期刊文献+
共找到88,497篇文章
< 1 2 250 >
每页显示 20 50 100
The Application of Nicotiana benthamiana as a Transient Expression Host to Clone the Coding Sequences of Plant Genes
1
作者 Jianzhong Huang Peng Jia +3 位作者 Xiaoju Zhong Xiuying Guan Hongbin Zhang Honglei Ruan 《American Journal of Molecular Biology》 CAS 2024年第2期54-65,共12页
Coding sequences (CDS) are commonly used for transient gene expression, in yeast two-hybrid screening, to verify protein interactions and in prokaryotic gene expression studies. CDS are most commonly obtained using co... Coding sequences (CDS) are commonly used for transient gene expression, in yeast two-hybrid screening, to verify protein interactions and in prokaryotic gene expression studies. CDS are most commonly obtained using complementary DNA (cDNA) derived from messenger RNA (mRNA) extracted from plant tissues and generated by reverse transcription. However, some CDS are difficult to acquire through this process as they are expressed at extremely low levels or have specific spatial and/or temporal expression patterns in vivo. These challenges require the development of alternative CDS cloning technologies. In this study, we found that the genomic intron-containing gene coding sequences (gDNA) from Arabidopsis thaliana, Oryza sativa, Brassica napus, and Glycine max can be correctly transcribed and spliced into mRNA in Nicotiana benthamiana. In contrast, gDNAs from Triticum aestivum and Sorghum bicolor did not function correctly. In transient expression experiments, the target DNA sequence is driven by a constitutive promoter. Theoretically, a sufficient amount of mRNA can be extracted from the N. benthamiana leaves, making it conducive to the cloning of CDS target genes. Our data demonstrate that N. benthamiana can be used as an effective host for the cloning CDS of plant genes. 展开更多
关键词 Coding sequence Genomic sequence Nicotiana benthamiana Plant Genes
下载PDF
Pig pangenome graph reveals functional features of non‑reference sequences
2
作者 Jian Miao Xingyu Wei +6 位作者 Caiyun Cao Jiabao Sun Yuejin Xu Zhe Zhang Qishan Wang Yuchun Pan Zhen Wang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第3期956-970,共15页
Background The reliance on a solitary linear reference genome has imposed a significant constraint on our compre-hensive understanding of genetic variation in animals.This constraint is particularly pronounced for non... Background The reliance on a solitary linear reference genome has imposed a significant constraint on our compre-hensive understanding of genetic variation in animals.This constraint is particularly pronounced for non-reference sequences(NRSs),which have not been extensively studied.Results In this study,we constructed a pig pangenome graph using 21 pig assemblies and identified 23,831 NRSs with a total length of 105 Mb.Our findings revealed that NRSs were more prevalent in breeds exhibiting greater genetic divergence from the reference genome.Furthermore,we observed that NRSs were rarely found within coding sequences,while NRS insertions were enriched in immune-related Gene Ontology terms.Notably,our investigation also unveiled a close association between novel genes and the immune capacity of pigs.We observed substantial differences in terms of frequencies of NRSs between Eastern and Western pigs,and the heat-resistant pigs exhibited a substantial number of NRS insertions in an 11.6 Mb interval on chromosome X.Additionally,we discovered a 665 bp insertion in the fourth intron of the TNFRSF19 gene that may be associated with the ability of heat tolerance in South-ern Chinese pigs.Conclusions Our findings demonstrate the potential of a graph genome approach to reveal important functional features of NRSs in pig populations. 展开更多
关键词 Heat tolerance Immune ability Non-reference sequences Pig pangenome
下载PDF
Phylogenetic, phylogeographic and divergence time analysis of Anopheles subpictus species complex using ITS2 and COI sequences
3
