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How Prime Numbers Are Interconnected and Built with Two Equations: Addition and Subtraction Rules the Function (6µ)
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作者 John Richard Wisdom 《Advances in Pure Mathematics》 2024年第4期228-241,共14页
Are all prime numbers linked by four simple functions? Can we predict when a prime will appear in a sequence of primes? If we classify primes into two groups, Group 1 for all primes that appear before ζ (such that , ... Are all prime numbers linked by four simple functions? Can we predict when a prime will appear in a sequence of primes? If we classify primes into two groups, Group 1 for all primes that appear before ζ (such that , for instance 5, ), an even number divisible by 3 and 2, and Group 2 for all primes that are after ζ (such that , for instance 7), then we find a simple function: for each prime in each group, , where n is any natural number. If we start a sequence of primes with 5 for Group 1 and 7 for Group 2, we can attribute a μ value for each prime. The μ value can be attributed to every prime greater than 7. Thus for Group 1, and . Using this formula, all the primes appear for , where μ is any natural number. 展开更多
关键词 Number Theory Prime Number Groups Twin Primes Prime Structure and sequence Prime Subtraction and Addition
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The 20 April 2013 Lushan, Sichuan, mainshock, and its aftershock sequence: tectonic implications 被引量:22
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作者 Jianshe Lei Guangwei Zhang Furen Xie 《Earthquake Science》 2014年第1期15-25,共11页
Using the double-difference relocation algo- rithm, we relocated the 20 April 2013 Lushan, Sichuan, earthquake (Ms 7.0), and its 4,567 aftershocks recorded during the period between 20 April and May 3, 2013. Our res... Using the double-difference relocation algo- rithm, we relocated the 20 April 2013 Lushan, Sichuan, earthquake (Ms 7.0), and its 4,567 aftershocks recorded during the period between 20 April and May 3, 2013. Our results showed that most aftershocks are relocated between 10 and 20 km depths, but some large aftershocks were relocated around 30 krn depth and small events extended upward near the surface. Vertical cross sections illustrate a shovel-shaped fault plane with a variable dip angle from the southwest to northeast along the fault. Furthermore, the dip angle of the fault plane is smaller around the mainshock than that in the surrounding areas along the fault. These results suggest that it may be easy to generate the strong earthquake in the place having a small dip angle of the fault, which is somewhat similar to the genesis of the 2008 Wenchuan earthquake. The Lushan mainshock is underlain by the seismically anomalous layers with low-Vp, low-Vs, and high-Poisson's ratio anomalies, possibly suggesting that the fluid-filled fractured rock matrices might signifi- cantly reduce the effective normal stress on the fault plane to bring the brittle failure. The seismic gap between Lushan and Wenchuan aftershocks is suspected to be vulnerable to future seismic risks at greater depths, if any. 展开更多
关键词 Lushan mainshock Aftershock sequence Double-difference algorithm - Shovel-shaped structure Variable dip angle
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Research on the Application of Time Structure Variation Analysis to the Jiashi-Bachu Earthquake Swarm Sequence 被引量:2
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作者 Yang Xin Long Haiying +1 位作者 Shangguan Wenming Nie Xiaohong 《Earthquake Research in China》 2008年第3期251-264,共14页
In 1997 - 2003, 27 earthquakes with M≥ 5.0 occurred in the Jiashi-Bachu area of Xinjiang. It was a rare strong earthquake swarm activity. The earthquake swarm has three time segments of activity with different magnit... In 1997 - 2003, 27 earthquakes with M≥ 5.0 occurred in the Jiashi-Bachu area of Xinjiang. It was a rare strong earthquake swarm activity. The earthquake swarm has three time segments of activity with different magnitudes in the years 1997, 1998 and 2003. In different time segments, the seismic activity showed strengthenin-qguiet changes in various degrees before earthquakes with M ≥ 5.0. In order to delimitate effectively the precursory meaning of the clustering (strengthening) quiet change in sequence and to seek the time criterion for impending prediction, the nonlinear characteristics of seismic activity have been used to analyze the time structure characteristics of the earthquake swarm sequence, and further to forecast the development