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Portal vein-variceal anastomosis for portal vein inflow reconstruction in orthotopic liver transplantation:A case report and review of literature

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World Journal of Transplantation 2022年第7期12卷 204-210页

作者： aviad Gravetz Department of Transplantation Rabin Medical CenterBeilinson HospitalPetach-Tikva 4941492Israel

BACKGROUND Portal vein thrombosis(PVT)is a frequent complication occurring in 5%to 26%of cirrhotic patients candidates for liver transplantation(LT).In cases of extensive portal and or mesenteric vein thrombosis,complex vascular reconstruction of the portal inflow may become necessary for a successful orthotopic LT(OLT).CASE SUMMARY A 54-year-old male with history of cirrhosis secondary to schistosomiasis complicated with extensive portal and mesenteric vein thrombosis and severe portal hypertension who underwent OLT with portal vein-left gastric vein *** We review the various types of PVT,the portal venous inflow reconstruction techniques.

关键词： Portal vein thrombosis Portal inflow reconstruction Orthotopic liver transplantation Splanchnic varices Left gastric varix Case report

Two-stage robust power cost minimization in a natural gas compressor station

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Petroleum Science 2022年第1期19卷 409-428页

作者： Yize Meng Ruoran Chen keren Zhang Tianhu Deng Department of Industrial Engineering Tsinghua UniversityBeijing100084China

Optimal operation of a compressor station is important since it accounts for 25%to 50%of a company’s total operating *** short-term management of a compressor station,handling demand uncertainty is important yet *** studies either require precise information about the distribution of uncertain parameters or greatly simplify the compressor *** build a two-stage robust optimization framework of power cost minimization in a natural gas compressor station with nonidentical *** the first stage,decision variables are the ON/OFF state of each compressor and discharge *** worst-case cost of the second stage is incorporated in the first *** decision variables feasibility is discussed and proper feasibility cuts are also proposed for the first *** employ a piece-wise approximation and propose accelerate *** numerical results highlight two advantages of robust approach when managing uncertainty in practical settings:(1)the feasibility of first-stage decision can be increased by up to 45%,and(2)the worst-case cost can be reduced by up to 25%compared with stochastic programming ***,our numerical experiments show that the designed accelerate algorithm has time improvements of 1518.9%on average(3785.9%at maximum).

关键词： Natural gas Single station power minimization Nonconvex robust optimization C&CG algorithm

Nanofabricated high turn-density spiral coils for on-chip electromagneto-optical conversion

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Microsystems & Nanoengineering 2024年第2期10卷 181-192页

作者： Ilhan Bok Alireza Ashtiani Yash Gokhale Jack Phillips Tianxiang Zhu aviad Hai Department of Biomedical Engineering University of Wisconsin–MadisonMadisonWIUSA Department of Electrical and Computer Engineering University of Wisconsin–MadisonMadisonWIUSA Wisconsin Institute for Translational Neuroengineering(WITNe) University of Wisconsin–MadisonMadisonWIUSA

Circuit-integrated electromagnets are fundamental building blocks for on-chip signal transduction,modulation,and tunability,with specific applications in environmental and biomedical micromagnetometry.A primary challenge for improving performance is pushing quality limitations while minimizing size and fabrication complexity and retaining spatial *** efforts have exploited highly involved three-dimensional synthesis,advanced insulation,and exotic material ***,we present a rapid nanofabrication process that employs electron beam dose control for high-turn-density diamond-embedded flat spiral coils;these coils achieve efficient on-chip electromagnetic-to-optical signal *** fabrication process relies on fast 12.3 s direct writing on standard poly(methyl methacrylate)as a basis for the metal lift-off *** with 70 micrometer overall diameters and 49–470 nm interturn spacings with corresponding inductances of 12.3–12.8 nH are *** utilize optical micromagnetometry to demonstrate that magnetic field generation at the center of the structure effectively correlates with finite element modeling *** designs based on our process can be integrated with photolithography to broadly enable optical magnetic sensing and spin-based computation.

