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A DEVELOPMENT ON APPROXIMATION BY MONOTONE SEQUENCES OF POLYNOMIALS 被引量:1
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作者 Wu Xiaoqing, Southwest Petroleum Institute, China Southwest Petroleum Institute Nanchong Sichuan, 637001 P. R. C. 《Analysis in Theory and Applications》 1998年第4期98-101,共4页
Recently people proved that every f∈C[0, 1] can be uniformly approximated by polynomial sequences {P_n}, {Q_n} such for any x∈[0,1] and n=1,2,…that Q_n(x)<Q_(n+1)(x)<f(x)<P_(n+1)(x)<P_n(x). For example... Recently people proved that every f∈C[0, 1] can be uniformly approximated by polynomial sequences {P_n}, {Q_n} such for any x∈[0,1] and n=1,2,…that Q_n(x)<Q_(n+1)(x)<f(x)<P_(n+1)(x)<P_n(x). For example, Xie and Zhou showed that one can construct such monotone polynomial sequences which do achieve the best uniform approximation rate for a continuous func- tion. Actually they obtained a result as ‖P_n(x)-Q_n(x)‖≤42E_n (f), (1) which essentially improved a conclusion in Gal and Szabados. The present paper, by optimal procedure, improves this inequality to ‖[P_n(x)-Q_n(x)‖≤(18+ε)E_n(f), where εis any positive real number. 展开更多
关键词 MATH A DEVELOPMENT ON approximation BY MONOTONE sequences OF POLYNOMIALS
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De novel heterozygous copy number deletion on 7q31.31-7q31.32 involving TSPAN12 gene with familial exudative vitreoretinopathy in a Chinese family
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作者 Shuang Zhang Hai-Ming Yong +4 位作者 Gang Zou Mei-Jiao Ma Xue Rui Shang-Ying Yang Xun-Lun Sheng 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第12期1952-1961,共10页
AIM:To investigate the genetic and clinical characteristics of patients with a large heterozygous copy number deletion on 7q31.31-7q31.32.METHODS:A family with familial exudative vitreoretinopathy(FEVR)phenotype was i... AIM:To investigate the genetic and clinical characteristics of patients with a large heterozygous copy number deletion on 7q31.31-7q31.32.METHODS:A family with familial exudative vitreoretinopathy(FEVR)phenotype was included in the study.Whole-exome sequencing(WES)was initially used to locate copy number variations(CNVs)on 7q31.31-31.32,but failed to detect the precise breakpoint.The long-read sequencing,Oxford Nanopore sequencing Technology(ONT)was used to get the accurate breakpoint which is verified by quantitative real-time polymerase chain reaction(QPCR)and Sanger Sequencing.RESULTS:The proband,along with her father and younger brother,were found to have a heterozygous 4.5 Mb CNV deletion located on 7q31.31-31.32,which included the FEVRrelated gene TSPAN12.The specific deletion was confirmed as del(7)(q31.31q31.32)chr7:g.119451239_123956818del.The proband exhibited a phase 2A FEVR phenotype,characterized by a falciform retinal fold,macular dragging,and peripheral neovascularization with leaking of fluorescence.These symptoms led to a significant decrease in visual acuity in both eyes.On the other hand,the affected father and younger brother showed a milder phenotype.CONCLUSION:The heterozygous CNV deletion located on 7q31.31-7q31.32 is associated with the FEVR phenotype.The use of long-read sequencing techniques is essential for accurate molecular diagnosis of genetic disorders. 展开更多
关键词 familial exudative vitreoretinopathy copy number variation copy number deletion TSPAN12 longread sequencing
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An Uncertainty Analysis and Reliability-Based Multidisciplinary Design Optimization Method Using Fourth-Moment Saddlepoint Approximation
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作者 Yongqiang Guo Zhiyuan Lv 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第3期1855-1870,共16页
