that assesses the difference between predicted and actual probability distributions. In this study, we propose cross entropy as a performance evaluation metric for image classifier models and apply it to the CT image classification of lung cancer. A convolutional neural network is employed as the deep neural network (DNN) image classifier, with the residual network (ResNet) 50 chosen as the DNN archi-tecture. The image data used comprise a lung CT image set. Two classification models are built from datasets with varying amounts of data, and lung cancer is categorized into four classes using 10-fold cross-validation. Furthermore, we employ t-distributed stochastic neighbor embedding to visually explain the data distribution after classification. Experimental results demonstrate that cross en-tropy is a highly useful metric for evaluating the reliability of image classifier models. It is noted that for a more comprehensive evaluation of model perfor-mance, combining with other evaluation metrics is considered essential. . 展开更多
关键词 cross Entropy Performance Metrics DNN Image Classifiers Lung Cancer Prediction Uncertainty
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DCFNet:An Effective Dual-Branch Cross-Attention Fusion Network for Medical Image Segmentation
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作者 Chengzhang Zhu Renmao Zhang +5 位作者 Yalong Xiao Beiji Zou Xian Chai Zhangzheng Yang Rong Hu Xuanchu Duan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期1103-1128,共26页
Automatic segmentation of medical images provides a reliable scientific basis for disease diagnosis and analysis.Notably,most existing methods that combine the strengths of convolutional neural networks(CNNs)and Trans... Automatic segmentation of medical images provides a reliable scientific basis for disease diagnosis and analysis.Notably,most existing methods that combine the strengths of convolutional neural networks(CNNs)and Transformers have made significant progress.However,there are some limitations in the current integration of CNN and Transformer technology in two key aspects.Firstly,most methods either overlook or fail to fully incorporate the complementary nature between local and global features.Secondly,the significance of integrating the multiscale encoder features from the dual-branch network to enhance the decoding features is often disregarded in methods that combine CNN and Transformer.To address this issue,we present a groundbreaking dual-branch cross-attention fusion network(DCFNet),which efficiently combines the power of Swin Transformer and CNN to generate complementary global and local features.We then designed the Feature Cross-Fusion(FCF)module to efficiently fuse local and global features.In the FCF,the utilization of the Channel-wise Cross-fusion Transformer(CCT)serves the purpose of aggregatingmulti-scale features,and the Feature FusionModule(FFM)is employed to effectively aggregate dual-branch prominent feature regions from the spatial perspective.Furthermore,within the decoding phase of the dual-branch network,our proposed Channel Attention Block(CAB)aims to emphasize the significance of the channel features between the up-sampled features and the features generated by the FCFmodule to enhance the details of the decoding.Experimental results demonstrate that DCFNet exhibits enhanced accuracy in segmentation performance.Compared to other state-of-the-art(SOTA)methods,our segmentation framework exhibits a superior level of competitiveness.DCFNet’s accurate segmentation of medical images can greatly assist medical professionals in making crucial diagnoses of lesion areas in advance. 展开更多
关键词 Convolutional neural networks Swin Transformer dual branch medical image segmentation feature cross fusion
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Crossed renal ectopia with rectal cancer:A case report