关键词： utilize retaining high

Quantum second-order optimization algorithm for general polynomials

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Science China(Physics,Mechanics & Astronomy) 2021年第10期64卷 54-63页

作者： Pan Gao keren Li Shijie Wei Gui-Lu Long State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084China Shenzhen JL Computational Science and Applied Research Institute Shenzhen 518109China Beijing Academy of Quantum Information Sciences Beijing 100193China Beijing National Research Center for Information Science and Technology and School of Information Tsinghua UniversityBeijing 100084China Frontier Science Center for Quantum Information Beijing 100084China

Quantum optimization algorithms can outperform their classical counterpart and are key in modern technology. The second-order optimization algorithm(the Newton algorithm) is a critical optimization method, speeding up the convergence by employing the second-order derivative of loss functions in addition to their first derivative. Here, we propose a new quantum second-order optimization algorithm for general polynomials with a computational complexity of O(poly(log d)). We use this algorithm to solve the nonlinear equation and learning parameter problems in factorization machines. Numerical simulations show that our new algorithm is faster than its classical counterpart and the first-order quantum gradient descent algorithm. While existing quantum Newton optimization algorithms apply only to homogeneous polynomials, our new algorithm can be used in the case of general polynomials, which are more widely present in real applications.

关键词： quantum computation quantum algorithm optimization

DEFYING DIFFICULTIES,STRIVING FOR A WAY OUT--Report on Guangdong Tannery Limited's Listing on the Stock Exchange of Hong Kong

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大经贸 1997年第3期 93-94页

作者： keren

The challenge is easy to imagine, when a fledging enterprise such as Nanhai Tannery Plant was listed on the Stock Exchange of Hong Kong, where it has to confront fierce competitions with other 500-plus enterprises.

关键词：出手海潮

Active Eutectoid Decomposition of α → γ + τ _(1) and the Morphological Evolution in a Ru-Containing TiAl Alloy

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Acta Metallurgica Sinica(English Letters) 2021年第8期34卷 1042-1050页

作者： Yulun Wu Rui Hu Jieren Yang keren Zhang Xuyang Wang State Key Laboratory of Solidifi cation Processing Northwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China School of Materials Science and Engineering Sichuan UniversityChengdu 610065China

The active eutectoid decomposition and its morphological evolution during slow cooling and isothermal holding were investigated in a Ru-containing Ti Al alloy. The fine τ 1/γ active eutectoid nodules precipitated at α grain boundary and interior during water quenching. The active eutectoid microstructure evolved from sheaf-like, granular to bulky net-like sluggish eutectoid morphology gradually with the decrease in quenching/holding temperatures. The active eutectoid reaction occurs from 1220 to 1290 ℃, while the beginning temperature of sluggish eutectoid locates at 1305 ± 5 ℃. The combination of the intact τ_(1) phase and immature nano-sized γ laths suggests a short incubation period of τ_(1) phase in the active type. Furtherly, the semiquantitative estimation shows that the growth velocity of active eutectoid is about ninety times higher than sluggish type. In addition, a representative feature of γ phase abruptly ripening along {111} crystallographic plane was also observed in the active eutectoid.

关键词： TiAl alloys Microstructure Eutectoid decomposition Heat treatment Cooling rate

Carbon nanosheets derived from reconstructed lignin for potassium and sodium storage with low voltage hysteresis

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Nano Research 2021年第12期14卷 4664-4673页

作者： keren Jiang Xuehai Tan Shengli Zhai Ken Cadien Zhi Li Department of Chemical and Materials Engineering University of AlbertaEdmontonAlbertaT6G 1H9Canada

Lignin is the second most abundant and the only nature polymer rich in aromatic *** aromatic-unit-rich precursors often yield soft carbon after carbonization,the side chains in lignin crosslink with the aromatic units and form a rigid three-dimensional(3D)structure which eventually leads to hard *** a graphene oxide-catalyzed decomposition and repolymerization process,we successfully reconstructed lignin by partially tailoring the side *** to directly carbonized lignin,the carbonized reconstructed lignin possesses significantly fewer defects,86%fewer oxygen-functionalities,82%fewer micropores,and narrower interlayer *** parameters can be tuned by the amount of catalysts(graphene oxide).When tested as anode for K-ion and Na-ion batteries,the carbonized reconstructed lignin delivers notably higher capacity at low-potential range(especially for Na-storage),shows much-improved performance at high current density,and most importantly,reduces voltage hysteresis between discharge and charge process by more than 50%,which is critical to the energy efficiency of the energy storage *** study reveals that the voltage hysteresis in K-storage is much severer than that in Na-storage for all *** practical K-ion battery applications,the voltage hysteresis deserves more attention in future electrode materials design and the reconstruct ion strategy introduced in this work provides potential low-cost solution.

