Epitaxial Ni–Mn–Ga/MgO(1 0 0) thin films ranging in thickness from 10 to 100 nm

Thin films of Ni–Mn–Ga alloy ranging in thickness from 10 to 100 nm have been epitaxially grown on MgO(1 0 0) substrate. Temperature-dependent X-ray diffraction measurements combined with room-temperature atomic force microscopy and transmission electron microscopy highlight the structural features of the martensitic structure from the atomic level to the microscopic scale, in particular the relationship between crystallographic orientations and twin formation. Depending on the film thickness, different crystallographic and microstructural behaviours have been observed: for thinner Ni–Mn–Ga films (10 and 20 nm), the L2₁ austenitic cubic phase is present throughout the temperature range being constrained to the substrate. When the thickness of the film exceeds the critical value of 40 nm, the austenite-to-martensite phase transition is allowed. The martensitic phase is present with the unique axis of the pseudo-orthorhombic 7M modulated martensitic structure perpendicular to the film plane. A second critical thickness has been identified at 100 nm where the unique axis has been found both perpendicular and parallel to the film plane. Magnetic force microscopy reveals the out-of-plane magnetic domain structure for thick films. For the film thickness below 40 nm, no magnetic contrast is observed, indicating an in-plane orientation of the magnetization.     

Chromene-Containing Aromatic Sulfonamides with Carbonic Anhydrase Inhibitory Properties

Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze the essential reaction of CO₂ hydration in all living organisms, being actively involved in the regulation of a plethora of patho/physiological conditions. A series of chromene-based sulfonamides were synthesized and tested as possible CA inhibitors. Their inhibitory activity was assessed against the cytosolic human isoforms hCA I, hCA II and the transmembrane hCA IX and XII. Several of the investigated derivatives showed interesting inhibition activity towards the tumor associate isoforms hCA IX and hCA XII. Furthermore, computational procedures were used to investigate the binding mode of this class of compounds, within the active site of hCA IX.     

快速凝固富钛Ti-V合金的微观组织和储氢性能

研究目的在于优化Ti0.8-0.9V0.2-0.1二元合金的相结构成分、微观组织和储氢性能。该合金主要用于从含有大量一氧化碳的高温气态混合物中吸收氢气。Ti0.8-0.9V0.2-0.1合金中的α-（HCP）和β-（BCC）相在纯氢气中基于氢化作用,形成单相FCC结构的氢化物,此过程与合金的化学成分无关。同步辐射X射线衍射的原位分析表明,在含有氢气和10%一氧化碳的混合气体中,只有β相转变成相应的氢化物。快速凝固（RS）处理细化了Ti0.8V0.2和Ti0.9V0.1合金的晶粒组织,而且,快速凝固处理增加了Ti0.9V0.1合金中的β相,其所占比例是普通熔铸条件下的两倍。扫描电子显微镜（SEM）分析表明,Ti0.9V0.1合金含有片状组织,层片的厚度约为300nm。热脱附谱（TDS）显示,微观组织的细化可以加快氢脱附的动力学过程。     

Synthesis and Properties of Novel Surface Active Monomers Based on Derivatives of 4‐Hydroxybutyric Acid and 6‐Hydroxyhexanoic Acid

Novel surface active maleate and methacrylate monomers based on derivatives of ω‐hydroxy carboxylic acids have been synthesized. The monomers are comprised of hydrophobic alkyl chains and hydrophilic poly(ethylene glycol), quaternary ammonium, sulfonate and carboxylic fragments. Synthesized monomers sufficiently reduce surface tension at the aqueous solution‐air interface. The copolymerization of synthesized monomers with 5‐tert‐butylperoxy‐5‐methyl‐2‐hexene‐3‐yne monomer and N‐vinylpyrrolidone in solvent and emulsion copolymerization of synthesized peroxide containing surface active monomer with styrene have been carried out. The synthesized surface active monomers have been shown to be suitable emulsifiers for obtaining polystyrene colloid dispersions. It has been ascertained that the surface active copolymers obtained can form stable interpolyelectrolyte complexes with oppositely charged polymers.     

Reinforced thin-film composite nanofiltration membranes: Fabrication,characterization, and performance testing

Hollow-fiber (HF) membranes have the advantage of a higher packing density compared to flat-sheet and spiral-wound configurations. However, the low pressure tolerance of HF membranes limits their applications in nanofiltration (NF). In this study, reinforced thin-film composite (r-TFC) HF NF membranes were fabricated and evaluated in tests with water containing different salts and organic matter. Reinforced polysulfone ultrafiltration membranes were used as a support for a polyamide layer prepared from piperazine and trimesoyl chloride monomers. The interfacial polymerization conditions were optimized via selection of the trimesoyl chloride reaction time that gave the highest membrane performance. A specific permeate flux of 5.1 L m^–2 h^–1 bar^–1, an MgSO₄ rejection of 69%, and an NaCl rejection of 26% at a transmembrane pressure of 6 bars were obtained with the optimized r-TFC membranes. Performance studies with water characterized by synthetic solution demonstrated removals of the total organic carbon, ultraviolet absorbance at 254 nm, and turbidity in excess of 65, 80, and 90%, respectively. The results of this study illustrate the feasibility of manufacturing r-TFC HFs and using them in water-treatment applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48001.     

