Source identification of individual P M2.5 particles in Shanghai air in the winter of 2007 with synchrotron X-ray fluorescence microprobe

In order to further understand the sources of PM2.5 in Shanghai air, the synchrotron X-ray fluores- cence microprobe at the BL-4A Beamline of Photon Factory of High Energy Accelerator Research Organization, Japan, was applied to analyze the individual PM2.5 particles collected from Shanghai air in the winter of 2007. Eight categories of emission sources were recognized in these individual particles. The source identification shows that most of the analyzed PM2.5 particles are derived from vehicle exhaust and metallurgical emissions. This suggests that the important emission sources of PM2.5 in Shanghai air would be vehicle exhaust and metallurgical activities.     

Noncritical vectorial phase matchings in nonlinear optics of crystals and infrared up-conversion

The exact analytic expressions for the vectorial group phase matching (PM) conditions have been obtained for sum and difference frequency generation processes ω₃ = ω₁ ± ω₂ (ω₃= ω₂ − ω₁) in nonlinear anisotropy crystals, which ensure a wide-band conversion of signals (ω₂) and images. The tangential PM conditions for all possible interaction types in the negative and positive uniaxial crystals have been studied. Scanning of the frequency of vectorial group PM has been studied by examples of LiNbO₃, LiIO, and HgGa₂S₄ crystals when changing the pump direction or pump frequency ω₁. The possibility of tuning the wide-band operation all over the transparency region of the LiIO₃, crystal has been shown. The double noncriticality conditions of PM in frequency cd; and acceptance angle have been studied and the possibility of their realization in a near and middle infrared region (IR) has been shown. A generalization of consideration to the other types of noncritical PMs (including multiples ones), has been made, including at an angle 90° between the propagation directions of waves with frequencies ω₁ (1) and ω₂ (2). The method of definition of the spectral bandwidths and acceptance angles of critical and noncritical PM taking into account the concordant change in the propagation angles of waves 1 and 2 has been proposed.     

Design and Experimental Characterization of Low‐Volume PM10/2.5/1.0 Trichotomous Sampler Inlet

This paper presents the development and laboratory evaluation of a PM10/2.5/1.0 trichotomous sampling inlet that consists of two main parts: a previously designed PM10 size‐selective inlet part and a PM2.5/1.0 two‐stage virtual impactor, which was newly fabricated and attached serially to the PM10 size selective inlet part. Particles are collected in three locations through the trichotomous sampling inlet to provide for not only particle concentration measurements of PM10, PM2.5 and PM1.0, but also those of PM2.5–10 and PM1.0–2.5.     

新系列超导相TlBaCan-1CunO2n+2.5(n=2,3)的晶体结构和超导电性

本文用粉末烧结法合成了Tl-Ba-Ca-Cu-O体系TlBa₂Ca_n-1Cu_nO_2n+2.5新系列超导相,用粉末衍射法测定了n=2和3的晶体结构,属简单四方单胞,空间群为D_4h¹-P4/mmm,点阵常数a相同,而c值不同,随n值而增大。a=3.847?,c分别为12.73?和15.89?,每单胞含一个化合式单位,阳离子沿四方晶系的(0,0,z)和(1/2,1/2,z)位置交替排列,排列的顺序相同,n=3比n=2依次多增加Ca和Cu及相应的氧离子。TlBa₂Ca_nCu_nO_2n+2.5,n=3时,零电阻超导转变温度T_c(0)=112K;n=2时,T_c(0)=101K,与Tl₂Ba₂Ca_n-1Cu_nO_2n+4型体心四方晶胞超导相不同,TlBa₂Ca_n-1Ca_nO_2n+2.5结构中缺氧类钙钛矿型结构单元[Ba₂Ca_n-1Cu_nO_2n+1]仅被TI-O单层所隔开,当n相同时,Tl-O双隔层的体心四方单胞比Tl-O单层的简单四方单胞的超导转变温度高10K左右,这说明Tl-Ba-Ca-Cu-O体系中超导相的转变温度不仅与类钙钛矿结构单元的[CuO₄]和[CuO₅]的数目有关,而且与Tl-O的隔层数目有关。 关键词：     

Electrostatic abatement of airborne respirable dust emission from mechanized tree-nut harvesting: Theoretical basis

The mechanized harvesting of tree nuts relies upon mechanically collecting and aerodynamically separating the nuts from extraneous vegetative and soil matter within the orchard using mobile power equipment. Typically the associated high-volume, high-velocity exhaust air disperses into the ambient atmosphere excessive concentrations of respirable-size particulate matter in the PM10 and PM2.5 micrometer realm creating a significant community air-quality problem. Our work developed a cyclonic-separation process for removing the PM10 dust and several candidate electrostatic-abatement processes for the smaller PM2.5 dust. We present the theoretical basis, including relevant mass- and charge-balances, for electrostatically abating the PM2.5 airborne dust via: (a) Ionized-field charging of the dust plume and its space-charge deposition within adjacent grounded tree-leaf canopies as air velocity subsides; (b) Injection of induction-charged spray of like polarity into the ion-charged-dust plume for space-charge-field enhancement; (c) Injection of charged spray alone into the dust plume; and (d) Injection of (+) polarity charged spray into the (?) polarity ionized-field-charged plume for electrostatic wet scrubbing of the dust. In addition to the theoretical basis, we report the technical development of a full-scale prototype to implement these electrostatic-abatement approaches on a mechanical harvester having ～10 g/s PM2.5 dust emission at ～27 m/s in an ～7 m³/s exhaust plume.     

