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991.
Tomiyama K Aoki H Oikawa T Sakurai K Kasahara Y Kawakami Y 《Natural product communications》2011,6(3):403-408
The volatile components of both peel and juice of Japanese citrus, Kabosu (Citrus sphaerocarpa Hort. ex Tanaka) were investigated using SAFE (Solvent Assisted Flavor Evaporation) technique after solvent extraction. In this study, wine lactone, rose oxide, (2E)-4,5-epoxy-2-decenal, mintsulfide, and indole were newly identified from Kabosu. AEDA (Aroma Extract Dilution Analysis) of the oxygenated fraction of the peel extract showed high FD (Flavor Dilution) factors for linalool, (2E)-4,5-epoxy-2-decenal, octanal, (4Z)-decenal, beta-citronellol, geraniol, and wine lactone, while wine lactone, linalool, eugenol, geraniol, and (2E)-4,5-epoxy-2-decenal from the juice extract. The enantiomeric distribution of linalool, cis-rose oxide, beta-citronellol, and wine lactone were also determined using a multidimensional chiral GC/MS. 相似文献
992.
Uniaxial elongational viscosity of SiO2/(acrylic polymer/epoxy (AP/EP)) suspensions with various SiO2 volume fractions (?) in a blend of acrylic polymer and epoxy was investigated at various temperatures (T). The matrix polymer ((AP/EP) blend) contained 70?vol.% of EP. At ?????35?vol.% at T????80°C, where the suspensions were in sol state, strain-hardening behavior was observed. This strain hardening of the suspensions is attributable to the elongational flow properties of (AP/EP) medium. At critical gel state (??=?35?vol.% and T?=?100°C) and in gel state (?????40?vol.%), the elongational viscosity exhibited the strain-softening behavior. These results strongly suggest that the strain softening results from the strain-induced disruption of the network structure of the SiO2 particles therein. 相似文献
993.
Yuji Aoki 《Rheologica Acta》2011,50(9-10):779-785
Linear viscoelastic properties of carbon black (CB) suspensions with various CB concentrations (cCB) in two suspending media, mixtures of a rosin-modified phenol resin-type varnish (Varnish-1)/an alkyd resin-type varnish (Varnish-2) and Varnish-1/petroleum solvent (AF) were investigated. The former medium has higher affinity and the latter has poorer affinity toward CB particles than Varnishi-1, although these two media have almost the same viscoelastic properties. Both CB/(Varnish-1/Varnish-2 = 60/40) and CB/(Varnish-1/AF = 80/20) suspensions exhibited a sol?Cgel transition on an increase in cCB, as similar to the behavior of CB/Varnish-1 suspensions. But, for the CB/(Varnish-1/Varnish-2 = 60/40) suspensions the critical gel concentration (cgel) was lower and the critical relaxation exponent (n) was higher than that of CB/Varnish-1 suspensions. In contrast, for the CB/(Varnish-1/AF = 80/20) suspensions cgel and n, respectively, were almost the same value as those of CB/Varnish-1 suspensions. These results strongly suggest that cgel and n are attributable to the medium affinity, but not to the medium viscosity, and the CB fractal structure changes from plane-like to straight-line structure with increasing medium affinity. 相似文献
994.
Young‐Jae Jin Toshiki Aoki Giseop Kwak 《Angewandte Chemie (International ed. in English)》2020,59(5):1837-1844
A substituted poly(phenylacetylene) derivative (PPAHB) with two hydroxymethyl groups at the meta position of the side phenyl ring was examined as a conformation‐switchable helical spring polymer that responds to solvent and heat stimuli in a precisely controlled manner. Intramolecular hydrogen bonds, which cause the helical structure of the polymer, were broken and re‐formed by adjusting the hydrogen‐bonding strength values (pKHB) of various combinations of solvents or by varying the temperature. In this process, a reversible conformational change from cis–cisoid to cis–transoid, accompanied by a phase transition in the form of a helix‐coil transformation occurred, with the polymer exhibiting critical changes of color fading and recovery in specific environments. These results demonstrate that PPAHB can be used as either a pKHB indicator or a thermometer. The color changes of the polymer solution are described in detail based on spectroscopic analyses and thermodynamic considerations. 相似文献
995.
