Basic equations for suspension flows with interphase mass-transfer

In the case of suspension flows, the rate of interphase momentum transfer M(k) and that of interphase energy transfer E(k), which were expressed as a sum of infinite discontinuities by Ishii, have been reduced to the sum of several terms which have concise physical significance. M(k) is composed of the following terms: (i) the momentum carried by the interphase mass transfer; (ii) the interphase drag force due to the relative motion between phases; (iii) the interphase force produced by the concentration gradient of the dispersed phase in a pressure field. And E(k) is composed of the following four terms, that is, the energy carried by the interphase mass transfer, the work produced by the interphase forces of the second and third parts above, and the heat transfer between phases. It is concluded from the results that (i) the term, (-alpha-k-nabla-p), which is related to the pressure gradient in the momentum equation, can be derived from the basic conservation laws without introducing the "shared-pressure presumption"; (ii) the mean velocity of the action point of the interphase drag is the mean velocity of the interface displacement, upsilonBAR-i. It is approximately equal to the mean velocity of the dispersed phase, upsilonBAR-d. Hence the work terms produced by the drag forces are f(dc) . upsilonBAR-d, and f(cd) . upsilonBAR-d, respectively, with upsilonBAR-i not being replaced by the mean velocity of the continuous phase, upsilonBAR-c; (iii) by analogy, the terms of the momentum transfer due to phase change are upsilonBAR-d-GAMMA-c, and upsilonBAR-d-GAMMA-d, respectively; (iv) since the transformation between explicit heat and latent heat occurs in the process of phase change, the algebraic sum of the heat transfer between phases is not equal to zero. Q(ic) and Q(id) are composed of the explicit heat and latent heat, so that the sum Q(ic) + Q(id)) is equal to zero.

