工件权重带限制的最小化最大加权完工时间的单机在线排序问题

本文考虑了最小化最大加权完工时间的单机在线排序问题,要求工件的权重在工件加工时间一定范围之内且工件的权重和工件加工时间具有一致性,即apj≤wj≤bpj(a≥(5√−1)/2b,b≥a)且若wi>wj则pi≥pj,如果wi=wj则pi=pj。工件以时间在线的方式到达,只有工件Jj在达到释放时间rj后,决策者才知晓工件的基本信息,如加工时间pj和权重wj。对于此问题,首先利用对手法证明了其下界为1+b/(b+a),随后给出了竞争比为1+b/(b+a)的最好可能的在线算法。特别地,当a=(5√−1)/2b时,该算法的竞争比为(5√+1)/2。

Pulmonary abscess caused by Streptococcus pseudopneumoniae in a child:A case report and review of literature

BACKGROUND Lung abscess found on chest X-ray and computed tomography examinations is rare in infants and young children.Several pathogens can cause lung abscesses,with the most common pathogens being anaerobes,Streptococci and Staphylococcus aureus.Streptococcus pseudopneumoniae(S.pseudopneumoniae)is a member of the Streptococcaceae family,and is mainly isolated from respiratory tract specimens.There are currently no cases of lung abscess caused by S.pseudopneumoniae in the literature.CASE SUMMARY A 2-year-old boy was admitted to hospital due to persistent cough and fever.Lung computed tomography examination suggested the formation of a lung abscess.His diagnosis was not confirmed by testing for serum respiratory pathogens(6 items),respiratory pathogen nucleic acid(27 items),and laboratory culture.Finally,metagenomic next-generation sequencing of bronchoalveolar lavage fluid revealed the presence of S.pseudopneumoniae,confirming its role in causing the lung abscess.After receiving antibiotic treatment,reexamination with lung computed tomography showed that the abscess was resorbed and the patient’s outcome was good.CONCLUSION This is the first report of a lung abscess in a child caused by S.pseudopneumoniae infection.Metagenomic next-generation sequencing of bronchoalveolar lavage fluid is helpful in achieving rapid and accurate pathogen identification.

High performance photodetector based on few-layer MoTe_(2)/CdS_(0.42)Se_(0.58) flake heterojunction

Two-dimensional(2D)transition metal dichalcogenides have been extensively studied due to their fascinating physical properties for constructing high-performance photodetectors.However,their relatively low responsivities,current on/off ratios and response speeds have hindered their widespread application.Herein,we fabricated a high-performance photodetector based on few-layer MoTe_(2) and CdS_(0.42)Se_(0.58) flake heterojunctions.The photodetector exhibited a high responsivity of 7221 A/W,a large current on/off ratio of 1.73×10^(4),a fast response speed of 90/120μs,external quantum efficiency(EQE)reaching up to 1.52×10^(6)%and detectivity(D*)reaching up to 1.67×10^(15) Jones.The excellent performance of the heterojunction photodetector was analyzed by a photocurrent mapping test and first-principle calculations.Notably,the visible light imaging function was successfully attained on the MoTe_(2)/CdS_(0.42)Se_(0.58) photodetectors,indicating that the device had practical imaging application prospects.Our findings provide a reference for the design of ultrahighperformance MoTe_(2)-based photodetectors.

Maximizing the Differences Between a Monotone DR-Submodular Function and a Linear Function on the Integer Lattice

In this paper,we investigate the maximization of the differences between a nonnegative monotone diminishing return submodular(DR-submodular)function and a nonnegative linear function on the integer lattice.As it is almost unapproximable for maximizing a submodular function without the condition of nonnegative,we provide weak(bifactor)approximation algorithms for this problem in two online settings,respectively.For the unconstrained online model,we combine the ideas of single-threshold greedy,binary search and function scaling to give an efficient algorithm with a 1/2 weak approximation ratio.For the online streaming model subject to a cardinality constraint,we provide a one-pass(3-√5)/2 weak approximation ratio streaming algorithm.Its memory complexity is(k log k/ε),and the update time for per element is(log^(2)k/ε).

Imaging-Guided Cancer Therapy Based on Multifunctional Magnetic Nanoparticles

In recent years,magnetic nanoparticles(MNPs)have received great attention within the field of biomedicine,especially for cancer therapy.This is because MNPs have many excellent physical and chemical properties to provide sufficient imaging information along with satisfactory therapeutic efficacy.Moreover,by virtue of various modification strategies,the obtained multifunctional MNPs can further achieve synergized multimodal cancer theranostic,which is worthy of further study.In this review,we summarize the recent developments in imaging-guided strategies and synergistic cancer therapy based on multifunctional MNPs.Then,we discuss the challenge and perspective of the next generation of MNPs-based imaging-guided cancer therapy,hoping to provide guidance in potential applications.

