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Production Chain Length and PPI-CPI Divergence:Analysis Based on the Global Input-output Price Model
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作者 Ni Hongfu Yan Bingqian Wu Liyuan 《China Economist》 2024年第3期49-69,共21页
Productivity and international energy price shocks are reflected in PPI and CPI via industrial chains.China’s in-depth participation into the global value chains has increasingly lengthened its industrial production ... Productivity and international energy price shocks are reflected in PPI and CPI via industrial chains.China’s in-depth participation into the global value chains has increasingly lengthened its industrial production chains.The question is how the changing length of production chains will affect CPI and PPI,as well as CPI-PPI correlation?By constructing a global input-output price model,this paper offers a theoretical discussion on the impact of production chain length on the CPI-PPI divergence.Our findings suggest that the price shock of international bulk commodities has a greater impact on China’s PPI than that on CPI.The effects on both China’s PPI and CPI estimated by using the single-country input-output model are higher than the results estimated with the global input-output model.However,the difference between CPI and PPI variations estimated with the global input-output model is greater than the result estimated with the single-country input-output model,which supports the view that the lengthening of production chains,especially international production chains,leads to a divergence between CPI and PPI.Empirical results based on cross-national panel data also suggest that the lengthening of production chains has reduced the CPI-PPI correlation for countries,i.e.the lengthening of production chains has increased the PPI-CPI divergence.That is to say,policymakers should target not just CPI in maintaining price stability,but instead focus on the stability of both PPI and CPI.Efforts can be made to proactively adjust the price index system,and formulate the industrial chain price index. 展开更多
关键词 Global value chains length of production chains consumer price index producer price index
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Effects of quaternary ammonium chain length on the antibacterial and remineralizing effects of a calcium phosphate nanocomposite 被引量:14
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作者 Ke Zhang Lei Cheng +2 位作者 Michael D Weir Yu-Xing Bai Hockin HK Xu 《International Journal of Oral Science》 SCIE CAS CSCD 2016年第1期45-53,共9页
Composites containing nanoparticles of amorphous calcium phosphate (NACP) remineralize tooth lesions and inhibit caries. A recent study synthesized quaternary ammonium methacrylates (QAMs) with chain lengths (CLs... Composites containing nanoparticles of amorphous calcium phosphate (NACP) remineralize tooth lesions and inhibit caries. A recent study synthesized quaternary ammonium methacrylates (QAMs) with chain lengths (CLs) of 3-18 and determined their effects on a bonding agent. This study aimed to incorporate these QAMs into NACP nanocomposites for the first time to simultaneously endow the material with antibacterial and remineralizing capabilities and to investigate the effects of the CL on the mechanical and biofilm properties. Five QAMs were synthesized: DMAPM (CL3), DMAHM (CL6), DMADDM (CL12), DMAHDM (CL16), and DMAODM (CL18). Each QAM was incorporated into a composite containing 20% NACP and 50% glass fillers. A dental plaque microcosm biofilm model was used to evaluate the antibacterial activity. The flexural strength and elastic modulus of nanocomposites with QAMs matched those of a commercial control composite (n = 6; P 〉 0.1). Increasing the CL from 3 to 16 greatly enhanced the antibacterial activity of the NACP nanocomposite (P 〈 0.05); further increasing the CL to 18 decreased the antibacterial potency. The NACP nanocomposite with a CL of 16 exhibited biofilm metabolic activity and acid production that were 10-fold lesser than those of the control composite. The NACP nanocomposite with a CL of 16 produced 