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作者 Zhen-Wei Tang Hui-Feng Yang +1 位作者 Zhao-Yu Wu Chang-You Wang 《World Journal of Clinical Cases》 SCIE 2024年第12期2122-2127,共6页
BACKGROUND Crossed renal ectopia(CRE)occurs when one kidney crosses the midline from the primary side to the contralateral side while the ureter remains on the primary side.Rectal cancer,one of the most common maligna... BACKGROUND Crossed renal ectopia(CRE)occurs when one kidney crosses the midline from the primary side to the contralateral side while the ureter remains on the primary side.Rectal cancer,one of the most common malignant tumors of the digestive tract,refers to cancer from the dentate line to the rectosigmoid junction.The concurrent presentation of CRE alongside rectal cancer is an uncommon clinical observation.CASE SUMMARY Herein,we report a 69-year-old male patient with rectal cancer who was diagnosed with CRE via computed tomography during hospitalization.Following thorough preoperative evaluations,the patient underwent Dixon surgery.CONCLUSION We performed laparoscopic radical resection of rectal cancer and adequate lymph node removal in a patient with CRE with no postoperative discomfort. 展开更多
关键词 Rectal cancer crossed renal ectopia ANATOMY Laparoscopic surgery Case report
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Corneal collagen cross-linking in patients with keratoconus from the Dresden protocol to customized solutions:theoretical basis
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作者 Ciro Caruso Luca D’Andrea +4 位作者 Mario Troisi Michele Rinaldi Raffaele Piscopo Salvatore Troisi Ciro Costagliola 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第5期951-962,共12页
Keratoconus is an ectatic condition characterized by gradual corneal thinning,corneal protrusion,progressive irregular astigmatism,corneal fibrosis,and visual impairment.The therapeutic options regarding improvement o... Keratoconus is an ectatic condition characterized by gradual corneal thinning,corneal protrusion,progressive irregular astigmatism,corneal fibrosis,and visual impairment.The therapeutic options regarding improvement of visual function include glasses or soft contact lenses correction for initial stages,gas-permeable rigid contact lenses,scleral lenses,implantation of intrastromal corneal ring or corneal transplants for most advanced stages.In keratoconus cases showing disease progression corneal collagen crosslinking(CXL)has been proven to be an effective,minimally invasive and safe procedure.CXL consists of a photochemical reaction of corneal collagen by riboflavin stimulation with ultraviolet A radiation,resulting in stromal crosslinks formation.The aim of this review is to carry out an examination of CXL methods based on theoretical basis and mathematical models,from the original Dresden protocol to the most recent developments in the technique,reporting the changes proposed in the last 15y and examining the advantages and disadvantages of the various treatment protocols.Finally,the limits of non-standardized methods and the perspectives offered by a customization of the treatment are highlighted. 展开更多
关键词 corneal collagen cross linking KERATOCONUS custom fast protocol Dresden protocol lambert-beer law Bunsen-roscoe law
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Identifying genetic susceptibility to Aspergillus fumigatus infection using collaborative cross mice and RNA-Seq approach
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作者 Roa'a H.S.Yosief Iqbal M.Lone +3 位作者 Aharon Nachshon Heinz Himmelbauer Irit Gat-Viks Fuad A.Iraqi 《Animal Models and Experimental Medicine》 CAS CSCD 2024年第1期36-47,共12页
