Structural and optoelectronic properties of antimony tin sulphide thin films deposited by thermal evaporation techniques

Thin films of SnSb₂S₄ have been prepared on glass substrate by using thermal evaporation techniques. The films were annealed in argon gas at low pressure in sealed glass ampoules at 85 °C, 150 °C, 275 °C and 325 °C. XRD of the films reveal that the low temperature annealed films are poly crystalline while the as deposited films and high annealed films are in amorphous states. There is no adequate variation in the photoconductivity response of the amorphous and crystalline phases. The transmittance of the films is low and having no transmittance below 740 nm. The band gap calculated by ellipsometry technique is in the range of 1.82–3.1 eV. The films have n-type conductivity but the film annealed at 325 °C show p-type conductivity.     

Nouve determinazioni concernenti l’equazione integrale non lineare di Volterra

Sunto Nella Nota dal titolo ?Sull’equazione integrale di Volterra ? apparsa nel volume di questi Annali, precedente a quello che accoglie la presente, applicando un nuovo metodo d’approssimazioni successive, sono stati conseguiti nuovi teoremi d’esistenza e d’unicità, nonché talune limitazioni, per la soluzione dell equazione considerata. Con la presente si fanno conoscere ulteriori risultati esistenziali e quantitativi, per la soluzione dell equazione stessa, dovuti all’applicazione aello stesso metodo di approssimazioni successive.

---

Summary In the paper entitled ?On the Volterra integral equation ? and published in the immediately preceding volume of these Annali, new existence and uniqueness theorems were given, by means of a successive approximation procedure. The present note shows further results concerning existence and uniqueness of the solution of that equations, which follow from the application of the same method.

---

---

Ad Antonio Signorini nel suo 70^mo compleanno.     

Reactive surface micropatterning by wet stamping

Hydrogel stamps are used to reactively micropattern various types of substrates. The method, called reactive wet stamping (r-WETS), is general in nature and overcomes several limitations of conventional soft-lithographic techniques. Illustrative applications of r-WETS in surface wettability modification, deposition of metallic microstructures, preparation of supports for electrostatic self-assembly, and multistep reactive patterning are discussed.     

Sul concetto di limite

Sunto Si dà un'esposizione compendiosa del concetto di limite per una variabile, intesa nella sua più ampia accezione, anche come elemento di uno spazio astratto, nell'espressione alla quale quel concetto è pervenuto ai nostri giorni, cercando di mettere bene in vista le proprietà che si devon richiedere agli insiemi percorsi dalla variabile, per la determinazione e la costruzione di un suo limite eventuale.

---

Summary A brief and comprehensive exposition is given of the notion of limit of a variable, a variable being defined in the wides sense also as an element of an abstract space. The notion is expressed in the more recent form it has acquired in our days. An attempt is made to state clearly the requirements that have to be verified in the sets, where the variable moves, in order to carry out the determination and construction of its eventual limit.

---

---

Redatta a Portofino Vetta (agosto del 1958).     

A study of the reaction 2H(π±, p)X

We have studied the excitation function of the reaction ²H(π^±, p)X at a fixed proton angle of 90° for several fixed proton momenta of the detected proton as a function of the incident pion energy. No signal was found for a previous candidate for a dibaryon resonance around a mass of 2.23 GeV. The general trend of the data is reproduced by a multiple scattering theory     

Capillary filling of anodized alumina nanopore arrays

The filling behavior of a room temperature solvent, perfluoromethylcyclohexane, in approximately 20 nm nanoporous alumina membranes was investigated in situ with small angle x-ray scattering. Adsorption in the pores was controlled reversibly by varying the chemical potential between the sample and a liquid reservoir via a thermal offset, DeltaT. The system exhibited a pronounced hysteretic capillary filling transition as liquid was condensed into the nanopores. These results are compared with Kelvin-Cohan theory, with a modified Derjaguin approximation, as well as with predictions by Cole and Saam.     

Pd-Xantphos-catalyzed direct arylation of nucleosides

Direct arylation of the exocyclic amino groups of nucleosides represents a simple approach to N-aryl nucleoside derivatives. To date, one limitation has been that only electron-deficient aryl bromides and triflates possessed adequate reactivity for efficient, direct N-arylation of nucleosides. We demonstrate herein that Pd-Xantphos catalytic systems lead to successful N-arylation of suitably protected 2'-deoxyadenosine and 2'-deoxyguanosine with a wide range of aryl bromides.