分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: We examine the status of dark matter (heavy photon) in the littlest Higgs model with T parity (LHT) in light of the new results from the LHC Higgs search, the Planck dark matter relic density, and the XENON100 limit on the dark matter scattering off the n
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: Due to the limited statistics so far accumulated in the Higgs boson search at the LHC, the Higgs boson property has not yet been tightly constrained and it is still allowed for the Higgs boson to decay invisibly to dark matter with a sizable branching rat
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: Confronted with the LHC data of a Higgs boson around 125 GeV, different models of low energy SUSY show different behaviors: some are favored, some are marginally survived and some are strongly disfavored or excluded. In this note we update our previous sc
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: We confront the little Higgs theory with the LHC Higgs search data (up to 17 fb-1 of the combined 7 and 8 TeV run). Considering some typical models, namely, the littlest Higgs model, the littlest Higgs model with T parity (LHT-A and LHT-B), and the simple
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: In light of the significant progress of the LHC to determine the properties of the Higgs boson, we investigate the capability of the Manohar-Wise model in explaining the Higgs data. This model extends the SM by one family of color-octet and isospin-double
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: Motivated by the recent LHC hints of a Higgs boson around 125 GeV, we assume a SM-like Higgs with the mass 123-127 GeV and study its implication in low energy SUSY by comparing the MSSM and NMSSM. We consider various experimental constraints at 2-sigma le
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: In the Next-to-Minimal Supersymemtric Standard Model (NMSSM), one of the neutral Higgs scalars (CP-even or CP-odd) may be lighter than half of the SM-like Higgs boson. In this case, the SM-like Higgs boson h can decay into such a light scalar pair and con
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-04-06
摘要: The bio-based diamine and epoxy monomer derived from isosorbide are synthesized. Especially, the diamine is obtained using microwave assistant thiol-ene coupling reaction in the aqueous media and the influence of reaction parameters, such as initiator con
分类: 材料科学 >> 材料科学(综合) 提交时间: 2017-03-30
摘要: The bio-based diamine and epoxy monomer derived from isosorbide are synthesized. Especially, the diamine is obtained using microwave assistant thiol-ene coupling reaction in the aqueous media and the influence of reaction parameters, such as initiator con
分类: 材料科学 >> 材料科学(综合) 提交时间: 2017-03-30
摘要: The bio-based diamine and epoxy monomer derived from isosorbide are synthesized. Especially, the diamine is obtained using microwave assistant thiol-ene coupling reaction in the aqueous media and the influence of reaction parameters, such as initiator con
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-04-06
摘要: A soft segment free thermoplastic polyester elastomer is fabricated by controlling the stereochemical structure of molecular chains with the utilization of the cis 1,4-cyclohexylene ring moiety (cis-CHRM) in poly(butylene 1,4-cyclohexanedicarboxylate) (PB
分类: 材料科学 >> 材料科学(综合) 提交时间: 2017-03-30
摘要: A soft segment free thermoplastic polyester elastomer is fabricated by controlling the stereochemical structure of molecular chains with the utilization of the cis 1,4-cyclohexylene ring moiety (cis-CHRM) in poly(butylene 1,4-cyclohexanedicarboxylate) (PB
分类: 材料科学 >> 材料科学(综合) 提交时间: 2017-03-30
摘要: A soft segment free thermoplastic polyester elastomer is fabricated by controlling the stereochemical structure of molecular chains with the utilization of the cis 1,4-cyclohexylene ring moiety (cis-CHRM) in poly(butylene 1,4-cyclohexanedicarboxylate) (PB
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-11-02 合作期刊: 《热科学学报》
摘要: This paper describes the numerical study on film cooling effectiveness and aerodynamic loss due to coolant and main stream mixing for a turbine guide vane. The effects of blowing ratio, mainstream Mach number, surface curvature on the cooling effectiveness and mixing loss were studied and discussed. The numerical results show that the distributions of film cooling effectiveness on the suction surface and pressure surface at the same blowing ratio (BR) are different due to local surface curvature and pressure gradient. The aerodynamic loss features for film holes on the pressure surface are also different from film holes on the suction surface.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-09-27
