期刊文献+
共找到6,273篇文章
< 1 2 250 >
每页显示 20 50 100
The 2-adic complexity of sum sequences of Legendre sequences
1
作者 JING Xiaoyan XU Zhefeng FENG Keqin 《纯粹数学与应用数学》 2025年第2期191-199,共9页
Binary sequences constructed by Legendre symbols are widely used in communication and cryptography since they have many good pseudo-random properties.In this paper,we determine the 2-adic complexity of the sum sequenc... Binary sequences constructed by Legendre symbols are widely used in communication and cryptography since they have many good pseudo-random properties.In this paper,we determine the 2-adic complexity of the sum sequence of any k many Legendre sequences and show that the 2-adic complexity of the sum sequences of any k many Legendre sequences reaches the maximum by proving the case of k=2 and 3,which implies that the sum sequences can resist the attack of rational approximation algorithm. 展开更多
关键词 2-adic complexity binary sequences Legendre symbol Legendre sequences
在线阅读 下载PDF
Generalized Harmonic Numbers Hn,k,r (α,β) with Combinatorial Sequences 被引量:1
2
作者 Rui Wang   Wuyungaowa 《Journal of Applied Mathematics and Physics》 2022年第5期1602-1618,共17页
In this paper, we observe the generalized Harmonic numbers H<sub>n,k,r</sub> (α,β). Using generating function, we investigate some new identities involving generalized Harmonic numbers H<sub>n,k,r&... In this paper, we observe the generalized Harmonic numbers H<sub>n,k,r</sub> (α,β). Using generating function, we investigate some new identities involving generalized Harmonic numbers H<sub>n,k,r</sub> (α,β) with Changhee sequences, Daehee sequences, Degenerate Changhee-Genoocchi sequences, Two kinds of degenerate Stirling numbers. Using Riordan arrays, we explore interesting relations between these polynomials, Apostol Bernoulli sequences, Apostol Euler sequences, Apostol Genoocchi sequences. 展开更多
关键词 Generating Function Riordan Arrays Generalized Harmonic Numbers Changhee sequences Daehee sequences Apostol Bernoulli sequences Degenerate Changhee-Genoocchi sequences
在线阅读 下载PDF
Non-Abelian Extensions of Rota-Baxter Pre-Lie Algebras and Wells Exact Sequences
3
作者 Shuangjian GUO Qun WANG 《Journal of Mathematical Research with Applications》 2025年第4期473-487,共15页
In this paper,we introduce non-abelian cohomology groups and classify the nonabelian extensions of Rota-Baxter pre-Lie algebras in terms of non-abelian cohomology groups.Next,we explore the inducibility of pairs of au... In this paper,we introduce non-abelian cohomology groups and classify the nonabelian extensions of Rota-Baxter pre-Lie algebras in terms of non-abelian cohomology groups.Next,we explore the inducibility of pairs of automorphisms and derive the analog Wells exact sequences under the circumstance of Rota-Baxter pre-Lie algebras.Finally,we discuss the inducibility problem of pairs of automorphisms about an abelian extensions of Rota-Baxter pre-Lie algebras. 展开更多
关键词 Rota-Baxter pre-Lie algebra non-abelian extension Wells exact sequences
原文传递
Some Convergence Results for Arbitrary Sequences under Moment Condition 被引量:6
4
作者 王学军 胡舒合 杨文志 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第4期585-589,共5页
Let {X n , n ≥ 1} be an arbitrary sequence of random variables. Some convergence results for the partial sums of arbitrary sequence of random variables are obtained, which generalize the known results for independent... Let {X n , n ≥ 1} be an arbitrary sequence of random variables. Some convergence results for the partial sums of arbitrary sequence of random variables are obtained, which generalize the known results for independent sequences, NA sequences, ρ-mixing sequences and φ-mixing sequences, and so on. 展开更多
关键词 strong law of large numbers NA sequences ρ-mixing sequences φ-mixing sequences
在线阅读 下载PDF
AUTOCORRELATIONS OF l-SEQUENCES WITH CERTAIN SHIFTS
5
作者 Xu Hong Qi Wenfeng 《Journal of Electronics(China)》 2007年第4期439-442,共4页
