Competition between Two Six-Wave Mixing Channels in Atomic Rb Vapor

Two six-wave mixing processes are achieved simultaneously in rubidium vapor and two channels are identified. Signal competition between the two channels is observed and phase matching conditions are analyzed for the two channels. The results show that the two six-wave mixing channels correspond to two parametric processes with weak coupling and, moreover, quantum interference and phase matching conditions primarily govern the signal competition.     

Formulation, characterization and hypersensitivity evaluation of an intravenous emulsion loaded with a paclitaxel-cholesterol complex

The objective of this paper was to develop a novel Cremophor-free, autoclave stable, intravenous emulsion for paclitaxel (PACE). A paclitaxel-cholesterol complex was used as the drug carrier to improve the solubility of paclitaxel in the oil phase of emulsions. The complex and PACE were prepared by rotary evaporation and high-pressure homogenization, respectively. Effects of oil phases, emulsifiers and pH values on the characteristics of PACE were investigated. PACE was characterized with regard to its appearance, morphology, osmolality, pH value, particle size, zeta potential, encapsulation efficiency and stability. Hypersensitivity was evaluated by guinea pig hypersensitivity reaction. The final formulation was composed of the complex, soybean oil, medium-chain triglyceridel, soybean lecithin, poloxamer 188 and glycerol. The resulting PACE had an encapsulation efficiency of 97.3% with a particle size of 135 nm and a zeta potential of -38.3 mV. Osmolality and pH of the formulation were 383 mOsmol/kg and 4.5, respectively. The formulation survived autoclaving at 115 °C for 30 min and remained stable for at least 12 months at 6 °C. PACE also exhibited a better tolerance than an equal dose of Cremophor-based paclitaxel injection in guinea pigs, as no obvious hypersensitivity reaction was observed. These results suggested that PACE has a great potential for industrial-scale production and clinical applications.     

加速溶剂萃取-固相萃取净化-气相色谱/质谱法测定沉积物中多氯联苯和多环芳烃

建立了加速溶剂萃取-固相萃取净化-气相色谱/三重四极杆串联质谱联用(ASE-SPE-GC-QqQ-MS/MS)法同时测定沉积物中28种多氯联苯(PCBs)和16种多环芳烃(PAHs)。对萃取、净化及仪器分析条件进行了优化。优化条件为:ASE萃取温度90℃,萃取时间6 min;净化小柱为硅胶-Florisil固相复合柱(填料自下而上为弗罗里硅土、0.7 g活化硅胶、1 g无水硫酸钠);洗脱溶液为丙酮-正己烷(1∶19,V/V)混合溶液,洗脱速率为0.6 mL/min。PCBs和PAHs在2～500μg/L和5～1000μg/L浓度范围内的线性相关系数(R2)分别为0.9987～0.9999和0.9939～0.9999;PCBs和PAHs方法检出限分别为0.001～0.08 ng/g和0.07～0.45 ng/g;定量限为0.003～0.25 ng/g和0.24～1.67 ng/g;实际样品平均加标回收率为95.6%～125.7%和70.4%～124.7%;方法相对标准偏差(n=6)为0.7%～6.4%和1.1%～12.8%。运用本方法对滇池入湖河口表层沉积物样品进行测定,该区域PCBs单体浓度为n.d.(未检出)～0.13 ng/g,PAHs单体浓度为0.79～131.12 ng/g。     

Study on the HOMs coupler design of spoke cavity

The superconducting spoke cavity has been proposed to accelerate the proton in the low energy section of high power proton linac for an Accelerator Driven Sub-critical System (ADS). Considering that the High Order Modes (HOMs) in the superconducting cavity have far reaching influence on power dissipation and beam stability, the analysis of HOMs of the spoke cavity is needed. In this paper, we put emphasis on the analysis of HOMs of the spoke cavity and the HOMs coupler design.     

Bi离子掺杂GeO2-Al2O3-M(M=Na2O，BaO，Y2O3)玻璃的光学性质

用高温熔融法制备了Bi离子掺杂浓度为1mol%的GeO-B₂O₃-Na₂O (GBNB)，GeO₂-Al₂O₃-Na₂O(GANB)，GeO₂-Al₂O₃-BaO(GABB)和GeO₂-Al₂O₃-Y₂O₃(GAYB)玻璃.测定了样品玻璃的差热曲线、吸收、发射光谱及荧光衰减曲线.实验发现GBNB，GANB，GAYB，GABB的吸收边带逐步发生红移.由于这些吸收边带是由Bi³⁺的6s²电子到Bi⁵⁺ 6s⁰空轨道的跃迁引起.因此推断GBNB，GANB，GAYB，GABB玻璃中Bi⁵⁺离子的含量逐步增加.在GABB，GAYB，GANB三个样品中观察到发光中心约1220nm超宽带荧光发射.荧光强度从GABB，GAYB，GANB逐步减弱，荧光半高宽和荧光寿命逐步变小.这些超宽带的荧光归属为Bi⁵⁺离子的发光所致.从吸收与荧光光谱的变化，推断在GeO₂-Al₂O₃玻璃中引入BaO，Y₂O₃组分有利于Bi⁵⁺离子的形成.讨论了BaO，Y₂O₃化学组分对Bi离子在玻璃中的价态影响的内在机理. 关键词： 5+离子')" href="#">Bi⁵⁺离子 超宽带发光 吸收带 荧光寿命     