In uncertainty analysis and reliability-based multidisciplinary design and optimization(RBMDO)of engineering structures,the saddlepoint approximation(SA)method can be utilized to enhance the accuracy and efficiency of... In uncertainty analysis and reliability-based multidisciplinary design and optimization(RBMDO)of engineering structures,the saddlepoint approximation(SA)method can be utilized to enhance the accuracy and efficiency of reliability evaluation.However,the random variables involved in SA should be easy to handle.Additionally,the corresponding saddlepoint equation should not be complicated.Both of them limit the application of SA for engineering problems.The moment method can construct an approximate cumulative distribution function of the performance function based on the first few statistical moments.However,the traditional moment matching method is not very accurate generally.In order to take advantage of the SA method and the moment matching method to enhance the efficiency of design and optimization,a fourth-moment saddlepoint approximation(FMSA)method is introduced into RBMDO.In FMSA,the approximate cumulative generating functions are constructed based on the first four moments of the limit state function.The probability density function and cumulative distribution function are estimated based on this approximate cumulative generating function.Furthermore,the FMSA method is introduced and combined into RBMDO within the framework of sequence optimization and reliability assessment,which is based on the performance measure approach strategy.Two engineering examples are introduced to verify the effectiveness of proposed method. 展开更多
关键词 Reliability-based multidisciplinary design optimization moment method saddlepoint approximate sequence optimization and reliability assessment performance measure approach
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Identification of a LMNA (c.646C>T) variant by whole-exome sequencing in combination with a dilated cardiomyopathy (DCM) related gene filter in a family with familiar DCM 被引量:2
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作者 Liang Chen Zhongyin Zhou +4 位作者 Huihe Lu Ye Xie Gang Li Jianfei Huang Dongsheng Zhao 《The Journal of Biomedical Research》 CAS CSCD 2018年第4期314-316,共3页
Dilated cardiomyopathy(DCM)is characterized by the dilated heart chambers and reduced systolic function in the absence of specific aetiology[1].Approximately one third of DCM cases are hereditary.In recent years,DCM... Dilated cardiomyopathy(DCM)is characterized by the dilated heart chambers and reduced systolic function in the absence of specific aetiology[1].Approximately one third of DCM cases are hereditary.In recent years,DCM concomitant with arrhythmias and sudden death resulting from gene mutation has been widely 展开更多
关键词 related gene filter in a family with familiar DCM AVB Identification of a LMNA c.646C T variant by whole-exome sequencing in combination with a dilated cardiomyopathy
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A High Efficiency Spread Spectrum Scheme Using Approximate Orthogonal Complex Sequences
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作者 Xiaohong SHI 《International Journal of Communications, Network and System Sciences》 2010年第1期79-82,共4页
This paper presents a high efficiency spread spectrum scheme using approximate orthogonal complex (AOC) sequences. In this scheme, the 64 AOC sequences picked up from 84 complex sequences space are employed for spread... This paper presents a high efficiency spread spectrum scheme using approximate orthogonal complex (AOC) sequences. In this scheme, the 64 AOC sequences picked up from 84 complex sequences space are employed for spreading spectrum. In modulation, 6 input bits is used to select one AOC sequence, and the selected sequence is then phase-rotated by another 2 input bits. In demodulator, a complex correlator detects the transmitted AOC sequence. Simulation results show that the proposed scheme has better BER performance than the existing complementary code keying (CCK) modulation scheme. For AOC, additional processing gain of 1.79dB can be obtained when the sequence length is 8. 展开更多
关键词 Spread Spectrum Communications approximATE ORTHOGONAL COMPLEX (AOC) sequences Modulation and DEMODULATION
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ON REMES ALGORITHA FOR THE BEST CHEBYSHEV APPROXIMATION FROM VARISOLVENT FAMILY
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作者 Wei Dan(Academia Sinica,China) 《Analysis in Theory and Applications》 1996年第1期62-67,共6页
In this paper, Remes algorithm is applied to compute the numerical solution of the best chebyshev approximation from varisolvent family. Feasibility and convergence of the algorithm are discussed carefully.