tendency of earthquake sequences in the future. Using the sequence catalogue recorded by the Kashi Station, and taking the earthquakes with Ms≥ 5.0 in the sequence as the starting point and the next earthquake with Ms = 5.0 as the end, statistical analysis has been performed on the time structure relations of the earthquake sequence in different stages. The main results are as follows: (1) Before the major earthquakes with M ≥ 5.0 in the swarm sequence, the time variation coefficient (δ-value) has abnormal demonstrations to different degrees. (2) Within 10 days after δ= 1, occurrence of earthquakes with M ≥ 5.0 in the swarm is very possible. (3) The time variation coefficient has three types of change. (4) The change process before earthquakes with M5.0 is similar to that before earthquakes with M6.0, with little difference in the threshold value. In the earthquake swarm sequence, it is difficult to delimitate accurately the attribute of the current sequences (foreshock or aftershock sequence) and to judge the magnitude of the follow-up earthquake by δ-value. We can only make the judgment that earthquakes with M5.0 are likely to occur in the sequence. (5) The critical clustering characteristics of the sequence are hierarchical. Only corresponding to a certain magnitude can the sequence have the variation state of critical clustering. (6) The coefficient of the time variation has a clear meaning in physics. After the clustering-quiet state of earthquake activity has appeared, it can describe clearly the randomness of the seismogenic system. Furthermore, it can efficiently clarify whether or not the clustering quiescence variation is of some prognostic meaning. In the case that the earthquake frequency attenuation is essentially normal (h 〉 1 ) and there is no remarkable clustering-quiescence state, it is still possible to discover the abnormal change of the sequence from the time variation coefficient. On the contrary, in the later period of swarm activity, after the appearance of many seismic quiescence phenomena, this coefficient did not appear abnormally, even when h 〈 1, suggesting that the δ-value diagnosis is more universal. 展开更多
关键词 Time variation coefficient Earthquake clustering RANDOMNESS Time structure ofearthquake sequence Jiashi earthquake swarm
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EFFECT OF SEQUENCE STRUCTURE ON THE THERMOTROPIC LIQUID CRYSTALLINE PROPERTIES OF POLYESTERAMIDES BASED ON DIMETHYLBENZIDINE, BISPHENOL-A AND ρ-TEREPHTHALYL CHLORIDE
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作者 戴彪 高彦芳 +2 位作者 王晓工 周其庠 刘德山 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1998年第1期81-85,共5页
A series of thermotropic liquid crystalline polyesteramides with differ-ent sequence structure based on dimethylbenzidine (DMBD), bisphenol-A(BPA) and p-terephthalyl chloride (TPC) was synthesized by changing the feed... A series of thermotropic liquid crystalline polyesteramides with differ-ent sequence structure based on dimethylbenzidine (DMBD), bisphenol-A(BPA) and p-terephthalyl chloride (TPC) was synthesized by changing the feeding order of monomers inlow temperature solution polycondensation system. By means of NMR and a computer pro-gram the sequence structure parameters were measured. The effect of sequence structureon liquid crystalline phase transition temperature of PEAs obtained was investigated. 展开更多
关键词 Liquid crystal POLYESTERAMIDE sequence structure Melting temperature
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STUDY ON THE SEQUENCE STRUCTURE OF BUTADIENE-STYRENE RUBBER BY ^(13)C-NMR METHOD Ⅲ. QUANTITATIVE CHARACTERIZATION OF SEQUENCE STRUCTURE
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作者 陈晓农 胡力平 +1 位作者 严宝珍 焦书科 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1990年第3期269-278,共10页
The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data Of ^(13)C-NMR.The calculating formulae whic... The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data Of ^(13)C-NMR.The calculating formulae which could be used to obtain diad concentration from the peak intensifies of carbon spectra, average block length, average number of block, and the microstructure composition of the molecular chain were derived. The quantitative result showed that on the molecular chain styrene unit had the tendency to attach to trans-1,4 butadiene unit. The calculated result of the microstructure was in good agreement with that obtained through IR measurement. 展开更多
关键词 sequence structure quantitative characterization SBR diad concentration average block length average number of block.
