Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPorphyrins. XXVI. Triplet excimer quenching of free base, zinc, palladium, and platinum complexesJames B. Callis, Joan M. Knowles, and Martin GoutermanCite this: J. Phys. Chem. 1973, 77, 2, 154–157Publication Date (Print):January 1, 1973Publication History Published online1…
Comparison of crystal structure parameters obtained for ThCl4 from quantitative X-ray powder data with those available from single-crystal studies has shown that it is possible to obtain reliable parameters from powder studies on simple compounds. Structure refinement based on powder data for ThCl4(R= 8·9%), PaCl4(R=…
The permittivity of doped nematics is found to increase approximately as (1/ω)2 at low frequency. The effect is accounted for by considering the space charge resulting from dissociation of the dopant. The space charge capacitance is obtained from experimental data and compared with that of a simple model.
熱容量が非常に小さい小型の加熱炉をつくり, これを通常の偏光顕微鏡に取りつけた. この高温顕微鏡を用いて, Li2O・2SiO2および33.3Li2O・66.7SiO2・1.5R2O(R; Na, K, Cs) ガラス中に析出する結晶の成長速度を測定した. Li2O・2SiO2ガラス中には, リチウム・2珪酸塩結晶のみが析出した. 成長速度の測定値および結晶成長理論より, この結晶は螺旋転位機構によって成長することが推察された. また, 結晶-融液界面における拡散の活性化エネルギーは, 融液の粘性の活性化エネルギーに等しいことを確めた. 33.3Li2O・66.7SiO2・1.5R2Oガラスからは, リチウム・2珪酸塩結晶とともに…
In material collected in 195? and 19?0 in localities situated between 59° 44' N and 61 °22'N in SW Greenland a total of 465 oligohalobous diatoms and 260 mesohalobous and polyhalobous diatoms is shown, 4 nov. var. and 4 nov. fo. included. A greatnumber of the species and their varieties are not previously shown in Gre…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMechanism and kinetics of calcium sulfate hemihydrate dehydration by nonisothermal and isothermal thermogravimetryVladimir. Satava and Jaroslav. SestakCite this: Anal. Chem. 1973, 45, 1, 154–159Publication Date (Print):January 1, 1973Publication History Published online1 May…
Modified permanent magnets of rare earth cobalt compounds, R(Co, Cu)5, are known as alloys having a complex decomposition mechanism. Studies of the variation of magnetic properties with temperature were carried out for Sm(Co, Cu)5 alloys containing 0 to 75 at% copper. The optimum area for magnetic values was shifted t…
Treatment of magnesium or zinc porphyrins with thallium(III) trifluoroacetate, followed by an acidic work-up affords oxophlorins in high yield. The oxophlorin oxygen atom is shown to be trifluoroacetate-derived by the isolation of meso-trifluoroacetoxyporphyrins as stable intermediates; a radical mechanism is suggeste…
A mathematical model is proposed to treat the transient response of a disk electrode to a change in the applied current. The analysis reduces to a well‐defined boundary value problem, which yields solutions in terms of newly defined eigenfunctions. The results allow the determination of time constants characteristic o…
Protoporphyrin IX dimethyl ester acts as a diene in Diels–Alder additions with dimethyl acetylenedicarboxylate and with tetracyanoethylene. The copper(II) complex of octaethylporphin reacts with ethyl diazoacetate to yield mainly two isomeric chlorins formed by carbene addition to the cross-conjugated double bonds on…
In comparison with hen egg white lysozyme, goose lysozyme is known to be aberrant in both its structure and its enzymatic behavior in the presence of polymers of N-acetylglucosamine or cell suspensions of Micrococcus luteus. Our chemical studies show, however, that like the hen enzyme, goose lysozyme has muramidase ac…
The rate of corrosion and total corrosion of mild steel in the presence of chemically prepared ferrous sulphide has been studied. The mild steel appears to corrode by a first order reaction. Continued high corrosion rates are observed in experiments where ferrous sulphide is added semi-continuously. Approximately 10 m…
The dependence of the etch rates of vapor‐deposited binary borosilicate, phosphosilicate, and arsenosilicate glasses on glass composition and per cent buffered HF ( 1 part 48 % HF to 10 parts 40 % NH 4 F ) in water are presented. The etch rates of these doped glasses generally increase with increasing dopant oxide con…
Strength and ductilily of two-IJhase iron aLLoys with a ductile second IJhase IHesent are studied. The aLLoys used in this investigation are Fe-C r-N i aLLoys com/Josed of austenite and ferrite , Fe-N i-C aLLoys com/Josed of austenite alld martensite, and Fe-C aLLoys comlJosed of ferrite and lIIartensite, wilh Ilze se…
Shallow range distributions are altered significantly by diffusion and surface erosion. It will be shown here that the simultaneous processes of implantation, diffusion, and surface erosion can be described by a second order differential equation which is mathematically tractable and yields general results in terms of…
The chromium‐depletion theory of intergranular corrosion has been confirmed for a ferritic stainless steel. The potential range over which intergranular attack occurs is limited by the passivation potential of the matrix and that of chromium‐free iron. The concentration of chromium in the depleted zone is less than 5%…
The formation of particulate TiO2 has been studied by the addition of small quantities (10–5–10–3 mol fraction) of TiCl4 vapour to a lean CO + O2+ N2 flame with a maximum temperature of about 1400°C. Measurements of TiCl4 concentration have been made as a function of height (residence time) by u.-v. absorption spectro…
For certain conditions, alloys composed of metals of different nobility anodically dissolve without noticeable preferential dissolution of the less noble metal (simultaneous dissolution). In principle, an induction period of disproportionate dissolution of the less noble metal should precede simultaneous (nonselective…
Pitting potential measurements were performed by potentiodynamic scanning at 200 mV/hr in and in , each saturated with nitrogen. Over the entire temperature range studied, 1°–70°C, molybdenum additions up to the limit of solid solubility caused a continuous increase in the pitting potentials of 18% Cr ferritic stainle…
Partially ordered polyarnide-hydrazides were produced by the poly condensation of diacid chlorides with aminobenz-hydrazides, the order that results being a consequence of the considerably more rapid reaction of a diacid chloride with the hydrazide group in competition with the aromatic amine group of the aminobenzhyd…