A. Aoki Y. Sakka Y. Muramatsu 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract We prepared fine hydroxyapatite powders by dropping ammonium bi-phosphate into a calcium acetate solution and by vigorously stirring at 3O°C. We measured the powders' specific surface area to be 290 m2/g by the BET technique. The powders were mono-dispersed ultrafine particles by transmission electron microscopy investigation. No phase other than hydroxyapatite (JCPDS: 9–432) was revealed by X-ray diffractometry. A quantitative chemical analysis gave a Ca/P ratio very close to the exact hydroxyapatite stoichiometry (Ca/P: 1.67). Shrinkage started up to 800°C according to a dilatometric measurement and the dense products were obtained when heated at 1000°C for 2 h in air. We used a quadrupole mass spectrometer to monitor the gases desorbed from the hydroxyapatite powders at a constant heating rate of 5°C/min in a high vacuum. It is noted here that there were two peaks of H2O and CO2, respectively, and that we observed an increase in desorption of H2. The two peaks were explained clearly with an infrared spectrometry analysis and a thermal analysis we made separately. 相似文献
996.
J. K. Stille N. Oguni D. C. Chung R. F. Tarvin S. Aoki M. Kamachi 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(5):745-760
Work carried out in the past few years aimed at elucidating the mechanism of initiation of vinyl polymerization when a donor and an acceptor molecule, one or both of which may be vinyl monomers, is summarized. The emphasis of our investigation has been on polymerizable ether donors and strong electron acceptors which do not undergo polymerization, or the acceptor vinylidene cyanide. Alkyl vinyl ethers were polymerized in the presence of tetracyanoquinodimethane (TCNQ) and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in polar solvents. Observation of the ESR spectrum of the DDQ radical anion and the isolation of a 1:1 addition product of DDQ and alkyl vinyl ether when the two are mixed in a 1:1 ratio and quenched in alcohol support an initiation mechanism involving a coupling reaction of the donor monomer (radical cation) and the acceptor initiator (radical anion). The reaction of vinylidene cyanide (VC) with the vinyl ethers p-dioxene, dihydropyran, ethyl vinyl ether, isopropyl vinyl ether, and ketene diethylacetal in a variety of solvents at 25°C spontaneously afforded poly(vinylidene cyanide), the cycloaddition products 7,7-dicyano-2,5-dioxo-bicyclo[4.2.0] octane, 8,8-dicyano-2-oxo-bicyclo[4.2.0] octane, the 1,1-dicyano-2-alkoxycyclo-butanes, and 1,1-diethoxy-2,2,4,4-tetracyanohexane, respectively, and with the exception of p-dioxene, homopolymers of the vinyl ethers. In the presence of AIBN at 80°C, alternating copolymers were obtained in addition to the homopolymers and cycloaddition products, supporting the involvement of donor-acceptor complexes. The reaction of styrene with VC spontaneously formed an alternating copolymer in addition to the 1:2 head-to-head cycloaddition product, 1,1,3,3-tetracyano-4-phenylcyclohexane. Mixing VC with any one of the cyclic ethers tetrahydrofuran, oxetane, 2,2-dimethyloxirane, 2-chloromethyloxirane, and phenyloxirane resulted in the polymerization of both the VC and the cyclic ether to afford homopolymers of both. The cyclic ethers trioxane, 3,3-bis(chloromethyl)oxetane, and oxirane initiated the polymerization of VC, but did not undergo ring-opening polymerizations themselves. Other ethers such as 1,3-dioxolane, tetrahydropyran, and diethyl ether did not initiate the polymerization of VC. In these polymerizations, VC and the cyclic ethers polymerize via anionic and cationic propagation reactions, respectively. 相似文献
997.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Alexeev GD Alkhazov G Alton A Alverson G Alves GA Ancu LS Aoki M Arnoud Y Arov M Askew A Åsman B Atramentov O Avila C BackusMayes J Badaud F Bagby L Baldin B Bandurin DV Banerjee S Barberis E Baringer P Barreto J Bartlett JF Bassler U Bazterra V Beale S Bean A Begalli M Begel M Belanger-Champagne C Bellantoni L Beri SB Bernardi G Bernhard R Bertram I Besançon M Beuselinck R Bezzubov VA Bhat PC Bhatnagar V Blazey G Blessing S Bloom K 《Physical review letters》2011,106(2):022001
We extract the total width of the top quark, Γ(t), from the partial decay width Γ(t → Wb) measured using the t-channel cross section for single top-quark production and from the branching fraction B(t → Wb) measured in tt events using up to 2.3 fb(-1) of integrated luminosity collected by the D0 Collaboration at the Tevatron pp Collider. The result is Γ(t) = 1.99(-0.55)(+0.69) GeV, which translates to a top-quark lifetime of τ(t) = (3.3(-0.9)(+1.3)) × 10(-25) s. Assuming a high mass fourth generation b' quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |V(tb')| < 0.63 at 95% C.L. 相似文献
998.
