使用六只晶体管的逻辑探头

图1中的电路用三只NPN晶体管和三只PNP晶体管做了一个逻辑探头。两只晶体管作为驱动LED的开关;逻辑1是绿色LED,逻辑0是红色LED。Q₁和Q₂测试探头尖的逻辑1状况,Q₃和Q₄测试逻辑O的状况。Q₁在Q₂射极电路中用作齐纳二极管。R₁₂和R₁₄构成的分压     

Novel three-component tandem reactions of cyclic mono ketones, isatin and sarcosine: formation of dispiropyrrolidines

One-pot, three-component tandem reactions of cyclic mono ketones, isatin and sarcosine affording dispiropyrrolidines stereoselectively are reported for the first time.     

Structural studies on fullerenes

Amongst the other physical properties, the structure of fullerene solids, and the structural transformations with temperature, pressure and doping have all evoked considerable interest and during the last two years tremendous progress has been made in this area. This paper provides a brief review of the studies on the structural properties of pristine and doped fullerenes. The results of our own investigations are also presented.     

Microwave remote sensing of soil moisture: elimination of textureeffect

In view of the influence of soil texture on microwave radiation, an attempt is made to eliminate the textural effects on the microwave reflectivity/emission. To determine the appropriate soil moisture parameter that minimizes the textural influences on microwave radiation from soils, soil moisture is expressed in terms of gravimetric and volumetric units and percentage of field capacity (M_fc ) and is plotted individually against the microwave reflectivity of soils. Only when soil moisture is in volumetric units are the textural influences significantly reduced. Therefore, a parameter, termed the critical water content (W_c), that takes into account the bound-water content of soils is used. An empirical relation between the interpolated values of W_c and the wilting point of soils has been developed. The soil water content above the W_c of each soil is considered as effective water M_eff     

Influence of temperature on the photometric determination of silicon by the molybdenum blue methods

Some systematic studies have been carried out on the influence of temperature on the photometric determination of silicon by the molybdenum blue procedure. It has been shown that temperature exerts a distinct influence on the colour intensities involved in the different procedures and the extent of this influence depends largely on the nature of the acid medium and the reducing agent employed. Ascorbic acid has been successfully employed to overcome the influence of temperature. Our thanks are due to the management of the Tata Iron and Steel Company for permitting the publication of this paper.     

Radiation effects in calcite

Calcite single crystals on neutron bombardment change their colour to pale red, red and deep red, as the duration of irradiation increases. The irradiated surface becomes rugged and on etching, a large number of micropits are observed. Using Vicker’s hardness indenter, it is observed that the hardress of the irradiated crystal increases with the increase in the total dosage. From Laue x-ray diffraction studies of irradiated crystals, distortion of lattice is observed. Absorption spectra in the visible region show an extra peak for irradiated samples which is absent for radiated ones. The radiation effects are annealed to a considerable extent on heat treatment. The implications are discussed.     

A study of the weak coupling limit of the pseudo SU(3) scheme

The usefulness of the pseudo SU(3) weak coupling limit for the study of even-even nuclei for which the protons and neutrons fill different major oscillator shells is examined. The content of proton and neutron configurations in the total wave function of the coupled space is estimated in order to understand their relative importance. The structure of ¹⁴⁴Ba is investigated in detail. Our calculations show that both proton and neutron configurations are important to study the collective excitations in nuclei and perhaps the strong coupling limit is more appropriate for nuclei such as those considered in this work.     

Titrimetric determination of gold by precipitation with hydroquinone

A rapid method for the volumetric determination of gold is described. Gold(III) is reduced to metal with excess of hydroquinone at room temperature and the excess is titrated with ceric sulphate. The effect of chloride ion on the reducibility of gold(III) to the metal is discussed. This method can be successfully employed for the determination of gold in presence of certain base and noble metals. The method was successfully adopted for the determination of gold in a commercial sample.