关键词 ON REMES ALGORITHA FOR THE BEST CHEBYSHEV approximation FROM VARISOLVENT family
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GENERALIZED I-NONEXPANSIVE MAPS AND INVARIANT APPROXIMATION RESULTS IN p-NORMED SPACES 被引量:1
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作者 N.Hussain 《Analysis in Theory and Applications》 2006年第1期72-80,共9页
Abstract We extend the concept of R-subeommuting maps due to Shahzad to the case of non-starshaped domain and obtain a common fixed point result for this class of maps on non-starshaped domain in the setup of p-norra... Abstract We extend the concept of R-subeommuting maps due to Shahzad to the case of non-starshaped domain and obtain a common fixed point result for this class of maps on non-starshaped domain in the setup of p-norraed spaces. As applications, we establish noncommutative versions of various best approximation results for generalized I-nonexpansive maps on non-starshaped domain. Our results unify and extend that of Al- Thagafi, Dotson, IIabiniak, Jungck and Senna, Latif, Sahab, Khan and Sessa and Shahzad. 展开更多
关键词 common fixed point contractive family of functions R-subcommuting maps invariant approximation
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ON POINTWISE R-SUBWEAKLY COMMUTING MAPS AND BEST APPROXIMATIONS
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作者 F. Akbar N. Sultana 《Analysis in Theory and Applications》 2008年第1期40-49,共10页
The main purpose of this paper is to prove some common fixed point theorems for pointwise R-subweakly commuting maps on non-starshaped domains in p-normed spaces and locally convex topological vector spaces. As applic... The main purpose of this paper is to prove some common fixed point theorems for pointwise R-subweakly commuting maps on non-starshaped domains in p-normed spaces and locally convex topological vector spaces. As applications, invariant approximation results are established. This work provides extension as well as substantial improvement of several results in the existing literature. 展开更多
关键词 common fixed point contractive family of functions pointwise R-subweaklycommuting maps invariant approximation
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A Note on the Statistical Approximation Properties of the Modified Discrete Operators
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作者 Reyhan Canatan 《Open Journal of Discrete Mathematics》 2012年第3期114-117,共4页
