转臂式离心机工作室内的瞬态温度求解与分析

考虑大型转臂式离心机圆柱形工作室各墙壁(顶板、底板和侧壁)的瞬态导热,建立各墙壁的瞬态温度控制方程,对控制方程进行Laplace变换并求解,得到了透过墙壁内表面的总热流量与工作室内空气温度的关系.同时,综合考虑离心机驱动系统输出功率与工作室内空气和固体部件吸热、墙壁系统的吸热和导热、出风口带出的热量,以及动能与进风口带入的热量和动能之差等供能与耗能之间的平衡关系,建立工作室内瞬态温度控制方程,导出了工作室内空气瞬态温度的Laplace变换像函数的解析表达式.然后,采用求解Laplace逆变换的展开定理,导出了工作室内空气瞬态温度随时间变化的级数型显式表达式.最后,以一台多用途离心机为例,进行了工作室内空气温度的理论计算,与以前只考虑墙壁稳态导热的理论计算相比,瞬态计算结果与实测结果更加接近.所建瞬态温度公式提高了工作室温度的预测精度,有助于提升大型转臂式离心机工作室温控设计的水平.     

同时测定旱芹抗性淀粉和抗性低聚糖含量

建立了同时测定旱芹中抗性淀粉（Resistant Starch,RS）和抗性低聚糖（Resistant Oligosacch-arides,RO）含量的方法.通过模拟人体胃肠道的生理条件,除去样品中脂类物质、蛋白质和可溶性淀粉后,分别采用紫外分光光度法和酶-重量法测定RS和RO含量.RS含量在0.0160-0.1600mg/mL（r=0.9993）范围内呈良好的线性关系（n=6）,平均回收率为90.7％,RSD=2.0％ （n=9）;RO含量测定平均回收率为87.3％,RSD=2.9％ （n=9）.实验结果表明：该方法线性、精密度、重复性、稳定性和回收率试验均符合方法学验证要求.该方法操作简便,结果准确,重复性好,为全面测定旱芹膳食纤维（DF）中各组分的含量提供了依据,使旱芹DF含量标示更准确.     

川西獐牙菜正丁醇提取物的GC-MS成分分析

利用气相色谱-质谱联用技术对川西獐牙菜的正丁醇提取物进行成分分离鉴定,并用峰面积归一法确定各组分的相对含量.实验中从川西獐牙菜正丁醇提取物非沥青质的3种馏分中共分离出122种化学成分,非极性馏分中以烷烃类为主,极性馏分中以饱和脂肪酸类为主.     

Ni/NHC-catalyzed cross-coupling of methyl sulfinates and amines for direct access to sulfinamides

It was reported to develop a simple and convenient method for the Ni/NHC-catalyzed cross-coupling of methyl sulfinates and amines without an acid/base to afford secondary or tertiary sulfinamides in moderate to good yields. The method can provide the desired products with broad substrate scope, good chemoselectivity and good functional group compatibility. The presented approach may enrich the Ni/NHC catalyst system and promote the applications of methyl sulfinates in the organic sulfur chemistry.     

Preparation and adhesive properties of colored Ti/Zr-based conversion coating on aluminum foil for lithium battery packaging

In this study, an aluminum (Al) foil used for lithium ion battery packaging film was treated with titanium (Ti)/zirconium (Zr) solution containing hexafluorotitanic acid and hexafluorozirconic acid using tannic acid as a colorant and metavanadate as an accelerator, respectively, and a golden conversion coating was successfully deposited on the surface of Al foil. The morphology and composition of the coating were characterized by scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy, and the hydrophilicity was assessed by contact angle measurement. The effect of Ti/Zr treatment on the adhesion properties of Al foil was evaluated by T-peeling test and compared with that of traditional chromate-phosphate treatment. The results show that tannic acid contributes to the formation of the golden coating, and metavanadate accelerates the formation of the conversion coating. The results also indicate that the Ti/Zr-based conversion coating is mainly composed of Al₂O₃, Al (OH)₃, AlF₃, TiO₂/ZrO₂, NH₄VO₃, and V₂O₅. The Ti/Zr treatment cannot only improve the heat-sealing strength, but also the T-peeling strength by approximately 12 times compared with that of untreated Al foil. Thus, Ti/Zr treatment has the potential to replace the traditional chromate conversion treatment.     

