碾子

前几日,我陪爱人去苍山看病,在医院的门旁看见一个老大娘正独自吃力地推着碾子碾压小麦。我忙跑过去,一边给老大娘搭讪,一边用手帮着推起了碾子。我问老大娘为什么不用机器？她说：＂弄的少,不值当的,再说用机器压出来的麦仁不好喝。＂我说：＂是吗？＂她说：＂是的,不信我给你带些尝尝。＂我忙说：＂不要的,大娘,家里有。

佛光寺东大殿檐部做法研究

根据清代文献中的记载,传统建筑下檐出占上檐出的0.75或者0.8,本文从文献中的这一规定出发,分析和整理了现存唐代遗构和深受唐代技术影响的日本8-12世纪末的遗构,发现早期实例中这一比值约在0.7-1.0之间。最后在实物研究的基础上文章又分析了佛光寺东大殿的檐部现状,初步认为该殿创建当初是不设飞子的檐部做法。

MATHEMATICAL MODEL OF SELF-REPAIRING FLIGHT CONTROL

The most prospective method for certain structural failures and damages that cannot employ redundancy is self-repairing techniques, to ensure especially the maximum flight safety. Based on the characters of self-repairing aircraft, this paper states some basic assumptions of the self-repairing aircraft, and puts forward some special new conceptions concerning the self-repairing aircraft: control input, operating input, command input, repair input and operating and control factor as well as their relationships. Thus it provides a simple and reliable mathematical model structure for the research on the self-repairing control of the aircraft.

A NEW ELECTRON IMPACT STORAGE ION SOURCE

A new electron impact storage ion source has been designed for time of flight mass spectrometers with a high mass resolving power and high sensitivity. Because of the storage and compressing focus of the source, the overall performance of the instrument has been improved greatly with a mass resolving power up to 3 500. The conditions of the second order of the focus are given and the storage ability is proved. The competer simulations and experiment results are given, too.

征稿

本刊是由广东省科学技术协会主管,广东省电子学会主办的优秀科技期刊。本刊始终坚持学术第一的标准和科学、创新、前瞻、实用的原则,刊载电子信息科技领域研究的新进展、新技术、新成果,促进学术交流,推动成果转换,提高该领域研究水平和科技装备水平,服务我国经济社会发展。

Femtosecond Two-Photon Detachment of Cu^- Studied By Photoelectron Imaging

The wavelength dependence of photoelectron angular distributions （PADs） of two-photon detachment of Cu^- has been directly studied by using the photoelectron map imaging. Results show that for the laser field intensity of 6.0×10^10W/cm^2, PADs exhibit dramatic change with the external field wavelength. Comparison between the experimental observation and the lowest-order perturbation theory prediction indicates that the pattern of PADs can be explained by the interference of the s and d partial waves in the final state. Relative contri- butions of s and d partial waves in the two-photon detachment at different laser wavelengths are obtained.

Experimental and Theoretical Study of Hydrogen Atom Abstraction from C2H6 and C4H10 by Zirconium Oxide Clusters Anions

The reactions of anionic zirconium oxide clusters ZrxOy- with C2H6 and C4H10 are investi-gated by a time of flight mass spectrometer coupled with a laser vaporization cluster source.Hydrogen containing products Zr2O5H- and Zr3O7H- are observed after the reaction. Den-sity functional theory calculations indicate that the hydrogen abstraction is favorable in the reaction of Zr2O5- with C2H6, which supports that the observed Zr2O5H- and Zr3O7H- are due to hydrogen atom abstraction from the alkane molecules. This work shows a newpossible pathway in the reaction of zirconium oxide cluster anions with alkane molecules.

Remote Three-Party Quantum State Sharing Based on Three-Atom Entangled States Assisted by Cavity QED and Flying Qubits

We present a remote three-party quantum state sharing （QSTS） scheme with three-atom Greenberger- Horne-Zeilinger （GHZ） states assisted by cavity QED and flying qubits. It exploits some photons to act as the flying qubits for setting up the quantum channel securely with three-atom systems in a GHZ state, which maybe make this remote QSTS scheme more practical than some other schemes based on atom systems only or ion-trap systems as photons interact with their environments weakly. The coherence of the stationary atom qubits in cavities provides the convenience for the parties in QSTS to check eavesdropping, different from entangled photon systems. Moreover, the present scheme works in a collective-noise condition and it may be more practical than others in applications in future.

