摘要：A series of benzohydrazide derivatives as novel ribosomal S6 kinase 2 （RSK2） inhibitors were designed and synthesized from a hit compound previously discovered by ligand-based virtual screening. Biological assays showed that these compounds possessed moderate inhibitory activities towards RSK2. The structural activity relationships （SAR） were elucidated by molecular docking and further optimization was performed.

摘要：A new approach which adopted the idea of coupling bionics to improve erosion resistance was presented, by taking the desert scorpion as the research object. The anti-erosion characteristic rules and mechanism of desert scorpion＇s surface under the dynamics effect of gas/solid mixed media were researched, especially the comprehensive influence mechanism of surface morphology, microstructure, creature flexibility and many other factors was studied. Simulation by CFD software was applied to predict the relative erosion severity. Samples with the coupled bionic configurations and flexibility were produced. Experiment optimum design theory was employed to design experiment scheme. Silica sand of particle size of 105-830 ~tm was used as the erodent. The erosion tests were carried out to validate the simulation results obtained. It is shown that the predicted results are in agreement with those obtained from the experiment. And contrast tests were carried out at the best and worst test points of erosion resistance for four samples. Contrast tests show that the erosion resistance trend occurs in such order with the best erosion resistance as coupling sample, groove, smooth and flexibility, and smooth, and the increasing rate of erosion resistances in sequence of 12.08%, 8.87%, 6.03% in the best test point. But in the poorest point, the increasing rate of erosion resistance is in sequence of 15.64%, 9.53%, 6.59%. The morphologies of eroded surface were examined by the scanning electron microscope, and the possible wear mechanism was discussed.

摘要：The high-temperature methanation of CO is an important reaction in the processes used to produce substitute natural gas,while the Ni-based catalysts prepared using the conventional impregnation method tend to deactivate under high-temperature reaction conditions. This paper describes the design and assembly of ordered mesoporous alumina(OMA) using highly disperse ~5 nm nickel nanoparticles(Ni NPs),via a one-pot,evaporation-induced self-assembly(EISA) method. Small-angle X-ray diffraction(XRD),transmission electron microscope(TEM),and N2 adsorption and desorption results revealed that this catalytic material had highly ordered mesopores,which were retained even after long-term stability tests. The catalyst exhibited excellent sintering-resistant and anti-coking properties in high-temperature CO methanation reactions(60% CO conversion after 50 hours of accelerated deactivation at 700°C). The improved catalytic performance was attributed to the matrix of the OMA,which effectively improved the dispersion of the nickel particles,and prevented the Ni NPs from sintering,via a particle migration and coalescence mechanism. The NiOMA catalyst demonstrated here shows promise for high-temperature methanation.

摘要：深入理解药物分子和核酸碱基间的相互作用机制对合理设计研发新型高效药物有重要意义.本文运用密度泛函理论B3LYP方法对核酸碱基尿嘧啶和胸腺嘧啶与药物分子槲皮素间的氢键相互作用位点进行了研究.使用B3LYP/6-31G(d)方法优化得到了30个稳定的氢键复合物结构,使用B3LYP/6-311++G(3df,2p)方法计算了这些复合物的结合能.研究结果表明,槲皮素可以使用5个不同的结合位点与尿嘧啶或胸腺嘧啶形成氢键复合物,尿嘧啶或胸腺嘧啶可以使用3个不同的结合位点与槲皮素形成氢键复合物.当槲皮素的结合位点固定时,槲皮素与尿嘧啶的位点u1或胸腺嘧啶的位点t1形成的氢键作用最强,与位点u2或位点t2形成的氢键强度最弱;当尿嘧啶或胸腺嘧啶的作用位点固定时,二者与槲皮素的位点qu1形成的氢键作用最强,与位点qu5作用强度次之,与位点qu3的作用强度最弱.分子中原子(AIM)和自然键轨道(NBO)分析计算结果表明,轨道作用在氢键中起重要作用.

摘要：基于奇异摄动理论结合动态逆设计的控制方法,研究了一类非仿射非线性系统的渐近稳定问题。通过将控制律定义为一个快动态系统的解,使原系统的状态能够准确地跟踪参考系统,且跟踪误差为零。同时给出了系统吸引区内的一个正不变子集,并证明了系统状态能够在有限时间内进入该子集,最终实现渐进稳定。用该方法构造的控制器实现起来较为简单,仿真结果表明了理论方法的有效性。

摘要：A series of naphthalimide azoles as potential antibacterial and antifungal agents were conveniently and efficiently synthesized starting from commercially available 6-bromobenzo[de]isochromene-l,3-dione. All the new compounds were characterized by NMR, IR, MS and HRMS spectra. Their antimicrobial activities were evaluated against four Gram-positive bacteria, four Gram-negative bacteria and two fungi using two-fold serial dilution technique. The biological assay indicated that most of the prepared compounds exhibited inhibition to the tested strains. In particular, the triazolium derivatives not only gave higher ef- ficacy than their corresponding precursory azoles, but also demonstrated comparable or even better potency than the reference drugs Chloromycin, Orbifloxacin and Fluconazole. Some factors including structural fragments, pH and ClogP values of the target molecules were also preliminarily discussed.

