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On the rate of convergence of two generalized Bernstein type operators

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Applied Mathematics(A Journal of Chinese Universities) 2020年第3期35卷 321-331页

作者： LIAN bo-yong CAI Qing-bo Department of Mathematics Yang-En UniversityQuanzhou 362014China School of Mathematics and Computer Science Quanzhou Normal UniversityQuanzhou 362000China

In this paper,we introduce the Bézier variant of two new families of generalized Bernstein type *** establish a direct approximation by means of the Ditzian-Totik modulus of smoothness and a global approximation theorem in terms of second order modulus of *** means of construction of suitable functions and the method of bojanic and Cheng,we give the rate of convergence for absolutely continuous functions having a derivative equivalent to a bounded variation function.

关键词： Bernstein operators modulus of smoothness rate of convergence bounded variation

Controversy over the use of intraoperative blood salvage autotransfusion during liver transplantation for hepatocellular carcinoma patients

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World Journal of Gastroenterology 2013年第22期19卷 3371-3374页

作者： bo zhai Xue-Ying Sun Hepatosplenic Surgery Center Department of General Surgery the First Affiliated Hospital of Harbin Medical University

Intraoperative blood salvage autotransfusion (IBSA) is used in various surgical procedures. However, because of the risk of reinfusion of salvaged blood contaminated by tumor cells, the use of IBSA in hepatocellular carcinoma (HCC) patients undergoing liver transplantation (LT) is controversial. The critical points include whether tumor cells can be cleared by IBSA, whether IBSA increases the risk of recurrence or metastasis, and what are the indications for IBSA. Moreover, is it warranted to take the risk of tumor dissemination by using IBSA to avoid allogeneic blood transfusion? Do the remaining tumor cells after additional filtration by leukocyte depletion filters still possess potential tumorigenicity? Does IBSA always work well? We have reviewed the literature and tried to address these questions. The available data indicate that IBSA is safe in LT for HCC, but randomized, controlled and prospective trials are urgently required to clarify the uncertainty.

关键词： Intraoperative blood salvage autotransfusion Liver transplantation Hepatocellular carcinoma Leukocyte depletion filters Allogeneic blood transfusion

In-situ constructed three-dimensional MoS_(2)–MoN heterostructure as the cathode of lithium–sulfur battery

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Rare Metals 2022年第5期41卷 1743-1752页

作者： Jing-Han Zuo Peng-bo zhai Qian-Qian He Lei Wang Qian Chen Xiao-Kang Gu Zhi-Lin Yang yong-Ji Gong School of Materials Science and Engineering Beihang UniversityBeijing 100191China

Lithium-sulfur batteries are recognized as one of the most promising next-generation high-performance energy storage systems. However, obstacles like the irreversible capacity loss hinder its broad application. Herein,we fabricated an interconnected three-dimensional MoS_(2)-MoN heterostructure(3D-MoS_(2)-MoN) via a facile salttemplate method, overcoming the intrinsic shortcomings such as poor conductivity and compact morphology of traditionally-synthesized transition metal sulfides(TMSs).Furthermore, excellent electrocatalysis ability and hierarchical pore structure effectively accelerate the sluggish lithium polysulfides conversions during cycling. As a result, 3D-MoS_(2)-MoN showed a high initial specific capacity of 1466 mAh·g^(-1)and excellent high-rate capability up to 4℃. A stable cycling performance with a sulfur loading of 2 mg·cm^(-2) was realized with a low decay rate of 0.069% per cycle. This work introduced a rational design route for the appliance of TMSs in the lithiumsulfur batteries.

