Preparation and characterization of the modulus intermediate layer in carbon fiber/epoxy composites by depositing sepiolites

An important aspect in development of multi‐scale reinforced composites is their mass production which can be easily realized. In this article, the sepiolites (Si12O30Mg8(OH)4(OH2)4·8H2O) are directly deposited onto the surface of JH‐T800 carbon fibers for the first time with no need for removal of the commercial sizing agent. The sepiolites adhering to the carbon fibers are uniformly distributed with random orientation, and participated in the formation of high modulus intermediate layer encompassing the carbon fiber. After the deposition of sepiolites, the interfacial shear strengths (IFSS) of the carbon fiber/epoxy composites are significantly improved as shown in single‐fiber composite fragmentation tests. Compared to the commercial carbon fiber composites, the sepiolite‐deposited fiber composites also exhibit obvious improvement in the interlaminar shear strength and flexural strength. As a new kind of multi‐scale reinforcement with industrial application value, the sepiolite‐deposited carbon fibers can further raise the level of mechanical properties of the existing carbon fiber reinforced composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43955.     

High‐performance polymer‐supported extractants with phosphonate ligands for scandium(III) separation

As the market demand for scandium has grown, a great deal of interest has been generated in its recovery. To substantially simplify the process and provide a green alternative for scandium separation, novel polymer‐supported extractants containing di(2‐ethylhexyl) phosphonate and bis(2,4,4‐trimethylpentyl) phosphonate, [D201][DEHP] and [D201][C272] are proposed because they demonstrate improved adsorption capacity and selectivity toward scandium(III). Scandium(III) adsorption is significantly affected by the solution pH, with the maximum adsorption occurring at a pH of approximately 0.78. The batch adsorption data fit well with the Langmuir isotherm and pseudo‐second‐order kinetic models. A combination of the Fourier transform infrared and XPS spectra suggest that the complexation of oxygen atoms in phosphate groups with scandium(III) is the predominant adsorption mechanism. Additionally, the two resins were used to recover scandium from leaching liquor of nickel laterite ore. [D201][DEHP] exhibits unusual selectivity for scandium and low competitive behavior with other metals, thus increasing its market potential. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2479–2489, 2016     

Significant Improvement of Superconducting Properties in Nano‐NiFe2O4‐Doped Y–Ba–Cu–O Single‐Grain Superconductor

Introduction of refined second‐phase particles in superconducting YBa₂Cu₃O_7?x (Y‐123) matrix is known to be an effective route to improve the δl‐type pinning and the performance of Y–Ba–Cu–O (YBCO) single‐grain superconductors, while the δT_c‐type pinning induced by spatial fluctuations in matrix composition is also important and contributes to the in‐field J_c performance and high‐field applications of bulk superconductors. In this communication, chemical doping of nano‐sized NiFe₂O₄ (mean size 50 nm) in single‐grain YBCO superconductor is performed using a novel top‐seeded infiltration growth (TSIG) technique based on a solid source pellet (SSP) of nano‐Y₂O₃ + BaCuO₂. The results indicate that, significant improvement of bulk performances including levitation force (33.93 N) and trapped field (0.3628 T) has been observed in the 0.2 wt% nano‐NiFe₂O₄‐doped sample, which are much higher than the undoped sample (28.81 N and 0.2754 T). T_c measurement indicates that, a decreased onset T_c of about 87.5 K and a broadened transition width of about 5 K are observed in the NiFe₂O₄‐doped sample, indicating appearance of weak superconducting regions in superconducting matrix caused by Ni and Fe substitutions in Y‐123 crystal lattice. This study supplies a practical approach to increase the YBCO bulk performance significantly.     

对水泥生料易烧性试验方法的改进

正0前言水泥生料易烧性是评价水泥原料和生料的重要工艺指标,是正确选择原料、设计生料、确定生料准备方法以及保证高产低耗的重要依据和参数[1]。目前,水泥生料的易烧性都是按照GB/T26566—2011《水泥生料易烧性试验方法》进行试验。但是在实际应用过程中发现,利用该标准方法进行检测时,由于加水量小而不易拌匀,且试体太小需反复制备试体。同时煅烧时需要在温度稍低的高温炉内先预烧,然后取出再放入更高温度的高温炉内煅烧,且煅     

