有限势库化学机最大输出功时循环最优构型

基于有限势容高化学势库和无限势容低化学势库间工作的等温内可逆化学机,在循环总时间一定的条件下,应用最优控制理论导出了一类普适传质规律下对应于最大输出功时化学机循环最优构型.特例分析表明传质定律为g∝△μ(△μ为化学势差)时循环最优构型为低化学势侧工质中关键组分的化学势(或浓度)为常数,而工质与有限势容高化学势库间关键组分的化学势(或浓度)均随时间呈非线性变化且化学势之差(浓度之比)为常数的等温内可逆化学机循环;传质定律为g∝△c(△c为浓度差)时循环最优构型与传质定律g∝△μ下循环最优构型存在显著不同;当高化学势库也为无限势容化学势库时,循环最优构型由两个等化学势传质分支和两个等质量流率分支组成,且与具体的传质定律无关.本文的研究对象具有一定的普适性,研究结果对于实际化学机的优化设计与最优运行具有一定参考价值.     

线性唯象传热规律下热驱动二元分离过程的最小平均耗热量

假设热源温度随时间和空间变化,将热驱动分离过程当作工作于高、低温热源之间并产生焓流和能量流的热机来研究,分析了线性唯象传热规律（q∝Δ（T-1））下热驱动二元分离过程的最优性能问题.应用数值方法求解凸优化问题,应用拉格朗日函数求解平均最优控制问题,引入无量纲熵产率系数和无量纲焓流率系数表示分离体系物性及不同分离要求等对分离过程性能有较大影响的因素,得到了热驱动二元分离过程的无量纲最小平均熵产率和无量纲最小平均耗热量,并与牛顿传热规律（q∝Δ（T））下的结果进行了比较.     

Optimal paths for a light-driven engine with a linear phenomenological heat transfer law

An irreversible light-driven engine is described in this paper, in which the heat transfer between the working fluid and the environment obeys a linear phenomenological heat transfer law [ q ∝Δ(T -1)], with a working fluid composed of the bimolecular reacting system 2SO 3 F■S 2 O 6 F2. Piston trajectories maximizing work output and minimizing entropy generation are determined for such an engine with rate-dependent loss mechanisms of friction and heat leakage. The optimal control theory is applied to determi...     

手性三菲咯啉合镍与DNA的立体选择性研究

有关 DNA与金属配合物反应机理和作用模式的探讨是生物无机化学研究的重要内容之一 .目前的研究 [1～ 4] 表明 ,有大共轭配体配位的八面体金属配合物以静电作用或插入方式与DNA结合 .外消旋 [Ni( phen) 3]2 +及其旋光异构体与 DNA作用机理的研究曾有报道 [4] .但用电化学方法研究其旋光异构体与 DNA作用则未见详细报道 .本文用电化学方法和 CD谱研究了 Δ- ,∧ - [Ni( phen) 3]2 +配合物与 DNA的作用 .两种方法所得结果均表明 Δ- ,∧ - [Ni( phen) 3]2 +与 DNA作用时 ,Δ构型配合物的插入作用比∧构型配合物的强 .该法与平衡透析…     

1-乙胺基-3-甲基咪唑四氟硼酸盐吸收CO_2的理论研究

采用密度泛函理论(DFT)对离子液体1-乙胺基-3-甲基咪唑四氟硼酸盐([NH2e-mim][BF4])吸收CO_2的反应机理进行了研究.在B3LYP/6-311++G(d,p)计算水平下,对离子液体[NH2e-mim][BF4]的结构及与CO_2反应的中间体、过渡态和产物进行了全优化,获得了优化结构的构型参数、振动频率和热力学数据.利用自然键轨道(NBO)分析了离子液体[NH2e-mim][BF4]和CO_2的自然电荷布居.计算结果表明,通过阳离子[NH2e-mim]+自偶解离产生的阳离子[NH3e-mim]2+能与阴离子[BF4]-结合形成更强的离子键.根据反应吉布斯自由能变(ΔG0—)和焓变(ΔH0—)的计算结果,判断离子液体[NH2e-mim][BF4]吸收CO_2按理论摩尔比2∶1分步进行反应,吸收过程中质子的转移需克服52.51 k J/mol的能垒.     

