A novel utilized method of tar derived from biomass gasification for fabricating binder-free all-solid-state hybrid supercapacitors

As an industrial pollutant, tar derived from biomass gasification is used as the precursor for fabricating a novel carbon-metal hydroxides composite electrode. A slurry (the mixture of tar, KOH and melamine) is daubed uniformly onto the nickel foam, which is directly carbonized to form NPC@LDH electrode material. This electrode is further coated with NiCo-LDH nanosheets using an electrodeposition method to form NF@NPC@LDH. The newly made NF@NPC@LDH electrode exhibits a high specific capacity of 9.6 F cm⁻² at a current density of 2 mA cm⁻² and good rate performance (55.3% retention). Furthermore, a hybrid NF@NPC@LDH//NF@PC all-solid-state supercapacitor is fabricated, and the device exhibits high energy density of 1.28 mWh cm⁻³ at a power density of 8.04 mW cm⁻³, low resistance and good cycling stability.     

Using direct competition to select for competent controllers in evolutionary robotics

Evolutionary robotics (ER) is a field of research that applies artificial evolution toward the automatic design and synthesis of intelligent robot controllers. The preceding decade saw numerous advances in evolutionary robotics hardware and software systems. However, the sophistication of resulting robot controllers has remained nearly static over this period of time. Here, we make the case that current methods of controller fitness evaluation are primary factors limiting the further development of ER. To address this, we define a form of fitness evaluation that relies on intra-population competition. In this research, complex neural networks were trained to control robots playing a competitive team game. To limit the amount of human bias or know-how injected into the evolving controllers, selection was based on whether controllers won or lost games. The robots relied on video sensing of their environment, and the neural networks required on the order of 150 inputs. This represents an order of magnitude increase in sensor complexity compared to other research in this field. Evolved controllers were tested extensively in real fully-autonomous robots and in simulation. Results and experiments are presented to characterize the training process and the acquisition of controller competency under different evolutionary conditions.     

Kinetic analysis of the coding properties of O6-methylguanine in DNA: the crucial role of the conformation of the phosphodiester bond

Production by N-nitroso compounds of O6-alkylguanine (O6-alkylG) in DNA directs the misincorporation of thymine during DNA replication, leading to G:C to A:T transition mutations, despite the fact that DNA containing O6-alkylG:T base pairs is less stable than that containing O6-alkylG:C pairs. We have examined the kinetics of incorporation by Klenow fragment (KF) of Escherichia coli DNA polymerase I of thymine (T) and of cytosine (C) opposite O6-MeG in the template DNA strand. Both T and C were incorporated opposite O6-MeG much slower than nucleotides forming regular A:T or G:C base pairs. Using various concentrations of dTTP, dCTP, or their phosphorothioate (Sp)-dNTP alpha S analogues, or a mixture of dTTP and dCTP, the progress of incorporation of a single nucleotide in a single catalytic cycle of a preformed KF-DNA complex was measured (pre-steady-state kinetics). The results were consistent with the kinetic scheme (Kuchta, R. D., Benkovic, P., & Benkovic, S. J. (1988) Biochemistry 27, 6716-6725): (1) binding of dNTP to polymerase-DNA; (2) conformational change in polymerase; (3) formation of phosphodiester between the dNTP and the 3'-OH of the primer; (4) conformational change of polymerase; (5) release of pyrophosphate. The results were analyzed mathematically to identify the steps at which the rate constants differ significantly between the incorporation of T and C. The only significant difference was the 5-fold difference in the rates of formation of the phosphodiester bond (for dTTP, kforward = 3.9 s-1 and kback = 1.9 s-1; for dCTP, kforward = 0.7 s-1 and kback = 0.9 s-1). These pre-steady-state progress curves were biphasic with a rapid initial burst followed by an apparently steady-state rise. Deconvolution of these curves gave direct evidence for the importance of the conformational change after polymerization by showing that the curves represented the sum of the rapid accumulation of the product of step 3 followed by the slow conversion of that to the product of step 5 (because of the rapidity of the release of pyrophosphate there was no significant accumulation of the product of step 4). The equilibrium constants for each step suggest that the greatest change in the Gibbs free energy occurs at the conformational change after polymerization and that while the formation of the phosphodiester bond to T is slightly exothermic, that to C is slightly endothermic.(ABSTRACT TRUNCATED AT 400 WORDS)     

