Determination of the solubility parameter of cellulose acrylate using inverse gas chromatography

The solubility parameters of cellulose acrylate substituted degree 2.12(CEA) have been calculated from the measured retention data by inverse gas chromatography at various temperatures. The weight frac-tion activity coefficients of the solvents at infinite dilution(Ω1∞),the Flory-Huggins thermodynamic in-teraction parameters between CEA and solvents(χ 1∞2),the excess molar heats of mixing(△H1s),the par-tial molar heats of mixing at infinite dilution(△H1∞),the solubility parameters of solvent(δ1),and the solubility parameters of CEA(δ2),were calculated at various temperatures. The δ2 of the CEA was 17.32,18.00,18.13,18.54,19.39 at 55,60,65,70 and 75℃,respectively.     

基于UNIFAC模型的离子液体相平衡及萃取研究

通过拟合季膦类、咪唑类离子液体中无限稀释的苯和醇类等溶质的实验数据,得到了离子液体中[TRP][BF₄]等7种新主基团的UNIFAC(universal functional activity coefficient)模型参数。基于该参数,预测了乙醇和甲醇在离子液体[EMIM][ES]和[BMIM][C₅H₁₂O₆S]中的气液相平衡,计算值与实验结果之间吻合较好,这表明本文中仅使用无限稀释溶液活度系数回归出的UNIFAC模型参数仍然是可靠的。最后,对4种离子液体在甲苯/苯-乙醇/甲醇体系中的萃取性能进行了筛选,发现[BMIM][C₅H₁₂O₆S]在甲苯/苯-醇类体系的萃取选择性最高,达到15:3。     

Minus domination number in cubic graph

An upper bound is established on the parameter Γ -(G) for a cubic graph G and two infinite families of 3-connected graphs G k, G * k are constructed to show that the bound is sharp and, moreover, the difference Γ -(G * k)-γ s(G * k) can be arbitrarily large, where Г -(G * k) and γ s(G * k) are the upper minus domination and signed domination numbers of G * k, respectively. Thus two open problems are solved.     

Julia sets of the random iteration systems and its subsystems

Suppose that P=(p\-1, p\-2, ..., p\-M)\% is a probability vector with p\-i>0 and Y={1, 2, ..., M}. Let (Y, 2\+Y, μ) be a probability space with μ(i)=p\-i, i=1, 2, ..., M, and (∑\-M, B, m)= Π \+∞\-0(Y, 2\+U, μ). It is shown that for any a \%(0≤a ≤1) \%, there exists a set U∈B such that m(U)=a and the Julia set associated with U is equal to the Julia set associated with ∑\-M\%. Moreover repelling fixed points with respect to U are dense in the Julia set associated with U.     

An extrapolation theorem on martingale spaces with Ap weights

In this paper, we prove an extrapolation theorem of operators in martingale spaces with A _p weights, which shows that for operators T defined on martingale space L _u ¹ , if T is bounded on martingale space L ^p0(w) for some 1 < p ₀ < ∞ and every, w∈ A _∞, so it is on L ^p,s (w) for every 1 < p, s < ∞, and w ∈ A _∞. We also get some properties of A _p weights and prove that if w ∈ A ₁, then the maximal operator M is bounded on L ^p,q (w) with 1 < p < ∞, 1 < q ≤ ∞.     

Almost sure convergence of weighted sums of NA sequences

For double arrays of constants {a _ni, 1≤i≤k _n, n≥1} and NA r.v. 's {X _n, n≥1}, conditions for almost sure convergence of are given. Both casesk _n ↑ ∞ andk _n=∞ are treated. A Marcinkiewicz-type theorem for i. d. NA sequences is obtained as a special case. Supported by the National Natural Science Foundation of China Cheng Riyan: born in 1968, MS student     

On random Taylor series

This paper deals with random Taylor series whose coefficients consist of independent random variables {X _n } with the property: αE ^1/2{|X _n |²}≤E{|X _n |}<∞,E{X _n }=0 (Ån) for some positive constant α. The convergence, growth, and value distribution of the series are investigated. Supported by the National Natural Science Foundation of China (No. 101960433) Ding Xiaoqing: born in Oct. 1958, Doctoral candidate     