六核钽铑二元混合簇合物的几何和电子结构

采用密度泛函理论对六核钽、铑八面体纯簇及其混合簇的几何结构和电子性质进行了研究.计算结果表明:大部分钽铑混合簇稳定构型的对称性均较低,为C1或Cs点群,只有[Ta2Rh4Cl4H8(CN)6]4-团簇的稳定构型对称性较高,为C2h或C4v点群;混合簇的最高占据分子轨道(HOMO)与最低未占据分子轨道(LUMO)能隙(ΔEH-L)均较小,介于0.52-1.00eV之间;混合簇的前线轨道主要由骨架金属原子的d电子贡献,随着Rh原子替代Ta原子个数的递增,Ta—Rh键对混合簇稳定构型所起作用逐渐增加,Ta—Ta键所起作用减小,而Rh—Rh键为非键或反键性质.     

对称性破缺:手性高氯酸乙酸·二(乙二胺)合锌(Ⅱ)的合成与结构(英文)

用简单的非手性原料醋酸锌和乙二胺在高氯酸钠的甲醇溶液中反应,反应过程中发生了对称性破缺现象,得到了一对对映体Δ-cis-[Zn(en)2Ac][ClO4](Δ-1)andΛ-cis-[Zn(en)2Ac][ClO4](Λ-1)(en=乙二胺,Ac-=醋酸根)。用元素分析、红外光谱、CD光谱和Xray单晶衍射对产物进行了表征。X-ray单晶衍射结果表明配合物Δ-1和Λ-1中的锌(Ⅱ)离子均与2个乙二胺上的4个氮原子和醋酸根上的2个氧原子顺式配位,形成六配位畸变的八面体构型。{Δ-cis-[Zn(en)2Ac]}+和{Λ-cis-[Zn(en)2Ac]}+单体通过氢键作用分别形成具有右手和左手双螺旋的一维链。用X-ray单晶衍射和CD光谱确定了配合物的手性特征。     

带有位阻基团的钌多吡啶手性配合物与DNA键合及其光断裂DNA性质的研究

合成了钌多吡啶手性配合物的对映异构体Δ-Ru(bpy)2DMNP](ClO4)2与Λ-[Ru(bpy)2DMNP](C1O4)2(Δ-1与Λ-1,DMNP=4-咪唑并[4,5-f](1,10)-邻菲咯啉-2-N,N二甲基苯胺),Δ-[Ru(bpy)2(BOPIP)](ClO4)2与Λ-Ru(bpy)2(BOPIP)](ClO4)2(Δ-2与Λ-2,BOPIP=2-(4-丁氧基基苯基-)咪唑并[4,5-f](1,10)-邻菲咯啉),用元素分析、核磁共振及旋光仪对手性配合物结构进行了表征,通过电子吸收光谱、荧光光谱、粘度实验对手性配合物与CT-DNA相互作用的性质进行了研究。结果表明:两对Δ-型异构体均与CT-DNA以插入模式作用。在紫外光照下,两对对映异构体均能使质粒pBR322DNA断裂,但Λ-1型异构体比Δ-1型异构体断裂DNA效率更高,说明存在立体选择性,而Δ-2与Λ-2对DNA断裂无明显区别。     

中性水杨醛亚胺镍催化烯烃聚合反应链引发机理的密度泛函研究

采用密度泛函理论(DFT),以乙烯为模型,在B3LYP/LANL2MB水平上研究了中性水杨醛亚胺镍催化烯烃聚合反应链引发机理.通过几何构型全优化,得到了链引发阶段的反应物、产物、中间体和过渡态的最可几构型.由于该催化剂中,与中心原子N i相联接的配体不对称性,使得反应存在两条可能路径(路径A甲基位于N i—O键的对位,路径B甲基位于N i—N键的对位).分别对这两条路径进行了分析和比较.结果表明反应并不只是简单地按一条路径进行,而是通过相互竞争,最终使反应在两条路径间转换,形成一条在能量上最为有利的反应途径.     