作者 Lihini Sandaleka Muthukumarana Methsala Madurangi Wedage +1 位作者 Samanthika Rathnayake Nissanka Kolitha De Silva 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2024年第5期214-225,I0004-I0038,共47页
Objective:To address the phylogenetic and phylogeographic relationship between different lineages of Anopheles(An.)subpictus species complex in most parts of the Asian continent by maximum utilization of Internal Tran... Objective:To address the phylogenetic and phylogeographic relationship between different lineages of Anopheles(An.)subpictus species complex in most parts of the Asian continent by maximum utilization of Internal Transcriber Spacer 2(ITS2)and cytochrome C oxidase I(COI)sequences deposited at the GenBank.Methods:Seventy-five ITS2,210 COI and 26 concatenated sequences available in the NCBI database were used.Phylogenetic analysis was performed using Bayesian likelihood trees,whereas median-joining haplotype networks and time-scale divergence trees were generated for phylogeographic analysis.Genetic diversity indices and genetic differentiation were also calculated.Results:Two genetically divergent molecular forms of An.subpictus species complex corresponding to sibling species A and B are established.Species A evolved around 37-82 million years ago in Sri Lanka,India,and the Netherlands,and species B evolved around 22-79 million years ago in Sri Lanka,India,and Myanmar.Vietnam,Thailand,and Cambodia have two molecular forms:one is phylogenetically similar to species B.Other forms differ from species A and B and evolved recently in the above mentioned countries,Indonesia and the Philippines.Genetic subdivision among Sri Lanka,India,and the Netherlands is almost absent.A substantial genetic differentiation was obtained for some populations due to isolation by large geographical distances.Genetic diversity indices reveal the presence of a long-established stable mosquito population,at mutation-drift equilibrium,regardless of population fluctuations.Conclusions:An.subpictus species complex consists of more than two genetically divergent molecular forms.Species A is highly divergent from the rest.Sri Lanka and India contain only species A and B. 展开更多
关键词 Molecular systematics ITS2 COI DNA sequences Phylogeny PHYLOGEOGRAPHY
下载PDF
On power series statistical convergence and new uniform integrability of double sequences
4
作者 Sevda Y■ld■z Kamil Demirci 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第3期519-532,共14页
In the present paper,we mostly focus on P_(p)^(2)-statistical convergence.We will look into the uniform integrability via the power series method and its characterizations for double sequences.Also,the notions of P_(p... In the present paper,we mostly focus on P_(p)^(2)-statistical convergence.We will look into the uniform integrability via the power series method and its characterizations for double sequences.Also,the notions of P_(p)^(2)-statistically Cauchy sequence,P_(p)^(2)-statistical boundedness and core for double sequences will be described in addition to these findings. 展开更多
关键词 power series methods statistical convergence uniform integrability double sequences
下载PDF
Secure Transmission of Compressed Medical Image Sequences on Communication Networks Using Motion Vector Watermarking
5
作者 Rafi Ullah Mohd Hilmi bin Hasan +1 位作者 Sultan Daud Khan Mussadiq Abdul Rahim 《Computers, Materials & Continua》 SCIE EI 2024年第3期3283-3301,共19页
Medical imaging plays a key role within modern hospital management systems for diagnostic purposes.Compression methodologies are extensively employed to mitigate storage demands and enhance transmission speed,all whil... Medical imaging plays a key role within modern hospital management systems for diagnostic purposes.Compression methodologies are extensively employed to mitigate storage demands and enhance transmission speed,all while upholding image quality.Moreover,an increasing number of hospitals are embracing cloud computing for patient data storage,necessitating meticulous scrutiny of server security and privacy protocols.Nevertheless,considering the widespread availability of multimedia