Almost sure convergence of weighted sums of NA sequences

For double arrays of constants {a _ni, 1≤i≤k _n, n≥1} and NA r.v. 's {X _n, n≥1}, conditions for almost sure convergence of are given. Both casesk _n ↑ ∞ andk _n=∞ are treated. A Marcinkiewicz-type theorem for i. d. NA sequences is obtained as a special case. Supported by the National Natural Science Foundation of China Cheng Riyan: born in 1968, MS student     

Synthesis and Characterization of Polyamide-Containing 2, 6- （Substituded） pyridine Derivatives

0 IntroductionPayrriodminaetiics hoenteer oofc ythcleics m .os tC oambupnoduanndts a cnodn tbaeisntin kgno twhnepyridine ring are widely distributedin nature,principally asenzymes and alkaloids . Pyridine enzymes have been foundintissues of all plants and ani mals examined thus far ,andare derivedfromeither nicotinic acid or Vitamin B6[1].Pyr-idine derivatives are also the building block of many phar-maceuticals with a wide range of functionalities that includeantitubercular compounds ,antivi…     

HSO3-functionalized Brønsted acidic ionic liquids promote esterification of aromatic acid

Esterification of aromatic acid can be promoted via HSO3-functionalized Br nsted acidic ionic liquids (ILs). Under the optimum conditions, using 1-(3-sulfonic acid) propyl-3-methylimidazolium hydrogen sulfate ([MimC3SO3H][HSO4]) and 1-(4-sulfonic acid) butyl-3-methylimidazolium hydrogen sulfate ([MimC 4 SO 3 H][HSO4 ]) as dual solvent-catalysts, the conversion of esterification of aromatic acid was determined to be more than 90%, indicating that HSO3-functionalized ILs show much better catalytic ability than those of non-functionalized ionic liquids. The separation of desired product was easily performed by extraction with diethyl ether and these HSO3-functionalized ILs could be reused 7 times after vacuum drying. Our data represent an environmentally friendly method for the preparation of aromatic esters.     

北部湾潮汐数值计算参数的试验

选不同的海底摩擦系数以及水平湍流摩擦系数,对北部湾的ki分潮进行了数值模拟试验。结果表明,当底摩擦系数取0.002~0.003,而水平湍流摩擦系数取1×10²~5×10³ m²/s时其模拟结果与实测潮波系统比较吻合。潮波动力学方程中的底摩擦项对数值结果影响较大,而水平湍摩擦项对数值结果的影响不甚明显。     

B-Valued Dyadic Derivative

The principles of the new maximal operator H＊ we defined are discussed. We prove that it is bounded from martingale Hardy-Lorentz L^Xp.q[0,1） to the Lorentz L^Xp.q[0,1） for 1/2〈 p〈∞, 0〈~ q ≤ ∞, where X is any Banach space. When the Banach space X has the RN property, the sequence dnHnf converges to f a.e. Meanwhile the convergence in L^Xp norm for 1≤p〈∞ is a consequence of that the family functions K （n∈N） is an approximate identity.     

Correlation between platelet gelsolin levels and different types of coronary heart disease

Gelsolin is an important cytoskeletal protein of platelets and studies have shown a close relationship between gelsolin and cardiovascular disease.However,the role of gelsolin in the development of coronary heart disease(CHD) is unclear.In this study,we record the distribution of gelsolin in human platelets and plasma and its association with different types of CHD.This study included 114 cases,with 33 stable angina pectoris(SAP) cases,81 acute coronary syndrome(ACS) cases—composed of 39 unstable angina pectoris(UAP) and 42 acute myocardial infarction(AMI) cases,and 31 healthy control participants.Gelsolin concentration in platelet rich plasma(PRP) and platelet poor plasma(PPP),actin filament(F-actin) and Gc-globulin of PPP were determined by enzyme-linked immunoadsorbent assay(ELISA).The fluorescence intensity of CD62p and cytoplasmic calcium([Ca2+] i) in human platelets measured by flow cytometry.We also used turbidimetry to detect the platelet aggregation rate(PAR).We analyzed the correlation between platelet gelsolin concentration and CD62p or plasma F-actin levels among each different patient group.Compared with the control group,the gelsolin level in PRP of UAP and AMI groups increased significantly(P<0.01),while the gelsolin level in PPP of all the three patient groups decreased markedly(P<0.01),and the CD62p,PAR,[Ca2+] i of platelets,F-actin and Gc-globulin of the UAP and AMI groups increased significantly(P<0.01).Compared with the SAP group,the gelsolin level in PRP,the PAR,[Ca2+] i of platelets and CD62p of other two groups increased significantly(P<0.01),F-actin of the AMI group increased markedly(P<0.01).Platelet cytoskeleton protein dynamics vary among the different types of CHD.Platelet gelsolin levels are markedly increased and accompanied by increased platelet activity,F-actin and [Ca2+] i of ACS patients,while gelsolin levels in PPP are markedly lower.Abnormally increased platelet gelsolin levels show high positive correlation with the level of platelet activity.Therefore,platelet gelsolin might be a novel molecular marker and/or a new potential therapeutic target of anti-platelet therapy of ACS.     