崖神传说

1.山上树林中夜一轮圆月挂在空中。树林中阴森恐怖,猫头鹰落在一棵枯藤老树上环视四周。一只蜘蛛在网上等待着猎物。鸟叫虫鸣充斥着森林。草丛一阵乱动,惊起飞鸟若干。一个幽灵般的鬼魅眼神贴近地面游走,黑子飞快地穿梭在草丛中,伴着沉重的喘息。（狗的视角）远处一阵狼吼,惊起飞鸟一片。黑子加快移动的步伐。（狗的视角）一阵哨音,鬼魅一样的幽灵身影荡着绳索从黑子跑过的地方荡过。

Evaluation of the WDM6 scheme in the simulation of number concentrations and drop size distributions of warm-rain hydrometeors: comparisons with the observations and other schemes

The number concentrations and drop size distributions(DSDs)of warm-rain hydrometeors play an important role in the simulation of microphysical processes.To evaluate the performance of the WDM6 scheme,which predicts the cloud number concentration(Nc)explicitly in aspects of warm-rain hydrometeors number concentrations and DSDs,the simulation of the WDM6 scheme is compared with airborne observations of a flight trial,as well as with the simulations of the Thompson scheme and Morrison scheme.Results show that the WDM6 scheme produces smaller(larger)cloud(rain)number concentrations and wider cloud DSDs compared to the observations,with the largest biases at upper levels of stratiform cloud(SC).The Thompson scheme and the Morrison scheme,both of which set the Nc as a constant,compare better to the observations than the WDM6 scheme in aspects of Nc and DSD.Sensitivity tests of the initial cloud condensation nuclei(CCN)number concentration(CCN0)of the WDM6 scheme show that a better choice of the initial CCN0 may improve the simulation of convective cloud but helps little in terms of SC.The simulation of rain number concentration and DSD is not sensitive to the CCN0 in the WDM6 scheme.

Helium Droplets： An Apparatus to Study Ultra Cold Chemistry

A new pulsed helium nano droplets machine has been constructed. The droplets were gener- ated by expansion of the pure helium through the cryogenic valve attached to a closed-cycle cryostat. The mean size of helium droplets can be controlled between 103 and 105 helium atoms by tuning the backing pressure （10-40 bar） and temperature （10-30 K）. Compared with the continuous-flow beam source, the density of droplet is at least one order of magni- tude higher, which offers the opportunity to combine the system with the commercial pulsed laser to study chemical reactions inside of the superfluid helium at ultra-low temperature. The performance for the system has been checked by studying the photodissociation of CH3I doped droplets at 252 nm with the velocity map imaging technique. The photofragments, CH3, were detected by （2＋1） resonance enhanced multiphoton ionization. The speed and angular distributions derived from resulting images show clear evidence of the relaxation effect by the surrounding helium atoms. The pulsed helium droplets depletion spectroscopy was also demonstrated. The depletion spectrum of benzene doped helium droplets indicates that less than 3% depletion can be observed with the newly constructed apparatus.

A Surface Femtosecond Two-Photon Photoemission Spectrometer for Excited Electron Dynamics and Time-Dependent Photochemical Kinetics

A surface femtosecond two-photon photoemission （2PPE） spectrometer devoted to the study of ultrafast excited electron dynamics and photochemical kinetics on metal and metal oxide surfaces has been constructed. Low energy photoelectrons are measured using a hemispherical electron energy analyzer with an imaging detector that allows us to detect the energy and the angular distributions of the photoelectrons simultaneously. A Mach-Zehnder interferom- eter was built for the time-resolved 2PPE （TR-2PPE） measurement to study ultrafast surface excited electron dynamics, which was demonstrated on the Cu（111） surface. A scheme for measuring time-dependent 2PPE （TD-2PPE） spectra has also been developed for studies of surface photochemistry. This technique has been applied to a preliminary study on the photochemical kinetics on ethanol/TiO2（110）. We have also shown that the ultrafast dynamics of photoinduced surface excited resonances can be investigated in a reliable way by combining the TR-2PPE and TD-2PPE techniques.