tools,the preservation of digital data integrity surpasses the significance of compression alone.In response to this concern,we propose a secure storage and transmission solution for compressed medical image sequences,such as ultrasound images,utilizing a motion vector watermarking scheme.The watermark is generated employing an error-correcting code known as Bose-Chaudhuri-Hocquenghem(BCH)and is subsequently embedded into the compressed sequence via block-based motion vectors.In the process of watermark embedding,motion vectors are selected based on their magnitude and phase angle.When embedding watermarks,no specific spatial area,such as a region of interest(ROI),is used in the images.The embedding of watermark bits is dependent on motion vectors.Although reversible watermarking allows the restoration of the original image sequences,we use the irreversible watermarking method.The reason for this is that the use of reversible watermarks may impede the claims of ownership and legal rights.The restoration of original data or images may call into question ownership or other legal claims.The peak signal-to-noise ratio(PSNR)and structural similarity index(SSIM)serve as metrics for evaluating the watermarked image quality.Across all images,the PSNR value exceeds 46 dB,and the SSIM value exceeds 0.92.Experimental results substantiate the efficacy of the proposed technique in preserving data integrity. 展开更多
关键词 Block matching algorithm(BMA) compression full-search algorithm motion vectors ultrasound image sequence WATERMARKING
下载PDF
Mechanism of Guangdong Shenqu in regulating intestinal flora in mice with food stagnation and internal heat based on 16S rDNA sequencing
6
作者 Yani Jiang Zhenhong Zhang +5 位作者 Han Chen Yanmin Wang Yanrui Xu Zijie Chen Yan Xu Jingjuan Wang 《Journal of Traditional Chinese Medical Sciences》 CAS 2024年第2期232-244,共13页
Objective:To investigate the effect of Guangdong Shenqu(GSQ)on intestinal flora structure in mice with food stagnation through 16S rDNA sequencing.Methods: Mice were randomly assigned to control,model,GSQ low-dose(GSQ... Objective:To investigate the effect of Guangdong Shenqu(GSQ)on intestinal flora structure in mice with food stagnation through 16S rDNA sequencing.Methods: Mice were randomly assigned to control,model,GSQ low-dose(GSQL),GSQ medium-dose(GSQM),GSQ high-dose(GSQH),and lacidophilin tablets(LAB)groups,with each group containing 10 mice.A food stagnation and internal heat mouse model was established through intragastric administration of a mixture of beeswax and olive oil(1:15).The control group was administered normal saline,and the model group was administered beeswax and olive oil to maintain a state.The GSQL(2 g/kg),GSQM(4 g/kg),GSQH(8 g/kg),and LAB groups(0.625 g/kg)were administered corresponding drugs for 5 d.After administration,16S rDNA sequencing was performed to assess gut microbiota in mouse fecal samples.Results: The model group exhibited significant intestinal flora changes.Following GSQ administration,the abundance and diversity index of the intestinal flora increased significantly,the number of bacterial species was regulated,andαandβdiversity were improved.GSQ administration increased the abundance of probiotics,including Clostridia,Lachnospirales,and Lactobacillus,whereas the abundance of conditional pathogenic bacteria,such as Allobaculum,Erysipelotrichaceae,and Bacteroides decreased.Functional prediction analysis indicated that the pathogenesis of food stagnation and GSQ intervention were primarily associated with carbohydrate,lipid,and amino acid metabolism,among other metabolic pathways.Conclusion: The digestive mechanism of GSQ may be attributed to its role in restoring diversity and abundance within the intestinal flora,thereby improving the composition and structure of the intestinal flora in mice and subsequently influencing the regulation of metabolic pathways. 展开更多
关键词 Guangdong Shenqu Food stagnation Gut microbiota High-throughput gene sequencing Species annotation Metabolic pathway
