滇东北茂租热液型铅锌矿床矿物组合共生分异的热力学Eh—pH相图

滇东北地区广泛分布的热液型铅锌矿床具有普遍的矿物组合分带特征,研究矿床矿物组合的共生分异特征,是了解该类型矿床的成矿流体在演化过程中,成矿元素迁移和沉淀的核心问题之一,通过共生矿物的热力学Eh—pH相图可以有效的诠释成矿流体中成矿元素在迁移、沉淀过程中的物理化学条件。本文以滇东北茂租铅锌矿床为例,对滇东北热液型铅锌矿床的金属矿物共生组合在时间、空间分带特征进行热力学相图分析,选取373K、423K、473K、523K四个温度截面对金属矿物共生组合稳定存在的Eh—pH范围进行计算,相图显示成矿流体中矿物迁移、沉淀机制主要是由于成矿流体的Eh、p H值双重制约:Eh值的变化控制着硫化物沉淀的时间分带,成矿流体从深部向浅部运移,Eh值将会逐渐增大,主要矿物从黄铁矿→方铅矿→闪锌矿依次开始析出;p H值控制硫化物的空间分带,随着p H值的增大,成矿元素从离子的形式转变为硫酸盐矿物进行迁移。研究表明,控制成矿流体中硫化物迁移、沉淀的物理化学条件除了温度、压力、金属离子浓度及流体的氧硫逸度之外,流体的酸碱度及氧化还原电位同样是控制矿物组合共生分异的重要影响因素,此研究对该类型矿床的成矿流体的演化和成矿机制提供了一定的理论依据。

Breakup of spherical vesicles caused by spontaneous curvature change

We present our theoretical analysis and coarse- grained molecular dynamics （CGMD） simulation results to describe the mechanics of breakup of spherical vesi- cles driven by changes in spontaneous curvature. System- atic CGMD simulations reveal the phase diagrams for the breakup and show richness in breakup morphologies. A the- oretical model based on Griffith fracture mechanics is devel- oped and used to predict the breakup condition.

氧化钙对贵州六盘水高硅铝煤灰熔融性的影响及机理

针对贵州六盘水老鹰山矿区的高硅铝难熔煤灰,在SiO_2-Al_2O_3-CaO三元相图指导下,通过添加CaO对煤灰的熔融性进行调节。利用水冷法研究了CaO对煤灰熔融性的影响机理。采用Factsage软件进行了CaO对煤灰熔融性影响机理的热力学计算。结果表明:随着CaO的增加,煤灰的熔融温度和完全熔化温度均呈现先下降后上升的趋势,当CaO为33.56%(质量分数)时,煤灰的流动温度(FT)为1 236℃;煤灰的高温物相变化和热力学计算均表明,莫来石和石英等高熔点物相的存在是导致高硅铝煤灰难熔的原因,而添加CaO能够破坏煤灰中的难熔矿物并形成钙长石、钙铝黄长石和硅灰石等低熔点化合物,这些矿物容易形成低温共熔混合物而降低煤灰的熔融温度,但过多的CaO会促使煤灰形成多余的钙铝黄长石,使得煤灰越过低共熔区域,导致煤灰的熔融温度升高。

Molten salt phase diagram evaluation by pattern recognition:Part I Divalent rare earth halide and alkali metal halide binary systems

At present CALPHAD (CALculation of PHAse Diagram) technique is notcapable of predicting whether there exists intermediate compound,much less predicting the formulae, the number, and the meltingcongruence of intermedi- ate compounds. To solve this problem, a newapproach called the phase diagram evaluation by pattern recognition(PDEPR) was improved. The micro-parameters. Such as the radius andthe electronegativity of the different features in multi-dimensionalspace.

Phase diagram of binary system C_(12)Zn-C_(18)Zn

The solid-solid phase transitions in the perovskite type layer materials(n-C_(12)H_(25)NH_3)_2ZnCl_4 (C_(12)Zn) and (n-C_(18)H_(37)NH_3)_2ZnCl_4 (C_(18)Zn) that are onekind of potential thermal storage material, were synthesized and, at the same time, a series oftheir mixtures C_(12)Zn/C_(18)Zn were prepared. The experimental binary phase diagram ofC_(12)Zn/C_(18)Zn was established by means of differential scanning calorimetry (DSC) and X-raydiffraction. In the phase diagram a stable solid compound(n-C_(12)H_(25)NH_3)(n-C_(18)H_(37)NH_3)ZnCl_4(C_(12)C_(18)Zn) and two eutectoid invariants wereobserved. It is noticeable that the phase diagram contains solid solution ranges.dodecylammonium