关键词： Heterostructure Transition metal sulfides Three-dimensional Electrocatalysis

An Extended Convex Combination Approach for Quadratic L_(2)Performance Analysis of Switched Uncertain Linear Systems

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IEEE/CAA Journal of Automatica Sinica 2022年第9期9卷 1706-1709页

作者： Yufang Chang Guisheng zhai Lianglin Xiong bo Fu Hubei Collaborative Innovation Center for High-efficiency Utilization of Solar Energy Hubei University of TechnologyWuhan 430068China the Department of Mathematical Sciences Shibaura Institute of TechnologySaitama 337-8570Japan the School of Mathematics and Computer Science Yunnan Minzu UniversityKunming 650500China

Dear Editor,This letter is concerned with quadratic L_(2) performance(quadratic stability and L_(2) gain)for switched uncertain linear systems(SULS)with norm-bounded *** that no single uncertain subsystem achieves quadratic L_(2) performanceγbut a convex combination of the subsystems can make it,we propose a state-dependent switching law such that the SULS achieves the desired quadratic L_(2) *** discussion is extended to the SULS with state feedback control,and a sufficient condition is proposed to design the state feedback gains and the switching law simultaneously.

关键词： quadratic letter Convex

Reduced spin-down rate of PSR J0738–4042 explained as due to an asteroid disruption event

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Research in Astronomy and Astrophysics 2016年第5期16卷 41-46页

作者： yong-bo Yu yong-Feng Huang Department of Astronomy Nanjing UniversityNanjing 210046China Key Laboratory of Modern Astronomy and Astrophysics(Nanjing University) Ministry of EducationNanjing 2 1 0046China

Long term observations by Brook et al. reveal that the derivative of rotational frequency of PSR J0738-4042 changed abruptly in 2005. Originally, the spin-down rate was relatively stable, with the rotational frequency derivative being - 1.14 x 10-14 s-2. After September 2005, the derivative began to rise. About 1000 days later, it arrived at another relatively stable value of about -0.98 x 10-24 s-2, indicating that the pulsar is spinning-down relatively slowly. To explain the observed change in spin-down rate, we resort to an asteroid disrupted by PSR J0738-4042. In our model, the orbital angular momentum of the asteroid is assumed to be parallel to that of the rotating pulsar, so that the pronounced reduction in the spin-down rate can be naturally explained as due to the transfer of angular momentum from the disrupted material to the central pulsar. The derived magnetospheric radius is about 7.0 x 109 cm, which is smaller than the tidal disruption radius （8.7 x 10^10cm）. Our model is self-consistent. It is shown that the variability in the spin-down rate of PSR J0738-4042 can be quantitatively accounted for by accretion from the asteroid disrupted by the central pulsar.

关键词： stars: neutron -- planet-star interactions -- pulsars: individual (PSR J0738-4042)

A two-step energy injection explanation for the rebrightenings of the multi-band afterglow of GRB 081029

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Research in Astronomy and Astrophysics 2013年第6期13卷 662-670页

作者： yong-bo Yu yong-Feng Huang Department of Astronomy Nanjing University Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University) Ministry of Education

The afterglow of GRB 081029 showed unusual behavior, with a signifi- cant rebrightening being observed at the optical wavelength at about 3000 s after the burst. One possible explanation is that the rebrightening resulted from an energy in- jection. Here we present a detailed numerical study of the energy injection process and interpret the X-ray and optical afterglow light curves of GRB 081029. In our model, we have assumed two periods of energy injection, each with a constant injec- tion power. One injection starts at 2.8 × 10^3 s and lasts for about 2500 s, with a power of 7.0 × 10^47 erg s-1. This energy injection mainly accounts for the rapid rebrighten- ing at about 3000 s. The other injection starts at 8.0 × 10^3 s and lasts for about 5000 s. The injection power is 3.5 × 10^47 erg s-1. This energy injection can help to explain the slight rebrightening at about 10 000 s. It is shown that the observed optical after- glow, especially the marked rebrightening at about 3000 s, can be reproduced well. In the X-ray band, the predicted amplitude of the rebrightening is much shallower, which is also consistent with the observed X-ray afterglow light curve. It is argued that the two periods of energy injection can be produced by clumpy materials falling onto the central compact object of the burster, which leads to an enhancement of accretion and gives rise to a strong temporary outflow.