Background:Aspergillus fumigatus(Af)is one of the most ubiquitous fungi and its infection potency is suggested to be strongly controlled by the host genetic back-ground.The aim of this study was to search for candidat... Background:Aspergillus fumigatus(Af)is one of the most ubiquitous fungi and its infection potency is suggested to be strongly controlled by the host genetic back-ground.The aim of this study was to search for candidate genes associated with host susceptibility to Aspergillus fumigatus(Af)using an RNAseq approach in CC lines and hepatic gene expression.Methods:We studied 31 male mice from 25 CC lines at 8 weeks old;the mice were infected with Af.Liver tissues were extracted from these mice 5 days post-infection,and next-generation RNA-sequencing(RNAseq)was performed.The GENE-E analysis platform was used to generate a clustered heat map matrix.Results:Significant variation in body weight changes between CC lines was ob-served.Hepatic gene expression revealed 12 top prioritized candidate genes differ-entially expressed in resistant versus susceptible mice based on body weight changes.Interestingly,three candidate genes are located within genomic intervals of the previ-ously mapped quantitative trait loci(QTL),including Gm16270 and Stox1 on chromo-some 10 and Gm11033 on chromosome 8.Conclusions:Our findings emphasize the CC mouse model's power in fine mapping the genetic components underlying susceptibility towards Af.As a next step,eQTL analysis will be performed for our RNA-Seq data.Suggested candidate genes from our study will be further assessed with a human cohort with aspergillosis. 展开更多
关键词 aspergillus fumigatus infection collaborative cross(CC)mice gene expression profile gene-network host susceptibility quantitative trait loci(QTL)mapping RNA-SEQ
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Impacts of monsoon break events in the western North Pacific on the cross-equatorial flows over the Maritime Continent
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作者 Xiaoxuan Zhao Minghao Bi +2 位作者 Ke Xu Jianqi Sun Riyu Lu 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第2期33-38,共6页
本文利用ERA5逐日再分析资料,探讨了1979-2020年间西北太平洋季风中断事件对海洋性大陆越赤道气流的影响.合成结果表明,西北太平洋季风中断事件会造成高,低空越赤道气流减弱,即高层南风异常,低层北风异常,与此相关的环流异常表现为西北... 本文利用ERA5逐日再分析资料,探讨了1979-2020年间西北太平洋季风中断事件对海洋性大陆越赤道气流的影响.合成结果表明,西北太平洋季风中断事件会造成高,低空越赤道气流减弱,即高层南风异常,低层北风异常,与此相关的环流异常表现为西北太平洋高层气旋,低层反气旋的斜压结构。特别的是,西北太平洋季风中断对高空越赤道气流的影响更为显著,92%的季风中断事件都导致高空越赤道气流减弱,而只有70%的事件造成低空越赤道气流减弱,这是由于低空越赤道气流同时还受到赤道中东太平洋海温异常的调控. 展开更多
关键词 西北太平洋夏季风 季风中断 越赤道气流 海洋性大陆
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基于肠源性高密度脂蛋白调控脂多糖介导Kupffer-肝细胞Cross-Talk探讨脾虚膏脂转输障碍的分子生物学基础 被引量:1
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作者 翟亚荣 孟嘉伟 +7 位作者 张琦 裘雪莹 于宁 王杰 曹慧敏 王群 隋国媛 贾连群 《中华中医药学刊》 CAS 北大核心 2023年第2期75-77,共3页
脾虚膏脂转输障碍是血脂异常的关键病机。脾失健运引起肝脏代谢功能障碍可能导致血脂异常。肠道功能紊乱是脾虚膏脂转输障碍的启动因素,以其介导“炎症-代谢”紊乱为切入点,深入揭示血脂异常疾病发病机制以提高中西医结合防治水平逐渐... 脾虚膏脂转输障碍是血脂异常的关键病机。脾失健运引起肝脏代谢功能障碍可能导致血脂异常。肠道功能紊乱是脾虚膏脂转输障碍的启动因素,以其介导“炎症-代谢”紊乱为切入点,深入揭示血脂异常疾病发病机制以提高中西医结合防治水平逐渐成为基础和临床研究焦点和热点。从肠源性高密度脂蛋白(high-density lipoprotein 3,HDL3)调控脂多糖(lipopolysaccharide,LPS)介导Kupffer-肝细胞cross-talk的角度,深入分析脾虚膏脂转输障碍的分子生物学机制,揭示健脾化浊法的效应机制,为临床防治血脂异常提供科学依据。 展开更多
关键词 肠源性HDL3 脂多糖 Kupffer细胞 肝细胞 cross-TALK
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Coordinate-Parametric Matrix Model Inspired Square-Conjoint Pattern in Cross Woven for Conventional Bamboo Mat 被引量:1
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作者 Ye Fu Liwen Deng +2 位作者 Jinbo Hu Ti Li Shanshan Chang 《Journal of Renewable Materials》 EI 2023年第12期4025-4038,共14页
In the study,it is proposed that a coordinate-parametric matrix model is performed to a square-conjoint pattern of cross woven(SCPCW)in the bamboo mat.The patterns of SCPCW are firstly detected according to the perspe... In the study,it is proposed that a coordinate-parametric matrix model is performed to a square-conjoint pattern of cross woven(SCPCW)in the bamboo mat.The patterns of SCPCW are firstly detected according to the perspective of configuration,which is divided into the basic-monomer shape and the basic combination shape.Secondly,the compositions of design patterns in SCPCW