关键词： lignin batteries polarization voltage hysteresis ring-forming defects

Mechanical property enhancements and amorphous thermal transports of ordered weberite-type RE_(3)Nb/TaO_(7) high-entropy oxides

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Journal of Advanced Ceramics 2023年第2期12卷 399-413页

作者： Lin CHEN keren LUO Baihui LI Mingyu HU Jing FENG Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China Peking University Shenzhen Graduate School Shenzhen 518055China

A_(3)BO_(7)-type(A=rare earth(RE),B=Nb or Ta)oxides have been studied as protective coating materials because of their low thermal conductivity;however,their hardness,toughness,and stiffness are insufficient,particularly for members with webeirte-type *** this work,we have synthesized two high-entropy oxides(HEOs)of weberite-type RE niobates/tantalates(RE_(3)Nb/TaO_(7)),i.e.,(Nd_(1/7)Sm_(1/7)Eu_(1/7)Gd_(1/7)Dy_(1/7)Ho_(1/7)Er_(1/7))_(3)NbO_(7)(7HEOs-Nb)and(Nd_(1/7)Sm_(1/7)Eu_(1/7)Gd_(1/7)Dy_(1/7)Ho_(1/7)Er_(1/7))3(Nb_(1/2)Ta_(1/2))O_(7)(7HEOs-NbTa),to overcome the mechanical *** short-and long-range ordered arrangements of RE cations in the A-site and Nb/Ta cations in the B-site were identified by the X-ray diffraction(XRD),scanning electron microscopy equipped with energy-dispersive spectrometry(EDS),and transmission electron *** enhancements in hardness(H=9.4 GPa)and fracture toughness(KIC=2.0 MPa·m^(1/2))were realized by grain refinement,solid solution strengthening,and high stiffness(K).The exceptional phase stability at 25-1500℃,amorphous thermal conductivity(k=1.5-1.7 W·m^(−1)·K^(−1) at 25-900℃),and high thermal expansion coefficients(TEC>11.0×10^(−6) K^(−1) at 1500℃)further supported their potential application as protective coating materials.

关键词： high-entropy oxides(HEOs) RE niobates/tantalates(RE_(3)Nb/TaO_(7)) stiffness(K) fracture toughness(KIC) thermal transports

Simultaneous manipulations of thermal expansion and conductivity in symbiotic ScTaO_(4)/SmTaO_(4) composites via multiscale effects

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Journal of Advanced Ceramics 2023年第8期12卷 1625-1640页

作者： Lin Chen Jiankun Wang Baihui Li keren Luo Jing Feng Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

Effective manipulations of thermal expansion and conductivity are significant for improving operational performances of protective coatings,thermoelectric,and *** work uncovers determinant mechanisms of the thermal expansion and conductivity of symbiotic ScTaO_(4)/SmTaO_(4) composites as thermal/environmental barrier coatings(T/EBCs),and we consider the effects of interface stress and thermal *** weak bonding and interface stress among composite grains manipulate coefficient of thermal expansion(CTE)stretching from 6.4×10^(−6) to 10.7×10^(−6) K^(−1) at 1300℃,which gets close to that of substrates in T/EBC *** multiscale effects,including phonon scattering at the interface,mitigation of the phonon speed(vp),and lattice point defects,synergistically depress phonon thermal transports,and we estimate the proportions of different *** interface thermal resistance(R)reduces the thermal conductivity(k)by depressing phonon speed and scattering phonons because of different acoustic properties and weak bonding between symbiotic ScTaO_(4) and SmTaO_(4) ceramics in the *** study proves that CTE of tantalates can be artificially regulated to match those of different substrates to expand their applications,and the uncovered multiscale effects can be used to manipulate thermal transports of various materials.

关键词： thermal management coefficient of thermal expansion(CTE) interface thermal resistance(R) thermal stress(σ) thermal/environmental barrier coatings(T/EBCs)