下载PDF
Accurate Diagnosis of SARS-CoV-2 JN.1 by Sanger Sequencing of Receptor-Binding Domain Is Needed for Clinical Evaluation of Its Immune Evasion
7
作者 Sin Hang Lee 《Journal of Biosciences and Medicines》 2024年第4期69-78,共10页
Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation... Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation. The immune evasion capability of JN.1 is a subject of scientific investigation. The US CDC used SGTF of TaqPath COVID-19 Combo Kit RT-qPCR as proxy indicator of JN.1 infections for evaluation of the effectiveness of updated monovalent XBB.1.5 COVID-19 vaccines against JN.1 and recommended that all persons aged ≥ 6 months should receive an updated COVID-19 vaccine dose. Objective: Recommend Sanger sequencing instead of proxy indicator to diagnose JN.1 infections to generate the data based on which guidelines are made to direct vaccination policies. Methods: The RNA in nasopharyngeal swab specimens from patients with clinical respiratory infection was subjected to nested RT-PCR, targeting a 398-base segment of the N-gene and a 445-base segment of the RBD of SARS-CoV-2 for amplification. The nested PCR amplicons were sequenced. The DNA sequences were analyzed for amino acid mutations. Results: The N-gene sequence showed R203K, G204R and Q229K, the 3 mutations associated with Omicron BA.2.86 (+JN.1). The RBD sequence showed 24 of the 26 known amino acid mutations, including the hallmark L455S mutation for JN.1 and the V483del for BA.2.86 lineage. Conclusions: Sanger sequencing of a 445-base segment of the SARS-CoV-2 RBD is useful for accurate determination of emerging variants. The CDC may consider using Sanger sequencing of the RBD to diagnose JN.1 infections for statistical analysis in making vaccination policies. 展开更多
关键词 Omicron JN.1 SARS-CoV-2 Sanger sequencing RBD L455S Mutation Immune Evasion Vaccination Policies CDC
下载PDF
Evaluation of genetic response of mesenchymal stem cells to nanosecond pulsed electric fields by whole transcriptome sequencing
8
作者 Jian-Jing Lin Tong Ning +5 位作者 Shi-Cheng Jia Ke-Jia Li Yong-Can Huang Qiang Liu Jian-Hao Lin Xin-Tao Zhang 《World Journal of Stem Cells》 SCIE 2024年第3期305-323,共19页
BACKGROUND Mesenchymal stem cells(MSCs)modulated by various exogenous signals have been applied extensively in regenerative medicine research.Notably,nanosecond pulsed electric fields(nsPEFs),characterized by short du... BACKGROUND Mesenchymal stem cells(MSCs)modulated by various exogenous signals have been applied extensively in regenerative medicine research.Notably,nanosecond pulsed electric fields(nsPEFs),characterized by short duration and high strength,significantly influence cell phenotypes and regulate MSCs differentiation via multiple pathways.Consequently,we used transcriptomics to study changes in messenger RNA(mRNA),long noncoding RNA(lncRNA),microRNA(miRNA),and circular RNA expression during nsPEFs application.AIM To explore gene expression profiles and potential transcriptional regulatory mechanisms in MSCs pretreated with nsPEFs.METHODS The impact of nsPEFs on the MSCs transcriptome was investigated through whole transcriptome sequencing.MSCs were pretreated with 5-pulse nsPEFs(100 ns at 10 kV/cm,1 Hz),followed by total RNA isolation.Each transcript was normalized by fragments per kilobase per million.Fold change and difference significance were applied to screen the differentially expressed genes(DEGs).Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed to elucidate gene functions,complemented by quantitative polymerase chain reaction verification.RESULTS In total,263 DEGs were discovered,with 92 upregulated and 171 downregulated.DEGs were predominantly enriched in epithelial cell proliferation,osteoblast differentiation,mesenchymal cell differentiation,nuclear division,and wound healing.Regarding cellular components,DEGs are primarily involved in condensed chromosome,chromosomal region,actin cytoskeleton,and kinetochore.From aspect of molecular functions,DEGs are mainly involved in glycosaminoglycan binding,integrin binding,nuclear steroid receptor activity,cytoskeletal motor activity,and steroid binding.Quantitative real-time polymerase chain reaction confirmed targeted transcript regulation.CONCLUSION Our systematic investigation of the wide-ranging transcriptional pattern modulated by nsPEFs revealed the differential expression of 263 mRNAs,2 miRNAs,and 65 lncRNAs.Our study demonstrates that nsPEFs may affect stem cells through several signaling pathways,which are involved in vesicular transport,calcium ion transport,cytoskeleton,and cell differentiation. 展开更多