关键词： gamma-rays: bursts -- ISM: jets and outflows -- individual:GRB 081029

Effect of wide-spectrum pulsed magnetic field on grain refinement of pure aluminium

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China Foundry 2023年第1期20卷 40-48页

作者： Ya-ming Bai Gang Li Ya-wei Sun yong-yong Gong Qi-jie zhai College of Science Shanghai University99 Shangda RoadShanghai 200444China Center for Advanced Solidification Shanghai University99 Shangda RoadShanghai 200444China School of Materials Science and Engineering Shanghai University99 Shangda RoadShanghai 200444China

A wide-spectrum pulsed magnetic field(WSPMF)was obtained by adjusting the number of current pulses and the pulse interval between adjacent *** effect of WSPMF on the grain refinement of pure aluminium was *** distribution of electromagnetic force and flow field in the melt under the WSPMF was simulated to reveal the grain refining *** show that the grain refinement is attributed to the combined effect of the melt flow and oscillation under a *** the pulse interval is 5 ms,the extreme value of electromagnetic force is the highest,and the size of the crystal nucleus is 0.35 *** the case of similar flow rates,the grain size gradually decreases as the pulse interval *** range of the harmonic frequency of the magnetic field gradually expands with the increase of the pulse interval,which can provide more energy for nucleation at the solid-liquid interface and promote nucleation.

关键词： wide-spectrum pulsed magnetic field forced flow grain refinement frequency components

Selective binding of bile salts by β-cyclodextrin derivatives with appended quinolyl arms

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Chinese Chemical Letters 2013年第6期24卷 442-446页

作者： Sha-Sha zhai yong Chen Yu Liu Department of Chemistry State Key Laboratory of Elemento-Organic ChemistryNankai University

Two β-cyclodextrin derivatives bearing appended quinolyl and isoquinolyl arms,***-（6-quinolyl- 6-deoxy）-β-cyclodextrin（1） and mono-（6-isoquinolyl-6-deoxy）-β-cyclodextrin（2） were synthesized in satisfactory yields and fully *** original conformations and binding behaviors toward four bile salt guests,that is,sodium cholate（CA）,sodium deoxycholate（DCA）,sodium glycocholate （GCA）,and sodium taurocholate（TCA）,were investigated by means of fluorescence,circular dichroism and 2D NMR *** study of solution structures revealed that both quinolyl and isoquinolyl arms were located outside the cyclodextrin *** results obtained from the fluorescence titrations showed that the binding abilities of hosts 1 and 2 with selected bile salts varied in an order of DCA 〉 CA 〉 *** selective binding of hosts toward bile salt guests was discussed from the viewpoints of induced-fit and multiple binding.

关键词： Cyclodextrin derivatives Bile salts Molecular recognition

Response to children's physical and mental needs during the COVID-19 outbreak

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World Journal of Pediatrics 2020年第3期16卷 278-279页

作者： Xiao-bo Zhang yong-Hao Gui Xiu Xu Da-Qian Zhu Yi-Hui zhai Xiao-Ling Ge Hong Xu Department of Respiratory Medicine Children's Hospital of Fudan UniversityShanghai 201102China Shanghai Medical College Fudan UniversityShanghai 201102China Department of Child Health Care Children's Hospital of Fudan UniversityShanghai 201102China Department of Psychology Children's Hospital of Fudan UniversityShanghai 201102China Department of Nephrology Children's Hospital of Fudan UniversityShanghai 201102China Department of Statistics and Data Management Children's Hospital of Fudan UniversityShanghai 201102China

School closure and stay-at-home,as a part of non-pharmaceutical interventions (NPI),have been implemented in China since February as an effective way to mitigate the spread of the virus during the COVID-19 *** concerns rose over the potential impacts of such NPI measures on children's health,such as longer exposure to digital screens,irregular sleep pattern,weight gain,and loss of cardiorespiratory fitness [1],the Chinese Government,experts on public health,educators on school health,and teachers have been making joint and massive efforts to provide distance learning with well-organized online courses to help.

关键词： massive children closure