在辉光放电中八氟环丁烷聚合的研究

I 理论部分：对未知结构聚合物的ESCA谱进行表征，一是利用已知结构小分子化合物的ESCA谱中结合能值进行标定，二是运用电荷电位模型经量子化学计算对谱峰进行归属。由于所处化学环境不同，用小分子化合物的ESCA谱峰位对象合物标定不够准确，量子化学计算又太复杂。本工作提出了电负性经验公式，可计算ESCA谱中C_(1S)结合能位移值，与实测值作对照即可判断聚合物结构，方法简便，准确可靠。电负性经验公式表达如下：聚合物分子链上某碳原子1S电子结合能位移ΔEc可看作该碳原子与相邻基团间电负性差值和的函数，即ΔEc = K_c ∑ from i=1 to 4 1/(n_i) (X_i - 2.5) + b。聚合物分子链上各碳原子的实际电负性为X_c = (∑ form j=1 to 4 1/(n_j) X_j/∑ form j=1 to 4 1/(n_j) + 2.5)/2运用电负性经验公式计算了九个模型化合物中C_(1S)的ΔEc，推导出F作为α、β、γ位碳上的取代基的对α位碳上1s电子结合能位移影响产生的效应值，即，对于ΔEc = aα + bβ + cγ，有α = 3.018 (±0.007)，β = 0.2513 (±0.0007) γ = 0.0176 (±0.003)。此结果与ESCA谱实测值相符。本工作设计了十六种化合物模型，模型中具有含氟等离子体聚合物中可能存在的大部分基团，通过电负性经验公式计算求得化学环境不同的C_(1S)结合能位移值，把ESCA谱的实测值和计算值进行对照，可对象合物的求知结构作出大致判断。II 在辉光放电中八氟环丁烷的聚合与刻蚀反应：在碳氧化合物的辉光放电中同时存在聚合与刻蚀两种相反的过程，聚合与刻蚀竞争的结果对聚合速率，产物结构都有很大影响。本工作通过测定聚合速率、IR谱、ESCA谱研究了反应条件对八氟环丁烷等离子体聚合与刻蚀的影响，得到了一致的和半定量的结果。实验证实，随着功率的增大或压力的减小，刻蚀有增强的趋势，不同的等离子气体对聚合与刻蚀的竞争过程有不同的影响，刻蚀强弱的顺序为Ar>N_2>H_2>He，增加等离子气体对单体的比率，引起刻蚀增加。聚合速率不随功率的改变而变化的状态是由聚合与刻蚀间的平衡引起的。随着功率增大或压力减少，聚合产物支化程度增加，线性程度减小，F/C比相应减小。同样随等离子气体种类不同，聚合物支化程度大小的顺序是Ar>N_2>H_2>He，F/C比相应变化。总之，聚合产物支化程度的变化和聚合与刻蚀的竞争结果相一致。对等离子体聚合与刻蚀竞争过程的定量描述未见文献报导。III 八氟环丁烷等离子体聚合物的结构和表征：用IR和ESR谱测得OFCB等离子体聚合物中存在五种元素：C、F、O、N、Si，并对可能存在于结构中的基因作了分析。通过NaHSO_3的亲核双键加成反应，用IR和ESR谱证实了等离子体聚合物中存在的双键及其类型。类似工作未见文献报导。用CuSO_4·5H_2作标样，测出PPOFCB中的自由基浓度为10~(19)自旋数/克。在80、100、120、140 ℃考察PPOFCB中俘获自由基的衰减过程，证实此过程涉及两类不同的反应，一是自由基的复合反应，二是自由基的氧气的终止反应。对上述两类反应进行动力学处理，求出了自由基复合反应在不同温度时的速度常数，并得到反应治化能为374焦耳/摩尔或8.869千卡/摩尔。氧和自由基的终止反应中，氧气的扩散过程是决定反应速度的步骤，反应速度常数就是扩散速度常数，K = 5.3 * 10~(-23)自旋数~(-1)、克分~(-1)。根据VPO测出的PPOFCB的分子量和自由基浓度，算出每4.5个分子中有一个自由基。类似工作未见文献报导。PPOFCB的分子量随反应条件不同而变化，用VPO测出，在80W和40W功率，在Ar存在下制备的OFCB等离子体聚合物的分子量分别为2736和2003。用~(19)F-NMR谱对PPOFCB中的基团进行定量计算，得出在一个90W，He气中制备的聚合物分子中，CF_3-CF_2为6.1，CF_2为13.5，CF_3-CF为7.9，CF为17.5，CF_3-C为6.1，C为13.5。在用上述方法进行结构表征的基础上，提出了OFCB等离子体聚合物的结构模型。IV 八氟环丁烷等离子体聚合的反应历程：以Ar、N_2、H_2、He为等离子气体，分别对OFCB等离子体聚合的气体冷凝物进行GC-Mg、~(19)F-NMR和ESR测试，观察到在气相中，OFCB经历了等离子态反应。单体被打断的程度，和高能电子浓度有关。体系中电子浓度依赖于气体的第一电离势和气相内的化学反应类型。初级粒子二氟卡宾：CF_2和中间体六氟丙烯是气相中的主要产物。~(19)F-NMR证实气相中存在支化产物，表明聚合物在气相中发生了重排。ESR谱测得，在气相产物中存在高浓度的由二种以上组分混合而成的自由基，自由基间的复合反应是生成聚合物的主要增长过程，气相产物的分子量随放电功率的升高而增大。根据聚合物中存在的高含量CF_3基团，分析了CF_3基团对聚合过程的影响。CF_3基团产生了屏蔽效应，它既保护了聚合物不致被降解，也限制了生成高分子量产物。实验证实，CF_3基团的生长来自F的重排，同时未自支化气相产物的非均相增长。OFCB等离子体聚合物中俘获自由基主要是由高能电子轰击聚合物表面产生的，同时来自被固相吸附的带有自由基的气相产物。在碳氟化合物的等离子体聚合中，吸附是和聚合同样重要的过程，气相产物被吸附后，可继续再引发、增长、刻蚀等反应过程、直到成为固相内层分子为止。ESR谱证实，高能粒子的轰击在辉光放电中起主导作用，紫外辐射对含氟聚合物引发和脱氟作用微弱。在气相和表面反应历程讨论的基础上，提出了OFCB等离子体聚合的反应历程模型，解释了碳氢和碳氟两个等离子体象合体系遵循不同反应历程的原因。本部分工作的实验和反应历程解释基本未见文献报导。

液相色谱在无机分析中的应用

论文工作依据色谱理论及与其相关的化学原理，对色谱这一现代实验技术在无机化学分析中的应用，进行了多方面的探讨。从高效离子交换色谱，到高效液—液分配色谱；从微库仑检测器到可见光度检测器；从高压到负压都做了不同程度的尝试。a，首次把草酸、硝酸钠体系的淋洗剂应用于高效离子交换色谱。并获得了对数种金属离子的较满意的分离结果。b，为解决反相液—液分配色谱分离出有色络合物的检测，我们自行对721型可见光度计进行了改装，对其性能检查结果表明，可见光度检测器对有色络合物的检测是较有前途的。c，自行合成的粉末状含巯基的离子吸附剂，可以通过酸度的梯度淋洗，实现多种元素的分离。由于时间关系，仅用它对金（III）在负压柱上进行了富集分离，并与石墨炉原子吸收法联测，建立了快速，准确的测金方法。