Abazov VM Abbott B Acharya BS Adams M Adams T Alexeev GD Alkhazov G Alton A Alverson G Alves GA Aoki M Arov M Askew A Åsman B Atkins S Atramentov O Augsten K Avila C BackusMayes J Badaud F Bagby L Baldin B Bandurin DV Banerjee S Barberis E Baringer P Barreto J Bartlett JF Bassler U Bazterra V Bean A Begalli M Begel M Belanger-Champagne C Bellantoni L Beri SB Bernardi G Bernhard R Bertram I Besançon M Beuselinck R Bezzubov VA Bhat PC Bhatnagar V Blazey G Blessing S Bloom K Boehnlein A Boline D 《Physical review letters》2011,107(24):241803
We measure the cross section and the difference in rapidities between photons and charged leptons for inclusive W(→lν) + γ production in eγ and μγ final states. Using data corresponding to an integrated luminosity of 4.2 fb(-1) collected with the D0 detector at the Fermilab Tevatron Collider, the measured cross section times branching fraction for the process pp → Wγ + X → lνγ + X and the distribution of the charge-signed photon-lepton rapidity difference are found to be in agreement with the standard model. These results provide the most stringent limits on anomalous WWγ couplings for data from hadron colliders: -0.4<Δκ(γ)<0.4 and -0.08<λ(γ)<0.07 at the 95% C.L. 相似文献
999.
Abe K Abgrall N Ajima Y Aihara H Albert JB Andreopoulos C Andrieu B Aoki S Araoka O Argyriades J Ariga A Ariga T Assylbekov S Autiero D Badertscher A Barbi M Barker GJ Barr G Bass M Bay F Bentham S Berardi V Berger BE Bertram I Besnier M Beucher J Beznosko D Bhadra S Blaszczyk FM Blondel A Bojechko C Bouchez J Boyd SB Bravar A Bronner C Brook-Roberge DG Buchanan N Budd H Calvet D Cartwright SL Carver A Castillo R Catanesi MG Cazes A Cervera A Chavez C Choi S Christodoulou G Coleman J Coleman W 《Physical review letters》2011,107(4):041801
The T2K experiment observes indications of ν(μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Δm(23)(2)| = 2.4×10(-3) eV(2), sin(2)2θ(23) = 1 and sin(2)2θ(13) = 0, the expected number of such events is 1.5±0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7×10(-3), equivalent to 2.5σ significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2θ(13) < 0.28(0.34) for δ(CP) = 0 and a normal (inverted) hierarchy. 相似文献
1000.
Atomic H chemisorption on the Si(111)√ 3×√ 3R30°-B surface has been studied by thermal desorption spectroscopy (TDS) and scanning tunneling microscopy (STM). The B-modified Si surface is known to be inert towards adsorbates, since the surface dangling bonds of Si adatoms are passivated by B atoms sitting in sub-surface sites. However, it was found that even on a perfectly passivated surface, H is adsorbed on the surface by destroying the original √ 3 × √ 3 structure. STM observations revealed that H exposure led to the creation of defects at surface sites, and H was subsequently adsorbed as Si-monohydride at these sites. H exposure also caused cluster island formation at the top surface. The islands are composed of hydrogenated amorphous Si atoms or B-hydrogen complexes. 相似文献