关键词 Nanosecond pulsed electric fields Whole transcriptome sequencing Mesenchymal stem cells Genetic response Stem cell engineering
下载PDF
Coseismic Coulomb stress changes induced by a 2020-2021 M_(W)>7.0 Alaska earthquake sequence in and around the Shumagin gap and its influence on the Alaska-Aleutian subduction interface
9
作者 Lei Yang Jianjun Wang Caijun Xu 《Geodesy and Geodynamics》 EI CSCD 2024年第1期1-12,共12页
Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6... Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6 Sand Point strike-slip earthquake on October 19,2020,and the M_(W)8.2 Chignik thrust earthquake on July 29,2021.The spatial and temporal proximity of these three earthquakes prompts us to probe stress-triggering effects among them.Here we examine the coseismic Coulomb stress change imparted by the three earthquakes and their influence on the subduction interface.Our results show that:(1)The Simeonof earthquake has strong loading effects on the subsequent Sand Point and Chignik earthquakes,with the Coulomb stress changes of 3.95 bars and 2.89 bars,respectively.The Coulomb stress change caused by the Sand Point earthquake at the hypocenter of the Chignik earthquake is merely around 0.01 bars,suggesting the negligible triggering effect on the latter earthquake;(2)The triggering effects of the Simeonof,Sand Point,and Chignik earthquakes on aftershocks within three months are not well pronounced because of the triggering rates of 38%,14%,and 43%respectively.Other factors may have played an important role in promoting the occurrence of these aftershocks,such as the roughness of the subduction interface,the complicated velocity structure of the lithosphere,and the heterogeneous prestress therein;(3)The three earthquakes caused remarkable coseismic Coulomb stress changes at the subduction interface nearby these mainshocks,with an average Coulomb stress change of 3.2 bars in the shallow region directly inwards the trench. 展开更多
关键词 The 2020-2021 Alaska earthquake sequencE Coseismic Coulomb stress change Mainshock-aftershock triggering The Alaska-Aleutian subduction interface The Shumagin gap
下载PDF
Influence of Production Sequence of Aluminum Alloy Hot Rolling on Strip Surface Quality
10
作者 Hui Song Weixuan Jiang 《Frontiers of Metallurgical Industry》 2024年第1期12-14,共3页
With the intensification of market competition in the aluminum alloy strip processing industry,it is dif-ficult to control the mass production of the same specifications,which is bound to affect the hot rolling produc... With the intensification of market competition in the aluminum alloy strip processing industry,it is dif-ficult to control the mass production of the same specifications,which is bound to affect the hot rolling production.This paper studied the effect of the hot rolling order of aluminum alloy on the surface quality of strip,such as roll printing,color difference,anodic oxidation,etc.,reasonable discharge sequence and corresponding optimization measures were formulated. 展开更多
关键词 hot rolling production sequence surface quality aluminum alloy chromate treatment
下载PDF
微电解-UASB-改良型两级A/O-序批沉淀工艺处理医药废水
11
作者 张金彪 《工业水处理》 CAS CSCD 北大核心 2024年第3期190-194,共5页
山东某医药化工厂综合废水包含浓污水、清污水和生活污水,且浓污水具有高COD和高NH3-N的特点,需对其进行分质预处理后再将其处理至达到污水处理厂接收水体的水质标准。首先采用微电解对浓污水进行预处理,之后将预处理后的浓污水与清污... 山东某医药化工厂综合废水包含浓污水、清污水和生活污水,且浓污水具有高COD和高NH3-N的特点,需对其进行分质预处理后再将其处理至达到污水处理厂接收水体的水质标准。首先采用微电解对浓污水进行预处理,之后将预处理后的浓污水与清污水及除悬浮物后的生活污水混合后采用UASB-改良型两级A/O-序批沉淀组合工艺进行后续处理。工程实践表明,所采用的工艺对综合废水具有良好的处理效果,且运行稳定,耐冲击负荷高。处理后出水COD、NH3-N、TN分别降至200、3、20 mg/L以下,满足《污水综合排放标准》(GB 8978—1996)表4中的二级标准,达到污水处理厂接收水体的水质要求。 展开更多