are analyzed to attain the trend of curve shape.Based on the coordinate-parametric matrix model,the specimens of SCPCW are subsequently accomplished to elaborate the woven logic of bamboo mats.The digital innovation of SCPCW,defined by a mathematical resolution,is implemented by the software of Grasshopper(GH),which plays a crucial role in capturing image information by the Image Sampler component.Successively,the weaving logic of coordinated matrix is referred to apply in the computing component of Grasshopper software.Finally,the computer simulation could demonstrate that the coordinate-parametric matrix model of SCPCWwould be realized to analyze the micro-weaving structure and overall weaving effect in the bamboo mat. 展开更多
关键词 cross woven configuration and composition coordinated parametrization weaving model
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Conceptual design of a Cs2LiLaBr6 scintillator‑based neutron total cross section spectrometer on the back‑n beam line at CSNS 被引量:1
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作者 Da‑Jun Zhao Song Feng +6 位作者 Pin‑Jing Cheng Rong Liu Wen Luo Hao‑Qiang Wang Jie‑Ming Xue Kun Zhu Bo Zheng 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第1期23-32,共10页
To reduce the experimental uncertainty in the 235 U resonance energy region and improve the detection efficiency for neutron total cross section measurements compared with those obtained with the neutron total cross s... To reduce the experimental uncertainty in the 235 U resonance energy region and improve the detection efficiency for neutron total cross section measurements compared with those obtained with the neutron total cross section spectrometer(NTOX), a dedicated lithium-containing scintillation detector has been developed on the Back-n beam line at the China Spallation Neutron Source. The Fast Scintillator-based Neutron Total Cross Section(FAST) spectrometer has been designed based on a Cs2Li La Br6(CLLB) scintillator considering the γ-ray flash and neutron environment on the Back-n beam line. The response of the CLLB scintillator to neutrons and γ-rays was evaluated with different 6Li/7 Li abundance ratios using Geant4. The neutron-γdiscrimination performance of the CLLB has been simulated considering different scintillation parameters, physical designs,and light readout modes. A cubic 6Li-enriched( > 90%) CLLB scintillator, which has a thickness of 4-9 mm and side length of no less than 50 mm to cover the Φ 50 mm neutron beam at the spectrometer position, has been proposed coupling to a side readout SiPM array to construct the FAST spectrometer. The developed simulation techniques for neutron-γ discrimination performance could provide technical support for other neutron-induced reaction measurements on the Back-n beam line. 展开更多
关键词 Neutron total cross section CLLB scintillator GEANT4 Pulse shape discrimination(PSD)
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Measurement of the ^(232)Th(n,f)cross section in the 1-200 MeV range at the CSNS Back-n 被引量:1
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作者 Zhi-Zhou Ren Yi-Wei Yang +77 位作者 Yong-Hao Chen Rong Liu Bang-Jiao Ye Jie Wen Hai-Rui Guo Zi-Jie Han Qi-Ping Chen Zhong-Wei Wen Wei-Li Sun Han Yi Xing-Yan Liu Tao Ye Jiang-Bo Bai Qi An Jie Bao Yu Bao Ping Cao Hao-Lei Chen Zhen Chen Zeng-Qi Cui Rui-Rui Fan Chang-Qing Feng Ke-Qing Gao Xiao-Long Gao Min-Hao Gu Chang-Cai Han Guo-Zhu He Yong-Cheng He Yang Hong Yi-Wei Hu Han-Xiong Huang Xi-Ru Huang Hao-Yu Jiang Wei Jiang Zhi-Jie Jiang Han-Tao Jing Ling Kang Bo Li Chao Li Jia-Wen Li Qiang Li Xiao Li Yang Li Jie Liu Shu-Bin Liu Ze Long Guang-Yuan Luan Chang-Jun Ning Meng-Chen Niu Bin-Bin Qi Jie Ren Xi-Chao Ruan Zhao-Hui Song Kang Sun Zhi-Jia Sun Zhi-Xin Tan Jing-Yu Tang Xin-Yi Tang Bin-Bin Tian Li-Jiao Wang Peng-Cheng Wang Zhao-Hui Wang Xiao-Guang Wu Xuan Wu Li-Kun Xie Xiao-Yun Yang Li Yu Tao Yu Yong-Ji Yu Guo-Hui Zhang Lin-Hao Zhang Qi-Wei Zhang Xian-Peng Zhang Yu-Liang Zhang Zhi-Yong Zhang Lu-Ping Zhou Zhi-Hao Zhou Ke-Jun Zhu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第8期142-153,共12页
