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关键词： Chloromethane to olefin (CMTO) reaction   Light olefin production   Mesoporous SAPO-34   Cerium incorporation   Deactivation behavior  

摘要： In this work, SAPO-34 and a series of meso-CeAPSO-34(mesoporous cerium incorporated silicoaluminophos-phate, X = Ce/Al molar ratio, X = 0, 0.02, 0.05, 0.07, and 0.10) catalysts with different Ce/Al molar ratio(X) were applied for olefin generation, especially propylene. The chloromethane to olefin (CMTO) reaction at 450 degrees C demonstrated that meso-CeAPSO-34(0.05) catalysts showed stable chloromethane conversion, with the highest propylene selectivity. The CM conversion increased with the introduction of mesoporosity. The mesopore volume increased and the amount of active sites maintained sufficiently high with the incorporation of cerium. The structural stability of the catalysts and the diffusivity of products improved with the addition of proper amount of cerium. In summary, the enhancement of the physicochemical properties of the catalysts played a crucial role in catalytic stability and the selective production of propylene in the CMTO reaction, resulting in stably high CM conversion and the highest propylene selectivity over meso-CeAPSO-34(0.05) catalyst.

关键词： nanomedicine   iron nanoparticle   physicochemical properties   colloidal iron carbohydrate drugs   non-biologic complex drugs   generic nanoparticles   sodium ferric gluconate  

摘要： Complex iron nanoparticle-based drugs are one of the oldest and most frequently administered classes of nanomedicines. In the US, there are seven FDA-approved iron nanoparticle reference drug products, of which one also has an approved generic drug product (i.e., sodium ferric gluconate (SFG)). These products are indicated for the treatment of iron deficiency anemia and are administered intravenously. On the molecular level, iron nanomedicines are colloids composed of an iron oxide core with a carbohydrate coating. This formulation makes nanomedicines more complex than conventional small molecule drugs. As such, these products are often referred to as nonbiological complex drugs (e.g., by the nonbiological complex drugs (NBCD) working group) or complex drug products (e.g., by the FDA). Herein, we report a comprehensive study of the physiochemical properties of the iron nanoparticle product SFG. SFG is the single drug for which both an innovator (Ferrlecit) and generic product are available in the US, allowing for comparative studies to be performed. Measurements focused on the iron core of SFG included optical spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), X-ray powder diffraction (XRPD), 57Fe Mossbauer spectroscopy, and X-ray absorbance spectroscopy (XAS). The analysis revealed similar ferric-iron-oxide structures. Measurements focused on the carbohydrate shell comprised of the gluconate ligands included forced acid degradation, dynamic light scattering (DLS), analytical ultracentrifugation (AUC), and gel permeation chromatography (GPC). Such analysis revealed differences in composition for the innovator versus the generic SFG. These studies have the potential to contribute to future quality assessment of iron complex products and will inform on a pharmacokinetic study of two therapeutically equivalent iron gluconate products.

关键词： Geopolymers   Gamma irradiation   Fly ash   Intermediate level waste   Slag  

摘要： The mechanistic effects of long-term. irradiation on the mineralogical, microstructural, structural, physical, and chemical properties of 40 wt% blast furnace slag + 60 wt% fly ash geopolymer pastes have been examined. Ambient curing for 28 days during normal equilibration was followed by exposure to Co-60 irradiation (1574, 4822, 10,214 kGy). The material characteristics are controlled largely through the competing mechanisms of beneficial equilibration at initial lower dosages, which enhances gelation and crosslinking, and detrimental equilibration at subsequent higher dosages, which causes structural and microstructural destabilisation. Irradiation for 2 months (1574 kGy) increases the compressive strength similar to 45% (similar to 57 to similar to 83 MPa) through conversion of less-crosslinked (Q(0)/Q(1)/Q(1)') to more-crosslinked (Q(2)/Q(3)/Q(4)) silicate species. The transition between these regimes occurs after similar to 5 months of irradiation (similar to 4000 kGy). Beyond this, the rates of beneficial equilibration and detrimental equilibration equalise upon completion of normal geopolymerisation. Additional geopolymerisation from gamma irradiation is controlled by the rate-limiting release of Si4+ from the unreacted aluminosilicates and silicates and their rapid incorporation in the geopolymer network. The aqueous leaching of the geopolymer pastes is not affected significantly by gamma irradiation. These data reveal the potential for these materials as intermediate-level wasteforms that can outperform Portland cement-based materials.