In this paper, the autocorrelations of maximal period Feedback with Carry Shift Register sequences (l-sequences) are discussed. For an l-sequence a with connection integer q = p^e(e ≥ 2) and period T = p^t-1(p- ... In this paper, the autocorrelations of maximal period Feedback with Carry Shift Register sequences (l-sequences) are discussed. For an l-sequence a with connection integer q = p^e(e ≥ 2) and period T = p^t-1(p- 1), and for any integer i, 1 ≤ i ≤ e/2, by calculating the number of certain sets, it is shown that the autocorrelation of a with shift τ= kT/2p^i is Ca(τ) =(-1)^k-1 T/p^2i-1, where 1 ≤ k ≤ 2p^i - 1, and gcd(k,2p^i) = 1. This result shows there do exist some shifts such that the autocorrelations of l-sequences are high although most autocorrelations are low. Such result also holds for the decimations of l-sequences. 展开更多
关键词 Pseudorandom sequences l-sequences Feedback with Carry Shift Register (FCSR) sequences AUTOCORRELATIONS
在线阅读 下载PDF
Microdissection of Haynaldia villosa Telosome 6VS and Cloning of Species-specific DNA Sequences 被引量:3
6
作者 孔凡晶 陈孝 +4 位作者 马有志 辛志勇 李连成 张增艳 林志姗 《Acta Botanica Sinica》 CSCD 2002年第3期307-313,共7页
The material T240_6 derived from SC 2 young embryo of the combination CA9211/RW15 (6D/6V alien substitution) was telosomic substitution line of 6VS identified by GISH (genomic in situ hybridization) analysis. The 6V... The material T240_6 derived from SC 2 young embryo of the combination CA9211/RW15 (6D/6V alien substitution) was telosomic substitution line of 6VS identified by GISH (genomic in situ hybridization) analysis. The 6VS was microdissected with a needle and transferred into a 0.5 mL Ep tube. In the 'single tube', all the subsequence steps were conducted. After two round of LA (Linker adaptor)_PCR amplification, the size of PCR bands ranged from 100 to 3 000 bp, with predominate bands 600-1 500 bp. The products were confirmed by Southern blotting analysis using Haynaldia villosa (L.) Schur. genomic DNA labeled with 32 P as probe. The PCR products were purified and ligated into clone vector-pGEM_T easy vector. Then, the plasmids were transformed into competence E. coli JM109 with cool CaCl 2. It was estimated that there were more than 17 000 white clones in the library. The size of insert fragments distributed from 100-1 500 bp, with average of 600 bp. Using H. villosa genomic DNA as probe, dot blotting results showed that 37% clones displayed strong and medium positive signals, and 63% clones had faint or no signals. It is demonstrated that there were about 37% repeat sequence clones and 67% single/unique sequence clones in the library. Eight H. villosa_specific clones were screened from the library, and two clones pHVMK22 and pHVMK134 were used for RFLP analysis and sequencing. Both of them were H. villosa specific clones. The pHVMK22 was a unique sequence clone, and the pHVMK134 was a repeat sequence clone. When the pHVMK22 was used as a probe for Southern hybridization, all the powdery mildew resistance materials showed a special band of 2 kb, while all the susceptible ones not. The pHVMK22 may be applied to detect the existence of Pm21. 展开更多
关键词 microdissection and microcloning of chromosome Haynaldia villosa genomic in situ hybridization alien substitution of telosome species_specific DNA sequences RFLP
在线阅读 下载PDF
Characterization of Two Groups of Low_copy and Specific DNA Sequences Isolated from Chromosome 7B of Common Wheat 被引量:2
7
作者 刘振兰 董玉柱 刘宝 《Acta Botanica Sinica》 CSCD 2002年第8期946-950,共5页
Recent work revealed that, in the genomes of polyploid wheat, there exists a class of low_copy and chromosome_specific sequences that are labile upon polyploid formation. This class of sequences was proposed to play ... Recent work revealed that, in the genomes of polyploid wheat, there exists a class of low_copy and chromosome_specific sequences that are labile upon polyploid formation. This class of sequences was proposed to play a critical role in the stabilization and establishment of nascent plant polyploids as new species. To further study this issue, five wheat chromosome 7B_specific sequences, isolated from common wheat (Triticum aestivum L.) by chromosome microdissection, were characterized. The sequences were