In this present paper, firstly, the modified positive operators and their discrete operators are constructed. Then, we investigate the statistical approximation properties and rates of convergence by using modulus of ... In this present paper, firstly, the modified positive operators and their discrete operators are constructed. Then, we investigate the statistical approximation properties and rates of convergence by using modulus of continuity of these positive linear operators. Finally, we obtain the rate of statistical convergence of truncated operators. 展开更多
关键词 sequence of Positive Linear OPERATORS Bohman-Korovkin THEOREM Statistical approximation MODULUS of CONTINUITY Rate of Convergence
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Family with sequence similarity 134 member B-mediated reticulophagy ameliorates hepatocyte apoptosis induced by dithiothreitol
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作者 Yi-Xin Guo Bing Han +5 位作者 Ting Yang Yu-Si Chen Yi Yang Jia-Yao Li Qin Yang Ru-Jia Xie 《World Journal of Gastroenterology》 SCIE CAS 2022年第23期2569-2581,共13页
BACKGROUND Endoplasmic reticulum(ER)stress-related hepatocyte apoptosis is responsible for multiple hepatic diseases.Previous studies have revealed that endoplasmic reticulophagy(ER-phagy)promotes the selective cleara... BACKGROUND Endoplasmic reticulum(ER)stress-related hepatocyte apoptosis is responsible for multiple hepatic diseases.Previous studies have revealed that endoplasmic reticulophagy(ER-phagy)promotes the selective clearance of damaged ER fragments during ER stress,playing a crucial role in maintaining ER homeostasis and inhibiting apoptosis.Family with sequence similarity 134 member B(FAM134B)is a receptor involved in ER-phagy that can form a complex with calnexin(CNX)and microtubule-associated protein 1 light chain 3(LC3).The complex can mediate the selective isolation of ER fragments to attenuate hepatocyte apoptosis.However,the precise regulatory mechanisms remain unclear.AIM To elucidate the effect of FAM134B-mediated ER-phagy on ER stress-induced apoptosis in buffalo rat liver 3A(BRL-3A)rat hepatocytes and the potential regulatory mechanisms.METHODS ER stress-related hepatocyte apoptosis was induced using dithiothreitol(DTT).Proteins related to ER stress and autophagy were measured with western blotting.Protein complex interactions with FAM134B were isolated by co-immunoprecipitation.ER-phagy was evaluated in immunofluorescence experiments.Cell cycle distribution and apoptosis were measured by flow cytometry.Mitochondrial Ca^(2+) levels were evaluated by the co-localization of intracellular Ca^(2+)-tracker and Mitotracker.The small interfering RNA against FAM134B was used to knockdown FAM134B in BRL-3A cells.RESULTS ER stress-related and autophagy-related proteins in BRL-3A cells were elevated by both short and long-term DTT treatment.Furthermore,co-immunoprecipitation