The ^(232)Th(n,f)cross section is very important in basic nuclear physics and applications based on the Th/U fuel cycle.Using the time-of-flight method and a multi-cell fast-fission ionization chamber,a novel measurem... The ^(232)Th(n,f)cross section is very important in basic nuclear physics and applications based on the Th/U fuel cycle.Using the time-of-flight method and a multi-cell fast-fission ionization chamber,a novel measurement of the^(232)Th(n,f)cross sec-tion relative to^(235)U in the 1–200 MeV range was performed at the China Spallation Neutron Source Back-n white neutron source(Back-n).The fission event-neutron energy spectra of^(232)Th and^(235)U fission cells were measured in the single-bunch mode.Corrected 232Th/235U fission cross-sectional ratios were obtained,and the measurement uncertainties were 2.5–3.7%for energies in the 2–20 MeV range and 3.6–6.2%for energies in the 20–200 MeV range.The^(232)Th(n,f)cross section was obtained by introducing the standard cross section of^(235)U(n,f).The results were compared with those of previous theoreti-cal calculations,measurements,and evaluations.The measured 232Th fission cross section agreed with the main evaluation results in terms of the experimental uncertainty,and 232Th fission resonances were observed in the 1–3 MeV range.The present results provide^(232)Th(n,f)cross-sectional data for the evaluation and design of Th/U cycle nuclear systems. 展开更多
关键词 232Th(n f)cross section Fast-fission ionization chamber Back-n white neutron source
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Measurement of^(134)Xe(n,2n)^(133m),gXe reaction cross sections in 14‑MeV region with detailed uncertainty quantification 被引量:1
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作者 Jun‑Hua Luo Jun‑Cheng Liang +3 位作者 Li Jiang Fei Tuo Liang Zhou Long He 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第1期33-42,共10页
A lead-shielded HPGe detector and offlineγ-ray spectra of the residual product were used to measure the cross section(CS)and ratios of isomeric CS(σm/σg)in^(134)Xe(n,2n)^(133m),gXe reactions at different energies(1... A lead-shielded HPGe detector and offlineγ-ray spectra of the residual product were used to measure the cross section(CS)and ratios of isomeric CS(σm/σg)in^(134)Xe(n,2n)^(133m),gXe reactions at different energies(13.5 MeV,13.8 MeV,14.1 MeV,14.4 MeV,14.8 MeV)relative to the^(93)Nb(n,2n)^(92)mNb reaction CS.The target was high-purity natural Xe gas under high pressure.The T(d,n)4He reaction produces neutrons.TALYS code(version 1.95)for nuclear reactions was used for calculations,with default parameters and nuclear level density models.The uncertainties in the measured CS data were thoroughly analyzed using the covariance analysis method.The results were compared with theoretical values,evaluation data,and previous experimental findings.CS data of the 134Xe(n,2n)133mXe and 134Xe(n,2n)133gXe reactions and the corresponding isomeric CS ratios at 13.5 MeV,13.8 MeV,and 14.1 MeV neutron energies are reported for the first time.This research advances our knowledge of pre-equilibrium emission in the(n,2n)reaction channel by resolving inconsistencies in the Xe data. 展开更多
关键词 ^(134)Xe(n 2n)reactions 14-MeV neutrons cross sections(CSs) Isomeric ratios(IRs) Covariance analysis
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Nonreciprocal Phonon Laser in an Asymmetric Cavity with an Atomic Ensemble
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作者 黄凯伟 王鑫 +2 位作者 邱庆洋 吴龙 熊豪 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第10期60-65,共6页