2-log decreases in the colony-forming units (CFU) of total microorganisms, total streptococci, and mutans streptococci. In conclusion, QAMs with CLs of 3-18 were synthesized and incorporated into an NACP nanocomposite for the first time to simultaneously endow the material with antibacterial and remineralization capabilities. Increasing the C/reduced the metabolic activity and acid production of biofilms and caused a 2-log decrease in CFU without compromising the mechanical properties. Nanocomposites exhibiting strong anti-biofilm activity, remineralization effects, and mechanical properties are promising materials for tooth restorations that inhibit caries. 展开更多
关键词 antibacterial nanocomposite calcium phosphate nanoparticles caries inhibition human saliva microcosm biofilm quaternary ammonium chain length
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Influence of Charge Density and Chain Length on the Interaction between Organic Anion and Montmorillonite 被引量:3
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作者 郑俊萍 LI Jian +1 位作者 HAO Hui YAO Kangde 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第1期6-11,共6页
Anionic surfantant sodium dodecyl sulfate (SDS), cationic surfactant cetyl trimethyl ammonium bromide (CTAB) and acrylic acid (AA) were introduced as molecular models to study the interaction between montmorillo... Anionic surfantant sodium dodecyl sulfate (SDS), cationic surfactant cetyl trimethyl ammonium bromide (CTAB) and acrylic acid (AA) were introduced as molecular models to study the interaction between montmorillonite and organic molecules with different charge or chain length. The compounds were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and 13C nuclear magnetic resonance (13C NMR). The results show organic anion could interact strongly with montmorillonite, even the molecules could intercalate into the layers of MMT. 展开更多
关键词 chain length charge density INTERACTION montmoriUonitc.
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The Effect of the Chain Length on MMA Free Radicl Polymerization
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作者 Wang, M Mao, YG +3 位作者 Lu, YY Yang, RF Li, F Shen, JC 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第11期1041-1042,共2页
In the polymerization process of methyl methacrylate (MMA), the Arrhenius parameters (activation energy and frequency factor) of propagating reaction monotonically decrease with increasing monomer conversion. At the b... In the polymerization process of methyl methacrylate (MMA), the Arrhenius parameters (activation energy and frequency factor) of propagating reaction monotonically decrease with increasing monomer conversion. At the beginning and middle stage of the propagating reaction, the increase of radical chain length is the main reason of above mentioned change. And at the end stage, the sharp decrease of k(p) indicates that the activation energy is approximately incline to zero and the propagating reaction is controlled by molecular diffusion motion. 展开更多
关键词 MMA ARRHENIUS parameters propagating reaction radical chain length
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Differences in Starch Chain Length Distribution and Structure Characteristics of Early-Indica Rice Under Different Temperature Treatments During Grain-Filling
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作者 ZHONGLian-jin CHENGFang-min +1 位作者 ZHANGGuo-ping SUNZong-xiu 《Agricultural Sciences in China》 CAS CSCD 2005年第1期21-25,共5页
Effects of temperature during grain-filling on chain length distribution and structure characteristics of 4 early-seasonindica rice cultivars were investigated under the environment-controlled conditions. The plants a... Effects of temperature during grain-filling on chain length distribution and structure characteristics of 4 early-seasonindica rice cultivars were investigated under the environment-controlled conditions. The plants at flowering stage weresubjected to two temperature treatments until maturity (the mean dairy air temperature, 22 and 32C for optimum temperaturetreatment and high temperature treatment, respectively). The result showed