confirmed an interaction between FAM134B,CNX,FAM134B,and LC3 in BRL-3A cells.Immunofluorescence assays revealed that autolysosomes significantly decreased following short-term DTT treatment,but increased after long-term treatment.Mitochondrial Ca2+levels and apoptotic rates were dramatically elevated,and more cells were arrested in the G1 stage after short-term DTT treatment;however,these decreased 48 h later.Moreover,FAM134B downregulation accelerated mitochondrial apoptotic pathway activation and aggravated hepatocyte apoptosis under ER stress.CONCLUSION FAM134B-mediated ER-phagy attenuates hepatocyte apoptosis by suppressing the mitochondrial apoptotic pathway.Our findings provide new evidence highlighting the importance of FAM134Bmediated ER-phagy in attenuating hepatocyte apoptosis. 展开更多
关键词 HEPATOCYTES Reticulophagy family with sequence similarity 134 member B Apoptosis Endoplasmic reticulum stress Endoplasmic reticulum homeostasis
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A LARGE CLASS OF BINARY ZCZ SEQUENCE FAMILIES CONSTRUCTED BY PERIOD DOUBLING
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作者 Wang Jinsong Qi Wenfeng 《Journal of Electronics(China)》 2007年第3期301-304,共4页
In an Approximately Synchronized Code Division Multiple Access (AS-CDMA) commu-nication system,a family with large number of Zero Correlation Zone (ZCZ) sequences is desired,which can satisfy the rapid increase of use... In an Approximately Synchronized Code Division Multiple Access (AS-CDMA) commu-nication system,a family with large number of Zero Correlation Zone (ZCZ) sequences is desired,which can satisfy the rapid increase of users. This paper presents a method to generate a (2L ,2M ,Zc' z )-ZCZsequence family from an original (L ,M ,Z cz)-ZCZsequence family,where Z c' z =Zcz if Z czis even and Z c' z = Zcz 1if Z czis odd. This method can also recursively act on a ZCZ sequence family to construct a series of ZCZ sequence families with large sequence number and zero correlation zone length identical to or one less than that of original ZCZ sequences. 展开更多
关键词 AS-CDMA通信系统 ZCZ序列集合 ZCZ长度 周期倍频
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Identification of 1q21.1 microduplication in a family:A case report
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作者 Ting-Ting Huang Hai-Feng Xu +7 位作者 Shang-Yu Wang Wen-Xin Lin Yie-Hen Tung Kaleem Ullah Khan Hui-HuiZhang Hu Guo Guo Zheng Gang Zhang 《World Journal of Clinical Cases》 SCIE 2023年第4期874-882,共9页