Phonon lasers,as a novel kind of lasers for generating coherent sound oscillation,has attracted extensive attention.Here,we theoretically propose a nonreciprocal phonon laser in a hybrid optomechanical system,which is... Phonon lasers,as a novel kind of lasers for generating coherent sound oscillation,has attracted extensive attention.Here,we theoretically propose a nonreciprocal phonon laser in a hybrid optomechanical system,which is composed of an asymmetric Fabry-Pérot cavity,an ensemble of N identical two-level atoms,and a mechanical oscillator.The effective driving amplitude related to driving direction leads to an obvious difference in mechanical gain and threshold power,bringing about a nonreciprocal phonon laser.In addition,the dependence of the phonon laser on the atomic parameters is also discussed,including the decay rate of the atoms and the coupling strength between the atoms and the cavity field,which provides an additional degree of freedom to control the phonon laser action.Our work provides a path to realizing a phonon laser in an atoms-cavity optomechanical system and may aid the manufacture of directional coherent phonon sources. 展开更多
关键词 reciprocal CAVITY driving
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Relaxed Stability Criteria for Delayed Generalized Neural Networks via a Novel Reciprocally Convex Combination
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作者 Yibo Wang Changchun Hua Poo Gyeon Park 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第7期1631-1633,共3页
Dear Editor,This letter examines the stability issue of generalized neural networks(GNNs) with time-varying delay based on a novel reciprocally convex combination(RCC). By considering a new matrix polynomial, the prop... Dear Editor,This letter examines the stability issue of generalized neural networks(GNNs) with time-varying delay based on a novel reciprocally convex combination(RCC). By considering a new matrix polynomial, the proposed novel reciprocally convex method leads to a tight bound for integral inequality combination and encompasses several existing approaches as special cases. 展开更多
关键词 CONVEX reciprocal INEQUALITY
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Unconventional Nonreciprocal Voltage Transition in Ag_(2)Te Nanobelts
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作者 冷鹏亮 曹翔宇 +4 位作者 马强 艾临风 张钰达 张警蕾 修发贤 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第12期126-130,共5页
Nonreciprocal effects are consistently observed in noncentrosymmetric materials due to the intrinsic symmetry breaking and in high-conductivity systems due to the extrinsic thermoelectric effect. Meanwhile, nonrecipro... Nonreciprocal effects are consistently observed in noncentrosymmetric materials due to the intrinsic symmetry breaking and in high-conductivity systems due to the extrinsic thermoelectric effect. Meanwhile, nonreciprocal charge transport is widely utilized as an effective experimental technique for detecting intrinsic unidirectional electrical contributions. Here, we show an unconventional nonreciprocal voltage transition in topological insulator Ag_(2)Te nanobelts. The nonreciprocal voltage develops from nearly zero to giant values under the applied current I_(ac) and external magnetic fields, while remaining unchanged under various current I_(dc). This unidirectional electrical contribution is further evidenced by the differential resistance(dV/dI) measurements. Furthermore, the transition possesses two-dimensional properties under a tilted magnetic field and occurs when the voltage between two electrodes exceeds a certain value. We propose a possible mechanism based on the development of edge channels in Ag_(2)Te nanobelts to interpret the phenomenon. Our results not only introduce a peculiar nonreciprocal voltage transition in topological materials but also enrich the understanding of the intrinsic mechanism that strongly affects nonreciprocal charge transport. 展开更多
关键词 VALUE reciprocal TOPOLOGICAL
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