北大别黄土岭麻粒岩变质演化：对大别造山带演化进程的指示意义

Granulites from Huangtuling in the North Dabie metamorphic core complex in eastern China preserve rare mineralogical and mineral chemical evidence for multistage metamorphism related to Paleoproterozoic metamorphic processes, Triassic continental subduction-collision and Cretaceous collapse of the Dabieshan Orogen. Six stages of metamorphism are established, based on detailed mineralogical and petrological studies: (I) amphibolite facies (6.3–7.0 kbar, 520–550 °C); (II) high-pressure/high-temperature granulite facies (12–15.5 kbar, 920–980 °C); (III) cooling and decompression (4.8–6.0 kbar, 630-700 °C); (IV) medium-pressure granulite facies (7.7–9.0 kbar, 690–790 °C); (V) low-pressure/high-temperature granulite facies (4.0–4.7 kbar, 860–920 °C); (VI) retrograde greenschist facies overprint (1–2 kbar, 340–370 °C). The P–T history derived in this study and existing geochronological data indicate that the Huangtuling granulite records two cycles of orogenic crustal thickening events. The earlier three stages of metamorphism define a clockwise P–T path, implying crustal thickening and thinning events, possibly related to the assembly and breakup of the Columbia Supercontinent ca. 2000 Ma. Stage IV metamorphism indicates another crustal thickening event, which is attributed to the Triassic subduction/collision between the Yangtze and Sino–Korean Cratons. The dry lower crustal granulite persisted metastable during the Triassic subduction/collision due to lack of hydrous fluid and deformation. Stage V metamorphism records the Cretaceous collapse of the Dabieshan Orogen，possibly due to asthenosphere upwelling or removal of the lithospheric mantle resulting in heating of the granulite and partial melting of the North Dabie metamorphic core complex. Comparison of the Huangtuling granulite in North Dabie and the high-pressure (HP)–ultrahigh-pressure (UHP) metamorphic rocks in South Dabie indicates that the subducted upper (South Dabie) and lower (North Dabie) continental crusts underwent contrasting tectonometamorphic evolution during continental subduction–collision and orogenic collapse. High-pressure granulites are generally characterized by the absence of orthopyroxene. However, the Huangtuling felsic granulite rarely preserves the high-pressure granulite facies assemblage of garnet + orthopyroxene + biotite + plagioclase + K-feldspar + quartz. To investigate the effects of bulk rock composition on the stability of orthopyroxene-bearing, high-pressure granulite facies assemblages in the NCKFMASHTO (Na2O–CaO–K2O–FeO–MgO–Al2O3–SiO2–H2O–TiO2–Fe2O3) system, we constructed a series of P–T–X pseudosections based on the melt-reintegrated composition of the Huangtuling felsic high-pressure granulite. Our calculations demonstrate that the orthopyroxene-bearing, high-pressure granulite facies assemblages are restricted to low XAl [Al2O3/(Na2O + CaO + K2O + FeO + MgO + Al2O3) < 0.35, mole proportion] or high XMg [MgO/(MgO + FeO) > 0.85] felsic–metapelitic rock types. Our study also reveals that the XAl values in the residual felsic–metapelitic, high-pressure granulites could be significantly reduced by a high proportion of melt loss. We suggest that orthopyroxene-bearing high-pressure granulites occur in residual overthickened crustal basement under continental subduction–collision zones and arc–continent collision belts.

The separation of Cerium(IV) from nitric acid solutions containing Thorium(IV) and Lanthanides(III) using pure [C(8)mim]PF6 as extracting phase

The extraction behavior of Ce(IV) along with Th(IV) and Ln(III) (Ln = Ce, Gd, Yb) nitrate by pure ionic liquid, [C(8)mim]PF6, was investigated. [C(8)mim]PF6 alone showed good extraction ability for Ce(IV), while it was slight for Th(IV) and negligible for Ln(III). The extraction behavior of Ce(IV) by [C(8)mim]PF6 was particularly studied, and the most probable extraction mechanism proposed was the anion exchange mechanism. Moreover, the stripping of Ce(IV) from IL phase was also investigated. The Ce(IV) in IL phase can be quantitatively recovered by water.