BACKGROUND Copy number variation(CNV)has become widely recognized in recent years due to the extensive use of gene screening in developmental disorders and epilepsy research.1q21.1 microduplication syndrome is a rare ... BACKGROUND Copy number variation(CNV)has become widely recognized in recent years due to the extensive use of gene screening in developmental disorders and epilepsy research.1q21.1 microduplication syndrome is a rare CNV disease that can manifest as multiple congenital developmental disorders,autism spectrum disorders,congenital malformations,and congenital heart defects with genetic heterogeneity.CASE SUMMARY We reported a pediatric patient with 1q21.1 microduplication syndrome,and carried out a literature review to determine the correlation between 1q21.1microduplication and its phenotypes.We summarized the patient’s medical history and clinical symptoms,and extracted genomic DNA from the patient,her parents,elder brother,and sister.The patient was an 8-mo-old girl who was hospitalized for recurrent convulsions over a 2-mo period.Whole exon sequencing and whole genome low-depth sequencing(CNV-seq)were then performed.Whole exon sequencing detected a 1.58-Mb duplication in the CHR1:145883867-147465312 region,which was located in the 1q21.1 region.Family analysis showed that the pathogenetic duplication fragment,which was also detected in her elder brother’s DNA originated from the mother.CONCLUSION Whole exon sequencing combined with quantitative polymerase chain reaction can provide an accurate molecular diagnosis in children with 1q21.1 microduplication syndrome,which is of great significance for genetic counseling and early intervention. 展开更多
关键词 1q21.1 microduplication syndrome EPILEPSY Copy number variation FAMILIAL Whole exon sequencing Congenital developmental disorders Case report
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Sin3A基因变异致Witteveen-Kolk综合征遗传学分析
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作者 卢亚亚 彭慧芳 +1 位作者 王剑 娄丹 《检验医学》 CAS 2024年第2期126-131,共6页
目的 探讨开关不敏感3转录调节因子家族成员A(Sin3A)基因变异导致的Witteveen-Kolk综合征临床表型和遗传学特点。方法 收集1例发育迟缓患儿的临床资料,对患儿及其父母进行全外显子基因测序,采用Sanger测序验证可疑变异,并进行家系分析... 目的 探讨开关不敏感3转录调节因子家族成员A(Sin3A)基因变异导致的Witteveen-Kolk综合征临床表型和遗传学特点。方法 收集1例发育迟缓患儿的临床资料,对患儿及其父母进行全外显子基因测序,采用Sanger测序验证可疑变异,并进行家系分析。结合文献分析Witteveen-Kolk综合征的临床特征和基因变异特点。结果 Witteveen-Kolk综合征患儿临床表现主要为轻中度智力障碍或发育迟缓、特殊面容(长脸、前额突出、鼻梁凹陷、长人中等)、身材矮小。颅脑磁共振成像(MRI)显示不同程度的脑畸形。全外显子基因测序结果显示,患儿Sin3A基因存在移码变异c.803dupC(p.Leu269Thrfs*37)(杂合)。Sanger测序证实存在变异位点,患儿父母该位点均为正常基因型。gnomAD等对照人群数据库未收录该变异位点,根据美国医学遗传学和基因组学学会(ACMG)/美国分子病理学学会(AMP)指南归类为“致病性”变异。结论 Sin3A基因变异可导致Witteveen-Kolk综合征。基因检测可明确生长发育迟缓伴特殊面容患儿的病因。 展开更多
关键词 开关不敏感3转录调节因子家族成员A基因 全外显子组测序 Witteveen-Kolk综合征 智力发育障碍 发育迟缓
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一测多评法测定法制半夏曲中11种成分含量及其GRA、EW-TOPSIS质量评价
