In (4) Young investigates the representation in terms of his exact seminormal units m^ of substitutional expressions which are unchanged on premultiplication by any permutation of a given set of consecutive letters, or which are changed in sign on premultiplication by an odd permutation of those letters. He illustrates his results by deducing the forms of the matrices representing the positive ...

Tamoxifen (ICI 46,474), the trans isomer of a substituted triphenylethylene, was discovered in the fertility program at Imperial Chemical Industries, Pharmaceuticals Division, Cheshire, England. The plan was to use tamoxifen to regulate fertility, but this failed and interest refocused outside the company for applications to treat breast cancer. The initial application of the nonsteroidal antie...

We use the density matrix renormalization group (DMRG) method to study the ground and low-lying excited states of three kinds of uniform and dimerized alternating spin chains. The DMRG procedure is also employed to obtain low-temperature thermodynamic properties of these systems. We consider a 2N site system with spins s1 and s2 alternating from site to site and interacting via a Heisenberg ant...

Through the main chemical reaction of metal ions and S2−, a new type sulfide precipitant was first prepared used to realize selective separation recovery copper arsenic from leaching solution soot. It is proven by experimental results that could efficient arsenic. Indeed, slag with Cu grade about 47% trisulfide As operation 98% be obtained. The energy calculation analysis SEM images illustrate ...

A necessary and sufficient condition is given for quasi-homogeneous polynomial Hamiltonian systems having a center. Then it shown that there exists bound on the number of limit cycles bifurcating from period annulus at any order Melnikov functions; explicit expression this in terms (n,k,s1,s2), where n degree perturbation polynomials, k first nonzero higher function, (s1,s2) weight exponent wit...

Table of Contents General methods S1 Reagents and materials S2 General protocol for the preparation of starting chiral ynamides S3 General procedures for the allylation of stereodefined trisubstituted copper enolate S5 Optimization reactions S8 Products of the enantioselective allylic alkylation reaction S9 Cleavage of oxazolidinone moiety 4 S19 References S21 X-Ray crystallographic analysis da...

Crop residues' inappropriate management is the main constraint causing decline in soil fertility and crop yields Burkina Faso. This study was conducted at Farako-Bâ Research Station from 2014 to 2019 assess effects of residue improve sustainability cotton-cereal based production systems. The experimental design complete randomized blocks Fischer with four replications. Three different...

This paper reviews relevant facts and statistics about the benefits impacts of growing use chemical fertilizer with a focus on soil fertility, crop productivity, alternative sources biofertilizers. Agriculture in Ethiopia is main source economy, it key contributor export value provider raw materials to processing industries. However, Ethiopian agronomical production characterized by low output,...