Characterizations of Graded Primitive Rings with Non-zero Graded Socles

In this paper, we characterize the structure of group graded primitive rings having minimal graded one-sided ideals in terms of graded dual modules. We also show that two structure representations of this class of graded primitive rings are both in a sense uniquely determined by the graded primitive rings considered.

Optimization of DC Resistance Divider Up to 1200 kV Using Thermal and Electric Field Analysis

Self-heating and electric field distribution are the primary factors affecting the accuracy of the Ultra High Voltage Direct Current(UHVDC)resistive divider.Reducing the internal temperature rise of the voltage divider caused by self-heating,reducing the maximum electric field strength of the voltage divider,and uniform electric field distribution can effectively improve the UHVDC resistive divider’s accuracy.In this paper,thermal analysis and electric field distribution optimization design of 1200 kV UHVDC resistive divider are carried out:(1)Using the proposed iterative algorithm,the heat dissipation and temperature distribution of the high voltage DC resistive divider are studied,and the influence of the ambient temperature and the power of the divider on the temperature of the insulating medium of the divider is analyzed;(2)Established the finite element models of 1200 kV and 2×600 kV DC resistive dividers,analyzed the influence of the size of the grading ring and the installation position on the maximum electric field strength of the voltage divider,and calculated the impact of the shielding resistor layer on the vicinity of the measuring resistor layer.The research indicates that:(1)The temperature of the insulating medium is linearly related to the horsepower of the voltage divider and the ambient temperature;(2)After the optimized design of the electric field,the maximum electric field strength of the 1200 kV DC resistive divider is reduced to 1471 V/mm,which is about 24% lower than that of the unoptimized design;(3)Installing the shielding resistor layer can significantly improve the electric field near the measuring resistor layer.This paper has an important reference function for improving the accuracy of the UHVDC resistive divider.

Experimental and numerical analyses of high voltage 4H-SiC junction barrier Schottky rectifiers with linearly graded field limiting ring

This paper describes the successful fabrication of 4H-SiC junction barrier Schottky （JBS） rectifiers with a linearly graded field limiting ring （LG-FLR）. Linearly variable ring spacings for the FLR termination are applied to improve the blocking voltage by reducing the peak surface electric field at the edge termination region, which acts like a variable lateral doping profile resulting in a gradual field distribution. The experimental results demonstrate a breakdown voltage of 5 kV at the reverse leakage current density of 2 mA/cm2 （about 80% of the theoretical value）. Detailed numerical simulations show that the proposed termination structure provides a uniform electric field profile compared to the conventional FLR termi- nation, which is responsible for 45% improvement in the reverse blocking voltage despite a 3.7% longer total termination length.

The Relative Properties of Graded Ring R and Smash Product R # G

Led G he a group, R be a G-graded ring, R,this paper deals with some relative properties of R and smash product R # G .We give out R is graded regular ring,graded right SF-ring, graded right V-ring, graded QF-ring if and only if R # G is regular ring,right SF-rign, right V-ring and QF-ring respectively.

750kV变电站瓷绝缘子的均压特性(英文)

Considering the complex environment in 750 kV AC substation,porcelain insulators have particular electric field and voltage distribution in comparison with those used in AC transmission line,meanwhile,the investigation of a typical 750 kV AC substation located in Lanzhou with ultraviolet imager(UVI) demonstrated that the corona discharge of some insulators is serious due to the improper structure design and installation,so research on porcelain insulators used in substation is needed.The three-dimensional finite element method(FEM) 750 kV AC substation calculation model was established to calculate electric field and voltage distribution of insulators,and the voltage distribution curves along insulators which are classified by type and suspension location were obtained using a novel FEM method which can effectively reduce the calculation amount without losing accuracy,meanwhile,the effect of the grading ring for improving voltage distribution of insulators was studied by adjusting the structure parameters of grading ring. Consequently,an optimization structure of rings was proposed by improving the voltage distribution of insulator string and reducing the electric strength of grading ring for the purpose of restricting corona noise,and the onsite observations by UVI showed that the newly manufactured and installed grading ring could obviously avoid the occurrences of corona discharge which validates the optimization design.This paper proposed an effective method combining UVI observation and FEM calculation to study voltage-sharing characteristics of porcelain insulators,and the results can provide experiences and references for the design of 750 kV AC substation.