微型“智能战士”治疗癌症:刺激响应型微纳机器人在化疗药物递送中的应用

近年来,纳米技术的进步为刺激响应型微纳机器人的发展奠定了基础,它们在癌症治疗中扮演着“智能战士”的角色.本文首先总结了各种刺激响应的机制,包括磁场、光、超声、pH和过氧化氢等介导的刺激响应,这些机制被用于触发肿瘤微环境中微纳机器人的运动和药物释放.随后,本文系统地归纳了用于化疗药物递送的微纳机器人的发展历程与最新进展.值得注意的是,虽然这些“智能战士”在精准化疗药物递送方面具有潜在的应用价值,但要充分发挥它们的作用,还需要持续的探索,以应对实现其在复杂体内微环境中的运动所面临的挑战.

Experimental and theoretical insights into copper phthalocyanine-based covalent organic frameworks for highly efficien radioactive iodine capture

Exploring efficient materials for capturing radioactive iodine in nuclear waste is of great significance for the progress of nuclear energy as well as the protection of ecological environment.Covalent organic frameworks(COFs)have emerged as promising adsorbents because of their predesignable and functionalizable skeleton structures.However,it remains a grand challenge to achieve large scale preparation of COFs.In this work,we developed a mild and efficient microwave irradiation method instead of the traditional solvothermal method to prepare copper phthalocyanine-based covalent organic frameworks(Cu_(x)Pc-COFs)within only 15 min.The nitrogen-rich 1,2,4,5-tetracarbonitrilebenzene(TCNB)was selected as the solely organic ligand to construct copper phthalocyanine-based 2D conjugated COFs.The resultant Cu_(x)Pc-COFs exhibited excellent iodine enrichment with 2.99 g/g for volatile iodine and 492.27 mg/g for iodine-cyclohexane solution,respectively,outperforming that of many porous materials.As indicated by spectroscopic analysis and DFT calculations,this impressive adsorption performance can be attributed to the charge transfer arising from nitrogen-rich phthalocyanine structures and electron-richπ-conjugated systems with iodine molecules.Moreover,the strong electrostatic interaction between Cu(Ⅱ)on chelate centers and polyiodide anions(I_(x)^(-))also play an important role in the firmly trapping radioactive iodine.Therefore,this study provides a facile and intelligent approach to implement metal-based COFs for the remediation of toxic radioactive iodine.

Polyoxometalate-based ionic liquids-promoted CO_2 conversion

Polyoxometalates(POMs) are a class of molecular metal oxides, showing numerous applications in various chemical processes due to their unique acid/base and redox features. By adjusting the tunable molecular structures of the anions and counter cations, plenty of POM-based ionic liquids(POM-based ILs) have been fabricated to be used in various fields, such as catalysis, structural chemistry and material science. As a class of excellent catalysts, POM-based ILs have shown advantages in the emerging field of CO_2 utilization such as CO_2 capture, cycloaddition of CO_2 to epoxides, and reduction of CO_2, owing to the efficient activation of CO_2 by POM anions. This review summarizes recent advances in the catalysis of POM-based ILs, and particularly highlights the areas that are related to CO_2 conversion.

Task-assignment problem;Ternary variables;Binary variables;Mixed integer programming problem

We consider the online scheduling with job rejection to minimize the total weighted completion time of the scheduled jobs plus the total rejection penalty of the rejected jobs.In the problem,a set of independent jobs arriving online over time has to be scheduled with the flexibility of rejecting some of the jobs,where preemption is not allowed and the information of each job,including its processing time,release date,weight,and rejection penalty,is not known in advance.For this problem,using a technique named Greedy-Interval-Rejection,we provide an online algorithm with a competitive ratio of at most 4+εon identical machines and an online algorithm with a competitive ratio of at most 8 on unrelated machines,respectively。

Fe(NO_3)_3-9H_2O-catalyzed aerobic oxidation of sulfides to sulfoxides under mild conditions with the aid of trifluoroethanol

Selective oxidation of sulfides to sulfoxides was successfully performed by employing readily available Fe（NO3）3-9H2O as the active catalyst with oxygen as the oxidant in 2,2,2-trifluoroethanol （TFE） without the formation of sulfones. Nitrate anion could play a crucial role in promoting the reaction due to the oxidation capacity under acidic media. High yields of sulfoxides were exclusively obtained from the corresponding sulfides. Furthermore, both aromatic and aliphatic sulfides gave moderate to high yields of sulfoxides with this protocol.