高分子纳米LB膜的制备及其光刻性能研究

合成并表征了N-十六烷基丙烯酰胺（HDA）和对叔丁基苯酚甲基丙烯酸酯（BPhMA）的共聚物p（HDA-BPhMA）s。当HDA含量较高时，共聚物可在气，液界面上形成稳定，排列紧密的单分子薄膜，并可以Y型膜的方式沉积在各种固体基片上，形成多层均匀的Langrnuir-Blodgett（LB）膜。这种LB膜被成功地应用于光刻，获得了分辨率为0.5μm的LB膜图形。以该图形为抗蚀层，可将图形进一步转移至金属薄膜上，得到分辨率较高的金属图形，在图形转移的过程中，这种LB膜显示出较高的抗蚀性，有望作为纳米抗蚀薄膜材料在亚微米刻蚀领域得到应用。     

Luminescence effect in amorphous PLT

Amorphous and crystalline powder of PLT phase was synthesized by using the Pechini method. Infrared (FTIR) analysis of the polymeric resin shows intense bands of organic materials from 250 to 1620 cm⁻¹. X-ray diffraction (XRD) and Raman spectra of calcined powder at different temperatures show amorphous phase at 450 °C/3 h, semi-crystalline phase at 550 °C/3 h and a crystalline phase at 800 °C/3 h. Luminescence effect was observed in amorphous powder calcined from 300 to 350 °/3 h with broad absorption peaks in 579 nm at 300 °C/3 h and 603 nm at 350 °C/3 h, respectively. The photoluminescence effect is attributed to emissions of Ti→O directly from the oxygen 2p orbital (valence band) to the titanate 3d orbital (conduction bands).     

11B and 15N solid state NMR investigation of a boron nitride preceramic polymer prepared by ammonolysis of borazine

A poly(aminoborazine), precursor for hexagonal boron nitride (h-BN) obtained by reaction of borazine B₃N₃H₆ with ammonia, and its pyrolysis derivatives have been extensively characterised by ¹⁵N and ¹¹B MAS NMR. The various B and N sites have been identified according to their first neighbouring atoms, as well as to the second ones in the case of ¹⁵N, and have also been quantified. This study demonstrates that a suitable choice of NMR techniques together with the use of isotopic enrichment can lead to a large improvement in spectral resolution, which allows a better understanding of such complex BN preceramic polymer structures and permits to follow the polymer-to-ceramic transformation.     

从烟草悬浮细胞中分离液泡前体的方法研究

通过跟踪含有液泡前体特异标记物的组分, 利用细胞壁酶水解胞壁制造原生质体, 并用真针头挤压的方法裂解细胞, 用蔗糖密度梯度离心的方法分离液泡前体. 通过相差显微镜观察, 发现所分离的液泡前体保持完整的结构. 利用不同细胞器的标记物抗体进行免疫标记检测, 证明所纯化的液泡前体不含其他细胞器, 具有较高的纯度.     

Suppression of MHC class II expression by human class II trans-activator constructs lacking the N-terminal domain

The class II trans-activator (CIITA) is a bi- or multi-functional domain protein which plays a critical role in the expression of MHC class II genes. We report that removal of the N-terminal 151 amino acids, encompassing all of the acidic domain but leaving intact the proline/serine/threonine-rich domain, results in a mutant protein with potent suppressive properties for MHC class II expression. HeLa cells stably or transiently transfected with mutant CIITA constructs showed up to 99% suppression of MHC class II antigen induction by IFN-gamma and marked suppression of HLA-DRA mRNA expression. Transient transfection of a B lymphoma line resulted in up to 89% reduction of constitutive MHC class II expression within 5 days and suppression of HLA-DRA mRNA synthesis.