摘要: Although there is mounting observational evidence that the expansion of our universe is undergoing a late-time acceleration, the mechanism for this acceleration is yet unknown. In the so-called Dvali-Gabadadze-Porrati (DGP) model this phenomena is attributed to gravitational leakage into extra dimensions. In this work, we mainly focus our attention to the constraints on the model from the gold sample of type Ia supernovae (SNeIa), the first year data from the Supernova Legacy Survey (SNLS) and the baryon acoustic oscillation (BAO) peak found in the Sloan Digital Sky Survey (SDSS). At 99.73% confidence level, the combination of the three databases provides m = 0.270+0.018−0.017 and rc = 0.216+0.012−0.013 (hence a spatially closed universe with k = −0.350+0.080−0.083), which seems to be in contradiction with the most recent WMAP results indicating a flat universe. Based on this result, we also estimated the transition redshift (at which the universe switches from deceleration to acceleration) to be 0.70 < zq=0 < 1.01, at 2#27;confidence level.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-08
摘要: Compared with the rapid progress on bio-based thermoplastics, research on bio-based thermosetting resins should have attracted much more attention, considering that they will have a bright future. In this paper, the current research progress on bio-based thermosetting resins is reviewed. We pay special attention to the synthesis and investigation of properties of epoxies and unsaturated polyesters derived from renewable plant oil, cardanol, rosin acid, lignin, glycerol, gallic acid, furan, isosorbide, itaconic acid, etc. This mini review gives an overall perspective for bio-based thermosets. © 2015 Society of Chemical Industry
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Non-planar ring contained polyester is synthesized as an effective toughening agent to modify poly- lactide (PLA). By systematically researching the relation between molecular structure and properties, the two key factors to pursue high toughness of PLA with non-planar ring contained polyester are carefully distinguished. For one thing, the polyester must own the ability to be well compatible with PLA. For the other, the polyester should have a rigid molecular chain but “non-rigid” aggregation structure. By suit- ably controlling the molecular design, poly(butylene adipate-co-1,4-cyclohexanedicarboxylate) (PBAC) is obtained. After using PBAC to toughen PLA, the elongation extremely increases to 196.1 ± 3.6% and the notched impact strength is also effectively improved with several times. Finally, our research establishes an important methodology to toughen PLA and thus fabricates tough PLA based blends.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: A series of bio-based unsaturated polyesters was synthesized by melt polycondensation of itaconic acid with 1,4-butanediol and glycerol. Their chemical structures were confirmed by FT-IR, 1H NMR, acid and hydroxyl values. Waterborne UV curable dispersion coatings based on these polyesters and acrylated epoxidized soybean oil (AESO) were formulated. The average particle size and their stability before curing as well as the coating properties after curing, including adhesion, flexibility, pencil hardness and solvent resistance, were investigated. Results demonstrated that the glycerol segment in the polyesters together with AESO led to the excellent coating properties in terms of highest grade of adhesion (5B), 0T flexibility, pencil hardness of 5H and excellent solvent resistance (no appearance change after 250 double rubs with ethanol and acetone). This work provided us the coating systems combining the merits of being bio-based, UV-curable and water dispersible.vv
提交时间: 2017-05-02
摘要: Poly[butylene terephthalate]-poly[tetramethylene glycol] [PBT-PTMG] copolymer is prepared with terephthalic acid [PTA] rather than its dimethyl ester [DMT] as starting material by a two-step melt polycondensation. This process includes the synthesis of PB
分类: 材料科学 >> 材料科学(综合) 提交时间: 2017-05-09
摘要: A unique non-planar ring structure 1,4-cyclohexanedicarboxylic acid (CHDA) is introduced to synthesize a poly(butylene adipate-co-butylene 1,4-cyclohexanedicarboxylate) (PBAC) copolyester. The impact of the stereochemistry of CHDA on the structure and properties of PBAC, especially the role of cis-CHDA in tuning the thermal, tensile and elastic properties of PBAC is explored in depth. Instead of considering PBAC as a diblock random copolymer consisting of poly(butylene adipate) (PBA) and poly(butylene 1,4- cyclohexanedicarboxylate) (PBC), our results reveal that PBAC can be considered as a random copolymer consisting of actually three blocks, namely PBA, a PBC unit with only trans-CHDA (trans- PBC), and PBC unit with only cis-CHDA (cis-PBC). The role of cis-CHDA is found to be rigid which initiates a high modulus and strength, and soft which results in a decreased melting temperature and increased elongation at break and elasticity.