关键词 医药废水 uasB 改良型两级A/O 序批沉淀
下载PDF
The structural analysis of protein sequences based on the quasi-amino acids code 被引量:2
12
作者 朱平 唐旭清 徐振源 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第1期363-369,共7页
Proteomics is the study of proteins and their interactions in a cell. With the successful completion of the Human Cenome Project, it comes the postgenome era when the proteomics technology is emerging. This paper stud... Proteomics is the study of proteins and their interactions in a cell. With the successful completion of the Human Cenome Project, it comes the postgenome era when the proteomics technology is emerging. This paper studies protein molecule from the algebraic point of view. The algebraic system (∑, +, *) is introduced, where ∑ is the set of 64 codons. According to the characteristics of (∑, +, *), a novel quasi-amino acids code classification method is introduced and the corresponding algebraic operation table over the set ZU of the 16 kinds of quasi-amino acids is established. The internal relation is revealed about quasi-amino acids. The results show that there exist some very close correlations between the properties of the quasi-amino acids and the codon. All these correlation relationships may play an important part in establishing the logic relationship between codons and the quasi-amino acids during the course of life origination. According to Ma F et al (2003 J. Anhui Agricultural University 30 439), the corresponding relation and the excellent properties about amino acids code are very difficult to observe. The present paper shows that (ZU, +,×) is a field. Furthermore, the operational results display that the eodon tga has different property from other stop codons. In fact, in the mitochondrion from human and ox genomic codon, tga is just tryptophane, is not the stop codon like in other genetic code, it is the case of the Chen W C et al (2002 Acta Biophysiea Siniea 18(1) 87). The present theory avoids some inexplicable events of the 20 kinds of amino acids code, in other words it solves the problem of 'the 64 codon assignments of mRNA to amino acids is probably completely wrong' proposed by Yang (2006 Progress in Modern Biomedicine 6 3). 展开更多
关键词 algebraic operation quasi-amino acids code protein sequences structural analysis
下载PDF
Architectural Building Detection and Tracking in Video Sequences Taken by Unmanned Aircraft System (UAS) 被引量:1
13
作者 Qiang He Chee-Hung Henry Chu Aldo Camargo 《Computer Technology and Application》 2012年第9期585-593,共9页
An Unmanned Aircraft System (UAS) is an aircraft or ground station that can be either remote controlled manually or is capable of flying autonomously under the guidance of pre-programmed Global Positioning System (... An Unmanned Aircraft System (UAS) is an aircraft or ground station that can be either remote controlled manually or is capable of flying autonomously under the guidance of pre-programmed Global Positioning System (GPS) waypoint flight plans or more complex onboard intelligent systems. The UAS aircrafts have recently found extensive applications in military reconnaissance and surveillance, homeland security, precision agriculture, fire monitoring and analysis, and other different kinds of aids needed in disasters. Through surveillance videos captured by a UAS digital imaging payload over the interest areas, the corresponding UAS missions can be conducted. In this paper, the authors present an effective method to detect and extract architectural buildings under rural environment from UAS video sequences. The SIFT points are chosen as image features. The planar homography is adopted as the motion model between different image frames. The proposed algorithm is tested on real UAS video data. 展开更多
关键词 Unmanned aircraft system (uas object detection and tracking planar homography scale invariant feature transform(SIFT).