内聚甲醇固定化硫酸盐还原菌小球去除硫酸盐和铬

Cr~(6+)和SO_4~(2-)对生态环境构成严重威胁,制备内聚甲醇为营养源的固定化硫酸盐还原菌小球处理初始Cr~(6+)浓度为100 mg·L-1和初始SO_4~(2-)浓度为200 mg·L-1的废水,探讨内聚甲醇固定化硫酸盐还原菌小球处理含Cr~(6+)和SO_4~(2-)的效果。结果表明,内聚甲醇为营养源的固定化硫酸盐还原菌小球对废水中Cr~(6+)和SO_4~(2-)具有较好的去除效果,对Cr~(6+)和SO_4~(2-)的最大去除量分别达到301.20μg·g-1和1 284.89μg·g-1。SEM分析表明,硫酸盐还原和吸附在其中发挥了重要作用,Cr~(6+)和SO_4~(2-)去除率最高达99.40%和97.49%。内聚甲醇的固定化硫酸盐还原菌小球是一种良好的处理含Cr~(6+)和SO_4~(2-)废水的新型生物吸附剂。     

钾对低温耐硫变换催化剂的影响

采用不同钾源制备低温耐硫变换催化剂Mo-Co-K/Al_2O_3,通过XRD、N_2吸附-脱附法和微反评价等研究钾源对催化剂的钾流失率、孔结构及反应过程中钾硫酸盐化的影响。结果表明,以K_2SO_4为钾源的催化剂钾流失率最大,活性最低。KNO_3和KOH对拟薄水铝石的胶溶能力较强,易形成小孔径结构的催化剂。K_2SiO_3可以有效避免催化剂中钾在反应过程中的硫酸盐化。     

Mechanism of Mitochondrial Connexin43′s Protection of the Neurovascular Unit under Acute Cerebral Ischemia-Reperfusion Injury

We observed mitochondrial connexin43 (mtCx43) expression under cerebral ischemia-reperfusion (I/R) injury, analyzed its regulation, and explored its protective mechanisms. Wistar rats were divided into groups based on injections received before middle cerebral artery occlusion (MCAO). Cerebral infarction volume was detected by 2,3,5-triphenyltetrazolim chloride staining, and cell apoptosis was observed by transferase dUTP nick end labeling. We used transmission electron microscopy to observe mitochondrial morphology and determined superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. MtCx43, p-mtCx43, protein kinase C (PKC), and p-PKC expression were detected by Western blot. Compared with those in the IR group, cerebral infarction volumes in the carbenoxolone (CBX) and diazoxide (DZX) groups were obviously smaller, and the apoptosis indices were down-regulated. Mitochondrial morphology was damaged after I/R, especially in the IR and 5-hydroxydecanoic acid (5-HD) groups. Similarly, decreased SOD activity and increased MDA were observed after MCAO; CBX, DZX, and phorbol-12-myristate-13-acetate (PMA) reduced mitochondrial functional injury. Expression of mtCx43 and p-mtCx43 and the p-Cx43/Cx43 ratio were significantly lower in the IR group than in the sham group. These abnormalities were ameliorated by CBX, DZX, and PMA. MtCx43 may protect the neurovascular unit from acute cerebral IR injury via PKC activation induced by mitoKATP channel agonists.     

Functional Characterization of PyrG,an Unusual Nonribosomal Peptide Synthetase Module from the Pyridomycin Biosynthetic Pathway

Pyridomycin is an antimycobacterial cyclodepsipeptide assembled by a nonribosomal peptide synthetase/polyketide synthase hybrid system. Analysis of its cluster revealed a nonribosomal peptide synthetase (NRPS) module, PyrG, that contains two tandem adenylation domains and a PKS‐type ketoreductase domain. In this study, we biochemically validated that the second A domain recognizes and activates α‐keto‐β‐methylvaleric acid (2‐KVC) as the native substrate; the first A domain was not functional but might play a structural role. The KR domain catalyzed the reduction of the 2‐KVC tethered to the peptidyl carrier protein of PyrG in the presence of the MbtH family protein, PyrH. PyrG was demonstrated to recognize many amino acids. This substrate promiscuity provides the potential to generate pyridomycin analogues with various enolic acids moiety; this is important for binding InhA, a critical enzyme for cell‐wall biosynthesis in Mycobacterium tuberculosis.