Bulk modulus of ternary chalcopyrite A(I)B(III)C(2)(VI) and A(II)B(IV)C(2)(V) semiconductors

Based on the complex crystal chemical bond theory, the formula of Liu and Cohen's, which is only suitable for one type of bond, has been extended to calculate the bulk modulus of ternary chalcopyrite A(I)B(III)C(2)(VI) and A(II)B(IV)C(2)(V) which contains two types of bonds. The calculated results are in fair agreement with the previous theoretical values reported and experimental values. (C) 1998 Elsevier Science Ltd. All rights reserved.

A novel short neurotoxin, cobrotoxin c, from monocellate cobra (Naja kaouthia) venom: isolation and purification, primary and secondary structure determination, and tertiary structure modeling

A novel short neurotoxin, cobrotoxin c (CBT C) was isolated from the venom of monocellate cobra (Naja kaouthia) using a combination of ion-exchange chromatography and FPLC. Its primary structure was determined by Edman degradation. CBT C is composed of 61 amino acid residues. It differs from cobrotoxin b (CBT B) by only two amino acid substitutions, Thr/Ala11 and Arg/Thr56, which are not located on the functionally important regions by sequence similarity. However, the LD50 is 0.08 mg/g to mice, i.e. approximately five-fold higher than for CBT B. Strikingly, a structure-function relationship analysis suggests the existence of a functionally important domain on the outside of Loop III of CBT C. The functionally important basic residues on the outside of Loop III might have a pairwise interaction with alpha subunit, instead of gamma or delta subunits of the nicotinic acetylcholine receptor (nAChR). (C) 2002 Elsevier Science Inc. All rights reserved.

Molecular cloning and expression pattern of 14 kDa apolipoprotein in orange-spotted grouper, Epinephelus coioides

A novel fish-specific apolipoprotein (apo-14 kDa) has been recently cloned from eel and pufferfish. However, its expression pattern has not been elucidated. in this study, EcApo-14 has been screened from hypothalamic cDNA library of male orange-spotted grouper, which shows 62.9%, 51%, 46.9%, 43.2%, and 31.9% identities to Apo-14 of European flounder, pufferfish, Japanese eel, gibel carp, and grass carp, respectively. RT-PCR analysis reveals that this gene is first transcribed in neurula embryos and maintains a relatively stable expression level during the following embryogenesis. EcApo-14 transcripts are at a very high level during embryonic and early larval development in the yolk syncytial layer (YSL), and decrease in YSL and form intense staining in liver at 3 days after hatching. In adult tissues, EcApo-14 is predominantly expressed in liver and brain. The data suggested that EcApo-14 might play an important role in liver and brain morphogenesis and growth. (c) 2005 Elsevier Inc. All rights reserved.

Study on fluorescence emission and synchronous-scan fluorescence spectrea of Nitzschia hantzschiana solution with FE(III)

The characterization of the algal Nitzschia hantzschiana solution with (or without) Fe(III) was carried out using fluorescence emission and synchronous-scan spectroscopy. An emission peak (excited at 440 nm) was observed at 675 nm for Nitzschia hantzschiana solution. The effective characterization method used was synchronous-scan fluorescence spectroscopy (SFS). A wavelength difference (Delta lambda) of 90 nm was maintained between excitation and emission wavelengths. The peak was observed at about 236(ex) nm (326(em) nm) for synchronous fluorescence spectroscopy. Fe(III) was an effective quencher. The relationship between I-0/I (quenching efficiency) and c (concentration of Fe (III) added) was a linear correlation for the algal solution with Fe(III). Effects of pH on synchronous-scan fluorescence intensity were evident.

The influence of growth temperature and input V/III ratio on the initial nucleation and material properties of InN on GaN by MOCVD

The effects of growth temperature and V/III ratio on the InN initial nucleation of islands on the GaN (0 0 0 1) surface were investigated. It is found that InN nuclei density increases with decreasing growth temperature between 375 and 525 degrees C. At lower growth temperatures, InN thin films take the form of small and closely packed islands with diameters of less than 100 nm, whereas at elevated temperatures the InN islands can grow larger and well separated, approaching an equilibrium hexagonal shape due to enhanced surface diffusion of adatoms. At a given growth temperature of 500 degrees C, a controllable density and size of separated InN islands can be achieved by adjusting the V/III ratio. The larger islands lead to fewer defects when they are coalesced. Comparatively, the electrical properties of the films grown under higher V/III ratio are improved.