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作者 舒波 雷果平 袁斌 《医药导报》 CAS 北大核心 2024年第7期1120-1126,共7页
目的采用一测多评(QAMS)法同时测定法制半夏曲中肌苷、鸟苷、腺苷等11种成分含量,并建立其灰色关联度分析(GRA)联合熵权逼近理想解排序分析法(EW-TOPSIS)综合质量评价方法。方法采用Shimadzu C 18色谱柱;乙腈-0.5%醋酸为流动相,梯度洗脱... 目的采用一测多评(QAMS)法同时测定法制半夏曲中肌苷、鸟苷、腺苷等11种成分含量,并建立其灰色关联度分析(GRA)联合熵权逼近理想解排序分析法(EW-TOPSIS)综合质量评价方法。方法采用Shimadzu C 18色谱柱;乙腈-0.5%醋酸为流动相,梯度洗脱,流速1.0 mL·min-1;检测波长254和290 nm。以对甲氧基肉桂酸乙酯为内参比物质,计算其他10个成分的相对校正因子(RCF),测定各成分含量。采用GRA联合EW-TOPSIS模型对法制半夏曲进行综合质量评价。结果法制半夏曲中11种成分在一定浓度范围内线性关系良好,相关系数均>0.999;平均加样回收率96.94%~100.12%(RSD<2.0%,n=9);QAMS与外标法(ESM)实测值无明显差异。GRA模型相对关联度0.2903~0.6187,EW-TOPSIS模型相对接近度0.2114~0.6343;GRA和EW-TOPSIS模型综合评价结果基本一致。结论QAMS法便捷、准确,可用于法制半夏曲多指标成分定量控制,GRA联合EW-TOPSIS模型可用于法制半夏曲综合质量评价。 展开更多
关键词 法制半夏曲 一测多评法 多指标成分 相对校正因子 灰色关联度分析 熵权-逼近理想解排序法 质量评价
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先天缺牙相关EDAR基因突变报道及携带双突变位点的HED家系分析
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作者 兰嵘 代庆刚 +4 位作者 喻康 卞晓玲 叶丽娟 吴轶群 王凤 《上海交通大学学报(医学版)》 CAS CSCD 北大核心 2024年第6期694-701,共8页
目的·探索先天缺牙相关的外异蛋白A受体(ectodysplasin A receptor,EDAR)基因突变位点,初步分析EDAR基因突变导致综合征型和非综合征型缺牙的原因。方法·研究对象为就诊于上海交通大学医学院附属第九人民医院口腔第二门诊部... 目的·探索先天缺牙相关的外异蛋白A受体(ectodysplasin A receptor,EDAR)基因突变位点,初步分析EDAR基因突变导致综合征型和非综合征型缺牙的原因。方法·研究对象为就诊于上海交通大学医学院附属第九人民医院口腔第二门诊部的先天缺牙患者及其家系成员,提取其外周血中的基因组DNA进行全外显子组测序。通过初步筛选后,用PolyPhen-2、Mutation Taster、Provean对潜在突变位点的有害性进行预测,对分析后的突变位点进行Sanger测序验证。进行突变位点的保守性分析,使用在线工具Swiss-Model进行同源建模,分析EDAR蛋白的三维结构变化。对患者及其家系成员的先天缺牙和全身发育情况进行临床检查。结果·在纳入的先天缺牙患者中共发现5名EDAR基因突变患者,1名患者携带移码突变c.368_369insC(p.L123fs),4名患者携带错义突变。在EDAR错义突变患者中,有2名患有非综合征型缺牙(nonsyndromic tooth agenesis,NSTA),分别携带c.77C>A(p.A26E)纯合突变和c.380C>T(p.P127L)杂合突变。另外2名患有少汗型外胚层发育不良(hypohidrotic ectodermal dysplasia,HED),均带有2个基因突变位点:1名为EDAR复合杂合患者,携带来自父亲的EDAR c.77C>T(p.A26V)和来自母亲的EDAR c.1281G>C(p.L427F);另1名为EDAR、外异蛋白A(ectodysplasin A,EDA)双基因突变患者,EDAR c.1138A>C(p.S380R)和EDA c.1013C>T(p.T338M)均来自母亲,这2个位点在此前的报道中仅与NSTA相关。EDAR c.1281G>C(p.L427F)、c.77C>A(p.A26E)为未被报道过的错义突变新位点。错义突变可能通过改变氨基酸残基极性、电荷或体积等,对蛋白空间构象造成影响;移码突变造成了非3整倍数的碱基增加,可能导致蛋白的截短或降解。结论·发现了2个新的EDAR错义突变位点,报道了由EDAR纯合突变导致的NSTA以及由EDA、EDAR双基因突变导致HED的病例,扩展了对于EDAR突变造成HED和NSTA的致病机制的理解。 展开更多
关键词 外胚层发育不良 家族性缺牙 外异蛋白A受体 外异蛋白A 全外显子组测序
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短周期PN序列水声直扩系统抗单频干扰能力的变化规律与试验验证
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作者 王晓玮 周其斗 +2 位作者 唐永壮 谢志勇 刘文玺 《海军工程大学学报》 CAS 北大核心 2024年第2期43-49,共7页
对无法定量分析短周期PN序列直扩系统抗单频干扰性能的问题,首先通过理论推导得到单频干扰经相关处理产生的干扰分量;然后,结合直扩系统对单频干扰的处理增益,针对水声系统扩频序列周期较短的现实情况,提出了周期性PN序列水声直扩系统... 对无法定量分析短周期PN序列直扩系统抗单频干扰性能的问题,首先通过理论推导得到单频干扰经相关处理产生的干扰分量;然后,结合直扩系统对单频干扰的处理增益,针对水声系统扩频序列周期较短的现实情况,提出了周期性PN序列水声直扩系统抗单频干扰性能定量分析的理论表达式;最后,通过仿真和试验验证了理论表达式的正确性。结果表明:单频干扰经相关处理后得到的干扰序列呈直流或正弦分布;单频干扰对系统误码率的影响与信干比、干扰频偏、相位偏差以及扩频码本身结构有关,误码率随干扰相位偏差变化呈周期分布;在干扰频偏值为整数倍码元带宽的所有工况中,频偏为一倍码元带宽的单频干扰对系统影响最大;简明的理论表达式,对快速预报现实短码水声系统抗单频干扰性能的变化规律具有重要意义。 展开更多
