Rational Profiling of Reinforced Rotating Disks

The problem of rational profiling of thermoelastic three-layered reinforced rotating disks of gas turbines is formulated. The conditions of equal-stressed reinforcement of the midlayer and the condition of equal-strength binder of the reinforced layer or external isotropic layers are used as criteria for rational designing. An iterative method is proposed for solving such problems. The problem of rational profiling of disks with radial and radially circumferential reinforcements, on condition that the fibers of the radial family are equally stressed, is solved analytically. The calculation results for B-Al and B-Ti disks, obtained by using both the criteria of rational design, are given for plane-parallel and 3D reinforcements. It is shown that, at an equal load-carrying capacity, the weight of such disks can be 30-60% smaller than that of reinforced disks of constant thickness, or, at an equal weight, they can have a considerably higher load-carrying capacity. The criterion of equal-stressed reinforcement, as a rule, is more efficient than the condition of equal-strength binder.     

Studies on Curing Chemistry of Aluminum-Chromium-Phosphates as Low Temperature Curable Binders

The curing behavior of metal phosphate binders, Al(H₂PO₄)₃ and Al₃Cr(H₂PO₄)_9,12, was compared and characterized in order to understand the changes in chemical structure and crystalline phase that occur when they are annealed at temperatures up to 1200°C. Based on IR, NMR and XRD measurements, Al(H₂PO₄)₃ as a starting phase of the aluminum phosphate (AP) binder transformed to AlH₃(PO₄)₂ at 200°C, to a linear Al(PO₃)₃ at 300°C, and finally to a cyclic Al(PO₃)₃ beginning at 500°C. The chemical and crystalline behaviors of the Al₃Cr(H₂PO₄)₉ (ACP-319) binder were developed in an almost identical manner to those of AP but with much a slower rate. In particular, the former was amorphous up to 500°C with slow crystallization kinetics. Furthermore, the presence of a filler or an increase in the Cr mole ratio enhanced the dehydrolytic condensation chemistry. In particular, the ACP-319 binder containing fillers showed the completion of curing reaction when pre-treated at 200°C.     

Miscellaneous PEDOT:PTS (polythiophenesulfonyl chloride) based conductive binder for silicon anodes in lithium ion batteries

Lithium ion batteries which are an energy storage system have increasing attention owing to suitability and advantages for many applications. Although it has ideal specifications, the capacity properties still have to be developed. In this study, the electrical conductivity of the anode was increased by using a conductive polymer binder and the active material content of the anode was also enhanced without adding carbon additives. Silicon based anodes were manufactured by using poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT:PSS) and poly(3,4-ethylenedioxythiophene)/polythiophenesulfonyl chloride (PEDOT:PTS) conductive polymer binders. Si/PEDOT:PTS anode showed about 2000 mAh/g specific capacities after 60 cycles with decreasing impedance.     

Thermomechanical characterization of BFRP and GFRP with different degree of conversion

Thermomechanical behavior of basalt fiber- and glass fiber-reinforced plastics (BFRP and GFRP) was characterized under the same conditions. The effect of an EDI binder formulation on Martens temperature was studied by varying the contents of a curing agent from 75 to 95 parts by weight (pbw) and of an accelerator from 1 to 2 pbw with respect to 100 pbw of an ED-22 resin. The Martens temperature was found to vary from 90 to 113 °С, depending on the component ratio. An optimum binder formulation was chosen, exhibiting stable results on heat resistance after curing at 150 °С for 2 and 10 h. To achieve different degree of conversion, BFRPs and GFRPs were fabricated using the chosen formulation and were cured at 100-110 °С for 30 min and then at 150 °С for 1 and 4 h. The said formulation can be recommended, with the maximum transition point of BFRPs and GFRPs reaching 137 °С.     

锂硫电池硫正极粘结剂的比较研究

本文将三类粘结剂体系(PVDF、LA133和CMC+SBR)用于构筑锂硫电池硫正极,表征了不同粘结剂材料的官能团结构、结晶性能、热力学性质、电解液吸收性与粘结强度,考察了粘结剂种类对电极电化学性能的影响。结果表明,由1∶1质量比的CMC+SBR制作的硫电极吸液率低,剥离强度低,循环稳定性较差;无定形LA133支持高的粘结强度,维稳电极结构的能力强;PVDF因半结晶状态制约粘结效果,制作的电极吸液量高,但电荷转移阻抗小。基于PVDF制作的硫正极具有相对最优的电化学性能,其0.2C下循环100周后保留的可逆容量达722mAh·g~(-1),容量保持率达82.9%。     

