高氟铝和铝引起低龄鸡骨发育不全

进行了高氟铝和铝对低龄鸡骨损害的实验。５７日龄鸡９６只随机分为８组,毒物加进饲料,实验期３个月。结果表明,各高氟、高氟铝组骨氟均数倍于对照组,低铝组骨氟显著升高;单饲ＮａＦ组骨铝增高近３倍,高氟铝组骨氟比ＮａＦ组和病区玉米组低１／３以上,骨铝低约５０％;单饲铝达对照４～２１倍的骨铝与对照组接近。饲氟与骨氟ｒ＝０．７７,与骨铝ｒ＝０．６５;饲铝与骨铝ｒ＝－０．４６,与骨氟ｒ＝－０．５３;骨氟与骨铝ｒ     

铝氟联合中毒大鼠骨、脑、血、尿中多元素含量动态检测

同批断乳两周的Wistar雄性大鼠59只,随机分为3个组,用同一病家的高岭土拌煤烘干与柴烘玉米加入配合饲料喂养.饲料含氟、铝3.9×10-6,12.4×10-6;107×10-6,40.4×10-6;212,66.8×10-6.实验11、20周分两批股动脉放血处死.检测了大鼠骨、脑、血、尿中多种元素.结果表明,血清钙一直较高,磷降低.实验11周,Ⅱ、Ⅲ组骨氟分别增高6、10倍,尿氟增高4、6倍;骨、脑、全血铝均随摄氟、铝量的增多而递减,尿铝递增.尿中其它元素多一直减少.骨中金属元素随骨铝的递减而递减.Ⅱ组全血锌显著下降.实验20周,Ⅱ、Ⅲ组骨氟是Ⅰ组的3.5和8.2倍,为实验11周时的58.1%和80.7%;尿氟是1.4和3倍.骨、脑铝随氟、铝摄入量的递增而递增,骨中金属元素含量也随之递增,骨磷降低.全血磷递增,锌均升高.本实验多元素含量由低向高变化的逆反过程与骨软化向硬化的病理转换相吻合;铝和氟彼此可影响对方的体内过程和在骨骼中的蓄积并引起多元素含量和相关性的显著变化.提示消化道内源性无机盐排泄过多;低龄动物的骨、脑对铝有排斥反应,但有铝危害表现.     

SIMOX上分子束外延生长Si／Ge0.5Si0.5应变层超晶格的TEM研究

以分子束外延技术在ＳＩＭＯＸ衬底上生长Ｓｉ／Ｇｅ_（０．５）Ｓｉ_（０．５）应变层超晶格。用剖面电子显微学（ＸＴＥＭ）对超晶格膜的结构进行分析。实验结果表明，Ｓｉ／Ｇｅ_（０．５）Ｓｉ_（０．５）应变层超晶格能成功地生长在ＳＩＭＯＸ衬底上。由于Ｓｉ／Ｇｅ_（０．５）Ｓｉ_（０．５）膜与ＳＩＭＯＸ衬底之间的晶格失配，引起晶格畸变，Ｓｉ／Ｇｅ_（０．５）Ｓｉ_（０．５）超晶格内存在的位错与ＳＩＭＯＸ衬底内的位错密度有关。     

硼酸系电结晶制[Co/Pt]_n(n≥40)金属多层膜的研究

于钝铜片及玻碳上采用双电解池恒电位结晶制取了［Ｃｏ（０．５ｎｍ～２．２ｎｍ）／Ｐｔ（２．０ｎｍ）］ｎ（ｎ≥４０）金属多层膜．低角度Ｘ射线衍射表明多层膜有良好的周期性调制结构,其Ｂｒａｇｇ峰的半幅值随着钴层电结晶电位的负移和铂层电结晶电位正移而减小．中角度Ｘ射线衍射表明界面上存在ＣｏＰｔ３金属化合物．多层膜的磁滞回线表明该多层膜的易磁化轴平行于膜面,表现出平面磁各向异性．以低过电位镀Ｃｏ（厚度约０．５ｎｍ）的多层膜的垂直方向磁滞回线形状较好,有望表现出垂直磁各向异性．     