that high temperature during grain-fillingsignificantly decreased the long B-chain content and increased the intermediate B-chain content. But the effect of hightemperature on other starch chains appeared to be cultivar-dependant. The crystalline characteristics of rice starch werealso affected by temperature during grain-filling. The intensity at 18 2q of X-ray diffraction pattern of rice samples underhigh temperature was higher than those under optimum temperature, though all rice starches performed A-crystallinetype. Moreover, the intensity at 18 2q was positive correlation with intermediate B-chain content and negative correlationwith long B-chain content. 展开更多
关键词 Rice (Oryza sativa L.) Temperature STARCH chain length distribution Crystalline structure
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Increased sedimentation of a Pseudomonas–Saccharomyces microbial consortium producing medium chain length polyhydroxyalkanoates 被引量:1
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作者 Chang Liu Lin Qi +2 位作者 Songyuan Yang Yun He Xiaoqiang Jia 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第7期1659-1665,共7页
Concerns about feasibility,separability,settleability,efficiency once hampered studies on polyhydroxyalkanoates(PHAs)production,which mainly focused on single strain microorganism or activated sludge rather than artif... Concerns about feasibility,separability,settleability,efficiency once hampered studies on polyhydroxyalkanoates(PHAs)production,which mainly focused on single strain microorganism or activated sludge rather than artificial microbial consortia.Here,a medium chain length PHAs(mcl-PHAs)producing Pseudomonas-Saccharomyces consortium with xylose as the main substrate was studied.Mcl-PHAs accumulation increased from 12.69 mg·L^-1 to 152.3 mg·L^-1 without any optimization method.The presence of Saccharomyces cerevisiae,though in a relatively low concentration,improved the sedimentation of cell mass of the mixed culture by 60%.Reasons for better sedimentation of the consortium were complex:first,the length of Pseudomonas putida increased two to three times in the consortium;second,the positive surface charge of P.putida was neutralized by S.cerevisiae;third,the adhesion proteins on the surface of S.cerevisiae interacted with the P.putida. 展开更多
关键词 MEDIUM chain length POLYHYDROXYALKANOATES Pseudomonas–Saccharomyces consortium SEDIMENTATION XYLOSE
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A re-evaluation of the average chain length of lacustrine sedimentary n-alkanes as a paleoproxy on the Qinghai-Tibet Plateau
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作者 Mingda WANG Qin LI +2 位作者 Jaime TONEY David HENDERSON Juzhi HOU 《Frontiers of Earth Science》 SCIE CSCD 2023年第4期905-919,共15页
Long-chain n-alkanes are one of the most common organic compounds in terrestrial plants and they are well-preserved in various geological archives.n-alkanes are relatively resistant to degradation and thus they can pr... Long-chain n-alkanes are one of the most common organic compounds in terrestrial plants and they are well-preserved in various geological archives.n-alkanes are relatively resistant to degradation and thus they can provide high-fidelity records of past vegetation and climate changes.Nevertheless,previous studies have shown that the interpretation of n-alkane proxies,such as the average chain length(ACL),is often ambiguous since this proxy depends on more than one variable.Both vegetation and climate could exert controls on the n-alkane ACL,and hence its interpretation requires careful consideration,especially in regions like the Qinghai-Tibet Plateau(QTP)where topography,biome type and moisture source are highly variable.To further evaluate the influences of vegetation and climate on the ACL in high-elevation lakes,we examined the n-alkane distributions of the surface sediments of 55 lakes across the QTP.Our results show that the ACL across a climatic gradient is significantly affected by precipitation,rather than by temperature.The positive correlation between ACL and precipitation may be because of the effect of microbial degradation during deposition.Finally,we suggest that more caution is needed in the interpretation of ACL data in different regions. 展开更多