A Duality Theorem Associated with the Smash Product of Graded Ring and G-set

Let G be a group, HG and R a G graded ring. We study the duality Theorem for G actions and smash products R#G/H of the G graded ring R and the G set G/H.

Homological dimension of graded semi-simple module

This paper proved that graded modules for greded division ring R are graded free modules and R is a IBN ring,and if R is a graded commutative ring,RM is a graded module andRM is a finite semisimple module,then gr.inj.dimRM=inj.dimRM.

Graded FS-Rings

In this paper, we introduce the notation of graded FS-module of the graded module over a group G-graded ring and obtain some characterization involving graded maximal graded left ideal for a graded FS-ring and some equivalent conditions between the ring R and group ring RG, the graded ring R and group ring of graded ring R[G].

NOETHERIAN GT-REGULAR RINGS ARE REGULAR

It is proved that for a left Nootherian z-graded ring A, if every finitely generated gradedA-module has finite projective dimension (i.e., A is gr-regular) then every finitely generatedA-module has finite projective dimension (i.e., A is regular). Some applications of this resultto filtered rings and some classical cases are also given.

Integrally Closed Ideals of Reduction Number Three

In a Cohen-Macaulay local ring(A,m),we study the Hilbert function of an integrally closed m-primary ideal I whose reduction number is three.,With a mild assump-tion we give an inequality ιA(A/I)≥e0(I)-e1(I)+(e2(I)+lA(I^(2)/QI)/2,where ei(I)denotes the ith Hilbert coeficient and Q denotes a minimal reduction of I.The inequality is located between inequalities of Itoh and Elias-Valla.Furthermore,this inequality be-comes an equality if and only if the depth of the associated graded ring of I is larger than or equal to dim A-1.We also study the Cohen-Macaulayness of the associated graded rings of determinantal rings.

Generalized Green Correspondence of Graded Modules

The author studies the Green correspondence and quasi-Green correspondence for indecomposable modules over strongly graded rings. The motivation is to investigate the influence of induction and restriction processes on indecomposability of graded modules.

Tameness and Artinianness of Graded Generalized Local Cohomology Modules

Let R = ⊙n〉0 Rn be a standard graded ring, a ∩ ⊙n〉0 Rn an ideal of R, and M, N two finitely generated graded R-modules. This paper studies the homogeneous components of graded generalized local cohomology modules. We show that for any i 〉 0, the n-th graded component Hiα（M, N）n of the i-th generalized local cohomology module of M and N with respect to a vanishes for all n 〉〉 0. Some sufficient conditions are pro- posed to satisfy the equality sup{end（Hiα （M, N）） [ i _〉 0} = sup{end（HiR＋ （M, N）） ｜ i 〉 0}. Also, some sufficient conditions are proposed for the tameness of Hiα（M, N） such that i = fRα＋（M,N） or i = cdα（M,g）, where fRα＋（M,N） and cdα（M,g） denote the R＋- finiteness dimension and the cohomological dimension of M and N with respect to a, respectively. Finally, we consider the Artinian property of some submodules and quotient modules of Hjα（M, N）, where j is the first or last non-minimax level of Hiα（M, N）.

Graded Antisimple Primitive Radical

We introduce the graded version of the antisimple primitive radical SJ, the graded an- tisimple prinfitive radical SJ_G. We show that SJ_G=SJ_(ref)=SJ^G when |G|<∞. where SJ_(ref) denotes the reflected antisimple primitive radical and SJ^G denotes the restricted antisimple primitive radical. Furthermore, we discuss the graded supplementing radical of SJ^G.