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STUDY ON THE SEQUENCE STRUCTURE OF BUTADIENE-STYRENE RUBBER BY ^(13)C-NMR METHOD V.CALCULATION METHOD OF DIAD COMPOSITION
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作者 陈晓农 陈卓 焦书科 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1994年第2期114-121,共8页
The calculating equations which could be used to obtain diad composition from the peakintensities of carbon spectra were derived. The result of the microstructure calculated from thediad compositions was in good agree... The calculating equations which could be used to obtain diad composition from the peakintensities of carbon spectra were derived. The result of the microstructure calculated from thediad compositions was in good agreement with that obtained through IR or;H-NMR measurement. 展开更多
关键词 sequence structure Diad composition SBR ^(13)C-NMR
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STUDIES ON THE SEQUENCE STRUCTURE OF TPA/EG/PHB LIQUID CRYSTALLINE COPOLYESTERS
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作者 龚烈忠 王晓工 +1 位作者 刘德山 周其庠 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1992年第4期304-310,共7页
In this paper, the sequence structure of TPA/EG/PHB liquid crystalline copolyesters made from different synthetic methods has been studied by;H-NMR with the help of computer program of processing peaks. The results sh... In this paper, the sequence structure of TPA/EG/PHB liquid crystalline copolyesters made from different synthetic methods has been studied by;H-NMR with the help of computer program of processing peaks. The results showed that the ether bonds were not observed in TPA./EG/PHB copolyesters and the synthetic process had a great effect on their sequence structure. Under certain conditions, the high,random TPA/EG/PHB copolyesters which were considered to have higher performances than PET/xPHB could be obtained. 展开更多
关键词 Liquid Crystalline Copolyester PET/xPHB sequence Structure
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Sequence Structure and Characteristics of Exon 1 of Mink MLPH Gene
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作者 ZHANG Min 《Animal Husbandry and Feed Science》 CAS 2011年第4期6-8,17,共4页
[ Objective] To clone exon 1 and its flanking sequences of MLPH gene from minks raised in western Liaoning region and to predict its structure. The study will provide a theoretical basis for breeding of colored mink. ... [ Objective] To clone exon 1 and its flanking sequences of MLPH gene from minks raised in western Liaoning region and to predict its structure. The study will provide a theoretical basis for breeding of colored mink. [Method] The exon 1 and its 5'-flanking sequences of MLPHgene were amplified from minks. SignalP 3.0 Server, ClustalX 1.83, Mega 4.1, TMHM 2.0, ProtComp v6.0 and other software were used for sequence analysis. [ Result] A 1 029-bp fragment was amplified with the expected size. As calculated with the Mega 4.1, the minks had the nearest genetic distance with rattus (0.540 5) and the farthest with human (0.655 2). Phylogenetic tree of mink was constructed. [ Conclusion] The mink MLPH gene encodes a secretory protein. 展开更多
关键词 Minks MLPH gene sequence structure
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SUBSTITUENT CHEMICAL SHIFT (SCS) AND THE SEQUENCE STRUCTURE OF ETHYLENE-VINYL ALCOHOL COPOLYMERS
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作者 周子南 田文晶 +4 位作者 吴盛容 戴莹琨 冯之榴 沈联芳 袁汉珍 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1992年第4期299-303,共5页
Three ethylene-vinyl alcohol copolymers were studied by means of the substituent chemical shift (SCS) method. The SCS parameters of hydroxy (-OH) in two different solvents were obtained: in deuterium oxide/phenol (20/... Three ethylene-vinyl alcohol copolymers were studied by means of the substituent chemical shift (SCS) method. The SCS parameters of hydroxy (-OH) in two different solvents were obtained: in deuterium oxide/phenol (20/80 W/W ) the parameters are S_1 = 42.77±0.08ppm, S_2 = 7.15±0.06 ppm, S_3 (s)= -4.08±0.02ppm, S_3 (t) =-3.09±0.20ppm,S_4 = 0.48±0.03ppm, S_5 = 0.26±0.05ppm. In o-dichloro-benzen-d_4 S_1(s)=44.79±0.61ppm, S_2=7.40±0.00ppm, S_3(s)=-4.51±0.17ppm, S_3(t)=-3.13 ±0.00 ppm, S_4 =0.63±0.04ppm, S_5=0.36±0.00ppm.Simultaneously the ^(13)CNMR spectra of EVA copolymers were assigned by using the SCS parameters obtained. 展开更多
关键词 Ethylene-α-olefine copolymers sequence structure Substituent chemical shift (SCS) ^(13)C NMR.