studied by genomic Southern hybridizations on a collection of polyploid wheats and their diploid progenitors. Four sequences hybridized to all polyploid species, but at the diploid level to only species closely related to the B_genome of polyploid wheat. This indicates that these sequences originated with the divergence of the diploid species, and was then vertically transmitted to polyploids. One sequence hybridized to all species at both the diploid and polyploid levels, suggesting its elimination after the polyploid wheat formation. The hybridization of this sequence to two synthetic polyploid wheats indicated that sequence elimination is a rapid event and probably related to methylation status of the sequence. Based on the above results, we suggest that selective changes of low_copy sequences occur rapidly after polyploid formation, which may contribute to the differentiation of chromosomes in newly formed allopolyploid wheats. 展开更多
关键词 polyploid wheat chromosome_specific DNA sequences sequence elimination DNA methylation genome evolution
在线阅读 下载PDF
Isolation of the Flanking Sequences Adjacent to Transgenic T-DNA in Brassica napus Genome by an Improved Inverse PCR Method 被引量:2
8
作者 杨坤 吴学龙 +1 位作者 朗春秀 陈锦清 《Agricultural Science & Technology》 CAS 2010年第2期65-68,139,共5页
[Objective] The research aimed to isolate flanking sequences adjacent to the transgenic T-DNA in Brassica napus by an improved inverse PCR method.[Method] Using single clone of transgenic FS4 in Brassica napus as the ... [Objective] The research aimed to isolate flanking sequences adjacent to the transgenic T-DNA in Brassica napus by an improved inverse PCR method.[Method] Using single clone of transgenic FS4 in Brassica napus as the research materials,total DNA was extracted from transgenic Brassica napus by using modified CTAB method.After enzyme digestion and purification,self-joining was made.Two circles of nested PCR and the sequence alignment were carried out.[Result] A fragement with the size of 4.0 kb was amplified ... 展开更多
关键词 Inverse PCR(IPCR) Flanking sequences Improved CTAB method Transgenic Brassica napus
在线阅读 下载PDF
SECURITY ANALYSIS BASED ON OVERSAMPLED CHAOTIC BINARY SEQUENCES 被引量:1
9
作者 张宏涛 王慧云 丁润涛 《Transactions of Tianjin University》 EI CAS 2001年第2期123-126,共4页
Some chaotic sequences generated from maps conjugated with tent map can be reconstructed precisely by short sequence prediction,since the problem of finite precision degrades the statistical properties of chaotic ma... Some chaotic sequences generated from maps conjugated with tent map can be reconstructed precisely by short sequence prediction,since the problem of finite precision degrades the statistical properties of chaotic maps.This paper discusses the topological conjugation properties of the chaotic maps;analyzes in detail the reconstruction process of the chaotic sequences and the security of the oversampled chaotic map (OSCM) binary sequences.The result demonstrates that OSCM binary sequences can sustain the attack of the short sequence prediction,that is,they cant be reconstructed.Furthermore,all attack strategies aiming at the chaotic systems based on synchronization will fail,meaning that they are secure. 展开更多
关键词 SECURITY OSCM sequences topological conjugation
在线阅读 下载PDF
A preliminary analysis of phylogenetic relationships of Arundinaria and related genera based on nucleotide sequences of nrDNA (ITS region) and cpDNA (trnL-F intergenic spacer) 被引量:5
10
作者 ZHUGEQiang DINGYu-long +3 位作者 XUChen ZOUHui-yu HUANGMin-ren WANGMing-xiu 《Journal of Forestry Research》 SCIE CAS CSCD 2005年第1期5-8,i001,共5页
