Results 21 to 30 of about 6,021,471 (299)
Progress and understanding on geology-drilling engineering-mechanics coupling mechanism of ultra-deep directional wells [PDF]
Youqicang pingjia yu kaifaDeep and ultra-deep oil and gas exploration and development are key strategic areas in China's energy sector, with ultra-deep directional drilling serving as a crucial technology for accessing these resources.
CHENG Hai,ZHANG Yiqun,WANG Yin,LIU Chao
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Jacobsons Lemma fails for nil-clean 2 × 2 integral matrices
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2020 We show that for two 2 × 2 integral matrices A, B, if the product AB is nil-clean then BA may not be nil-clean. Despite the fact that for many special cases, BA is also nil-clean, we finally found three counterexamples.
Călugăreanu Grigore, Pop Horia F.
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Singular matrices that are products of two idempotents or products of two nilpotents
Special Matrices, 2021 Over commutative domains we characterize the singular 2 × 2 matrices which are products of two idempotents or products of two nilpotents. The relevant casees are the matrices with zero second row and the singular matrices with only nonzero entries.
Călugăreanu Grigore
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On idempotent stable range 1 matrices
Special Matrices, 2022 We characterize the idempotent stable range 1, 2 × 2 matrices over commutative rings and in particular the integral matrices with this property. Several special cases and examples complete the subject.
Călugăreanu Grigore, Pop Horia F.
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2×2 operator matrix with real parameter and its spectrum [PDF]
E3S Web of ConferencesIn the present paper we consider a linear bounded self-adjoint 2×2 block operator matrix Aμ (so called generalized Friedrichs model) with real parameter μ ∈ R.
Dilmurodov Elyor B. +4 more
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Cayley's hyperdeterminant, the principal minors of a symmetric matrix and the entropy region of 4 Gaussian random variables [PDF]
, 2009 It has recently been shown that there is a connection between Cayley's hypdeterminant and the principal minors of a symmetric matrix. With an eye towards characterizing the entropy region of jointly Gaussian random variables, we obtain three new results ...
Hassibi, Babak, Shadbakht, Sormeh
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Biology Open, 2016 Current advances in producing genetically modified mice using genome-editing technologies have indicated the need for improvement of limiting factors including zygote collection for microinjection and their cryopreservation.
Yoshiko Nakagawa +7 more
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Matrix models and N=2 gauge theory
, 2004 We describe how the ingredients and results of the Seiberg-Witten solution to N=2 supersymmetric U(N) gauge theory may be obtained from a matrix model.Comment: 6 pages, AMSLaTeX (ws-procs9x6.cls included). Presented at QTS3 (Cincinnati, Ohio, Sept.
Naculich, S. G. +2 more
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Precipitation of secondary phase in Mg-Zn-Gd alloy after room-temperature deformation and annealing
Journal of Materials Research and Technology, 2018 Mg-Zn-RE alloys reinforced with quasicrystals have been investigated extensively because they show excellent balance in mechanical properties. Here, we perform deformation and annealing for Mg-1.50Zn-0.25Gd (at.%) alloy at various temperatures, aimed to ...
Hua Huang +4 more
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Thermosolutal and binary fluid convection as a 2 x 2 matrix problem
, 2001 We describe an interpretation of convection in binary fluid mixtures as a superposition of thermal and solutal problems, with coupling due to advection and proportional to the separation parameter S.
Tuckerman, Laurette S.
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