下载PDF
QUASI-SYNCHRONOUS MULTICARRIER DS-CDMA USING Z-COMPLEMENTARY SEQUENCES 被引量:1
14
作者 Tu Yifeng Fan Pingzhi +1 位作者 Yuan Weina Hao Li 《Journal of Electronics(China)》 2009年第4期487-491,共5页
In this paper, a multicarrier DS-CDMA system which employs Z-Complementary Se- quences (ZCS) as spreading code is investigated. The new system can not only eliminate multipath interference and Multiple Access Interfer... In this paper, a multicarrier DS-CDMA system which employs Z-Complementary Se- quences (ZCS) as spreading code is investigated. The new system can not only eliminate multipath interference and Multiple Access Interference (MAI), but also support flexible number of users com- pared with system using Orthogonal Complementary (OC) codes. Multicarrier DS-CDMA using OC codes can be regarded as a special case of our proposed system. Zero Correlation Zone (ZCZ) of ZCS can be flexibly adjusted to meet the requirements on the user number and maximum multipath and in- ter-user delay, in this way, more users can be supported without losing interference-free property. The effectiveness of the proposed system is validated through theoretical analysis and simulation results. 展开更多
关键词 Orthogonal Complementary (OC) codes Multicarrier DS-CDMA Z-Complemen-tary sequences (ZCS) Zero Correlation Zone (ZCZ)
下载PDF
Quadrilaterals, extremal quasiconformal extensions and Hamilton sequences
15
作者 CHEN Zhi-guo ZHENG Xue-liang YAO Guo-wu 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2010年第2期217-226,共10页
The relationship between Strebel boundary dilatation of a quasisymmetric function h of the unit circle and the dilatation indicated by the change in the modules of the quadrilaterals with vertices on the circle intrig... The relationship between Strebel boundary dilatation of a quasisymmetric function h of the unit circle and the dilatation indicated by the change in the modules of the quadrilaterals with vertices on the circle intrigues many mathematicians. It had been a conjecture for some time that the dilatations Ko(h) and K1(h) of h are equal before Anderson and Hinkkanen disproved this by constructing concrete counterexamples. The independent work of Wu and of Yang completely characterizes the condition for Ko(h) = K1 (h) when h has no substantial boundary point. In this paper, we give a necessary and sufficient condition to determine the equality for h admitting a substantial boundary point. 展开更多
关键词 Extremal quasiconformal mapping quasisymmetric mapping Hamilton sequence substantial boundary point.
下载PDF
Almost sure limit theorem for the maximum of a class of quasi-stationary sequences
16
作者 ZHUANG Guang-ming PENG Zuo-xiang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2014年第1期44-52,共9页
This paper investigates the problem of almost sure limit theorem for the maximum of quasi-stationary sequence based on the result of Turkman and Walker. We prove an almost sure limit theorem for the maximum of a class... This paper investigates the problem of almost sure limit theorem for the maximum of quasi-stationary sequence based on the result of Turkman and Walker. We prove an almost sure limit theorem for the maximum of a class of quasi-stationary sequence under weak dependence conditions of D (uk, un) and αtm,ln = 0 ((log log n)-(1+ε)). 展开更多
