FeZSM－5中不同化学环境的铁上乙苯氧化脱氢制苯乙烯的催化活性

ＦｅＺＳＭ－５中不同化学环境的铁上乙苯氧化脱氢制苯乙烯的催化活性张春雷，吴志芸，阚秋斌（吉林大学化学系，长春１３００２３）关键词ＦｅＺＳＭ－５沸石，铁，化学环境，乙苯，氧化脱氢，苯乙烯，多功能催化剂杂原子引入分子筛，除能调变分子筛的酸性和微孔孔径外，...     

Flexible and transparent moisture getter film containing zeolite

Organic light-emitting devices (OLED) are extremely sensitive to moisture and oxygen. Without high-performance hermetic seals, the life of these devices will be limited. A large amount of desiccant has been used in the packaging of OLED to ensure a dry environment. However, for top-emitter OLEDs, particularly for active matrix displays where the OLEDs are directly integrated on top of a thin film transistor (TFT) layer, the light must pass through a transparent encapsulating layer above the OLED, leaving little room to house the desiccant. Thus, a transparent layer with embedded moisture getter, such as zeolite, would be desirable. Here we report an effort to prepare such a transparent composite film containing zeolite nanoparticles, and show that such architecture is indeed possible.     

New diterpenoids from stems and roots of Caesalpinia crista

Nine new cassane-type diterpenes, named taepeenin A-I, and two new norcassane-type diterpenes, named nortaepeenin A-B, were isolated from the stems and roots of Caesalpinia crista along with three known diterpenes: vinhaticoic acid, methyl vinhaticoate and ent-11β-hydroxy-rosa-5,15-diene. Their structures were elucidated on the basis of spectroscopic analysis. In addition, the structure of taepeenin A was confirmed by X-ray diffraction analysis.     

纳秒强光场下呋喃的激光电离中高价离子的产生

利用 2 5ns脉冲Nd :YAG 5 32nm的激光 ,在 10 11W/cm2 的光场强度下 ,用飞行时间质谱对不同条件下呋喃的激光电离过程进行了研究 .当利用氩作为载气时 ,首次观察到了较强的Cn + (n =2～ 4 )和Om + (m =2～ 3)离子信号 .通过测定峰分裂和数值模拟计算的方法可以确定其中C2 + 、C3 + 和C4+ 的最可几平动能分别为 2 1、6 3和 10 0eV ,O2 + 和O3 + 的最可几平动能分别为 2 0和 4 0eV .质谱峰型的分裂现象和激光延迟实验结果表明 ,这些高价离子可能来源于呋喃团簇的库仑爆炸过程 .     

Additively separable duality theory

In duality theory, there is a trade-off between generality and tractability. Thus, the generality of the Tind-Wolsey framework comes at the expense of an infinite-dimensional dual solution space, even if the primal solution space is finite dimensional. Therefore, the challenge is to impose additional structure on the dual solution space and to identify conditions on the primal program, such that the properties that are typically associated with duality, like weak and strong duality, are preserved.In this paper, we consider real-valuedness, continuity, and additive separability as such additional structures. The virtue of the latter property is that it restores the one-to-one correspondence between primal constraints and dual variables as it exists in Lagrangian duality. The main result of this paper is that, roughly speaking, the existence of realvalued, continuous, and additively separable dual solutions that preserve strong duality is guaranteed, once the primal program satisfies a certain stability condition. The latter condition is ensured by the well-known regularity conditions that imply constraint qualification in Karush-Kuhn-Tucker points. On the other hand, if instead of additive separability, a mild tractability condition is imposed on the dual solution space, then stability turns out to be a necessary condition for strong duality in a well-defined sense. This result, combined with the observation that applicability of some well-known augmented Lagrangian methods to constrained optimization.This study was supported by the Netherlands Foundation for Mathematics (SMC) with financial aid from the Netherlands Organization for Scientific Research (NWO).     

一类以鞅为驱动的随机泛函微分方程强解的存在性与唯一性

在积分型Lipschitz条件下,证明了一类以连续鞅为驱动的随机泛函微分方程解的存在性与唯一性.     

Uptake and Sequestration of Naphthalene and 1,2-Dichlorobenzene by C60

The interactions of common environmental contaminants with C₆₀ have been studied to evaluate the environmental impact of carbon nanomaterials. The adsorption and desorption interaction of the hydrophobic contaminants naphthalene and 1,2-dichlorobenzene with C₆₀ was characterized. Processes that cause the wetting and disaggregating of C₆₀ particles also affect the extent of organic contaminant sorption to C₆₀ aggregates by orders of magnitude. C₆₀ dissolved in organic solvents such as toluene can form stable nanoscale aggregates upon vigorous mixing in water. These nanoscale C₆₀ particles form stable suspensions in water and are referred to as ‘nano-C₆₀’. Desorption of contaminants from stable suspensions of nano-C₆₀ exhibits hysteresis. The experimentally observed adsorption/desorption hysteresis is described by a two-compartment desorption model: first, adsorption to the external surfaces that are in contact with water, and second, adsorption to the internal surfaces within the aggregates.     

Transition from zero-dimensional to one-dimensional behavior in InAs and CdSe nanorods

Tunneling and optical spectroscopy performed on InAs nanorods 7–25 nm long, reveal a clear dependence of the band gap on length. This (zero-dimension like) behavior is different from that of CdSe rods, where the band gap is nearly independent of length, a signature of quasi-one-dimensionality. The transition between these two regimes is governed by the ratio between the Bohr radius and the nanorods length. The gaps measured by tunneling spectroscopy are larger than the optical gaps by a factor that depends on the tunneling configuration. This is attributed to a combination of the Coulomb interaction and the voltage division between the two tunnel junctions in the STM experiment. However, the tunneling gaps were found to reduce in dense aggregates of rods.     

Offset quantum-well method for tunable distributed Bragg reflector lasers and electro-absorption modulated distributed feedback lasers

A two-section offset quantum-well structure tunable laser with a tuning range of 7 nm was fabricated using offset quantum-well method. The distributed Bragg reflector (DBR) was realized just by selectively wet etching the multiquantum-well (MQW) layer above the quaternary lower waveguide. A threshold current of 32 mA and an output power of 9 mW at 100 mA were achieved. Furthermore, with this offset structure method, a distributed feedback (DFB) laser was integrated with an electro-absorption modulator (EAM),which was capable of producing 20 dB of optical extinction.