Conjugates between minor groove binders and Zn(II)-tach complexes: Synthesis,characterization, and interaction with plasmid DNA

A new family of conjugates between a Zn(II)-tach complex and (indole)₂ or benzofuran-indole amide minor groove binders connected through alkyl or oxyethyl linkers of different lengths has been prepared. The conjugates bind strongly to DNA. However, the complexation to DNA to promote the Zn(II) catalyzed hydrolytic cleavage of the DNA results instead in its inhibition. This inhibition effect has been confirmed also using Cu(II). Modeling studies suggest that in the most stable complex conformation, the minor groove binder and the linker lie in the minor groove hampering the interaction between the metal complex and the phosphate backbone of DNA. Therefore, the linear arrangement of minor groove binder-linker-metal complex appears to be effective to ensure tight binding but unproductive from a hydrolytic point of view.     

The Crystal Structures of two Anhydrous Magnesium Hydroxychloride Phases from in situ Synchrotron Powder Diffraction Data

The crystal structures of two members of the solid solution series Mg(OH)_xCl_y x+y = 2, Mg(OH)_1.7Cl_0.3 (P$\tilde {3}$ m1, a = 3.169(2) Å, c = 5.530(12), V = 48.1(1) ų at T = 365 °C) and MgOHCl (R$\tilde {3}$ m, a = 3.3877(4) Å, c = 17.534(4) Å, V = 174.27(6) ų at T = 625 °C) were determined from in situ synchrotron powder diffraction data at high temperature upon dehydration of 3Mg(OH)₂·MgCl₂·8H₂O (F3) and 5Mg(OH)₂·MgCl₂·8H₂O (F5) phases. The crystal structures of Mg(OH)_1.7Cl_0.3 (example of ss‐type‐OH) and MgOHCl (example of ss‐type‐Cl) can be related to the C19 (CdCl₂) and C6 (CdI₂) structure type, respectively, with the disordered chloride and hydroxide anions occupying the same crystallographic site in layers.     

石蜡或聚丁二烯填充型高吸油树脂的合成及其性能比较

以过氧化二苯甲酰 (BPO)为引发剂、二甲基丙烯酸乙二酯 (EGDMA)为化学交联剂、甲基丙烯酸十二酯 (DMA)和苯乙烯 (St)为单体、石蜡 (Paraffin)或聚丁二烯 (PB)为填充剂 ,用悬浮聚合法合成了填充型高吸油树脂 .研究了单体配比、填充剂用量以及化学交联度对树脂吸油性能及凝胶分率的影响 .对石蜡和PB填充的高吸油树脂进行比较 ,发现PB填充的高吸油树脂中存在物理交联 ,而石蜡填充的树脂中不含物理交联 ;PB填充的高吸油树脂随PB用量的增加 ,吸油倍率提高 ,凝胶分率上升 ,脱油速率增大 ;而石蜡填充的树脂随石蜡用量的增加 ,吸油倍率提高 ,但凝胶分率和脱油速率变化不大     

Hard X‐ray‐induced damage on carbon–binder matrix for in situ synchrotron transmission X‐ray microscopy tomography of Li‐ion batteries

The electrode of Li‐ion batteries is required to be chemically and mechanically stable in the electrolyte environment for in situ monitoring by transmission X‐ray microscopy (TXM). Evidence has shown that continuous irradiation has an impact on the microstructure and the electrochemical performance of the electrode. To identify the root cause of the radiation damage, a wire‐shaped electrode is soaked in an electrolyte in a quartz capillary and monitored using TXM under hard X‐ray illumination. The results show that expansion of the carbon–binder matrix by the accumulated X‐ray dose is the key factor of radiation damage. For in situ TXM tomography, intermittent X‐ray exposure during image capturing can be used to avoid the morphology change caused by radiation damage on the carbon–binder matrix.     

嘧啶并嘧啶酮类化合物作为L3MBTL1选择性络合剂的设计与合成

用嘧啶并嘧啶酮替换Lethal 3 malignant brain tumor 1(L3MBTL1)小分子络合剂UNC669分子中的芳香部分,合成了一系列嘧啶并嘧啶酮类化合物.采用同质邻近发光放大法(AlphaScreen^®)测试了其活性,得到IC₅₀值为1.21 μmol/L的化合物8a;通过对其5位基团进行改造,最终获得了3个选择性L3MBTL1络合剂8g, 8o与8p,它们仅对L3MBTL1有活性,对其同源蛋白L3MBTL3在内的其它甲基化识别蛋白则无活性.