配合物[M(CO)3(PPh2py)2](M=Fe,Ru)异构体的理论研究

对PPh2py配合物[M(CO)3(PPh2py)2](M=Fe, Ru)的三种构型的异构体1-6进行了研究. 其中PPh2py以两个P原子与M配位形成HH构型1(Fe)和4(Ru), 以一个P和一个N原子与M配位形成HT构型2(Fe)和5(Ru), 以两个N原子与M配位形成HH’构型3(Fe)和6(Ru). 结果表明, (1) PPh2py中P原子对HOMO轨道的贡献最大, PPh2py作为电子给体时易以P原子与金属原子结合. (2)从分子能量和相互作用能数据表明, 配合物中HH构型最稳定, HH'构型最不稳定, 这与合成产物为HH构型的结果一致. (3) 键长和Wiberg键级均表明P—M键比N—M键结合力强. P、M原子间存在σ键, 而N、Fe原子间仅存在nN→n*M或nN→σ*M-P的电荷转移作用. (4) HH构型中M对HOMO的贡献最大, PPh2py向M的电荷转移最强, 使M的负电荷最大, 故HH构型最易作为电子给体以M原子与第二个金属配位形成双核配合物.     

嘧霉胺的标准生成焓及其抗灰葡萄孢菌作用

用苯胺、氨基氰、乙酰丙酮三种物质合成了杀菌剂嘧霉胺(C12N3H13).并用溶解量热法在常压、298.15K下,分别测定了苯胺、氨基氰、乙酰丙酮和嘧霉胺在混合溶剂(VDMF:VDMSO=2:1)中的溶解焓:ΔsHmΘ(C6NH7(l),298.15K)=-(12.48±0.16)kJmol-1、ΔsHmΘ(NH2CN(s),298.15K)=-(8.06±0.42)kJmol-1、ΔsHmΘ(CH3COCH2COCH3(l),298.15K)=(1.26±0.03)kJmol-1和ΔsHmΘ[C12N3H13(s),298.15K]=(13.84±0.12)kJmol-1.根据热化学原理求出了298.15K时,合成反应的标准反应热ΔrHmΘ=-(35.65±0.47)kJmol-1,以及嘧霉胺(C12N3H13(s))的标准摩尔生成焓ΔfHmΘ(C12N3H13(s),298.15K)=(198.5±1.5)kJmol-1;用TAMair微量热仪测定了嘧霉胺(C12N3H13(s))在301.15K时对灰葡萄孢菌作用的产热曲线,根据产热曲线求算了在嘧霉胺作用下,灰葡萄孢菌生长代谢的最大发热功率Pmax、最大产热功率的时间tmax、速率常数k和抑制率I等热动力学参数.结果表明:嘧霉胺在低浓度下对灰葡萄孢菌有刺激作用,高浓度下为抑制作用,即嘧霉胺对微生物的生长具有双向生物效应,也称为Hormsis效应.     

Variation of Power Output with Changing Working Fluid in a Liquid-Piston Two-Phase Heat Engine

Emphasis is placed upon selecting working fluid in the drinking bird heat engine. The power output is correlated with thermal efficiency, temperature gradient and heat transfer coefficient. Experimental results are illustrated by our theoretical approaches. We find that thermal efficiency will he largely improved if energy loss due to reheating is eliminated. Method of avoiding reheating and choice of connector height are also discussed. The selection of working fluid mainly depends upon temperature difference. Our theoretical development and experimental results are very useful in constructing a real engine.     