Mn(III)-Promoted cyclization of substituted thioformanilides under microwave irradiation: a new reagent for 2-substituted benzothiazoles

Manganese triacetate is introduced as a new reagent to replace potassium ferricyanide or bromine for radical cyclization of substituted thioformanilides. 2-Substituted benzothiazoles are generated in 6 min under microwave irradiation.     

水平管道段塞流特征参数的压差波动分析

分析了压力波动信号互相关求液塞速度存在的不足，引入了压差波动分析法；明确了液塞到达和离开上、下游测压点的时刻与压差波动信号起峰点与落峰点位置的关系；指出了压差信弓脉冲宽度为液塞义到达上游测压点和液塞尾离开下游测压点的时间间隔，脉冲宽度与液塞速度的乘积为液塞长度与差压传感器间距之和．把空气－水、柴油和机械油的试验结果与文献中经验关系式进行了对比，验证了该测量方法的正确性．     

Lagrange系统形式不变性和Lutzky守恒量

研究Lagrange系统形式不变性导致的Lutzky守恒量．给出Lagrange系统形式不变性的判据，得到了系统的形式不变性是Lie对称性的充分必要条件．利用Lutzky的结论[6]证明了Lagrange系统形式不变性能导致Lutzky守恒量．举例说明结果的应用．     

单糖衍生物的电喷雾质谱裂解规律研究

以1-(2-萘基)-3-甲基-5-吡唑啉酮(NMP)作单糖标识剂, 经在线串联的LC-ESI-MS建立了单糖衍生物的电喷雾质谱裂解方法.衍生物在质谱裂解中糖类化合物特有的规范信息.借助糖类化合物在ESI-MS条件下表现出的分子离子峰m/z [M H] , 及在ESI-MS/MS条件下呈现出的特征碎片离子峰m/z 473, 可有效地确定出单糖类化合物的组成. 尽管一些脂肪醛和芳香醛也能同时被标识, 然而在质谱条件下不产生m/z 473的特征碎片离子峰, 且它们的洗脱远在糖类组分之后, 因此不干扰糖类化合物的分离和结构确定.通过建立的LC-ESI-MS方法, 对水解蜂花粉中的单糖进行了分析.结果表明: 水解的蜂花粉中含甘露糖(Man)、半乳糖醛酸(GalUA)、葡萄糖醛酸(GlcUA)、鼠李糖(Rha)、葡萄糖 (Glc)、半乳糖(Gal)、阿拉伯糖(Ara)、木糖(Xyl)和岩藻糖(Fuc).本方法为环境样品中单糖类化合物的确定提供了准确、可靠的技术手段.     

氟利昂F1110分子在飞秒激光脉冲作用下的多光子解离动力学

含氟利昂在内的含氯化合物在太阳光辐射下解离生成破坏臭氧的游离态氯原子, 是破坏大气臭氧层的主要元凶. 本文利用飞行时间质谱技术及离子速度成像技术研究了氟利昂F1110(四氯乙烯)分子在800 nm飞秒脉冲光作用下的多光子解离动力学. 利用飞行时间质谱探测技术, 得到了四氯乙烯在800 nm飞秒激光脉冲作用下发生多光子解离产生的碎片质谱, 发现了两个主要碎片离子C₂Cl₃⁺和 C₂Cl₂⁺. 对应的解离机理分别为单个C-Cl键断裂直接生产氯自由基C₂Cl₄⁺→C₂Cl₃⁺ +Cl 和两个C—Cl 键断裂C₂Cl₄⁺→C₂Cl₂⁺+2Cl: 利用离子速度成像技术对这两种机理产生的碎片离子进行成像, 得到了C₂Cl₃⁺ 和C₂Cl₂⁺ 离子的速度影像. 分析发现这两个碎片离子的动能分布均可由两个高斯分布曲线拟合, 说明这两种解离机理分别还对应了两种解离通道. 通过影像分析得到了解离的平动能分布和角向分布各向异性参数等详尽的动力学信息. 通过高精度密度泛函理论计算对解离动力学进行了进一步的分析和讨论.