人体内的氟

成年人体内氟约为２－９ｇ，比锌略多，仅次于硅和铁。人体内的氟含量由于受铝、钙、镁等元素的影响而有所波动。但是，从满足人体对氟的需要到由于过多而导致中毒的量之间相差不多。因此，氟对人体的安全范围比其他元素要窄得多。正因为这样，就更要注意自然界、饮水及食物中氟含量对人体健康的影响，尤其是工业排放的氟对环境的污染给人带来的危害。氟的生理需要量为０－５～１ｍｇ／ｄ。氟在人体中的分布主要集中在骨骼、牙齿、指甲和毛发中，尤以牙釉质中含量最多，骨骼中以长骨的含氟量最多。依次为股骨＞肱骨＞掌骨＞颅骨＞腰椎。男人…     

盐酸氟桂嗪离子选择性电极的制备及应用

研制了盐酸氟桂嗪离子选择性电极。利用正交设计法综合研究了活性的类型、含量以及增塑剂等因素对ＰＶＣ膜电极响应性能的影响，结果表明，以盐酸氟桂嗪－四苯硼钠离子缔合物为活性物质，ＤＢＰ或ＤＯＰ为增塑剂制成的ＰＶＣ膜电极的性能最佳。其响应范围为１．０×１０＾－４－５．０×１０＾－３ｍｏｌ／Ｌ，检测下限为３．５×１０＾５ｍｏｌ／Ｌ，响应斜率为５８ｍＶ（２５℃）。应用该电极对合成样品及胶囊样品中盐酸氟桂嗪含量     

碳纤维汞膜微电极1.5次微分伏安法测定米托蒽醌的研究

米托蒽醌（ＭＸＴ）能吸附在碳纤维汞膜微电极表面，阴极溶出时，产生一个灵敏的１．５次微分溶出峰，其峰电流和米托葱酿的浓度在１．０×１０－５ｍｏｌ／Ｌ～１．３×１０－９ｍｏｌ／Ｌ范围内具有良好的线性关系，经３ｍｉｎ的富集，检出限可达１．０×１０－１０ｍｏｌ／Ｌ，据此建立了测定ＭＸＴ的灵敏的新方法，本文讨论了实验条件，并对血样中的ＭＸＴ进行了测定。     

气相色谱/质谱法测定大鼠脑中5-羟色胺的含量

采用气相色谱／质谱法（ＧＣ／ＭＳ）测定了正常大鼠和服药大鼠脑组织中５－羟色胺（５－ＨＴ）的浓度。大鼠脑组织制成匀浆后,先将５－ＨＴ酰化,酰化物经乙酸乙酯提取后,再经七氟丁酸酐衍生化,用ＧＣ／ＭＳ测定。ＭＳ采用电子捕获负离子化学电离（ＥＣＮＩＣＩ）模式。方法的线性范围为０．５０～５０．０μｇ／Ｌ,回归方程为Ｙ＝０．１３４８Ｘ－０．０７９９５（ｒ＝０．９９９６）;平均回收率为９８．２％±３．８％（ｎ＝１０）;检测限为０．５μｇ／Ｌ;相对标准偏差小于１０％。     

X射线荧光光谱分析法测定多金属矿中的铅锌铜

采用粉末压制的样片进行Ｘ射线荧光光谱分析，测定多金属矿选矿流程中的Ｐｂ、Ｚｎ、Ｃｕ。选择康普顿散射线作Ｐｂ的内标，分析线附近的散射线作Ｚｎ、Ｃｕ的内标，用经验系数法校正基体效应。其分析范围是Ｐｂ：０．１９～７９．２９％，Ｚｎ：０．４５～５０．１１％，Ｃｕ：０．０２１～３１．１０％，分析结果与化学法相符。     