摘要：目的:工业的不断发展对航空发动机、泵、燃气轮机等旋转机械的动力性能提出了更高的要求。转子系统是旋转机械的重要组成部分。复杂的转子系统在高速运转时会产生故障和非线性振动,从而影响系统的可靠性。因此,开展转子系统的非线性动力性研究,研究转子系统在高速运转时的非线性响应及其抑制作用对转子系统的设计和故障诊断具有重要的意义。创新点:1.在建模的时候考虑转子系统的实际结构,在不对中模型中引入齿式联轴器啮合力,在滚动轴承模型中考虑弹流润滑影响;2.探究挤压油膜阻尼器参数对转子系统非线性特性抑制的影响,总结其变化规律。方法:1.基于Hertz接触和弹流润滑理论,建立滚动轴承动力学模型,同时考虑齿式联轴器齿之间的啮合力,建立不对中故障下的齿式联轴器啮合力模型,并在此基础上,根据转子系统的支撑形式,建立0-2-1支撑的转子动力学模型;2.开展转子动力学实验,验证模型的准确性并分析不对中量对系统频谱特性的影响;3.在分析不对中故障非线性特性的基础上,研究挤压油膜阻尼器参数对于非线性特性抑制的作用。结论:1.齿式联轴器啮合作用和滚动轴承的弹流润滑对不对中故障下转子系统的失稳产生一定的影响,润滑会导致系统发生分岔的窗口推迟;2.对于转子系统的弹性支撑,其一阶临界转速和振幅随着刚度的增大而增大,选择合适的刚度有利于转子系统的稳定运行;3.挤压油膜阻尼器的参数对转子系统故障引起的非线性具有较好的抑制作用,其作用的大小取决于不对中量和挤压油膜阻尼器的油膜间隙的耦合,合理地调节油膜间隙有助于增大系统的稳定区间范围。

摘要：Long propagation delay, limited bandwidth, and high bit error rate pose great challenges in media access control （MAC） protocol design for underwater acoustic networks. A MAC protocol called slotted floor acquisition multiple access （slotted-FAMA） suitable for underwater acoustic networks is proposed and analyzed. This FAMA based protocol adds a time slot mechanism to avoid DATA packet collisions. However, slotted-FAMA is not suitable for dense networks since the multiple request-to-send （RTS） attempts problem in dense networks is serious and greatly limits the network throughput. To overcome this drawback, this paper proposes a slotted-FAMA based MAC protocol for underwater acoustic networks, called RC-SFAMA. RC-SFAMA introduces an RTS competition mechanism to keep the network from high frequency of backoff caused by the multiple RTS attempts problem. Via the RTS competition mechanism, useful data transmission can be completed successfully when the situation of multiple RTS attempts occurs. Simulation results show that RC-SFAMA increases the network throughput efficiency as compared with slotted-FAMA, and minimizes the energy consumption.

摘要：Tanner图最小停止集的大小决定LDPC码在迭代译码时的性能.为此,提出准循环LDPC码无小停止集的充要条件.根据该文所提定理及推论,不仅可以设计出无小停止集的准循环LDPC码,而且还给出了小停止集数目的计算方法.在BER为le-5时,该文设计的准循环LDPC码与随机LDPC码相比具有0.3 dB的增益.该算法可有效评估LDPC码的性能,也可计算LDPC码的短环数,较之现有算法具有更低的计算复杂度.

摘要：Due to the different lighting environments or other reasons, the pixel colors may be quite different in one image which causes distinct visual discontinuities. It makes the analysis and processing of such an image more difficult and sometime impossible. In this paper, a unified multi-toning image adjustment method is proposed to solve this problem. First, a novel unsupervised clustering method was proposed to partition the source and the target image into a certain number of subsets with similar color statistics. By matching the texture characteristics and luminance distribution between the blocks, it can create optimized correspondence. Then, the color information was transferred from the matched pixels in the source blocks to the target ones. Graph cut method was used to optimize the seams between different subsets in the final step. This method can automatically perform color adjustment of a multi-toning image. It is simple and efficient. Various results show the validity of this method.