Phylogenetic relationships of Arundinaria and related genera (Pleioblastus, Pseudosasa, Oligostachyum, Bashania, Clavinodum, etc.) were assessed by analyzing the sequences of the nrDNA internal transcribed spacer (ITS... Phylogenetic relationships of Arundinaria and related genera (Pleioblastus, Pseudosasa, Oligostachyum, Bashania, Clavinodum, etc.) were assessed by analyzing the sequences of the nrDNA internal transcribed spacer (ITS) and the cpDNA trnL-F intergenic spacer (IGS). Comparison with trnL-F IGS sequence, the ITS region provided the higher number of parsimony informative characters, and the interspecific variation of the ITS sequence was higher than that of the trnL-F IGS sequence.The tree obtained by combining both sets of data showed that the species sampled in Arundinaria and the related genera were monophyletic and divided into two clades. The relationships and positioning of all the taxa surveryed (including A. oleosa, A. hsienchuensis, A. chino, A. amara, A. yixingensis, A. amabilis, A. fortunei, A. pygmaea, A. gramineus, A. fargesii, A. faberi, A. hupehense, Pseudosasa japonica cv. Tsutsumiana, P. japonica and Brachystachyum densiflorum) were also discussed. The results from the sequences were broadly consistent with morphological characters, appearing all these taxa sampled belong to the genus of Arundinaria. The topologies of the trees generated from individual data and the combined data were similar. 展开更多
关键词 Arundinaria Internal transcribed spacers (ITS) sequences trnL-F intergenic spacer (IGS) sequences Phylogenetic relationships
在线阅读 下载PDF
Phylogeny of Ptychostomum (Bryaceae,Musci) inferred from sequences of nuclear ribosomal DNA internal transcribed spacer (ITS) and chloroplast rps4 被引量:2
11
作者 Chen-Ying WANG Jian-Cheng ZHAO 《Journal of Systematics and Evolution》 SCIE CSCD 北大核心 2009年第4期311-320,共10页
The phylogeny of Ptychostomum was first spacer (ITS) region of the nuclear ribosomal (nr) DNA DNA rps4 sequences. Maximum parsimony, maximum undertaken based on analysis of the internal transcribed and by combinin... The phylogeny of Ptychostomum was first spacer (ITS) region of the nuclear ribosomal (nr) DNA DNA rps4 sequences. Maximum parsimony, maximum undertaken based on analysis of the internal transcribed and by combining data from nrDNA ITS and chloroplast likelihood, and Bayesian analyses all support the conclusion that the reinstated genus Ptychostomum is not monophyletic. Ptychostomum funkii (Schwagr.) J. R. Spence (≡ Bryum funkii Schwaigr.) is placed within a clade containing the type species of Bryum, B. argenteum Hedw. The remaining members of Ptychostomum investigated in the present study constitute another well-supported clade. The results are congruent with previous molecular analyses. On the basis of phylogenetic evidence, we agree with transferring B. amblyodon Mull. Hal. (≡ B. inclinatum (Brid.) Turton≡ Bryum archangelicum Bruch & Schimp.), Bryum lonchocaulon Mull. Hal., Bryum pallescens Schleich. ex Schwaigr., and Bryum pallens Sw. to Ptychostomum. 展开更多
关键词 Bryum molecular phylogeny nuclear ribosomal DNA internal transcribed spacer sequences Ptychostomum rps4 sequences.
在线阅读 下载PDF
Characteristic atom sequences of Nb-Mo alloys system in BCC structure and properties of disordered alloys
12
作者 彭红建 武青 +1 位作者 李小波 谢佑卿 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第5期1190-1196,共7页
Comprehensively considering energy, volume and electronic structure of alloys, the ninth equation was determined as the interaction function of Nb-Mo alloys system in BCC structure on the basis of idea of systematic s... Comprehensively considering energy, volume and electronic structure of alloys, the ninth equation was determined as the interaction function of Nb-Mo alloys system in BCC structure on the basis of idea of systematic science of alloys, experimental lattice constants and heats of formation of disordered Nb(1-x)Mox alloys. The structural parameters and properties of Nb and Mo characteristic atoms sequences and corresponding characteristic crystals sequences were determined in Nb-Mo alloys system. The electronic structure and physical properties of disordered Nb(1-x)Mox alloys system were calculated according to concentration of characteristic atoms of disordered alloys. The change trend of physical properties is the same as that of electronic structure. 展开更多
关键词 Nb-Mo alloys system characteristic atom sequences disordered alloys properties
在线阅读 下载PDF
Auto-selection order of Markov chain for background sequences with chi-square test