Dispersion of CoCl2 into γ-Al2O3 studied by positron

Co²⁺/γ-Al₂O₃ samples were prepared by incipient wetness impregnation of γ-Al₂O₃ with different concentration solution of CoCl₂ and dried at 40 °C. We measured the positron lifetime spectra of the samples of different Co²⁺ mass fractions (0%–8.24%) heated at different temperatures (100–500°C). All lifetime spectra were resolved into four components, in which the third and the fourth components were related to the surface state of the micropores and the secondary pores of the γ-Al₂O₃. The experimental results showed that the Co²⁺ was mainly located in the micropores and the secondary pores near to the exterior of the support. For low Co²⁺ mass fraction samples, when the heating temperature was above 400 °C, dispersal was almost finished. When the Co²⁺ mass fraction was above 5.59%, Co²⁺ and Cl⁻ were dispersed into the secondary pores in the form of multiple layers.     

A class of complex quasi-Orlicz spaces and their analytic RN property

LetX be a complex quasi-Banach space and Φ:[0,∞)→[0,∞) an increasing convex function with Φ(0)=0, and Φ∈Δ₂. ThenL _Φ ^* (X) is a quasi-Banach space with continuous quasi-norm andL _Φ ^* (X) has the ARNP if and only ifX does. Supported by the National Natural Science Foundation of China Liu Peide: born in 1943, Professor     

Characterizations of <Emphasis Type="Italic">L</Emphasis><Subscript><Emphasis Type="Italic">p</Emphasis></Subscript>(<Emphasis Type="Italic">R</Emphasis>) using tight wavelet frames

In this paper,a Littlewood-Paley function characterization of the spaces L p(R),1相似文献   

Third-order optical nonlinearities for lanthanum (III) complexes with 1, 10-phenanthroline components

The nonlinear refractive indexesn ₂ for the ethanol solutions of 1, 10-phenanthroline (2.0 × 10⁻³ mol · L⁻¹), [bis(l, 10-phenanthroline) lanthanum (III)] nitrate (1.0 × 10⁻³ mol · L⁻¹), and [nitrato-fluoracil-bis (1, 10_{-phenanthroline}) lanthanum (III) ] nitrate (1.0 × 10⁻³ mol · L⁻¹) are first measured, the third-order nonlinear optical susceptibilities χ(³) and 〈γ〉 are calculated, and the mechanisms of the third-order optical nonlinearities enhanced by lanthanum (III) are discussed preliminarily.     

Correlation between the standard formation enthalpy and the path index of pyridine-derivatives

A formulated as △fH _m ^◯ (PPDs,g)=a+Σb_iP_i + c_if_i is put forward for estimating standard formation enthalpies of pyridine-derivatives (PDDs), in which,P _i is path index andc _i f _i is an amended term of interaction between substituent and N atom on pyridine ring. The Calculations based on the model were carried out for some pyridine-derivatives. The values of standard formation enthalpy calculated are consistent with those in literature. Foundation item: Supported by the National Natural Science Foundation of China (29971024) Biography: LI Liang-chao (1958-), male, Associate professor, Research direction: calculating chemistry.     

Average widths and optimal recovery of multivariate Besov classes inL p (Rd)

Some weak asymptotic results for average σ-K width and average σ_L width of the isotropic Besov classes S r pθB(R d), S r pθb(R d) and the anisotropic Besov classes S r pθB(R d), S r pθb(R d) in L p(R d) (1≤p<∞) are obtained, and the corresponding weak asymptotic optimal subspaces are identified. Furthermore, the weak asymptotic behavior of optimal recovery is established for the isotropic Besov classes S r pθB(R d) in L p(R d) (1≤p≤∞).