十八胺/杂多阴离子杂化LB膜的制备与表征

采用界面吸附法制备了５种十八／杂多阴离子杂化ＬＢ膜ＯＤＡ／ＨＰＡ（ＨＰＡ＝ＰＷ１２,ＰＭo12,MPo12,PW6Mo6,PW9Mo3,P2Mo18).对５种本合物在空气／水界面上单分子膜的行为进行了研究,它们有较高的崩溃压４６．０－４８．０mN,m^-1,均能开稳定的单分子膜,用红外光谱,紫外光谱,小角Ｘ射线衍射（ＬＸＲＤ）和荧光光谱对ＬＢ膜的沉积特性与结构进行了鉴定,结果表明,制备的ＬＢ膜具有中心对称性,其层状结构由杂多阴离子的单层与表面活性剂双层交替组成。     

Grafting of hydroxymethylacrylamide and acrylic acid copolymer onto polyvinylidene fluoride membrane by supercritical carbon dioxide and its application in dye separation

We report a thermally induced graft copolymerization of acrylic acid and N‐hydroxymethylacrylamide onto polyvinylidene fluoride microporous membrane by using supercritical carbon dioxide as a solvent and carrier agent. The effects of monomer mole ratio, pressure, reaction temperature, time, and initiator concentration on the degree of grafting were investigated. The morphology of the grafted membrane was studied via scanning electron microscopy. Attenuated total reflectance infrared spectroscopy spectroscopy and X‐ray diffraction proved the existence of grafting monomers. The results of contact angle measurement and water filtration at different pH levels indicated pronounced pH‐sensitive behavior and increased hydrophilicity of the polyvinylidene fluoride grafted membrane. In particular, the grafted membrane was applied to the removal of methylene blue with a relative rejection of 98.1% compared with 30.5% of rejection observed from the pristine polyvinylidene fluoride membrane. Copyright © 2014 John Wiley & Sons, Ltd.     

Porous poly(vinylidene fluoride) membrane modified with hyperbranched poly(amine‐ester)

Poly(vinylidene fluoride) (PVDF) membranes were hydrophilic modified with hydroxyl group terminated hyperbranched poly(amine‐ester) (HPAE). Fourier transform infrared spectroscopy (FT‐IR) was used to study the chemical change of PVDF membranes. X‐ray photoelectron spectroscopy (XPS) indicated that some HPAE molecules were retained in PVDF membrane through polymer chain coiling. The presence of HPAE would improve the hydrophilicity of PVDF membrane. Scanning electron microscopy (SEM) was employed to characterize the morphology of different membranes. The thermodynamic stability for PVDF/DMAc/HPAE/Water system was characterized by the determination of the gelation values. Precipitation kinetics for PVDF/DMAc/HPAE/Water system was studied by precipitation time measurement. The water contact angle indicated that the hydrophilicity and the biocompatibility corresponding to protein adsorption of PVDF membrane were improved significantly after blending with hydrophilic HPAE molecules. Copyright © 2011 John Wiley & Sons, Ltd.     

Structure and pH‐sensitive properties of poly (vinylidene fluoride) membrane changed by blending poly (acrylic acid) microgels

pH‐sensitive poly (vinylidene fluoride) (PVDF)/poly (acrylic acid) (PAA) microgels membranes are prepared by phase inversion of the N, N‐dimethylformamide solution containing PAA microgels and PVDF in aqueous solution. The composition and structure of the blend membrane are investigated by Fourier transform infrared spectra, X‐ray photoelectron spectroscopy measurements, thermo gravimetric analysis, field‐emission scanning electron microscope and atomic force microscope. The results indicate the surface and cross section of the blend membranes have a porous structure with PAA microgels immobilized inside the pore and on the membrane surface. The blend PVDF membranes exhibit pH‐sensitive water flux, with the most drastic change in permeability observed between pH 3.7 and 6.3. The blend membranes are fouled by bovine serum albumin, and their antifouling property is enhanced by increasing PAA microgels, mainly derived from the improved hydrophilic property. Copyright © 2013 John Wiley & Sons, Ltd.     