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Isolation and Identification of Staphylococcus chromogenes and 3 D Structural Analysis of the katA Gene
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作者 HU Xiu-cai LV Ai-jun +3 位作者 WANG Yi LI Xue MING Qing-lei ZHUAi-hua 《Animal Husbandry and Feed Science》 CAS 2013年第4期192-197,共6页
[Objective]Staphylococcus arthritis became an increasingly significant health problem in intensive chicken farming in China.[Method]In this study,a bacteria strain was isolated from the broiler chicken suffering from ... [Objective]Staphylococcus arthritis became an increasingly significant health problem in intensive chicken farming in China.[Method]In this study,a bacteria strain was isolated from the broiler chicken suffering from arthritis and named as the strain Gg1.[Result]It was then identified as Staphylococcus chromogenes by the biochemical tests and phylogenetic tree analysis based on 16S rDNA sequence.Furthermore,the catalase(katA)gene was amplified by PCR using the designed primers,and the expected fragment was 1 232 bp long encoding a protein of 410 amino acids that shares the conserved motifs including catalase,heme-binding ligand and active center motif.Six phosphorylation sites(Ser95,Thr96,Ser241,Ser242,Thr281,Ser338),four conserved residues(Ser95,His216,Tyr281,Asp341)and two active sites(His56,Asn129)were demonstrated by multiple sequence alignment and homology comparisons.The homology modeling of 3D structure of katA protein was done by SWISSMODEL server based on the template retrieved from the catalase(PDB:2ISA_A)of Vibrio salmonicida.The katA protein represents a four-domain globular protein,the quality and reliability of the resulting protein structure was further verified by Ramachandran plot.[Conclusion]To our knowledge,this is the first report of S.chromogenes linked to arthritis in chicken and the bioinformatic characterization of its katA gene. 展开更多
关键词 Staphylococcus chromogenes Isolation and identification katA sequence analysis 3D structure
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Genetic Diversity and Population Structure in Landraces and Improved Rice Varieties from India 被引量:4
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作者 Shailesh D.KUMBHAR Pawan L.KULWAL +3 位作者 Jagannath V.PATIL Chandrakant D.SARAWATE Anil P.GAIKWAD Ashok S.JADHAV 《Rice science》 SCIE CSCD 2015年第3期99-107,共9页
A set of 50 rice genotypes comprising landraces, local selections, and improved varieties were characterized using simple sequence repeat(SSR) and inter simple sequence repeat(ISSR) markers to study genetic divers... A set of 50 rice genotypes comprising landraces, local selections, and improved varieties were characterized using simple sequence repeat(SSR) and inter simple sequence repeat(ISSR) markers to study genetic diversity and population structure. Following unweighted pair group method with arithmetic mean based clustering using binary data of polymorphic markers, the genotypes were grouped into 5 clusters and 11 sub-clusters, whereas population structure analysis separated 50 rice genotypes into 5 sub-populations. Grouping of rice genotypes showed better resemblance with the pedigree information of the genotypes. Both genetic diversity and population structure analysis separated majority of the improved varieties from landraces and local selections. Some of the SSR markers amplified unique alleles which were specific to a particular genotype and could distinguish them from the rest. The results indicate that these rice genotypes exhibit a higher genetic diversity and can be very useful in rice improvement program. 展开更多
关键词 rice genetic diversity molecular marker population structure simple sequence repeat
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Monte Carlo simulation of sequential structure control of AN-MA-IA aqueous copolymerization by different operation modes 被引量:1
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作者 Tong Qin Zhenhao Xi +1 位作者 Ling Zhao Weikang Yuan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第6期231-242,共12页
