Tagging of η mesons using the pd → 3Heη reaction near threshold

A zero-degree spectrometer for tagging η mesons on the CELSIUS/WASA facility is described, and its characteristics are presented. Tagging of η mesons is performed by detecting ³He ions produced by reaction pd → ³Heη close to the production threshold. The low background level (<2%) is in good agreement with the data obtained earlier on the SATURNE accelerator.     

Status of Work on the VÉPP-5 Injection Complex

The VÉPP-5 injection complex under construction at the Institute of Nuclear Physics of the Siberian Branch of the Russian Academy of Sciences is a powerful source of intense electron and positron bunches at 510 MeV, which covers all needs of the electron–positron colliding beam setups currently operating and under construction at the Institute of Nuclear Physics. The complex includes a 285 MeV linear electron accelerator, a 510 MeV linear positron accelerator, and an accumulator–cooler with beam injection and ejection channels. Intense work on the design, assembly, and tuning of the linear electron accelerator has been conducted in the last 2 yr. As a result, by August 2002 the linear electron accelerator was put into operation with all standard subsystems. By this time, the isochronous achromatic turning of the electron beam, a system for converting electrons into positrons, and the first accelerating structure of the linear positron accelerator were assembled and put into operation. All this made it possible to accelerate the positron beam up to 75 MeV. Preliminary results of tests of the linear accelerators are presented.     

Provably correct runtime monitoring

Runtime monitoring is an established technique to enforce a wide range of program safety and security properties. We present a formalization of monitoring and monitor inlining, for the Java Virtual Machine. Monitors are security automata given in a special-purpose monitor specification language, ConSpec. The automata operate on finite or infinite strings of calls to a fixed API, allowing local dependencies on parameter values and heap content. We use a two-level class file annotation scheme to characterize two key properties: (i) that the program is correct with respect to the monitor as a constraint on allowed program behavior, and (ii) that the program has a copy of the given monitor embedded into it. As the main application of these results we sketch a simple inlining algorithm and show how the two-level annotations can be completed to produce a fully annotated program which is valid in the standard sense of Floyd/Hoare logic. This establishes the mediation property that inlined programs are guaranteed to adhere to the intended policy. Furthermore, validity can be checked efficiently using a weakest precondition based annotation checker, thus preparing the ground for on-device checking of policy adherence in a proof-carrying code setting.     

Electrowelded straight-seam high-strength pipe for structural use

Technical Specifications TU 1381-068-00186654–2016 have been developed for large-diameter electrowelded straight-seam high-strength pipe used in special-purpose structures, including those that operate in severe climatic conditions. Pipe made from thick sheet with a low impurity content by thermomechanical rolling with accelerated cooling is characterized by low-temperature strength, crack resistance, thermal stability, and resistance to fatigue-crack propagation. Such pipe resists mechanical aging and withstands seismic shocks. Research data permit the formulation of Technical Specifications TU 1381-068-00186654–2016 such that the special-purpose structures made from electrowelded straight-seam pipe will operate reliably.     

FINE STRUCTURE VARIATION OF 18R MARTENSITE UNDER DEFORMATION IN POLYCRYSTALLINE CuZnAl AI JOY

The transmission electron microscopy has been used to investigate the fine structure variationof 18R martensite under deformation in a polycrvstalline CuZnAl shape memory alloys.Ithas been found that the strain is gabined by the reorientation of martensite variants in the ini-tial deformation stage.In addition to the result of optical microscopy studies,however,thereorientation is often incomplete and the interfaces among the prior variants still remain.A lotof twins will appear in martensite under enormous deformation,and the twin plane is(001)phane of martensite lattice.The dislocations has also been observed in some regions.In thiscase,the martensite will lose its thermoelasticitv and the shape memory effect will bedamaged.     

Study of a Nanostructured Anatase Coating on the Rutile Surface

Russian Journal of Non-Ferrous Metals - Nanosized titanium dioxide allows solving complex engineering problems. One such a problem is the development of materials and coatings that reduce the...     

远程制导炮弹有控段弹道优化设计

文中对某远程制导炮弹进行弹道优化设计,为了能够很好的控制炮弹飞行,将有控段分成滑翔段、增速段和过重补偿段进行研究。根据制导炮弹滑翔段的特点,建立了制导炮弹的弹道模型,然后根据所建立的模型,给出了一种基于滑翔段的弹道优化算法。该算法避免了繁杂的梯度计算,相对于序列二次规划法其计算量大大降低了。仿真结果表明,所设计的弹道方案不仅增大了弹丸的射程,也提高了弹丸的命中概率。     

Structural special features and infrared spectra of absorption of ultradisperse boron nitride

Conclusions The ultradisperse powders of boron nitride with the mean particle size of 5.3–66 nm showed marked anisotropic deformation of the crystal lattice as a result of the structural stresses which are caused by the dimensional factor and are distributed nonuniformly through the volume of the particle.The turbostratic strain leads mainly to weakening of the interlayer bonds and shifts the maximum of the band of the interplanar oscillations to lower frequency by 17 cm^–1 for the specimen with a dispersion of 5.3 nm. In addition to this, the turbostratic strain causes asymmetric widening of the band of the intraplanar oscillations in the short-wave wing of the curve and displaces the maximum of this band by 20 cm^–1 to the short-wave range (for the specimen with a dispersion of 5.3 nm).Examination by the IR spectral method showed that the interatomic bonds shorten on the average by 10^–4 nm within the limits of the flat lattices. The investigations revealed the regular nature of the removal of the strain of the crystal lattice from the ultradisperse boron nitride during vacuum heat treatment accompanied by sintering of the powder.Translated from Poroshkovaya Metallurgiya, No. 1(301), pp. 85–91, January, 1988.     

A verification tool for ERLANG

This paper presents an overview of the main results of the project Verification of ERLANG Programs , which is funded by the Swedish Business Development Agency (NUTEK) and by Ericsson within the ASTEC (Advanced Software TEChnology) initiative. Its main outcome is the ERLANG Verification Tool (EVT), a theorem prover which assists in obtaining proofs that ERLANG applications satisfy their correctness requirements formulated as behavioural properties in a modal logic with recursion. We give a summary of the verification framework as supported by EVT, discuss reasoning principles essential for successful proofs such as inductive and compositional reasoning, and an efficient treatment of side-effect-free code. The experiences of applying the tool in an industrial case study are summarised, and an approach for supporting verification in the presence of program libraries is outlined.EVT is essentially a classical proof assistant, or theorem-proving tool, requiring users to intervene in the proof process at crucial steps such as stating program invariants. However, the tool offers considerable support for automatic proof discovery through higher-level tactics tailored to the particular task of the verification of ERLANG programs. In addition, a graphical interface permits easy navigation through proof tableaux, proof reuse, and meaningful feedback about the current proof state, to assist users in taking informed proof decisions.