关键词 quasi-stationary sequence MAXIMUM limit distribution almost sure central limit theorem
下载PDF
Application of Zero Correlation Zone Sequences in Quasi-synchronous CDMA Systems
17
作者 LI Shu-feng JIA Zhi-cheng WANG Jing LI Qi 《Semiconductor Photonics and Technology》 CAS 2007年第1期39-42,52,共5页
In a quasi-synchronous code division multiple access(QS-CDMA) system, the correlation functions around the origin influence the system performance and odd functions are as important as the even functions. Three kinds ... In a quasi-synchronous code division multiple access(QS-CDMA) system, the correlation functions around the origin influence the system performance and odd functions are as important as the even functions. Three kinds of zero correlation zone(ZCZ) sequences are used to analyze and compare the correlation functions. Binary phase shift keying(BPSK) simulations of QS-CDMA system with the three kinds of QS sequences as spreading codes on additive white Gaussian noise(AWGN) channel show that these sequences are quasi-orthogonal, so they are suitable for QS-CDMA system. The correlation between the system performance and the zero correlation zone of the sequence is also proved. 展开更多
关键词 QS-CDMA spreading sequence ZCZ sequence
下载PDF
基于OPC UA的分布式数据采集处理系统架构研究
18
作者 扈静 柏晨 +1 位作者 张玺 葛茂根 《合肥工业大学学报(自然科学版)》 CAS 北大核心 2024年第8期1028-1034,共7页
随着物联网与互联网融合的不断深化,感知层与应用层之间的互联互通要求不断提高。针对现有数据采集系统存在的规范性、扩展性和适应性不足的问题,文章提出一套基于对象连接与嵌入过程控制统一架构(object linking and embedding for pro... 随着物联网与互联网融合的不断深化,感知层与应用层之间的互联互通要求不断提高。针对现有数据采集系统存在的规范性、扩展性和适应性不足的问题,文章提出一套基于对象连接与嵌入过程控制统一架构(object linking and embedding for process control unified architecture,OPC UA)协议的分布式数据采集处理系统架构。对数据采集处理系统各个模块进行功能解耦和架构重组,分别介绍该系统硬件和软件架构;针对发布订阅模式下负载的特异性,提出一种改进的适用于OPC UA分布式订阅的负载均衡算法;最后在某车企实例验证该系统架构。结果表明,基于OPC UA的分布式数据采集处理系统数据采集处理效果良好,证明了该系统架构的可行性及有效性。 展开更多
关键词 系统架构 分布式 基于对象连接与嵌入过程控制统一架构(OPC ua)协议 负载均衡
下载PDF
基于OPC UA的虚实结合实验设计与实践
19
作者 姚晓宁 郭琼 《湖南工业职业技术学院学报》 2024年第1期20-26,共7页
OPCUA是一种面向未来的工业通信技术,是实现智能制造的关键技术之一,在工业网络系统中得到越来越广泛的应用。为促进教学资源同步技术发展,以OPCUA技术为出发点,设计了基于OPCUA通信的客户端仿真、系统虚拟仿真、实践操作三个进阶实验... OPCUA是一种面向未来的工业通信技术,是实现智能制造的关键技术之一,在工业网络系统中得到越来越广泛的应用。为促进教学资源同步技术发展,以OPCUA技术为出发点,设计了基于OPCUA通信的客户端仿真、系统虚拟仿真、实践操作三个进阶实验项目。项目开发充分利用行业已有客户端测试软件和虚拟仿真软件资源,兼顾线上、线下学习,内容由基础到综合、虚实结合,旨在提升学生新技术应用能力和自主创新能力,更好地服务于智能制造转型升级和发展,为相关专业的实践教学及资源开发提供参考。 展开更多
关键词 OPC ua PLC 虚实结合 虚拟仿真 实践操作
下载PDF
基于OPC UA的纤维缠绕机信息模型开发和应用
20
作者 田会方 李勇清 吴迎峰 《机床与液压》 北大核心 2024年第4期100-105,共6页
为实现对复合材料纤维缠绕机生产过程的监测,以缠绕机及其辅助设备为研究对象,针对实际加工设备的多样性造成的加工数据采集的异构性,基于OPC UA建立缠绕机的信息模型架构。根据OPC基金会发布的OPC UA规范和相关的行业标准,建立纤维缠... 为实现对复合材料纤维缠绕机生产过程的监测,以缠绕机及其辅助设备为研究对象,针对实际加工设备的多样性造成的加工数据采集的异构性,基于OPC UA建立缠绕机的信息模型架构。根据OPC基金会发布的OPC UA规范和相关的行业标准,建立纤维缠绕机系统的信息模型和实例化。基于开源项目open62541,导入编译后的缠绕机的信息模型代码,自定义开发出符合使用规范的OPC UA服务器,然后利用UA客户端实现对服务器的连接,客户端能够通过服务器查询系统的加工数据,解决加工数据的异构性问题以达到监测缠绕机生产加工过程的目的;最后验证了建立的纤维缠绕机信息模型能够正确导入到开源项目open62541中,实现了加工数据监测。 展开更多
关键词 缠绕机 OPC ua 信息模型 加工数据监测
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部