13
作者 谢雪英 孙啸 陆祖宏 《Journal of Southeast University(English Edition)》 EI CAS 2003年第4期311-316,共6页
Modeling non coding background sequences appropriately is important for the detection of regulatory elements from DNA sequences. Based on the chi square statistic test, some explanations about why to choose higher ... Modeling non coding background sequences appropriately is important for the detection of regulatory elements from DNA sequences. Based on the chi square statistic test, some explanations about why to choose higher order Markov chain model and how to automatically select the proper order are given in this paper. The chi square test is first run on synthetic data sets to show that it can efficiently find the proper order of Markov chain. Using chi square test, distinct higher order context dependences inherent in ten sets of sequences of yeast S.cerevisiae from other literature have been found. So the Markov chain with higher order would be more suitable for modeling the non coding background sequences than an independent model. 展开更多
关键词 non coding sequences regulatory elements chi square test Markov chain
在线阅读 下载PDF
The Structures of the AR Sequences of Tilted Algebras
14
作者 章璞 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第3期58-65,共8页
In this paper,We give the forms of AR sequences of a tilted algebra with terms all belonging to x(A_T),or all belonging to y(A_T).The sink maps of a tilted algebra which end at the indecompos able projective modules a... In this paper,We give the forms of AR sequences of a tilted algebra with terms all belonging to x(A_T),or all belonging to y(A_T).The sink maps of a tilted algebra which end at the indecompos able projective modules and the source maps of starting at the indecomposable injective modules are also obtained.These results together with the connecting sequecnes given in [3] determine the AR quiver of the tilted algcbra,morever,this can be done directly from the AR quiver of the correspond ing hereditary algebra. 展开更多
关键词 tilted algebra AR sequences
在线阅读 下载PDF
Strong Limit Theorems for Arbitrary Fuzzy Stochastic Sequences
15
作者 费为银 《Journal of Donghua University(English Edition)》 EI CAS 2008年第5期556-560,共5页
Based on fuzzy random variables, the concept of fuzzy stochastic sequences is defined. Strong limit theorems for fuzzy stochastic sequences are established. Some known results in non-fuzzy stochastic sequences are ext... Based on fuzzy random variables, the concept of fuzzy stochastic sequences is defined. Strong limit theorems for fuzzy stochastic sequences are established. Some known results in non-fuzzy stochastic sequences are extended. In order to prove results of this paper, the notion of fuzzy martingale difference sequences is also introduced. 展开更多
关键词 fuzzy random variables fuzzy conditional expectation strong law of large numbers fuzzy stochastic sequences fuzzy martingale difference sequences
在线阅读 下载PDF
MAXIMUM TREES OF FINITE SEQUENCES
16
作者 WU SHIQUAN 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1995年第2期223-228,共6页
Let n, s1, s2,..., sn be non-negative integers and M(s1, s2,...,sn) ={(a1, a2,..., a.)| ai is an integer and 0≤ai ≤si for each i}. In this paper, the cardinality of maximum trees of finite sequences in M(s1, s2,...,... Let n, s1, s2,..., sn be non-negative integers and M(s1, s2,...,sn) ={(a1, a2,..., a.)| ai is an integer and 0≤ai ≤si for each i}. In this paper, the cardinality of maximum trees of finite sequences in M(s1, s2,..., sn) sn) is obtained, which generalizes some of Frankl's results on families of finite sets with prescribed cardinalities for pairwise intersections. 展开更多
关键词 Tree of subsets finite sequences tree of finite sequences.
在线阅读 下载PDF
The Law of the Iterated Logarithm for the Sums of φ-Mixing Sequences with Duple Suffixes
17
作者 杨善朝 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第4期68-71,共4页
Hu Shuhe gets a sufficient condition on the law of the iterated logarithm for the sums of φ-mixing sequences with duple suffixes. This paper greatly improves his condition.