Remarks on interpretations of the Eotvos experiment and misinterpretation of E=mc^2

The Eotvos experiment on the verification of equivalence between inertial mass and gravitational mass of a body is famous for its accuracy. A question is, however, can these experimental results be applied to the case of a physical space in general relativity, where the space coordinates could be arbitrary？ It is pointed out that it can be validly applied because it has been proven that Einstein＇s equivalence principle for a physical space must have a frame of reference with the Euclidean-like structure. Will claimed further that such an overall accuracy can be translated into an accuracy of the equivalence between inertial mass and each type of energy. It is shown that, according to general relativity, such a claim is incorrect. The root of this problem is due to an inadequate understanding of special relativity that produced the famous equation E=mc^2, which must be understood in terms of energy conservation. Concurrently, it is pointed out that this error is a problem in Will＇s book, ‘Theory and Experiment in Gravitational Physics＇.     

Entropy of Quantum Dynamical Systems and Sufficient Families in Orthomodular Lattices with Bayessian State

The purpose of the present paper is to study the entropy hs（Ф） of a quantum dynamical systems Ф = （ L, s, Ф）, where s is a bayessian state on an orthomodular lattice L. Having introduced the notion of entropy hs（ Ф, A） of partition A of a Boolean algebra B with respect to a state s and a state preserving homomorphism Ф, we prove a few results on that, define the entropy of a dynamical system hs（Ф）, and show its invariance. The concept of sufficient families is also given and we establish that hs （Ф） comes out to be equal to the supremum of hs （Ф,A）, where A varies over any sufficient family. The present theory has then been extended to the quantum dynamical system （ L, s, Ф）, which as an effect of the theory of commutators and Bell inequalities can equivalently be replaced by the dynamical system （B, s0, Ф）, where B is a Boolean algebra and so is a state on B.     

Status and accuracy of the Monte Carlo generators for luminosity measurements

The status and accuracy of the precision Monte Carlo generators used for luminosity measurements at flavour factories is reviewed. It is shown that, thanks to a considerable, long-term effort in tuned comparisons between the predictions of independent programs, as well as in the validation of the generators against the presently available calculations of the next-to-next-to-leading order QED corrections to Bhabha scattering, the theoretical accuracy reached by the most precise tools is of about one per mille. This error estimate is valid for realistic experimental cuts, appears to be quite robust and is already sufficient for very accurate luminosity measurements. However, recent progress and possible advances to further improve it are also discussed.     

Beam tail effect of a performance-enhanced EC-ITC RF gun

The beam tail effect of multi-bunches will influence the electron beam performance in a high intensity thermionic RF gun. Beam dynamic calculations that illustrate the working states of single beam tail and multi-pulse feed-in of a performance-enhanced EC-ITC （external cathode independent tunable cavity） RF gun for an FEL （free electron laser） injector are performed to estimate the extracted bunch properties. By using both Parmela and homemade MATLAB codes, the effects of a single beam tail as well as interactions of multi-pulses are analyzed, where a ring-based electron algorithm is adopted to calculated RF fields and the space-charge field. Furthermore, the procedure of unexpected deviated-energy particles mixed with an effective bunch head is described by the MATLAB code as well. As a result, the performance-enhanced EC-ITC RF gun is proved to have the capability to extract continual stable bunches suitable for a high requirement THz-FEL.     

First-Principles Calculations of Atomic and Electronic Properties of T1 and In on Si（111）

The atomic and electronic structures of T1 and In on Si（111） surfaces are investigated using the firstprinciples total energy calculations. Total energy optimizations show that the energetically favored structure is 1/3 ML T1 adsorbed at the T4 sites on Si（111） surfaces. The adsorption energy difference of one T1 adatom between （√3 × √3） and （1 × 1） is less than that of each In adatom. The DOS indicates that TI 6p and Si 3p electrons play a very important role in the formation of the surface states. It is concluded that the bonding of TI adatoms on Si（111） surfaces is mainly polar covalent, which is weaker than that of In on Si（111）. So T1 atom is more easy to be migrated than In atom in the same external electric field and the structures of T1 on Si（111） is prone to switch between （√3 × √3） and （1 × 1）.     