关键词 ACL average chain length N-ALKANES leaf wax lake sediments Qinghai-Tibet Plateau
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Influence of the alkyl side chain length on the room-temperature phosphorescence of organic copolymers 被引量:2
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作者 Qingyang Xu Liangwei Ma +2 位作者 Xiaohan Lin Qiaochun Wang Xiang Ma 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第6期2965-2968,共4页
Pure organic room-temperature phosphorescence(RTP)materials have attracted wide attention owing to their excellent luminescent properties and great potential in various applications.In this work,iminostilbene and its ... Pure organic room-temperature phosphorescence(RTP)materials have attracted wide attention owing to their excellent luminescent properties and great potential in various applications.In this work,iminostilbene and its analogues are applied to realize RTP emission by copolymerizing with acrylamide.It can be concluded that the growth of alkane chain in monomers can enhance the lifetime and photoluminescence quantum yield of RTP emission,and polymers with the larger conjugated structure of the monomer show a longer RTP emission wavelength.This work provides a series of new pure organic RTP materials and might provide new thoughts for designing more advanced and superior RTP materials. 展开更多
关键词 Room-temperature phosphorescence Alkyl chain length Conjugated structure Amorphous polymer
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A MONTE CARLO SIMULATION STUDY OF THE EFFECT OF CHAIN LENGTH ON THE HYDROLYSIS OF POLY(LACTIC ACID) 被引量:1
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作者 Zhuo-li Lin Jun Luo +4 位作者 Zheng-jian Chen Jun Yi Hong-liang Jiang Ke-hua Tu 王利群 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2013年第11期1554-1562,共9页
The intrinsic relationship between molecular chain length and the probability of chain reaction during poly(lactic acid) (PLA) hydrolysis was investigated by Monte Carlo simulation. The chain reaction rate was cal... The intrinsic relationship between molecular chain length and the probability of chain reaction during poly(lactic acid) (PLA) hydrolysis was investigated by Monte Carlo simulation. The chain reaction rate was calculated by introducing a power function of different molecular chain lengths. The hydrolysis of both amorphous and extended-chain crystal PLA was selected as the model system. It is found that, the chain reaction probability was proportional to the chain length with a power of 0.4 for amorphous PLA and 0.7-1 for extended-chain crystal PLA, respectively. These results indicate that PLA with longer chain length usually exhibits larger reaction rate than that with shorter length. Comparing the hydrolysis of the two kinds of PLA, the competition between longer and shorter chains in the different condensed structures is different. 展开更多
关键词 Monte Carlo SIMULATION chain length Poly(lactic acid) HYDROLYSIS Molecular weight distribution.
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Effect of nonionic side chain length of polycarboxylate-ethe卜based high-range water-reducing admixture on properties of cementitious systems 被引量:1
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作者 Sileyman OZEN Muhammet Gokhan ALTUN +1 位作者 Ali MARDANI-AGHABAGLOU Kambiz RAMYAR 《Frontiers of Structural and Civil Engineering》 SCIE EI CSCD 2020年第6期1573-1582,共10页