Perfluoroalcohols: The Preparation and Crystal Structures of Heptafluorocyclobutanol and Hexafluorocyclobutane‐1,1‐diol

The first X‐ray crystal structure of an α‐fluoroalcohol is reported. Heptafluorocyclobutanol was obtained in quantitative yield from hexafluorocyclobutanone by HF addition in anhydrous hydrogen fluoride. The compound was characterized by its X‐ray single crystal structure. Heptafluorocyclobutanol readily undergoes hydrolysis to hexafluorocyclobutane‐1,1‐diol, which was also structurally characterized by X‐ray diffraction.     

Antifouling poly(vinylidene fluoride) ultrafiltration membranes containing amphiphilic comb polymer additive

An amphiphilic comb polymer consisting of poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) [P(VDF‐co‐CTFE)] main chains and poly(oxyethylene methacrylate) (POEM) side chains was synthesized using direct initiation of the chlorine atoms in CTFE units through atom transfer radical polymerization, as confirmed by ¹H NMR and FTIR spectroscopy. The P(VDF‐co‐CTFE)‐g‐POEM comb polymer was introduced as an additive to prepare poly(vinylidene fluoride) antifouling ultrafiltration membranes. As the contents of comb polymer increased, the mechanical properties of membranes slightly decreased due to the decreased crystallinity of the membranes, as revealed by universal testing machine and X‐ray diffraction. However, water contact angle measurement and X‐ray photoelectron spectroscopy showed that the hydrophilic POEM segments spontaneously segregated on the membrane surfaces. As a result, the antifouling property of the membranes containing P(VDF‐co‐CTFE)‐g‐POEM comb polymer was considerably improved with a slight change of water flux. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 183–189, 2010     

离子选择性电极多次标准加入法测量氟离子电极电势

建立了选择性电极中离子传递的模型。活化后的离子选择性电极 ,在电极表面形成活化层 ,阳离子和等量的阴离子分布在电极活化层的两侧 ,离子由溶液与活化层的界面经活化层传递到固定组成膜与活化层界面。在一定的条件下 ,电极膜电势随时间的变化与溶液和活化层的界面离子浓度随时间的变化成正比。在控制电势随时间的变化率基本恒定的情况下 ,方法被用于手工测量氟离子选择性电极电势 ,电极斜率。溶液离子浓度直接由 Gran方程求解。     

Development of a simultaneous measurement system of x‐ray diffraction and raman spectra: Application to structural study of crystalline‐phase transitions of chain molecules

The development of a bench‐top‐type system for simultaneous measurement of X‐ray diffraction and Raman spectra has been made to investigate structural changes in the phase transitions of chain molecules such as polyethylene, n‐alkane, and so forth from various viewpoints. For the X‐ray diffraction measurement an imaging plate or a charge‐coupled device camera was used as a two‐dimensional detector. For the Raman spectral measurement a miniature Raman spectrometer was used with optical fibers for the irradiation of incident laser beams and collection of scattered signals. For example, in the heating process of the n‐C₃₀H₆₂ sample, the phase transition from orthorhombic‐to‐hexagonal lattices could be detected clearly by the X‐ray and Raman measurements. By comparing these two different types of data in detail, an intimate relationship between conformational disordering and rotational motion of molecular chains is detected more clearly than before. Also, similar discussion can be made for the orthorhombic‐to‐hexagonal phase transition of the geometrically constrained polyethylene sample occurring immediately below the melting point. Another example concerns the structural change in the photoinduced solid‐state polymerization of cis,cis‐diethylmuconate single crystal. From the shifts in the X‐ray reflection position and Raman frequency characteristic of the produced polymer, it was found that the molecular deformation of the polymer chains and lattice strain was induced in the early stage of the polymerization reaction. For the ferroelectric‐phase transition of vinylidene fluoride copolymer, the simultaneous measurement was made for collecting triple information of small‐angle and wide‐angle X‐ray scatterings and Raman spectra to know the relationship between the structural change in the crystal lattice and the morphological change in the lamellar stacking mode. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 495–506, 2002; DOI 10.1002/polb.10112     