中频放大器产生自激振荡的原理

中频放大器在工作频率小于中频的情况下,有可能产生自激振荡,破坏其正常工作。本文运用晶体管等效电路、LC网络的阻抗频率特性、相量图、反馈等基础理论,对晶体管的内部反馈进行了具体分析,阐明了产生自激振荡的原理。

蟾蜍毒素微乳的制备及体外透皮吸收考察

目的:制备蟾蜍毒素微乳并考察其理化性质及体外经皮给药特性。方法:通过溶解度试验和伪三元相图筛选蟾蜍毒素微乳处方,考察蟾蜍毒素微乳的外观形态、粒径分布、Zeta电位及稳定性,通过透皮扩散仪考察蟾蜍毒素微乳的体外透皮过程。采用RP-HPLC测定蟾蜍毒素含量,色谱条件为ZORBAX SB-C18色谱柱(4.6 mm×150 mm,5μm),流动相甲醇-水(70∶30),流速1.0 mL·min-1,柱温30℃,检测波长300 nm,进样量10μL。结果:优选的微乳处方为辛酸癸酸三甘油酯-聚氧乙烯氢化蓖麻油-二乙二醇单乙基醚-水(10.47%∶33.69%∶11.23%∶44.61%),载药量(1.36±0.12)%。制得的蟾蜍毒素微乳外观圆整,平均粒径(31.33±5.362)nm,多分散指数(0.103±0.025),Zeta电位-(30.85±3.25)mV。蟾蜍毒素微乳12 h的累积渗透量1 339.32μg·cm-2,皮肤滞留量1 895.36μg,分别是蟾蜍毒素水溶液的3.96,4.89倍。结论:蟾蜍毒素微乳稳定性较好,可显著促进蟾蜍毒素的透皮吸收。

复方痛痹舒自微乳释药系统基质组成的研究

目的筛选复方痛痹舒自微乳释药系统(SMEDDS)的基质组成并确定配方比例。方法采用溶解度方法测定复方痛痹舒中主要有效成分在不同油相、乳化剂和助乳化剂中的溶解度,结合不同油相与乳化剂的配伍结果,筛选油相、乳化剂与助乳化剂,采用水滴定法绘制伪三元相图,以澄清度、粒径和自乳化时间为考察指标,筛定油相、乳化剂和助乳化剂的类型及其组成范围。结果复方痛痹舒SMEDDS基质组成:油相为肉豆蔻酸异丙酯(IPM),乳化剂为RH40/聚山梨酯-80(1∶1),助乳化剂为甘油;各相系占SMEDDS基质组成的比例范围按质量分数计:油相9.96%~40.49%,乳化剂23.31%~59.97%,助乳化剂19.83%~60.02%。结论筛定的复方痛痹舒SMEDDS基质,其分散相粒径可以达到10~100 nm,为进一步研究奠定基础。

一维扩展离子Hubbard模型的相图研究

应用密度矩阵重整化群方法,研究了存在交错离子势△时一维半满扩展Hubbard模型的相图.通过计算关联函数、结构因子、位置算符等方法,描绘了从Mott绝缘体-键有序绝缘体-Band绝缘体的特性并给出了精确的相边界.研究发现:中间的键有序绝缘体相在相图中占据了很小的一部分区域,当存在离子势△的情况下,这个区域将会有所增大;而当相互作用足够强时,这个中间相消失.给出了离子Hubbard模型(最近邻电子-电子相互作用=0)的相图.

Thermodynamic assessment of the Al–Dy, Dy–Zr and Al–Dy–Zr systems

Like Al3Sc,the Al30Dy7Zr3compound has an L12structure,implying that it could probably be used to improve the strength of aluminum alloys at elevated temperatures.Thus,it is extremely important to understand the phase relations of the Al–Dy–Zr system in the Al-rich corner.Firstly,the phase diagram of the Al–Dy binary system was re-assessed with the C15_Laves phase treated as a stoichiometric compound.Then,using the special quasirandom structure containing 16 atoms(SQS_16)to simulate Dy1-xZrx(x=0.25,0.5,and 0.75)hcp_A3 solid solutions,their enthalpies of mixing at 0 K were calculated by the first-principles method.Based on these results and the evaluated phase diagram in literature,the Dy–Zr binary system was optimized thermodynamically.Integrating the thermodynamic descriptions of the three constituent binary systems,the phase diagram of the Al–Dy–Zr ternary system in the Al-rich corner was optimized finally by coupling the first-principles calculation with the CALculation of PHAse Diagram method.A good agreementhas been reached between the calculated phase relations and the experimental results,which indicates that the current thermodynamic description is reasonable.