摘要：通过传统的方法,制备了两种对水和空气稳定的四烷基膦类离子液体。离子液体是:己基三丁基膦四氟化硼和己基三丁基膦双三氟甲基磺酸亚胺。在T=283.15-353.15 K温度范围内,测定了两个离子液体的密度、动力粘度及电导率。讨论了温度、阴离子结构对离子液体的性质的影响。结合文献报道的其它离子液体,讨论了该类离子液体性质随阳离子结构的变化规律,并与咪唑类离子液体的性质进行了比较。通过经验方程,利用密度数据计算了两个离子液体的重要热力学性质参数,例如:分子体积、标准摩尔熵及晶格能等。并将估算性质与传统的咪唑、吡啶类离子液体进行了对比。通过密度和电导率确定了离子液体的摩尔电导率。讨论了Vogel-Fulcher-Tamman(VFT)方程和Arrhenius方程对于粘度和电导率拟合的可行性,并估算了电导活化能及流动活化能。通过Walden规则,描述了密度、粘度及电导率之间的联系。有关研究对新型离子液体的合成及其工业化的应用具有十分重要意义。

摘要：制备了功能化离子液体1-丁腈-3-甲基咪唑双三氟甲基磺酸亚胺。在T为283.15-353.15 K温度范围内,测定了该功能化离子液体的密度、动力粘度、电导率及折光率。讨论了亚甲基的增减对该类功能化离子液体的密度、动力粘度、电导率及折光率等性质的影响,并与传统咪唑类、吡啶类离子液体物理化学性质的变化趋势进行了对比。通过经验方程计算了该功能化离子液体的热膨胀系数、分子体积、标准摩尔熵及晶格能等热力学性质参数。讨论了Vogel-Fulcher-Tamman(VFT)方程和Arrhenius方程的适用性,得出VFT方程适用于该功能化离子液体,而Arrhenius方程并不适用。有关研究对新型离子液体的合成及其工业化的应用具有十分重要的意义。

摘要：汽车倒车防撞预警系统可以有效降低汽车倒车时发生刮擦碰撞事故的几率。该系统以AT89S52微处理器为主控制器，采用HC—SR04超声波测距传感器实现倒车时后方空间的测距，在主控单元设计和测距模块设计的基础上，进行了数据通信电路设计，并设计了软件系统，最后进行了测试实验。经过实验数据分析，系统探测距离范围在2～400cm，测距精度达到3mm。结果表明：该系统测距范围较大，测距精度不会造成对汽车的损害，能够满足汽车在狭小空间内的倒车预警要求。

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：The ecological costs of open pit metal mining are quantified, which include lost value of direct eco-services, lost value of indirect eco-services, prevention and restoration costs, and cost of carbon emission from energy consumption. These ecological costs are incorporated in an iterative ultimate pit optimization algorithm. A case study is presented to demonstrate the influence of ecological costs on pit design outcome. The results show that it is possible to internalize ecological costs in mine designs. The pit optimization outcome shifts considerably to the conservative side and the profitability decreases substantially when ecological costs are accounted for.

摘要：Long-lasting phosphorescent （LLP） materials have attracted considerable attention since green and blue emitting persis- tent Eu2＋ doped alkaline earth phosphors were reported in the mid-1990s [1-3]. Over the past few decades, a consid- erable effort has been made to design novel LLP materials for a wide range of applications such as emergency lighting, interior decoration, road signs, and in vivo bioimaging [4-6]. For these applications, long persistence times are often desir- able. Two types of active center involved are： emitters and traps in LLP phosphors. Emitters are capable of emitting ra- diation after being excited, and their color is determined by the emission wavelength of the LLP phosphor. Traps states usually do not emit radiation, but store the excitation energy later releasing it to the emitters under thermal disturbance. Thus, traps play an important role in photo-energy storage of LLP phosphors. The trap type and trap distribution are gen- erally associated with lattice defects and/or co-dopants. The overall nature of the trap states determines the persistence in- tensity and time. Thus, design of LLP phosphors focuses on generating suitable trap levels and trap densities.

