Abstract:
The present invention provides strategies for improving the quality of the insulating layer in MIS and SIS devices in which the insulator layer interfaces with at least one pnictide-containing film. The principles of the present invention are based at least in part on the discovery that very thin (20 nm or less) insulating films comprising a chalcogenide such as i-ZnS are surprisingly superior tunnel barriers in MIS and SIS devices incorporating pnictide semiconductors. In one aspect, the present invention relates to a photovoltaic device, comprising: a semiconductor region comprising at least one pnictide semiconductor; an insulating region electrically coupled to the semiconductor region, wherein the insulating region comprises at least one chalcogenide and has a thickness in the range from 0.5 nm to 20 nm; and a rectifying region electrically coupled to the semiconductor region in a manner such that the insulating region is electrically interposed between the collector region and the semiconductor region.
Abstract:
A strain gauge amplifier assembly for operationally connecting between a strain gauge having first and second differential voltage output values and a PC, including a board; an amplifier mounted to the board and configured for electrically connecting with first and second outputs of a strain gauge; a main controller mounted to the board and having data management elements including at least one controller core, a serial port, an A/D converter and an EEPROM, the amplifier being operationally connected with the main controller; a digital potentiometer assembly mounted to the board and operational to adjust at least one of the gain and offset values of the amplifier; and, a port assembly for connecting with a strain gauge and receiving first and second differential voltage values and with an external PC.
Abstract:
A catalyst composition comprising a zirconium complex of a polyvalent aryloxyether and an alumoxane, polymerization processes employing the same, especially the continuous, solution polymerization of ethylene and one or more C 3-30 olefins or diolefins to prepare copolymers having reduced cocatalyst by-product content, are disclosed.
Abstract:
A process for polymerization of propylene, optionally ethylene, and further optionally one or more C 4-30 α-olefins and/or one or more conjugated or nonconjugated dienes under continuous, solution polymerization conditions to prepare a high molecular weight polymer or interpolymer, said process comprising conducting the polymerization in the presence of a catalyst composition comprising a hafnium complex of a polyvalent aryloxyether.
Abstract:
A combinatorial method for identifying a catalyst composition for use in the homogeneous addition polymerization of an olefin monomers, said catalyst composition comprising a transition metal compound, a cocatalyst and a polymerization modifier, as well as catalyst compositions and improved olefin polymerization processes resulting therefrom.
Abstract:
A method for releasing gas from a gas hydrate without melting the gas hydrate by substituting the gas with a releasing agent that forms a more stable hydrate structure than the gas.
Abstract:
Polymer blends that exhibit good impact resistance comprise a crystalline polypropylene matrix and a partly crystalline copolymer impact modifier with a molecular weight lower than that of the matrix polymer. The matrix polymer can comprise any crystalline propylene homo- or copolymer. The impact modifying copolymers are characterized as comprising at least about 60 weight percent wt.% of units derived from propylene and, in certain embodiments, as having at least one, preferably two or more, of the following properties: i 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, ii a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt.%, iii a skewness index, Six, greater than about -1.20, iv a DSC curve with a Tme that remains essentially the same and a Tmax that decreases as the amount of comonomer in the copolymer is increased, and v an X-ray diffraction pattern that reports more gamma-form crystals than a comparable copolymer prepared with a Ziegler-Natta Z-N catalyst.
Abstract:
Fibers comprising a propylene homopolymer or a copolymer of propylene and at least one of ethylene and one or more unsaturated comonomers exhibit desirable properties. The homopolymers are characterized as having 13 C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. The copolymers are characterized as (A) comprising at least about 60 weight percent (wt%) of units derived from propylene, and (B) having at least one of the following properties: (i) 13 C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a 13-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt%, (iii) a skewness index, S ix , greater than about -1.20, (iv) a DSC curve with a T me that remains essentially the same and a T max that decreases as the amount of comonomer in the copolymer is increased, and (v) an X-ray diffraction pattern that reports more gamma-form crystals than a comparable copolymer prepared with a Ziegler-Natta (Z-N) catalyst.
Abstract:
A method of nucleating a propylene homo- or copolymer, the method comprising contacting the propylene polymer with a semi-crystalline branched or coupled polymeric nucleating agent under nucleation conditions. In one embodiment, the propylene homopolymer is characterized as having 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. In another embodiment, the copolymer is characterized as comprising at least about 60 weight percent (wt%) of units derived from propylene, and as having at least one of the following properties: (i) 13 C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content, i.e., the units derived from ethylene and/or the unsaturated comonomer(s), of the copolymer is at least about 3 wt%, (iii) a skewness index, Si x , greater than about -1.20, (iv) a DSC curve with a T me that remains essentially the same and a Tmax that decreases as the amount of comonomer, i.e., the units derived from ethylene and/or the unsaturated comonomer(s), in the copolymer is increased, and (v) an X-ray diffraction pattern that reports more gamma-form crystals than a comparable copolymer prepared with a Ziegler-Natta (Z-N) catalyst.
Abstract translation:一种使丙烯均聚物或共聚物成核的方法,所述方法包括在成核条件下使所述丙烯聚合物与半结晶支化或偶联聚合物成核剂接触。 在一个实施方案中,丙烯均聚物的特征在于具有对应于约14.6和约15.7ppm的区域误差的13 C NMR峰,约等强度的峰。 在另一个实施方案中,共聚物的特征在于包含至少约60重量%(wt%)的衍生自丙烯的单元,并具有至少一种以下性质:(i)13 C NMR 在约14.6和约15.7ppm处对应于区域误差的峰,约等强度的峰,(ii)当共聚单体含量(即衍生自乙烯和/或不饱和单体的单元)的B值大于约1.4时 (iii)偏度指数Si x大于约-1.20,(iv)具有T sub>的DSC曲线, 基本上保持相同,并且随着共聚单体的量,即共聚物中衍生自乙烯和/或不饱和共聚单体的单元的量增加,T max降低,以及(v) 报道比用齐格勒 - 纳塔(ZN)催化剂制备的可比较的共聚物更多的γ-型晶体的X-射线衍射图。 p>