Despite the large variations in the behaviors of water-reducing admixtures upon changes in their structures,most previous reports on the cement-admixture compatibility did not provide suficient information on the stru... Despite the large variations in the behaviors of water-reducing admixtures upon changes in their structures,most previous reports on the cement-admixture compatibility did not provide suficient information on the structure of the admixture.Hence,the evaluation and generalization of the reports on the cement-admixture compatibility are challenging.In this study,three different polycarboxylate-ether-based water-reducing admixtures with the same free nonionic content,anionic/nonionic molar ratio,and main chain length and different side chain lengths were produced.The compatibility of these admixtures with a CEM I 42.5R-type cement was investigated.In addition,an analysis of variance was performed on the experiment results to evaluate the contributions of the admixture type,admixture/cement ratio,and elapsing time to the Marsh funnel flow time,mini-slump,slump flow,and compressive strength.The water-reducing admixtures having long or short side chains reduced the initial flow characteristics of the cementitious systems.However,the admixture having the shortest side chain was better with regard to flow retention.The side chain length of the admixture did not have significant effects on the compressive strength and water absorption capacity of the mortar mixtures and mini-slump performances of the cement paste mixtures.Regarding the behaviors of the admixtures in the cementitious systems,an optimal admixture side chain molecular weight is proposed. 展开更多
关键词 water-reducing admixture side chain length cement paste FLUIDITY compressive strength
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AgAuSe quantum dots with absolute photoluminescence quantum yield of 87.2%:The effect of capping ligand chain length
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作者 Ziqiang Sun Cheng Liu +5 位作者 Hongchao Yang Xiaohu Yang Yejun Zhang Hongzhen Lin Youyong Li Qiangbin Wang 《Nano Research》 SCIE EI CSCD 2022年第9期8555-8563,共9页
Surface ligands of colloidal quantum dots(QDs)have a profound influence on their surface states,which has been verified in the studies of the effect of ligand head groups on the photoluminescence(PL)properties of QDs.... Surface ligands of colloidal quantum dots(QDs)have a profound influence on their surface states,which has been verified in the studies of the effect of ligand head groups on the photoluminescence(PL)properties of QDs.However,the investigation of the ligand chain length is limited.Here,we systematically explored the effect of chain length on the Ag_(2)Se QDs by selecting three ligands,1-octanethiol(OTT),1-dodecanethiol(DDT),and 1-hexadecanethiol(HDT),with diverse chain lengths.We found that the PL intensity of Ag_(2)Se QDs increased with the decrease of the ligand chain length due to the enhanced passivation of surface defects emerging from the robust QD-ligand interface binding affinity and the weaker hydrophobic chain–chain interaction.Subsequently,AgAuSe QDs terminated with OTT were obtained by alloying parent OTT-Ag_(2)Se QDs with Au precursor with a record absolute PL quantum yield(PLQY)of 87.2%at 970 nm,facilitating ultrasensitive in vivo angiography imaging in a nude mouse model.We expect that our finding of the important role of the ligand chain length on the optical properties of QDs will be suggestive to the design and synthesis of high-quality QDs,and also look forward to the clinical applications of the ultra-bright AgAuSe QDs. 展开更多
关键词 quantum dots surface ligand ligand chain length photoluminescence quantum yield BIOIMAGING
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Preparation of nanometer gold particles by phospholipids with different chain lengths at the air-water surface
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《Chinese Science Bulletin》 SCIE CAS 1998年第9期789-790,共2页
关键词 gold particles by phospholipids with different chain lengths at the air-water surface Preparation of nanometer
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Effects of anions and alkyl chain length of imidazolium-based ionic liquids at the Au(111)surface on interfacial structure:a first-principles study
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作者 Chunlei Wei Kun Jiang +1 位作者 Timing Fang Xiaomin Liu 《Green Chemical Engineering》 2021年第4期402-411,共10页