Measurement of polar C-plane and nonpolar A-plane InN/ZnO heterojunctions band offsets by x-ray photoelectron spectroscopy

The valence band offsets of the wurtzite polar C-plane and nonpolar A-plane InN/ZnO heterojunctions are directly determined by x-ray photoelectron spectroscopy to be 1.76 +/- 0.2 eV and 2.20 +/- 0.2 eV. The heterojunctions form in the type-I straddling configuration with a conduction band offsets of 0.84 +/- 0.2 eV and 0.40 +/- 0.2 eV. The difference of valence band offsets of them mainly attributes to the spontaneous polarization effect. Our results show important face dependence for InN/ZnO heterojunctions, and the valence band offset of A-plane heterojunction is more close to the "intrinsic" valence band offset.

Temperature dependent spectral response characteristic of III-V compound tandem cell

The GaInP/GaAs/Ge triple-junction tandem cells with a conversion efficiency of 27.1% were fabricated using metalorganic chemical vapor deposition (MOCVD) technique. Temperature dependence of the spectral response measurements of the GaInP/GaAs/Ge tandem cell was performed by a quantum efficiency system at temperatures ranging from 25A degrees C to 160A degrees C. The red-shift phenomena of the absorption limit for all subcells were observed with increasing temperature, which is dued to the energy gap narrowing with temperature. The short-circuit current densities (J (sc)) of GaInP, GaAs and Ge subcells at room temperature calculated based on the spectral response data were 12.9, 13.7 and 17 mA/cm(2), respectively. The temperature coefficient of J (sc) for the tandem cell was determined to be 8.9 mu A/(cm(2) center dot A degrees C), and the corresponding temperature coefficient of the open-circuit voltage deduced from the series-connected model was -6.27 mV/A degrees C.

Effects of V/III ratio on InGaAs and InP grown at low temperature by LP-MOCVD

Effects of V/III ratio on heavily Si doped InGaAs and InP were studied using low pressure metalorganic chemical vapor deposition (LP-MOCVD) at a growth temperature of 550degreesC. In InGaAs, as the V/III ratio decreases from 256 to 64, the carrier concentration increases from 3.0 x 10(18) to 5.8 x 10(18) cm(-3), and the lattice mismatch of InGaAs to InP was observed to vary from -5.70 x10(-4) to 1.49 x 10(-3). In InP, when the V/III ratio decreases from 230 to 92, the same trend as that in Si doped InGaAs was observed that the carrier concentration increases from 9.2 x 10(18) to 1.3 x 10(19) cm(-3). The change of AsH3 was found to have stronger effect on Si incorporation in InGaAs at lower growth temperature than at higher growth temperature. (C) 2003 Elsevier B.V. All rights reserved.

The influence of V/III ratio in the initial growth stage on the properties of GaN epilayer deposited on low temperature AlN buffer layer

The V/III ratio in the initial growth stage of metalorganic chemical vapor deposition has an important influence on the quality of a GaN epilayer grown on a low-temperature AIN buffer layer and c-plane sapphire substrate. A weaker yellow luminescence, a narrower half-width of the X-ray diffraction peak, and a higher electron mobility result when a lower V/III ratio is taken. The intensity of in situ optical reflectivity measurements indicates that the film surface is rougher at the beginning of GaN growth, and a longer time is needed for the islands to coalesce and for a quasi-two dimensional mode growth to start. A comparison of front- and back-illuminated photoluminescence spectra confirms that many threading dislocations are bent during the initial stage, leading to a better structural quality of the GaN layer. (C) 2007 Elsevier B.V. All rights reserved.

High-resolution X-ray diffraction analysis of the Bragg peak integrated intensity in highly mismatched III-N epilayers

A new method of measuring the thickness of GaN epilayers on sapphire (0 0 0 1) substrates by using double crystal X-ray diffraction was proposed. The ratio of the integrated intensity between the GaN epilayer and the sapphire substrate showed a linear relationship with the GaN epilayer thickness up to 2.12 mum. It is practical and convenient to measure the GaN epilayer thickness using this ratio, and can mostly eliminate the effect of the reabsorption, the extinction and other scattering factors of the GaN epilayers. (C) 2003 Elsevier Science B.V. All rights reserved.