5-氨基间苯二甲酸钠和5-羟基间苯二甲酸钠的热力学性质

在水溶液中合成了5-氨基间苯二甲酸钠(1)和5-羟基间苯二甲酸钠(2)固态样品,元素分析和TG-DTG确定其组成符合C8H5O4NNa2·H2O(1)和C8H4O5Na2·H2O(2).用精密自动绝热热量计测定了它们在78～400K温区的低温热容,将实验值用最小二乘法拟合,得到热容随温度变化的多项式方程,用此方程进行数值积分,得到该温区内每隔5K的舒平热容值和各种热力学函数值.用RD496-2000型微热量计测定了样品在298.15K时的标准摩尔溶解焓分别为ΔsolHmθ(1,s)=-44.552±0.164kJmol-1和θΔsolHm(2,s)=-36.055±0.154kJmol-1,计算了其水合阴离子标准摩尔生成焓分别为θΔfHm(C8H5O4N2-,aq)=-684.56±1.67kJmol-1和ΔfHmθ(C8H4O52-,aq)=-1263.43±2.13kJmol-1.用RBC-II型精密转动弹热量计测定了样品的恒容燃烧热分别为ΔcU(1,s)=-13382.14±5.28Jg-1和ΔcU(2,s)=-10339.15±4.15Jg-1,计算了它们的标准摩尔燃烧焓和标准摩尔生成焓分别为ΔcHmθ(1,s)=-3252.90±1.28kJmol-1和θΔcHm(2,s)=-2522.64±1.01kJmol-1,ΔfHmθ(1,s)=-1406.46±1.66kJmol-1,θΔfHm(2,s)=-1993.79±1.46kJmol-1.     

镨配合物的热化学及其对酵母菌作用的热动力学研究

用六水合氯化镨、硫代脯氨酸(C4H7NO2S)和水杨酸(C7H6O3)合成了三元固体配合物[Pr(C7H5O3)2(C4H6NO2S)]-2H2O.根据盖斯定律设计一个热化学循环,用溶解-反应量热法研究得到合成反应的标准摩尔焓变为(133.70±1.02)kJ/mol,配合物298.15K时的标准摩尔生成焓为-(2909.3±3.2)kJ/mol.用TAMair微量热仪测定其在28.00℃时对粟酒裂殖酵母作用的产热曲线,进而算出在配合物作用下,酵母菌生长代谢的最大发热功率Pmax、速率常数κ、传代时间tG、抑制率I和半抑制浓度cI,50等热动力学参数.结果表明:稀土水杨酸硫代脯氨酸配合物在低浓度下对酵母菌有刺激作用,高浓度下为抑制作用,即稀土配合物对微生物的生长具有双向生物效应,也称为Hormesis效应.     

三元钴配合物[Co（NCS）2（ql）2]（q1=喹啉）的合成及其晶体结构和荧光性质

合成了含异硫氰酸根和喹啉（q1）混合配体的钴配合物[Co（NCS）2（q1）2];利用红外光谱、紫外光谱和X射线单晶衍射等手段对其结构进行了表征;研究了配合物在室温下的荧光发射光谱特性．单晶结构解析结果表明,标题化合物属于单斜晶系,P21／c空间群,晶胞参数为：a=1．48633（5）nm,6=0．84444（3）nm,c=1．54116（5）nm,β=92．093（2）,V=1．9330（2）nm^3,Z=4,Dc=1．489g／cm^3,μ=1．116mm^-1,F（000）=884,R1=0．0322,wR2=0．0786．配合物中钴离子采用四配位的四面体配位构型,晶体堆积中通过π-π作用形成一维超分子结构．     

Steady hydromagnetic flow of a non-Newtonian power law fluid due to a rotating porous disk with heat transfer

The steady magnetohydrodynamic (MHD) flow of an incompressible viscous non-Newtonian power law fluid above an infinite rotating porous disk with heat transfer is studied. A uniform magnetic field is applied perpendicularly to the plane of the disk and a uniform injection or suction is applied through the surface of the disk. Numerical solutions of the nonlinear differential equations which govern the hydromagnetic and heat transfer are obtained. The effects of characteristics of the non-Newtonian fluid, the magnetic field parameter and the suction or injection velocity on the velocity and temperature distributions are considered.     