浅析单脚起跳扣球技术

单脚起跳扣球技术,是经历了一个从使用——不使用——发展的过程。在五十年代初,就有人在比赛中使用这项技术,但当时却被人称之为“不规格的扣球技术”,随着时间的流逝慢慢地被淘汰了。七十年代初期,以辽宁女排的于子飞等队员为代表,又重新掌握了这项技术,并在比赛运用中取得了较好的效果,引起了人们的关注。

Modification of Reflectron Time-of-Flight Mass Spectrometer for Photodissociation of Mass-Selected Cluster lons

We introduce a modification of reflectron time-of-flight mass spectrometer for laser photodissociation of mass-selected ions. In our apparatus, the ions of interests were selected by a mass gate near the first space focus point and decelerated right after the mass gate, were then crossed by a laser beam for dissociation. The daughter ions and surviving parent ions were re-accelerated and analyzed by the reflectron time-of-flight mass spectrometer. Compared to the designs reported by other research groups, our selection-deceleration-dissociation-reacceleration approach has better daughter-parent-ions-separation, easier laser timing, and better overlapping between the ion beam and laser beam. We also conducted detailed cal- culations on the parent ion and daughter ion flight times, and provided a simplified formula for the calibration of daughter ion mass.

A New kHz Velocity Map Ion/Electron Imaging Spectrometer for Femtosecond Time-Resolved M olecular Reaction Dynamics Studies

A new velocity map imaging spectrometer is constructed for molecular reaction dynamics studies using time-resolved photoelectron/ion spectroscopy method. By combining a kHz pulsed valve and an ICCD camera, this velocity map imaging spectrometer can be run at a repetition rate of 1 kHz, totally compatible with the fs Ti：Sapphire laser system, facilitating time-resolved studies in gas phase which are usually time-consuming. Time-resolved velocity map imaging study of NH3 photodissociation at 200 nm was performed and the time-resolved total kinetic energy release spectrum of H＋NH~ products provides rich information about the dissociation dynamics of NH3. These results show that this new apparatus is a powerful tool for investigating the molecular reaction dynamics using time-resolved methods.

Ion-Pair Photodissociation of Trichloromonofluoromethane

fragments, F- and Cl- including two isotope species 35Cl- and 37Cl-, are observed in the photoexcitations of CFC13. The ion-pair anion efficiency spectra of 35Cl- and 37Cl- are recorded in the photon energy range of 7.75-22.00 eV. The threshold of ion-pair dissociation CFCl3-CFC12＋＋Cl- is experimentally determined to be 7.944-0.04 eV. With the references of the high-resolution photoabsorption spectra reported in the literatures, we make tentative assignments of the electron valence-to-Rydberg transitions. Furthermore, the multibody ion-pair fragmentation processes to Cl- are discussed by comparison between the calculated thermochemical thresholds and the experimental efficiency spectrum.

郑州航空港区空管小区唐代墓葬

2014年4月,郑州市文物考古研究院对郑州机场二期扩建空管工程空管综合小区进行考古发掘,发现了一批唐代的墓葬。 发掘清理的7座唐代墓葬均为砖室墓。其中M5保存较好,为长方形竖穴砖室墓,墓内出土有铜镜、铜耳勺、铜刀、眉夹、铜钱等遗物。其中铜镜上有铭文＂真子飞霜＂,是人物故事镜。铜钱为唐代安史之乱时期史思明所建政权铸造的钱币——＂顺天元宝＂＂得壹元宝＂。

樊哙怨(讽刺诗)

萧何捋须笑呵呵:“左”的思潮属君多.樊哙无端怨萧何:韩信拜帅实失策,领导岗位没干过,年纪太轻少资格……

Saving Graces

A while ago a Dickinson College studentasked the white-haired chairman of the Eng-lish department if he had ever read Tolstoy’sWar and Peace from cover to cover.The el-derly don considered his answer before speak-