两个基于刚性线型三羧酸配体的镍(Ⅱ)配合物的合成

采用水热方法,选用刚性线型三羧酸配体(H3L)和2,2′-联吡啶(2,2′-bipy)与NiCl2·6H2O分别在120和160℃温度下反应,得到了一个具有零维双核镍结构的配合物[Ni2(μ-HL)2(2,2′-bipy)2(H2O)4]·6H2O (1)和一个一维链状配位聚合物{[Ni(μ-HL)(2,2′-bipy)(H2O)2]·H2O}n(2),并对其结构和磁性质进行了研究。结构分析结果表明2个配合物均属于三斜晶系,P1空间群。配合物1具有零维双核镍结构,而且这些双核镍单元通过O-H…O/N氢键作用进一步形成了三维超分子框架,而配合物2具有一维链结构。2个配合物的结构差异可能是由于水热反应温度不同造成的。研究表明,配合物2中相邻镍离子间存在反铁磁相互作用。     

Enhanced deep-red emission in donor-acceptor molecular architecture:The role of ancillary acceptor of cyanophenyl

Organic solid-state luminescent materials with high-efficiency deep-red emission have attracted considerable interest in recent years.Constructing donor-acceptor(D-A) type molecules has been one of most commonly used strategies to achieve deep-red emission,but it is always difficult to achieve high photoluminescence(PL) quantum yield(η_(PL)) due to forbidden charge-transfer state.Herein,we report a new D-A type molecule 4-(7-(4-(diphenylamino)phenyl)-9-oxo-9 H-fluoren-2-yl)benzonitrile(TPAFOCN),deriving from donor-acceptor-donor(D-A-D) type 2,7-bis(4-(diphenylamino)phenyl)-9 Hfluoren-9-one(DTPA-FO) with a fluorescence maximum of 627 nm in solids.This molecular design enables a transformation of acceptor from fluorenone(FO) itself to 4-(9-oxo-9 H-fluoren-2-yl)benzonitrile(FOCN).Compared with DTPA-FO,the introduction of cyanophenyl not only shifts the emission of TPA-FOCN to deep red with a fluorescence maximum of 668 nm in solids,but also maintains the high η_(PL) of 10%.Additionally,a solution-processed non-doped organic light-emitting diode(OLED)was fabricated with TPA-FOCN as emitter.TPA-FOCN device showed a maximum luminous efficiency of0.13 cd/A and a maximum external quantum efficiency(EQE) of 0.22% with CIE coordinates of(0.64,0.35).This work provides a valuable strategy for the rational design of high-efficiency deep-red emission materials using cyanophenyl as an ancillary acceptor.     

Study of nanocarbon black as synergist on improving flame retardancy of ethylene-vinyl acetate/brucite composites

Nanocarbon black (CB) was introduced into ethylene-vinyl acetate/brucite (EM) composites to investigate the synergistic effect of CB and metal hydroxide on improving the flame retardancy of EVA. Flammability properties of the as-prepared EVA composites were investigated by thermogravimetric analysis, limiting oxygen index (LOI), UL-94 test and cone calorimetry test. The results indicated that the optimum mass ratio of CB/brucite was 1/54, at which the EVA composites displayed dramatic improvement on thermal stability and flame retardancy. The LOI value was as high as 35.3%, the UL-94 passed the V-0 rating, and the peak heat release rate reduced 79% in comparison with pure EVA. Based on the morphology and structure analysis for residue chars, the flame-retardant mechanism was attributed mainly to the positive synergistic effect of CB and brucite on promoting the formation of better carbon protective layer during combustion.

     

Determination of thermodynamic properties of aqueous mixtures of RbCl and Rb2SO4 by the EMF method at T=298.15 K

The thermodynamic properties, including activity coefficients, osmotic coefficients and excess Gibbs free energy for RbCl and Rb₂SO₄ aqueous mixtures at T=298.15 K and in 0.01 mol · kg⁻¹ to 5 mol · kg⁻¹ ionic strength, were determined by emf measurements. The Rb–ISE and Ag–AgCl electrodes used in this work were prepared in our laboratory and had a reasonably good Nernst response. The experimental data were fitted by using the Harned rule and Pitzer model. The Harned coefficients and the Pitzer binary and ternary interaction parameters for the system have been evaluated. The experimental results obey the Harned rule. The Pitzer model can be used to describe this aqueous system satisfactorily.