Heavy‐Atom Labeled Transmembrane β‐Peptides: Synthesis,CD‐Spectroscopy,and X‐ray Diffraction Studies in Model Lipid Multilayer

Transmembrane β‐peptides are promising candidates for the design of well‐controlled membrane anchors in lipid membranes. Here, we present the synthesis of transmembrane β‐peptides with and without tryptophan anchors, as well as a novel iodine‐labeled d ‐β³‐amino acid. By using one or more of the heavy‐atom labeled amino acids as markers, the orientation of the helical peptide was inferred based on the electron‐density profile determined by X‐ray reflectivity. The β‐peptides were synthesized through manual Fmoc‐based solid‐phase peptide synthesis (SPPS) and reconstituted in unilamellar vesicles forming a right‐handed 3₁₄‐helix secondary structure, as shown by circular dichroism spectroscopy. We then integrated the β‐peptide into solid‐supported membrane stacks and carried out X‐ray reflectivity and grazing incidence small‐angle X‐ray scattering to determine the β‐peptide orientation and its effect on the membrane bilayers. These β‐peptides adopt a well‐ordered transmembrane motif in the solid‐supported model membrane, maintaining the basic structure of the original bilayer with some distinct alterations. Notably, the helical tilt angle, which accommodates the positive hydrophobic mismatch, induces a tilt of the acyl chains. The tilted chains, in turn, lead to a membrane thinning effect.     

Effects of double promoters on direct synthesis of triethoxysilane in gas–solid stirred fluidized bed

The reaction of silicon with ethanol was carried out in a gas–solid stirred fluidized bed, with cuprous chloride prepared by a wet process as the catalyst. The effect of hydrogen fluoride and ethyl chloride addition on formation of triethoxysilane in the direct process was described and discussed. The catalytic activity was evaluated using online gas chromatography, X‐ray diffraction and scanning electron microscopy to study the contact mass. The results show that the promoters hydrogen fluoride and ethyl chloride not only supplemented anions, but also depressed the catalytic activity of metallic copper. The comparison of technical‐grade silicon and polycrystalline silicon showed many differences in reactivity, reaction rate and induction period. Furthermore, the yield, selectivity of triethoxysilane and reaction rate were improved significantly with additions of hydrogen fluoride and ethyl chloride. Copyright © 2011 John Wiley & Sons, Ltd.     

Anion exchange membranes derived from nafion precursor for the alkaline fuel cell

Robust hydroxide conducting membranes are required for long‐lasting, low‐cost solid alkaline fuel cells (AFCs). In this study, we synthesize Nafion‐based anion exchange membranes (AEMs) via amination of the Nafion precursor membrane with 1,4‐dimethylpiperazine. This initial reaction produces an AEM with covalently attached dimethylpiperazinium cations neutralized with fluoride anions, while a subsequent ion exchange reaction produces a hydroxide ion conducting membrane. These AEMs possess high thermal stability and different thermal transition temperatures compared to Nafion, while small‐angle X‐ray scattering reveals a similar ionic morphology. The hydroxide ion conductivity of the Nafion‐based AEM is fivefold lower than the proton conductivity of Nafion at 80 °C and 90% relative humidity. More importantly, the hydroxide conductivity is insensitive to drying and rehydrating the membrane, which is atypical of other AEMs with quaternary ammonium cations. The high chemical and thermal stability of this hydroxide conducting Nafion‐based AEM provides a promising alternative for AFCs. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011