关键词： Ampicillin drug   nicotinamide   mixed ligand complexes   antibacterial   DFT, docking study  

摘要： A novel series of mixed-ligand complexes of the type, [ML1(L-2)(3)]Cl-x [M= Cr(III), Fe(III), Co(II),Ni(II), Cu(II), Cd(II) and Hg(II), n = 2, 3], was synthesized using Schiff base (HL1) as main ligand, nicotinamide (L-2) as secondary ligand, and the corresponding metal ions in 1:3:1 molar ratio. The main ligand, HL1 was prepared by the interaction of ampicillin drug and 4-chlorobenzophenone. The synthesized mixed ligand complexes were characterized by elemental analysis, UV-Vis, FT-IR, H-1-NMR, C-13-NMR and TG/DTG studies. In the mixed-ligand complexes, the Schiff base ligand, HL1 showed coordination to the central metal ion in tridentate manner via azomethine nitrogen, beta-lactam ring oxygen and deprotonated carboxylic oxygen atoms, whereas the secondary ligand L-2 (nicotinamide, Nam) coordinated through pyridine nitrogen atoms. The synthesized complexes exhibited significant antimicrobial activity when evaluated against P. pseudomonas, E. coli, S. aureus and B. subtilis microbes. The DFT calculations were also carried out to ascertain the bonding insights into the structure. In addition, molecular docking analysis was performed carried out to know the interactions between complexes and their probable binding sites in penicillin binding protein (PBP2). Moreover, drug-likeness and toxicity of the compounds were also performed to predict the suitability of the complexes as drugs. (C) 2020 Elsevier B.V. All rights reserved.

关键词： aliphatic dicarboxylic acids   berberine chloride   salt-cocrystals   melting point   intrinsic dissolution rate   odd-even alternation  

摘要： In this study, various structurally similar aliphatic dicarboxylic acids, namely, succinic acid, glutaric acid, adipic acid, and pimelic acid, were employed as coformers to obtain phase pure cocrystals with berberine chloride (BCl) by a slow solvent evaporation method. The structures of the four novel salt-cocrystals of BCl were determined by single crystal X-ray diffraction analysis and their solid-state properties were characterized. Compared with BCl center dot 2H(2)O, all the cocrystals showed a higher melting point, improved powder dissolution and intrinsic dissolution rate (IDR), and lower hygroscopicity. It is noteworthy that the melting points and IDRs of these cocrystals exhibit an odd-even alternation with the carbon chain length of the acids.

关键词： Selenophene   Diselenopheno[3,2-b:2 ' 3 '-d]thiophene   Double annulation   Tetrabromothiophene   Semiconductor  

摘要： A series of diselenopheno[3,2-b:2',3'-d]thiophenes were designed and synthesized from tetrabromothiophene in two steps. Tetrabromothiophene was converted into the corresponding 2,5-dialkynyl-3,4dibromothiophenes by selective Sonogashra reactions and subsequent acetylene-activated SNAr-anionic cyclization cascades by Na2Se afforded the corresponding diselenopheno[3,2-b:2',3'-d]thiophenes (3a-d). The absorption and emission spectra of these compounds were investigated for optical properties. Electrochemical studies of 3a-d were carried out for their redox behaviors. (C) 2020 Elsevier B.V. All rights reserved.

