Asymptotic Theory of Slightly Rarefied Gas Flow and Force on a Closed Body

Steady gas flows at small Knudsen numbers around arbitrary bodies (asymptotic behavior for small Knudsen numbers of the solution of time-independent boundary value problems of the Boltzmann equation over a general domain) are considered when the Reynolds number of the system is of the order of unity. The generalized slip flow theory developed for the Boltzmann-Krook-Welander equation is extended for the standard Boltzmann equation. From the result, the effect of gas rare faction on the flow (the relation between Boltzmann and hydrodynamic systems) is clarified, and several features of the force on a closed body in the gas are derived

日本とその周辺諸国における赤痢菌スペクトラムの展望補遺

A detailed observation of type and subtype distribution within each serogroup of Shigella was made in Japan, Korea, Taiwan, and Continental China, based principally on the same references as those used in the previous report (Vol.10,No.2 of this journal). Some references have been rejected because of insufficient taxonomic details. Others were adopted as the work by Japanese authors around 1945 and a survey of the etiologic structure of dysentery in the southern most territories of U.S.S.R. In Japan short after the war\u27s end, S. dysenteriae 1 and S. flexneri 2a were the main etiologic agents. Though the former decreased abruptly and for several years is scarcely found, the predominance of the latter continued till 1963. The organism ranking second within the Flexner group during the years until 1957 was 2b, but 3a took this position since 1958 and has been holding top rank since 1964, just when S. sonnei assumed dominance over the entire S. flexneri group. Flexner 2a is the member of the S. flexneri group occurring most frequently in Korea and Taiwan at present. In Continental China, Flexner 2a also had been ranking first within this serogroup in the 1950\u27s, but it appears that some change took effect there around 1960. S. dysenteriae 1 still exists in Korea as well as in Continental China. In Continental China, S. boydii type 4 represents the majority of typable strains in that serogroup. On the other hand, type 1 which is frequent in Japan and ranks first in Korea, indeed is scarce in Continental China.日本,韓国,台湾,中国大陸,北辺について赤痢菌各群内の型や亜型の分布を詳細に観察した.資料は前報(本誌第10巻第2号)のものと大体同じであるが,詳細な分類が行なわれていないものは除外し,その後に知ったものを採用し,終戦前後日本人によってなされた研究を記録に残す意味で加え,さらに最近知ることができたソ聠沿海州や南樺太の資料も引用した.終戦直後日本では志賀菌とフレキシナー2aが最も多かったが,前者は間もなく急激に減少し,現在はほとんど検出できない.後者2aは1963年まで終始首位を保っていたが1964年,あたかも前報で述べたソンネ菌がフレキシナー群を圧倒したその年に3aに首位を譲った.二位は1957年まで2bであったが,その後は上記の3aが躍進した.現在韓国と台湾では2aが首位にある.中国大陸でも1950年代は2aが首位にあったが,1960年前後にかなり形勢の変化があったようである.志賀菌は韓国と中国大陸にまだ存在する.中国大陸ではボイド群4型が型別可能菌中絶対優勢を占め.一方日本では優位に,韓国では首位にある1型が極めて少い

日本とその近隣諸国における赤痢菌群分布の展望

An outline of the distribution of shigellae in Japan, Korea, Taiwan, Hong Kong, Continental China, the Philippines, and other countries to the south is presented in the form of a survey from data compiled in the literature in terms of the spectrum of Shigella group. Japan is the only country to date with S. sonnei in an absolute majority, though it is gradually increasing also in the other areas. S. dysenteriae and S. boydit are seldom detected in urban communities of Japan but the former is found at a rate of 5 to 10 per cent in the other countries except Taiwan and Hong Kong. The latter appears in the same proportion, particularly in Vietnam. In Japan, the change in the ratio of S. flexneri and S. sonnei has been demonstrable in minute, year by year steps since 1951. In Korea, Taiwan, Hong Kong, and Mainland China an identical change is taking place approximately within a given period of time.日本,韓国,台湾,香港,中国大陸,フィリピン,さらに南方各国の赤痢菌分布を赤痢菌群スペクトラムの形に整理した資料で概観した.現在の日本はS. sonneiが絶対多数を占める唯一の国である.S. dysenteriaeとS. boydiiは日本の大都市一帯ではほとんど検出されないが,前者は台湾と香港を除くほかの国々で5～10%に見出され,後者は特にベトナムに大体この率で存在する.S. flexneriの減少とS. sonneiの増加が,日本では1951年以降逐年明示され,韓国,台湾,香港,中国大陸でも,ある時期において大体示されていた.特に中国大陸の大都会の小児患者分離株ではこの傾向が日本より早期かつ顕著であった

Laser Phase and Frequency Stabilization Using Atomic Coherence

We present a novel and simple method of stabilizing the laser phase and frequency by polarization spectroscopy of an atomic vapor. In analogy to the Pound-Drever-Hall method, which uses a cavity as a memory of the laser phase, this method uses atomic coherence (dipole oscillations) as a phase memory of the transmitting laser field. A preliminary experiment using a distributed feedback laser diode and a rubidium vapor cell demonstrates a shot-noise-limited laser linewidth reduction (from 2 MHz to 20 kHz). This method would improve the performance of gas-cell-based optical atomic clocks and magnetometers and facilitate laser-cooling experiments using narrow transitions.Comment: 7 pages, 6 figures, appendix on the derivation of Eq.(3) (transfer function for a polarization-spectroscopy-based frequency discriminator) has been adde

Two dimensional lattice Gross--Neveu model with domain-wall fermions

We investigate the two dimensional lattice Gross--Neveu model in large flavor number limit using the domain-wall fermion formulation, as a toy model of lattice QCD. We study nonperturbative behaviorn of the restoration of chiral symmetry of the domain-wall fermions as the extent of the extra dimension $(N_s)$ is increased to infinity. We find the the parity broken phase (Aoki phase) for finite $N_s$, and study the phase diagram, which is related to the mechanism of the chiral restoration in $N_s\to\infty$ limit. The continuum limit is taken and $O(a)$ scaling violation of observables vanishes in $N_s\to\infty$ limit. We also examine the systematic dependencies of observables to the parameters.Comment: 36 pages (26 figures), Latex (epsf style-file needed

Gauge Freedom in Chiral Gauge Theory with Vacuum Overlap

Dynamical nature of the gauge degrees of freedom and its effect to fermion spectrum are studied at $\beta=\infty$ for two- and four-dimensional nonabelian chiral gauge theories in the vacuum overlap formalism. It is argued that the disordered gauge degrees of freedom does not contradict to the chiral spectrum of lattice fermion.Comment: 3 pages. LaTeX with espcrc2. Talk given at Lattice '97, Edinburg