Coordinated Control of Multi-Agent Systems with a Varying-Velocity Leader and Input Saturation

In this paper, we investigate a leader-following tracking problem for multi-agent systems with bounded inputs. We propose a distributed bounded protocol for each follower to track a leader whose states may not be completely measured. We theoretically prove that each agent can follow the leader with estimable track errors. Finally, some numerical simulations are presented to illustrate our theoretical results.     

Study on the pre-chopper in CSNS LEBT

Physical designing of the pre-chopper in CSNS LEBT is carried out, which includes the deflecting voltage, the length and the width of the deflecting plates, and the gap between the deflecting plates. The most outstanding feature of the design is that both the gap and the width vary with the beam envelope size. So both the requried deflecting voltage and the loaded capacitance are lowered. In order to avoid destruction of the space charge neutralization by the pre-chopper in the whole LEBT, an electron-trapping electrode is arranged to confine the electrostatic field of the pre-chopper to the local area. To examine the reliability of the pre-chopping design in CSNS LEBT, a similar pre-chopping design in ADS RFQ LEBT is set up and an experiment on the pre-chopper is prepared. 3-dimensional simulations are carried out to determine the loaded capacitance and the applied voltage of the electron-trapping electrode.     

Synchronization in a Mutualism Ecosystem Induced by Noise Correlation

Understanding the cause of the synchronization of population evolution is an important issue for ecological improvement. Here we present a Lotka-Volterra-type model driven by two correlated environmental noises and show, via theoretical analysis and direct simulation, that noise correlation can induce a synchronization of the mutualists. The time series of mutual species exhibit a chaotic-like fluctuation, which is independent of the noise correlation, however, the chaotic fluctuation of mutual species ratio decreases with the noise correlation. A quantitative parameter defined for characterizing chaotic fluctuation provides a good approach to measure when the complete synchronization happens.     

Metric of States

Metric of quantum states plays an important role in quantum information theory. In this letter, we find the deep connection between quantum logic theory and quantum information theory. Using the method of quantum logic, we can get a famous inequality in quantum information theory, and we answer a question raised by S. Gudder.     

Status of KLOE-2

In a few months the KLOE-2 detector is expected to start data taking at the upgraded DAФNE φ-factory of INFN Laboratori Nazionali di Frascati. It aims to collect 25 fb^-1 at the φ（1020） peak, and about 5 fb^-1 in the energy region between 1 and 2.5 GeV. We review the status and physics program of the project.     

A Bi-Hamiltonian Lattice System of Rational Type and Its Discrete Integrable Couplings

By considering a new discrete isospectral eigenvalue problem, a hierarchy of lattice soliton equations of rational type are derived. It is shown that each equation in the resulting hierarchy is integrable in Liouville sense and possessing bi-Hamiltonian structure. Two types of semi-direct sums of Lie algebras are proposed, by using of which a practicable way to construct discrete integrable couplings is introduced. As applications, two kinds of discrete integrable couplings of the resulting system are worked out.     

On Camassa-Holm Equation with Self-Consistent Sources and Its Solutions

Regarded as the integrable generalization of Camassa-Holm （CH） equation, the CH equation with self-consistent sources （CHESCS） is derived. The Lax representation of the CHESCS is presented. The conservation laws for CHESCS are constructed. The peakon solution, N-soliton, N-cuspon, N-positon, and N-negaton solutions of CHESCS are obtained by using Darboux transformation and the method of variation of constants.     

Measurements of the γγ＊ → π^0 and γγ＊ → ηc transition form factors at BABAR

We present measurements of the γγ＊ → π^0 transition form factor for the momentum transfer range Q^2=4-40 GeV^2 and the γγ＊ → ηc transition form factor for the range Q^2=2-50 GeV^2. The current status of measurements of the meson-photon transition form factors for the η and η＇ mesons is discussed. The results of the measurement of the ηc mass, total and two-photon widths are also presented.     

Study of spin sum rules （and the strong coupling constant at large distances）

We present recent results from Jefferson Lab on sum rules related to the spin structure of the nucleon. We then discuss how the Bjorken sum rule with its connection to the Gerasimov-Drell-Hearn sum, allows us to conveniently define an effective coupling for the strong force at all distances.     

Collective multipole excitations of exotic nuclei in relativistic continuum random phase approximation

The isoscalar and isovector collective multipole excitations in exotic nuclei are studied in the framework of a fully self-consistent relativistic continuum random phase approximation （RCRPA）. In this method the contri- bution of the continuum spectrum to nuclear excitations is treated exactly by the single particle Green＇s function. Different from the cases in stable nuclei, there are strong low-energy excitations in neutron-rich nuclei and proton-rich nuclei. The neutron or proton excess pushes the centroid of the strength function to lower energies and increases the fragmentation of the strength distribution. The effect of treating the contribution of continuum exactly is also discussed.