The interfacial structure and adsorption mechanism of imidazolium-based ionic liquids(ILs)on Au(111)surface were investigated via first-principles calculation.Electron density analysis and Bader charge analysis were u... The interfacial structure and adsorption mechanism of imidazolium-based ionic liquids(ILs)on Au(111)surface were investigated via first-principles calculation.Electron density analysis and Bader charge analysis were used to explore the electronic structure of Au(111)-ILs interface.Computations show that the alkyl chain length and anions play a significant role in designing Au(111)-ILs interfacial structure.On the one hand,the stability of interface and adsorption energy tend to be enhanced as the alkyl chain length increases.It attributes to the methylene group of alkyl chain which could easily anchor on the gold interface.On the other hand,the difference in anions makes the adsorption behavior quite different.The adsorption energy follows the order:[C_(n)mim][Br]>[C_(n)mim][Cl]>[Cnmim][TFSA]>[C_(n)mim][OAc]>[C_(n)mim][PF6]>[C_(n)mim][BF_(4)].The nonfluorinated ILs(containing Br,Cl,and O atoms of anions)always have a drastic charge transfer among gold-ILs interface.However,the larger van der Waals(vdWs)volumes of the fluorinated anions have a more diffused electron density which lead to the relatively weak interaction.To sum up,a detailed and systematic investigation of the variation of anions and alkyl chain length of ILs which will affect the interfacial structure is fully studied.The above study could be helpful to understand electrode-electrolyte microscopic interface and design of functional materials for energy storage. 展开更多
关键词 Au|ionic liquids interface Variation of anions Alkyl chain length First-principles simulation SUPERCAPACITOR
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Effect of chain length on the conformation and friction behaviour of DNA
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作者 WANG Mian CUI ShuXun +1 位作者 YU BingJun QIAN LinMao 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第12期2927-2933,共7页
Four double-stranded DNA films with different chain lengths were prepared on 3-aminopropyltriethoxysilane(APS)-modified mica surfaces in the NaCl solution with concentration ranging from 0.001 to 0.1 M.By using an ato... Four double-stranded DNA films with different chain lengths were prepared on 3-aminopropyltriethoxysilane(APS)-modified mica surfaces in the NaCl solution with concentration ranging from 0.001 to 0.1 M.By using an atomic force microscope,the force-distance curves and friction behaviour of each DNA film were studied in the NaCl solution that was used in the sample preparation.When adsorbed on mica as films in salt solution,the conformation of DNA molecules would be a combination of loops and"train-like".As the chain length increased from 50 to 20000 bp,the extension rate of DNA film increased from 7.1to 11.5 in 0.001 mol/L NaCl solution,which suggested that the DNA molecule with long chain likely resulted in more extended conformation.In addition,under low normal load,low NaCl concentration could increase the friction of DNA film and the chain length revealed insignificant effect on the friction force of DNA film.Therefore,long chain DNA with low salt concentration is more conducive to the nanopore sequencing process,since extended conformation can make DNA molecules easier to reach into nanopore and the high friction can reduce the translocation speed.These results may benefit the development of the third-generation sequencing technique based on nanopore. 展开更多
关键词 双链DNA 摩擦行为 链长度 构象 NACL溶液 NaCl浓度 DNA分子 原子力显微镜
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Effects of Particle Size and Chain Length on Flotation and Adsorption of Quaternary Ammonium Salts onto Kaolinite
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作者 XU Longhua HU Yuehua +4 位作者 WU houqin DONG Faqin JIANG Hao WANG zhen LIU Ruohua 《矿物学报》 CAS CSCD 北大核心 2013年第S1期119-119,共1页