Antineoplastic Isoflavonoids Derived from Intermediate ortho‐Quinone Methides Generated from Mannich Bases

The regioselective condensations of various 7‐hydroxyisoflavonoids with bis(N,N‐dimethylamino)methane in a Mannich reaction provided C‐8 N,N‐dimethylaminomethyl‐substituted isoflavonoids in good yield. Similar condensations of 7‐hydroxy‐8‐methylisoflavonoids led to the C‐6‐substituted analogs. Thermal eliminations of dimethylamine from these C‐6 or C‐8 N,N‐dimethylaminomethyl‐substituted isoflavonoids generated ortho‐quinone methide intermediates within isoflavonoid frameworks for the first time. Despite other potential competing outcomes, these ortho‐quinone methide intermediates trapped dienophiles including 2,3‐dihydrofuran, 3,4‐dihydro‐2H‐pyran, 3‐(N,N‐dimethylamino)‐5,5‐dimethyl‐2‐cyclohexen‐1‐one, 1‐morpholinocyclopentene, and 1‐morpholinocyclohexene to give various inverse electron‐demand Diels–Alder adducts. Several adducts derived from 8‐N,N‐dimethylaminomethyl‐substituted isoflavonoids displayed good activity in the 1–10 μm concentration range in an in vitro proliferation assay using the PC‐3 prostate cancer cell line.     

电磁复合场协同激光熔覆制备TiBw/Ti网状结构复合涂层

目的利用电磁复合场(EMCF)辅助激光熔覆制备TiB_w/Ti网状结构复合涂层,探索电磁场对涂层组织结构的影响。方法以TiB_2∶Ti=1∶1(摩尔比)的混合粉末为熔覆材料,TC4作为基板材料,通过外加电磁复合场进行激光熔覆试验。通过扫描电子显微镜(SEM)观察洛伦兹力方向对熔覆层组织结构的影响,利用X射线衍射仪(XRD)和维氏显微硬度计分析施加电磁复合场前后熔覆层的相组成和硬度分布。结果未施加电磁复合场的熔覆层组织主要为细针状、粗棒状和颗粒状组织。而施加电磁复合场后,熔覆层出现了网状结构,而且方向向下的洛伦兹力可使涂层内部形成空间间距更大的网状结构。此外,单独施加稳态磁场后,熔覆层只出现细针状和粗棒状组织。电磁复合场施加前后熔覆层硬度与基体相比,均有很大的提高。但未施加电磁复合场的熔覆层硬度变化幅度较大;施加电磁复合场后,随着距熔覆层表面距离的增加,硬度的变化幅度比较平缓。结论在洛伦兹力作用下,可得到TiB_w/Ti网状结构的复合涂层,电磁复合场使TiB_w/Ti网状结构强化相均匀分布,同时提高涂层的显微硬度。     

Linear and Nonlinear Development of the <Emphasis Type="Italic">m</Emphasis> = 0 Instability in Z-Pinch Equilibria with Axial Sheared Flows

The effect of sheared flows on the m = 0 instability development in a z-pinch is numerically investigated using a 2D magnetohydrodynamic (MHD) code. The behavior of both internal and free-boundary modes is studied by using two types of initial configurations: a diffuse Bennett equilibrium and a free-boundary parabolic equilibrium. It was found that sheared flows change the m = 0 development by reducing the linear growth rates, decreasing the saturation amplitude, and modifying the instability spectrum. Full stability can be obtained for supersonic plasma flows, but a larger shear is needed to obtain stabilization of free-boundary modes.     

Numerical Modeling of a Magnetic Flux Compression Experiment

A possible plasma target for Magnetized Target Fusion (MTF) is a stable diffuse z-pinch in a toroidal cavity, like that in MAGO experiments. To examine key phenomena of such MTF systems, a magnetic flux compression experiment with this geometry is under design. The experiment is modeled with 3 codes: a slug model, the 1D Lagrangian RAVEN code, and the 1D or 2D Eulerian Magneto-Hydro-Radiative-Dynamics-Research (MHRDR) MHD simulation. Even without injection of plasma, high-Z wall plasma is generated by eddy-current Ohmic heating from MG fields. A significant fraction of the available liner kinetic energy goes into Ohmic heating and compression of liner and central-core material. Despite these losses, efficiency of liner compression, expressed as compressed magnetic energy relative to liner kinetic energy, can be close to 50%. With initial fluctuations (1%) imposed on the liner and central conductor density, 2D modeling manifests liner intrusions, caused by the m = 0 Rayleigh-Taylor instability during liner deceleration, and central conductor distortions, caused by the m = 0 curvature-driven MHD instability. At many locations, these modes reduce the gap between the liner and the central core by about a factor of two, to of order 1 mm, at the time of peak magnetic field.