The regulation of polyacrylonitrile(PAN)copolymer composition and sequence structure is the precondition for producing high-quality carbon fiber high quality.In this work,the sequential structure control of acrylonitr... The regulation of polyacrylonitrile(PAN)copolymer composition and sequence structure is the precondition for producing high-quality carbon fiber high quality.In this work,the sequential structure control of acrylonitrile(AN),methyl acrylate(MA)and itaconic acid(IA)aqueous copolymerization was investigated by Monte Carlo(MC)simulation.The parameters used in Monte Carlo were optimized via machine learning(ML)and genetic algorithms(GA)using the experimental data from batch copolymerization.The results reveal that it is difficult to control the aqueous copolymerization to obtain PAN copolymer with uniform sequence structure by batch polymerization with one-time feeding.By contrary,it is found that the PAN copolymer with uniform composition and sequence structure can be obtained by adjusting IA feeding quantity in each reactor of a train of five CSTRs.Hopefully,the results obtained in this work can provide valuable information for the understanding and optimization of AN copolymerization process to obtain high-quality PAN copolymer precursor. 展开更多
关键词 POLYACRYLONITRILE Monte Carlo simulation Machine learning Genetic algorithms sequence structure Operation method
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Synthesis and Structure of Butylene Terephthalate-ε-Caprolactone Copolyesters 被引量:1
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作者 Xiao Min CHENG Xiao Lie LUO +1 位作者 Zhi Bo LI De Zhu MA(Department of Polymer Science and Engineering. University of Science and Technology of China.Hefei. Anhui 230026) 《Chinese Chemical Letters》 SCIE CAS CSCD 1999年第7期593-596,共4页
A series of butylene terephthalate-E-caprolactone copolyesters (BCL) with different hard segment content were successfully synthesized and characterized by 1H-NMR. DSC. PLM and U viscometer, The sequence structure and... A series of butylene terephthalate-E-caprolactone copolyesters (BCL) with different hard segment content were successfully synthesized and characterized by 1H-NMR. DSC. PLM and U viscometer, The sequence structure and crystallization characteristics of BCL copolyesters were carefully investigated. 展开更多
关键词 BCL copolyesters POLYCONDENSATION hard segment soft segment sequence structure crystallization behavior spherulite morphology
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Informative ISSR Markers Help Identify Genetically Distinct Accessions of Oryza rufipogon in Yield Improvement 被引量:3
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作者 G.HARITHA T.SUDHAKAR +3 位作者 D.CHANDRA T.RAM B.DIVYA N.SARLA 《Rice science》 SCIE CSCD 2016年第5期225-241,共17页
Inter simple sequence repeat(ISSR) polymorphism was used to determine genetic diversity and phylogenetic relationships in 90 genotypes of wild and cultivated species of Oryza from different geographical regions of t... Inter simple sequence repeat(ISSR) polymorphism was used to determine genetic diversity and phylogenetic relationships in 90 genotypes of wild and cultivated species of Oryza from different geographical regions of the world. In all the 17 primers used in ISSR-PCR, a total of 11 464 bands were amplified at 253 band positions/loci. The primer UBC-809 amplified the maximum bands(1 059) at 21 band positions. UBC-810 and UBC-835 amplified the minimum of 391 bands each at 7 and 14 band positions, respectively. The mean polymorphism information content ranged from 0.44 to 0.84 and resolving power ranged from 8.69 to 23.53. Un-weighted pair group method with arithmetic mean dendrogram and population structure based on the 17 primers separated all genotypes into 4 major clusters with a genetic similarity of 53%–100%. The first two clusters consisted of 30 O. rufipogon accessions each. In the third cluster, O. nivara and O. longistaminata grouped as one sub-cluster and all other O. nivara accessions and cultivars grouped as another sub-cluster. The fourth cluster had only five O. rufipogon accessions which can be a source of new genes. Four sub-populations were identified within O. rufipogon and two sub-populations within O. nivara at K = 7. A subset of six primers with high resolving power values were the most informative and grouped all genotypes almost similarly as the 17 primers did. Use of these six highly informative primers in ISSR-PCR is a cost effective and robust method for assessing genetic diversity in large germplasm collections of wild rice species. 展开更多