关键词 φ-Mixing sequences Sum of Double Suffix sequences Law of Iterated Logarithm
在线阅读 下载PDF
ITS1 SEQUENCES OF NUCLEAR RIBOSOMAL DNA IN WILD RICES AND CULTIVATED RICES OF CHINA AND THEIR PHYLOGENETIC IMPLICATIONS 被引量:22
18
作者 周毅 邹喻苹 +2 位作者 洪德元 周骏马 陈受宜 《Acta Botanica Sinica》 CSCD 1996年第10期785-791,共7页
The first internal transcribed spacer(ITS1) of nuclear ribosomal DNA of three wild rice species and two subspecies of cultivated rice, which are distributed in China, was amplified using PCR technique and sequenced wi... The first internal transcribed spacer(ITS1) of nuclear ribosomal DNA of three wild rice species and two subspecies of cultivated rice, which are distributed in China, was amplified using PCR technique and sequenced with automated fluorescent sequencing. The sequences of ITS1 ranged from 193 bp to 218 bp in size and G/C content varied from 69.3% to 72.7%. In pairwise comparisons among the five taxa, sequence site divergence ranged from 1.5% to 10.6%. Phylogenetic analysis of ITS1 sequences using Wagner parsimony generated a single well resolved tree, which revealed that Oryza rufipogon was much more closely related to cultivated rice species than to the other two wild species. Oryza granulata was less closely related to either cultivated rice species or the other two wild species, and might be a unique and isolated taxon in the genus Oryza. The phylogenetic relationships of the three wild rice species and two cultivated rice subspecies inferred from ITS1 sequences is highly concordant with those based on the molecular evidence from isozyme, chloroplast DNA (cpDNA), mitochondrial DNA(mtDNA) and nuclear DNA (nDNA) of the genus Oryza . 展开更多
关键词 Wild rice Cultivated rice ITS1 of rDNA Sequence analysis PHYLOGENY
在线阅读 下载PDF
MINER RULE CONSIDERING FUZZINESS OF STRESS DAMAGE UNDER DIFFERENT LOAD SEQUENCES 被引量:8
19
作者 王旭亮 聂宏 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2008年第3期182-186,共5页
Since the traditional Miner rule ignores the influence of the load sequence on the fatigue life, the fuzzy rules are used to analyze the fuzziness of the fatigue damage caused by the stress nearby the fatigue limit un... Since the traditional Miner rule ignores the influence of the load sequence on the fatigue life, the fuzzy rules are used to analyze the fuzziness of the fatigue damage caused by the stress nearby the fatigue limit under different load sequences. The improved fuzzy Miner rule can reflect the influence of the load sequence on the fatigue life. Results of the example show that the prediction error can be reduced from 61.6% to 21.7%. 展开更多
关键词 atigue damage fuzzy rules membership functions load sequence Miner rule
在线阅读 下载PDF
Isolation of Zizania latifolia Species-specific DNA Sequences and Their Utility in Identification of Z. latifolia DNA Introgressed into Rice 被引量:5
20
作者 刘振兰 董玉柱 刘宝 《Acta Botanica Sinica》 CSCD 2000年第3期324-326,共3页
根据两个植物抗病基因N和RPS2中核酸结合位点 (NBS)和富亮氨酸重复区 (LRR)中的保守序列设计了一对特异引物 ,用PCR从具有水稻 (OryzasativaL .)改良所需要的许多优良性状的水稻近缘野生种菰 (Zizanialatifolia(Griseb .)Turcz.exStapf... 根据两个植物抗病基因N和RPS2中核酸结合位点 (NBS)和富亮氨酸重复区 (LRR)中的保守序列设计了一对特异引物 ,用PCR从具有水稻 (OryzasativaL .)改良所需要的许多优良性状的水稻近缘野生种菰 (Zizanialatifolia(Griseb .)Turcz.exStapf)的基因组DNA中扩增同源片段。PCR产物经克隆后 ,分别以菰和水稻的基因组DNA为探针 ,通过点杂交对所得克隆进行了分析。点杂交结果表明 ,在所分析的 6 0个克隆中有 2个克隆是菰专化的序列 ,即它们与水稻无杂交信号。基因组DNA的Southern杂交进一步证实了这 2个克隆的专化性。为了验证一些可能的“水稻_菰”渐渗杂交系是否确实含有源自供体菰的DNA ,以这 2个克隆为探针 ,与经EcoRⅠ酶切的 5个可能的渐渗杂交系进行了Southern杂交。结果表明 ,这 2个克隆均能检测出其中的一个系含有其同源序列。这一结果为曾经报道的经一种非常规有性杂交方法将菰DNA导入水稻提供了确凿的证据。 展开更多
关键词 species_specific DNA sequence introgression lines Zizania latifolia RICE
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部