关键词： X-ray diffraction   Spectroscopy   Hirshfeld surface   DFT  

摘要： (C6H4NH3F)(HSO4)center dot H2O (I) and (C8H12N)(HSO4)center dot H2O (II) have been prepared by reaction of 2-fluoroaniline and 2,6-dimethylaniline, respectively, with acidic aqueous solution at room temperature. Molecular structures of these compounds were determined by single crystal X-ray diffraction analysis. Both sulfates crystallize in the monoclinic space group P2(1)/c with Z=4. In both structures organic and inorganic (anion and H2O) moieties are separately stacked to form alternating layers parallel to the (a,c) plane in (I) and to the (b,c) plane in (II). The anionic and cationic layers are linked through N-H center dot center dot center dot O hydrogen bonds involving the aniline NH3+ groups. The enrichment ratio from the Hirshfeld surface analysis was used to investigate which kind of contacts is over-or under-represented in the crystal packing. These two new salts were also characterized by solid-state C-13 CP-MAS NMR spectroscopy and by infrared spectroscopy. NMR peaks were attributed with the help of DFT calculations. Moreover, electronic properties such as HOMO and LUMO energies were determined. (C) 2020 Elsevier B.V. All rights reserved.

关键词： 物理化学   二硝酰胺铵   ADN   燃烧特性   燃烧催化剂   固体推进剂  

摘要： 系统介绍了二硝酰胺铵(ADN)燃烧的最新研究动态,综述了国内外近年来报道的ADN燃烧时发生的物理化学变化、ADN燃烧机理、催化剂/ADN混合物燃烧性能以及ADN基固体推进剂燃烧特性的最新研究进展。首先指出了ADN的燃烧主要受凝聚相反应控制,ADN燃烧波结构包括固相层、泡沫层(包括固-气和液-气)和气相层;其次,总结了ADN基固体推进剂燃烧特性的研究现状,对现有研究中存在的局限性进行了分析;最后,指出继续开发适用于ADN基固体推进剂的新型燃烧催化剂是今后研究的重点方向之一。另外,随着非异氰酸酯固化体系在ADN基固体推进剂中的应用,需进一步加深ADN基固体推进剂燃烧性能的研究,尤其是三唑环的引入对ADN热分解及推进剂中其他组分热分解的影响。

关键词： 物理化学   高氯酸铵   球形化AP   溶解度   冷却结晶法  

摘要： 为获得球形化高氯酸铵(AP),利用重力法测试了AP在水中的溶解度,采用Vant′t Hoff方程和Apelblat方程对溶解度数据进行拟合,建立溶解度模型;采用冷却结晶法制备了球形化AP晶体,分析了结晶液初始质量分数、搅拌速率、降温速率及养晶时间对产品形貌及粒度分布的影响;分别对非球形AP原料和球形化AP样品进行了吸湿性能、松散堆积密度、流散性、热稳定性的表征。结果表明,AP在水中的溶解度随着温度的升高而增加,Apelblat方程和Vant′t Hoff方程的R^(2)接近于1,且MAPD均小于3%;最佳冷却结晶工艺为:搅拌速率为230r/min,结晶液初始质量分数为35%,降温速率为0.5℃/min,养晶时间为3h;球形化AP样品的吸湿性能、松散堆积密度、流散性、热稳定性相比于非球形AP原料有明显改善。

关键词： 物理化学   30mm高压炮   高能叠氮硝胺发射药   动态燃烧性能   压力波  

摘要： 为了研究高能发射药膛内燃烧规律,通过半溶剂法制备了一种火药力高达1240J/g的新型高能叠氮硝胺发射药(ADR),采用高压密闭爆发器和30mm高压模拟试验装置,分别研究了不同温度下ADR发射药定容高压燃烧性能和装填密度、温度以及石墨光泽处理对ADR发射药膛内高压燃烧稳定性的影响。结果表明,不同温度条件下(-40、20和50℃)ADR发射药静态及动态燃烧性能稳定性良好,燃烧过程无异常;随着温度的增加,ADR发射药点火性能提高,增加了膛内燃烧稳定性;装填密度0.48~0.64g/cm^(3)范围内,随着装填密度的增加,ADR发射药膛内压力波强度逐渐增加,但增长幅度减小;对发射药进行石墨光泽处理,增加了ADR发射药起始缓燃效果,使不同温度下膛内压力波强度明显降低;与RGD7发射药相比,ADR发射药火药力较高,爆温较低,发射装药膛内高压燃烧稳定性相当,在高膛压环境中应用前景较好。