关键词 水声通信 短周期PN序列 单频干扰 标准高斯近似
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考虑分离特性的包带式星箭连接结构优化设计
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作者 于宝石 张大鹏 +2 位作者 唐雨 张文沁 雷勇军 《宇航学报》 EI CAS CSCD 北大核心 2024年第5期680-691,共12页
针对高鲁棒性包带式星箭连接结构(CBJ)优化设计问题,提出一种兼顾结构的连接承载性能与分离冲击响应的包带式星箭连接结构轻量化设计方法。优化设计基于包带结构三维非线性有限元参数化模型,以连接框与夹块径向截面尺寸参数为设计变量,... 针对高鲁棒性包带式星箭连接结构(CBJ)优化设计问题,提出一种兼顾结构的连接承载性能与分离冲击响应的包带式星箭连接结构轻量化设计方法。优化设计基于包带结构三维非线性有限元参数化模型,以连接框与夹块径向截面尺寸参数为设计变量,以结构静力学承载性能与动力学分离冲击为约束,以轻量化为目标。针对优化中设计空间高维度、非规则导致的算法收敛困难问题,提出了基于近似模型与序列采样策略的约束序列近似优化(CSAO)算法。结果表明:算法可实现在复杂设计域内迅速收敛至最优解,相较于初始设计,优化结构的质量降低了5.62%,同时,结构连接刚度提升了19.27%,卫星下裙解锁冲击降低了18.52%,在满足性能约束的条件下减重效果明显,验证了提出方法的有效性。设计的优化构型兼顾了连接与分离特性,具有一定的工程应用价值。 展开更多
关键词 包带式星箭连接结构 轻量化设计 连接刚度 冲击响应 序列近似优化
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偏头痛的遗传学研究进展
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作者 徐菲 刘儒昶 +1 位作者 王天云 郭淮莲 《中国疼痛医学杂志》 CSCD 北大核心 2024年第1期52-56,共5页
偏头痛是一种常见的原发性头痛,临床表现多样,亚型众多。除家族性偏瘫型偏头痛(familial hemiplegic migraine, FHM)已发现明确致病基因外,无先兆偏头痛(migraine without aura, MO)、有先兆偏头痛(migraine with aura, MA)和其他类型... 偏头痛是一种常见的原发性头痛,临床表现多样,亚型众多。除家族性偏瘫型偏头痛(familial hemiplegic migraine, FHM)已发现明确致病基因外,无先兆偏头痛(migraine without aura, MO)、有先兆偏头痛(migraine with aura, MA)和其他类型如月经性偏头痛(menstrual migraine, MM)、前庭性偏头痛(vestibular migraine, VM)的遗传基础尚未完全明确。本文通过回顾偏头痛及各亚型的连锁研究、关联研究及测序研究,总结其遗传学发现,并讨论各个亚型的特点。偏头痛不同亚型的遗传位点极少重叠,未来针对表型一致性高的亚型进行研究并结合组学信息有望明确致病基因。 展开更多
关键词 偏头痛 家族性偏瘫型偏头痛 月经性偏头痛 高通量测序 遗传位点
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白芷全基因组测序分析及BGLU基因家族分析
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作者 王雅兰 周罗静 +3 位作者 张灵迂 章景 卞金辉 高继海 《广西植物》 CAS CSCD 北大核心 2024年第4期777-792,共16页
白芷为常用的药食同源物种,既是临床常用中药,又是香料,用途十分广泛。为获取白芷全基因组序列信息,该研究首次以杭白芷叶片DNA为材料,采用Nanopore测序技术构建杭白芷全基因组数据库,并利用生物信息学方法对获得的核苷酸序列进行组装... 白芷为常用的药食同源物种,既是临床常用中药,又是香料,用途十分广泛。为获取白芷全基因组序列信息,该研究首次以杭白芷叶片DNA为材料,采用Nanopore测序技术构建杭白芷全基因组数据库,并利用生物信息学方法对获得的核苷酸序列进行组装、功能注释以及进化分析研究。结果表明:(1)原始测序数据过滤后获得662 Gb三代数据,Read N50约为32932 bp,经过组装得到杭白芷基因组大小为5.6 Gb,Contig N50约为806638 bp。(2)组装后的序列通过与KOG、GO、KEGG等功能数据库比对,得到了功能注释的基因占66.47%,KOG功能注释结果表明杭白芷的蛋白功能主要集中在一般功能预测、翻译后修饰、蛋白质转换、伴侣以及信号转导机制;GO功能分类表明杭白芷的基因集中在生物学过程及细胞组分;KEGG通路注释表明参与代谢途径的基因占主要地位。(3)杭白芷中鉴定到45个BGLU家族基因。该研究首次利用第三代测序技术对杭白芷全基因组进行解析,为杭白芷的系统生物学研究和BGLU在杭白芷生长发育中的后续功能研究提供了重要的理论参考。 展开更多
关键词 杭白芷 基因组 第三代测序技术 BGLU 基因家族 药用植物
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丢番图逼近与三角数列的极限
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作者 李志国 邵泽玲 李慧云 《大学数学》 2024年第4期81-85,共5页
利用丢番图逼近理论中的无理测度方法得到了三角数列的一些极限公式,并给出了其在幂级数中的一些应用.
关键词 丢番图逼近 刘维尔数 无理测度 三角数列 幂级数
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