Effects of particle size and chain length on flotation of quaternary ammonium salts (QAS) onto kaolinite have been investigated by mico-flotation tests. The two kinds of quaternary ammonium salts [RN(CH3)3] with diffe... Effects of particle size and chain length on flotation of quaternary ammonium salts (QAS) onto kaolinite have been investigated by mico-flotation tests. The two kinds of quaternary ammonium salts [RN(CH3)3] with different chain lengths, dodecyltrimethylammonium chloride (DTAC) and cetyltrimethylammonium chloride (CTAC) were used as collectors for kaolinite in different particle size fractions (0.075–0.01 mm, 0.045–0.075 mm, 0–0.045 mm). The anomalous flotation behavior of kaolinite have been further explained based on crystal structure considerations by adsorption tests and molecular dynamics (MD) simulation. The results show that the flotation recovery of kaolinite in all different particle size fractions decreases with an increase in pH when DTAC and CTAC are used as collectors. As the concentration of collectors increases, the flotation recovery increases. The longer the carbon chain of QAS is, the higher the recoveries of coarse kaolinite (0.075–0.01 mm and 0.045–0.075 mm) are. But the flotation recovery of the finest kaolinite (0–0.045 mm) decreases with chain lengths of QAS collectors increasing, which is consistent with the flotation results of unsifted kaolinite (0–0.075 mm). It is explained by the froth stability related to the residual concentration of QAS collector. In lower residual concentration, the froth stability becomes worse. Within the range of flotation collector concentration, it's easy of CTAC to be completely adsorbed by kaolinite in the particle size fraction (0–0.045 mm), which led to lower flotation recovery. Moreover, it is interesting that the particle size of kaolinite is coarser, the flotation recovery is higher. The anomalous flotation behavior of kaolinite is rationalized based on crystal structure considerations. The results of MD simulations show that the (001) kaolinite surface has the strongest interaction with DTAC, compared with the (001), (010) and (110) surfaces. On the other hand, when particle size of kaolinite is altered, the number of basal planes and edge planes is changed. It is observed that the finer kaolinite particles size become, the greater relative surface area of edges is, and the more the number of edges is. It means that fine kaolinite particles have more edges to adsorb less cationic colletors than that of coarse kaolinite particles, which is responsible for the poorer floatability of fine kaolinite. 展开更多
关键词 KAOLINITE PARTICLE size chain length DTAC CTAC FLOTATION ADSORPTION molecular dynamics
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Development of Fok-I based nested polymerase chain reaction-restriction fragment length polymorphism analysis for detection of hepatitis B virus X region V5M mutation 被引量:2
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作者 Hong Kim Seok-Hyun Hong +2 位作者 Seoung-Ae Lee Jeong-Ryeol Gong Bum-Joon Kim 《World Journal of Gastroenterology》 SCIE CAS 2015年第47期13360-13367,共8页
AIM: To develop a Fok-I nested polymerase chain reaction(PCR)-restriction fragment length polymorphism analysis(PRA) method for the detection of hepatitis B virus X region(HBx) V5 M mutation.METHODS: Nested PCR was ap... AIM: To develop a Fok-I nested polymerase chain reaction(PCR)-restriction fragment length polymorphism analysis(PRA) method for the detection of hepatitis B virus X region(HBx) V5 M mutation.METHODS: Nested PCR was applied into DNAs from 198 chronic patients at 2 different stages [121 patients with hepatocellular carcinoma(HCC) and 77 carrier patients]. To identify V5 M mutants, digestion of nested PCR amplicons by the restriction enzyme Fok-I(GGA TGN9↓) was done. For size comparison, the enzymetreated products were analyzed by electrophoresis on 2.5% agarose gels, stained with ethidium bromide, and visualized on a UV transilluminator.RESULTS: The assay enabled the identification of 69 patients(sensitivity of 34.8%; 46 HCC patients and 23 carrier patients). Our data also showed that V5 M prevalence in HCC patients was significantly higher than in carrier patients(47.8%, 22/46 patients vs 0%, 0/23 patients, P < 0.001), suggesting that HBx Ag V5 M mutation may play a pivotal role in HCC generation in chronic patients with genotype C infections.CONCLUSION: The Fok-I nested PRA developed in this study is a reliable and cost-effective method to detect HBx Ag V5 M mutation in chronic patients with genotype C2 infection. 展开更多