关键词 Oryza wild species genetic diversity population structure inter simple sequence repeat
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Study on Structure and Crystallinity of A New Biodegradable Aliphatic-Aromatic Copolyester
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作者 Wang Xiaohui Shi Jun +2 位作者 Chen Ying Fu Zhifeng Shi Yan 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2011年第4期64-69,共6页
A series of biodegradable aliphatic-aromatic copolyesters, poly(butylene terephthalate-co-butylene adipate-co- ethylene terephthalate-co-ethylene adipate) (PBATE), were synthesized from terephthalic acid (PTA), adipic... A series of biodegradable aliphatic-aromatic copolyesters, poly(butylene terephthalate-co-butylene adipate-co- ethylene terephthalate-co-ethylene adipate) (PBATE), were synthesized from terephthalic acid (PTA), adipic acid (AA), 1,4-butanediol (BG) and ethylene glycol (EG) through direct esterification and polycondensation. The sequence structure and crystallinity of the copolyester were investigated by 1H NMR spectroscopy and the wide-angle X-ray diffractometry (WAXD). The analytical results showed that the PBATE copolyester was a random copolymer and the composition of PBATE copolyester was almost consistent with the feed molar ratios. The crystal structure of PBATE copolyester belonged to the triclinic crystalline system; The variation in melting point of the synthesized PBATE copolyester agreed well with the estimation obtained by the Flory equation and was applicable to the random copolymer. 展开更多
关键词 biodegradable polyester sequence structure CRYSTALLINITY ALIPHATIC AROMATIC
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The Hydraulic Control Using LabVIEW for a Synthetic Rubber Spring Testing Machine
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作者 Alejandro Borda(博尔达) +1 位作者 WANG Xu-yong(王旭永) 《Journal of Shanghai Jiaotong university(Science)》 EI 2005年第4期381-386,共6页
The application is a control movement of two hydraulic cylinder for a synchronize movement. The main purpose of this paper is to show a short programming code in LabVIEW to control the movement of two cylinders with a... The application is a control movement of two hydraulic cylinder for a synchronize movement. The main purpose of this paper is to show a short programming code in LabVIEW to control the movement of two cylinders with an automatic control program using only analog inputs from the sensor of pressure and linear displacement sensor and the digital output from the hydraulic valves. This is designed for one of the test of this synthetic rubber spring testing machine. 展开更多
关键词 rubber elasticity multi layer rubber spring stacked sequence structure
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Precise Synthesis of Acrylate Copolymer via RAFT Polymerization and Its Application
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作者 Lei Li Jinxing Song +4 位作者 Xin Yang Shengpeng Wang Zuguang Li Yingying Chen Aiyuan You 《Journal of Materials Science and Chemical Engineering》 2021年第6期59-67,共9页
<div style="text-align:justify;"> A series of different sequence structure containing stearyl acrylate (SA) and hydroxyethyl acrylate (HEA) copolymer were synthesized via reversible addition-fragmentat... <div style="text-align:justify;"> A series of different sequence structure containing stearyl acrylate (SA) and hydroxyethyl acrylate (HEA) copolymer were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The crystallization property of PHEA-<em>b</em>-PSA, PHEA-<em>b</em>-PSA-<em>b</em>-PHEA, PSA-<em>b</em>-PHEA-<em>b</em>-PSA, PHEA-<em>co</em>-PSA, and PHEA-<em>grad-b</em>-PSA were characterized by Differential Scanning Calorimetry (DSC). The condensed structure of different sequence copolymers were investigated using small-angle X-ray scattering (SAXS). A series of copolymers with different sequence structure were coated on the surface of polyester fabric, which can be found that PHEA-b-PSA-b-PHEA block copolymer has good water repellency. </div> 展开更多