An ethanol biosensor based on a bacterial cell-immobilized eggshell membrane

An ethanol biosensor was fabricated based on a Methylobacterium organophilium-immobilized eggshell membrane and an oxygen（O₂） electrode.A linear response for ethanol was obtained in the range of 0.050-7.5 mmol/L with a detection limit of 0.025 mmol/L（S/N= 3） and a R.S.D.of 2.1%.The response time was less than 100 s at room temperature and ambient pressure. The optimal loading of bacterial cells on the biosensor membrane is 40 mg（wet weight）.The optimal working conditions for the microbial biosensor are pH 7.0 phosphate buffer（50 mmol/L） at 20-25℃.The interference test,operational and storage stability of the biosensor are studied in detail.Finally,the biosensor is applied to determine the ethanol contents in various alcohol samples and the results are comparable to that obtained by gas chromatographic method and the results are satisfactory.Our proposed biosensor provides a convenient,simple and reliable method to determine ethanol content in alcoholic drinks.     

多级离心连续逆流手性萃取模型及模拟

基于单级手性萃取数学模型和质量守恒定律,建立了多级离心手性萃取数学模型,设计了多级离心萃取数学模型程序,并对多级离心萃取分离苯基琥珀酸（PSA）对映体进行了模拟.模拟了相比、萃取剂浓度、对映体浓度、进料位置和萃取级数等工艺参数对萃取效果（产物纯度和产率）的影响.模拟结果表明,考察的工艺参数共同影响萃取相和萃余相的产物纯度及产率;采用中间位置进料和较大的W/F相比有利于对称分离.实验发现：采用中间位置进料,10级离心萃取后萃取相中苯基琥珀酸的光学纯度ee（对映体过量）达到56%以上.模拟结果还表明,采用26级离心萃取器,中间进料,逆流分级萃取,萃取相及萃余相中的光学纯度ee都能达到98%以上.     

Vapor compression CuCl heat pump integrated with a thermochemical water splitting cycle

In this paper, the feasibility of using cuprous chloride (CuCl) as a working fluid in a new high temperature heat pump with vapor compression is analyzed. The heat pump is integrated with a copper–chlorine (Cu–Cl) thermochemical water splitting cycle for internal heat recovery, temperature upgrades and hydrogen production. The minimum temperature of heat supply necessary for driving the water splitting cycle can be lowered because the heat pump increases the working fluid temperature from 755 K up to ～950 K, at a high COP of ～6.5. Based on measured data available in past literature, the authors have determined the T–s diagram of CuCl, which is then used for the thermodynamic modeling of the cycle. In the heat pump cycle, molten CuCl is flashed in a vacuum where the vapor quality reaches ～2.5%, and then it is boiled to produce saturated vapor. The vapor is then compressed in stages (with inter-cooling and heat recovery), and condensed in a direct contact heat exchanger to transfer heat at a higher temperature. The heat pump is then integrated with a copper–chlorine water splitting plant. The heat pump evaporator is connected thermally with the hydrogen production reactor of the water splitting plant, which performs an exothermic reaction that generates heat at 760 K. Additional source heat is obtained from heat recovery from the hot reaction products of the oxy-decomposer. The heat pump transfers heat at ～950 K to the oxy-decomposer to drive its endothermic chemical reaction. It is shown that the heat required at the heat pump source can be obtained completely from internal heat recovery within the plant. First and second law analyses and a parametric study are performed for the proposed system to study the influence of the compressor's isentropic efficiency and temperature levels on the heat pump's COP. Two new indicators are presented: one represents the heat recovery ratio (the ratio between the thermal energy obtained by internal heat recovery, and the energy needed at the heat pump evaporator), and the other is the specific heat pump work per mole of hydrogen produced. This new heat pump with CuCl as a working fluid can be attractive in other industrial contexts where high temperature heat is needed. One may replace a common heating technology (combustion or electric heating) with the present sustainable method that uses heat recovery and high efficiency temperature upgrading for heating applications.