摘要：目的:对广西莪术(Curcuma kwangsiensis)的根茎进行化学成分研究。方法:运用硅胶、Sephadex LH-20柱色谱、ODS柱色谱和制备HPLC等分离手段进行化学成分的分离纯化,根据其波谱数据鉴定其结构。结果:从广西莪术中分离得到 7个化合物,分别鉴定为:[4-(1′-hydroxy-1′-methylethyl) benzoate-1′-O-β-D-glucopyranoside](1),[4-(1′-hydroxy-1′-methylethyl) ben-zoic acid-1′-O-β-D-glucopyranoside](2),2, 3,5-trihydroxy-1-(3-methoxy-4-hydroxyphenyl)-7-(3,5-dimethoxy-4-hydroxyphenyl) hep-tane(3) and 2,3, 5-trihydroxy-1-(4-hydroxyphenyl)-7-(3,5-dimethoxy-4-hydroxyphenyl)heptane(4),以及 1,5-epoxy-3α-hydroxy- 1-(3,4-dihydroxy-5-methoxyphenyl)-7-(3,4-dihydroxy)heptane(5),(3R′,5S′)-3,5-dihydroxy-1-(4-hydroxy-3-methoxyphenyl)-7-(3,4-dihydroxyphenyl) heptane(6),2,4,6-trihydroxyacetophenone-2,4-di-O-β-D-glucopyranoside(7)。结论:化合物1-4为新化合物,化合物3-7对脂多糖所致巨噬细胞产生一氧化氮表现出强的抑制活性。

摘要：A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,X-ray photoelectron spectroscopy,and N2 adsorption-desorption were used to characterize the crystalline phase,morphology,particle size,chemical composition,and surface area of the WO3 *** formation of hexagonal（h-WO3） and monoclinic（m-WO3） crystal structures of WO3 at different temperatures or different times was confirmed by XRD.m-WO3 is formed at 600 ℃,while m-WO3 starts to transform into h-WO3 at 800℃.However,h-WO3,which forms at 800℃,may transform into m-WO3 by increasing the calcination temperature to 1000℃.SEM results indicate that m-WO3 particles exhibit a bulky shape with heavy aggregates,while h-WO3 particles exhibit a rod-like ***,m-WO3 crystals are sporadically patched on the surface of the h-WO3 rod-like particles,resulting in the exposure of both m-WO3 and h-WO3 on the *** is observed that the monoclinic phase（m-WO3）/hexagonal phase（h-WO3） junction was fabricated by tuning the calcination temperature and calcination *** relative ratios between m-WO3 and h-WO3 in the phase junction can readily be tailored by control of the calcination *** photocatalytic activities of WO3 with different crystalline phases were evaluated by the photocatalytic degradation of rhodamine B as a model pollutant.A higher photocatalytic activity was observed in the WO3 sample with the m-WO3/h-WO3junction as compared with the sample with only *** improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate owing to the formation of the phase junction,whose presence has been confirmed by HRTEM and photoluminescence spectra.

摘要：下一代互联网NGI(next generation Intemet)需要提供服务质量QoS(quality of service)路由能力.由于NGI网络状态难以精确测量与表达,因此,QoS路由基于的信息应该是模糊的.随着网络运营的渐趋商业化,付费上网要求实现QoS计费,而网络提供方与用户的利益冲突要求实现效用双赢.设计了一种基于模糊积分和博弈论的QoS组播路由机制.该机制由边评判、博弈分析和组播路由树建立算法组成,基于模糊积分和适合隶属度函数对边进行模糊综合评判,通过博弈分析确定网络提供方与用户在边上的效用能否达到Nash均衡,通过组播路由树建立算法使得在建立的组播路由树上不仅用户QoS要求得到满足,而且网络提供方效用与用户效用达到或接近Nash均衡下的Pareto最优.仿真结果表明,与QoSMIC等机制相比,该机制具有较好的性能.