关键词 RAFT Polymerization Different sequence Structure Crystallization Prop-erty Water Repellency
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SEQUENCE STRUCTURE OF ETHYLENE-VINYL SUBSTITUTED COPOLYMER WITH ^(13)C NMR IV——CHLORINATED POLYETHYLENE
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作者 周子南 戴莹琨 +3 位作者 田文晶 吴盛容 景凤英 冯之榴 《Science China Chemistry》 SCIE EI CAS 1992年第7期769-775,共7页
The substituent chemical shift (SCS) has been applied to the assignment of the ^(13)C NMRspectrum of chlorinated polyethylene (CPE). CPE of different chlorine contents has been em-ployed and their sequence structure d... The substituent chemical shift (SCS) has been applied to the assignment of the ^(13)C NMRspectrum of chlorinated polyethylene (CPE). CPE of different chlorine contents has been em-ployed and their sequence structure discussed. The results show that characteristic of CPEwith medium chlorine content is the dichloroethane structure in molecular chain. SCS param-etets have been obtained from the ^(13)C NMR spectra. It was found that the effects of chlorinecontent and temperature on SCS are negligible, but the substituent parameter S_1 reduced by0.39 ppm when C_2Cl_4 was added to solvent ODCB. 展开更多
关键词 chlorinated polyethylene ^(13)C NMR sequence structure substituent chemieal shift
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Impact of the next-generation sequencing data depth on various biological result inferences 被引量:3
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作者 HOU Rui YANG ZhenXing +1 位作者 LI MingHui XIAO HuaSheng 《Science China(Life Sciences)》 SCIE CAS 2013年第2期104-109,共6页
Next-generation sequencing(NGS) technologies have revolutionized the field of genomics and provided unprecedented opportunities for high-throughput analysis at the levels of genomics,transcriptomics and epigenetics.Ho... Next-generation sequencing(NGS) technologies have revolutionized the field of genomics and provided unprecedented opportunities for high-throughput analysis at the levels of genomics,transcriptomics and epigenetics.However,the cost of NGS is still prohibitive for many laboratories.It is imperative to address the trade-off between the sequencing depth and cost.In this review,we will discuss the effects of sequencing depth on the detection of genes,quantification of gene expression and discovering of gene structural variants.This will provide readers information on choosing appropriate sequencing depth that best meet the needs of their particular project. 展开更多
关键词 next-generation sequencing DEPTH gene discovery gene expression structure variation next-generation sequencing DEPTH gene discovery gene expression structure variation
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PERVAPORATION FOR SEPARATING BENZENE/CYCLOHEXANE MIXTURE BY P(AA-MA) COPOLYMER MEMBRANES
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作者 朱蔚璞 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2011年第3期288-295,共8页
P(AA-MA) copolymers composed of acrylic acid and methyl acrylate with different molecular weights and sequence structures were synthesized by combination of ATRP and selective hydrolysis. These copolymers were used ... P(AA-MA) copolymers composed of acrylic acid and methyl acrylate with different molecular weights and sequence structures were synthesized by combination of ATRP and selective hydrolysis. These copolymers were used as membrane materials to separate benzene/cyclohexane mixture by pervaporation. The effects of molecular weight and sequence structure of the copolymers on the pervaporation performance were investigated in detail. For the random copolymers, the permeate flux decreased rapidly with the increasing of molecular weight. The separation factor was also influenced by the molecular weight, which was changed from no selectivity to cyclohexane selectivity with increasing the molecular weight. Contrarily, the block copolymer membrane showed good benzene selectivity with separation factor of 4.3 and permeate flux of 157 g/(m2h) to 50 wt% benzene/cyclohexane mixture. 展开更多
关键词 PERVAPORATION ATRP Copolymer Molecular weight sequence structure Benzene/cyclohexane mixture.
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