关键词 Hepatitis B virus X ANTIGEN Polymerasechain reaction-restriction FRAGMENT length polymorphismanalysis V5M MUTATION Hepatocellur carcinoma
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A NEW KIND OF SURFACTANT:LONG-CHAIN ALKYLTRIPHENYLPHOSPHONIUM HALIDES Ⅲ.AN“ABNORMAL”QUENCHING OF PYRENE FLUORESCENCE BY PHOSPHONIUMS WITH DIFFERENT LENGTHS OF ALKYL CHAIN
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作者 Yun Bao JIANG Jin Gou XU GUO Zhen CHEN Department of Chemistry,Xiamen University,Xiamen361005 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第1期57-58,共2页
A study of the quenching of pyrene fluorescence by a series of alkyltriphenylphosphonium bromides indi- cated the coiling conformation of ionic surfactant in aqueous solution.Formation of pyrene excimer in cetyltriph-... A study of the quenching of pyrene fluorescence by a series of alkyltriphenylphosphonium bromides indi- cated the coiling conformation of ionic surfactant in aqueous solution.Formation of pyrene excimer in cetyltriph- enylphosphonium solution strengthened the conclusion. 展开更多
关键词 AN QUENCHING OF PYRENE FLUORESCENCE BY PHOSPHONIUMS WITH DIFFERENT lengthS OF ALKYL chain A NEW KIND OF SURFACTANT ABNORMAL
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Differentiation of Helicobacter pylori isolates by polymerase chain reaction-restriction fragment length polymorphism
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作者 施理 孙勇 +2 位作者 张亚力 张振书 周殿元 《Journal of Medical Colleges of PLA(China)》 CAS 2002年第1期14-16,共3页
Objective: To investigate the association between the diversity of urease gene and urease activity of clinical isolates of Helicobacter pylori (H. pylori). Methods: Polymerase chain reaction-restriction fragment lengt... Objective: To investigate the association between the diversity of urease gene and urease activity of clinical isolates of Helicobacter pylori (H. pylori). Methods: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of urease gene and rapid urease activity test were used to study the urease activity of different clinical isolates of H. pylori. Results: H. pylori clinical isolates were divided into 4 types according to their PCR-RFLP results of urease gene and urease activity. Type Ⅰ , possessing strong urease activity (0. 11) and presented 1 fragment of 1. 7 kb by PCR-RFLP, had close relations with gastric ulcer; type Ⅱ , with the weakest urease activity (0. 07) and 2 fragments (1. 3 and 0. 4 kb respectively) , was associated with duodenal bulb ulcer; type Ⅲ , with the strongest urease activity (0. 12) and 2 fragments (0. 4 and 0. 17 kb) with or without 1 fragment (0. 23 or 0. 37 kb) , was responsible for gastritis; type Ⅳ , with weak urease activity (0. 09) and 2 展开更多
关键词 幽门螺旋杆菌 PCR 限制片段长度多态性 株系多样化
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数字化转型、创新发展与制造业价值链高质量发展
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作者 齐平 宋威辉 《广东财经大学学报》 北大核心 2024年第1期4-18,共15页
创新驱动发展战略背景下,企业数字化转型对制造业价值链高质量发展具有重要意义。采用2007—2021年沪深A股制造业上市企业数据,从价值链上游度即“强链”和价值链长度即“延链”双重视角,探析企业数字化转型对制造业价值链高质量发展的... 创新驱动发展战略背景下,企业数字化转型对制造业价值链高质量发展具有重要意义。采用2007—2021年沪深A股制造业上市企业数据,从价值链上游度即“强链”和价值链长度即“延链”双重视角,探析企业数字化转型对制造业价值链高质量发展的影响效果、作用机制与异质性特征。研究结果表明:企业数字化转型从“强链”和“延链”两方面推动了制造业价值链高质量发展,且该结论通过了稳健性检验。作用机制检验表明,企业创新发展在此过程中具有显著的正向传导作用。异质性分析表明,在非国有制企业、技术密集型行业、劳动密集型行业和创新引领型城市,企业数字化转型通过“强链”和“延链”推动制造业价值链高质量发展的效果更为显著。为此,在城市层面应健全数字化转型治理体系,在行业层面应加快“新基建”建设进程,促进数字化均衡发展,在企业层面应鼓励以强带弱、协同发展,为企业数字化转型提速增质。 展开更多
关键词 数字化转型 制造业价值链 高质量发展 创新发展 价值链上游度(“强链”) 价值链长度(“延链”)
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脂质链长度与特应性皮炎相关性研究进展
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作者 夏欣(综述) 姚志荣(审校) 《临床儿科杂志》 CAS CSCD 北大核心 2024年第1期80-84,共5页
特应性皮炎(atopic dermatitis,AD)是一种慢性、复发性炎症性皮肤病。越来越多证据表明,皮肤屏障功能障碍是导致AD的重要原因。皮肤最外层的脂质基质角质层(stratum corneum,SC)对皮肤屏障功能的维系至关重要。大量研究显示,角质层脂质... 特应性皮炎(atopic dermatitis,AD)是一种慢性、复发性炎症性皮肤病。越来越多证据表明,皮肤屏障功能障碍是导致AD的重要原因。皮肤最外层的脂质基质角质层(stratum corneum,SC)对皮肤屏障功能的维系至关重要。大量研究显示,角质层脂质含量降低、链长度缩短、神经酰胺(ceramide,CER)亚类水平改变以及炎症反应等都会影响AD患者皮肤屏障功能。本文就角质层脂质链长度与AD患者皮肤屏障功能的关系做一综述。 展开更多
关键词 角质层脂质 脂肪酸链长度 皮肤屏障 特应性皮炎
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