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Sources,characteristics,toxicity,and control of ultrafine particles:An overview

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Geoscience Frontiers 2022年第1期13卷 512-526页

作者： Andrea L.Moreno-Ríos Lesly P.Tejeda-Benítez Ciro F.Bustillo-Lecompte Department of Civil and Environmental Universidad de la CostaCUCCalle 58#55–66BarranquillaAtlánticoColombia Research Group in Biomedical Toxicological and Environmental Sciences(Biotoxam)University of CartagenaCampus of ZaragocillaCartagenaColombia School of Occupational and Public Health Ryerson University350 Victoria StreetTorontoON M5B 2K3Canada

Air pollution by particulate matter(PM)is one of the main threats to human health,particularly in large cities where pollution levels are continually *** to their source of emission,geography,and local meteorology,the pollutant particles vary in size and *** particles are conditioned to the aerodynamic diameter and thus classified as coarse(2.5–10μm),fine(0.1–2.5μm),and ultrafine(aller *** particles can get into the lungs and translocate into vital organs due to their size,causing significant human health ***,PM pollutants have been linked to respiratory conditions,genotoxic,mutagenic,and carcinogenic activity in human *** paper presents an overview of emission sources,physicochemical characteristics,collection and measurement methodologies,toxicity,and existing control mechanisms for ultrafine particles(UFPs)in the last fifteen years.

关键词： Particulate matter Ultrafine particles Air pollution Toxicity Measurement methodologies

New Economy Companies:Impact of COVID-19 on Valuation

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Journal of Modern Accounting and Auditing 2022年第3期18卷 105-114页

作者： Gladie Lui Connie shum ESCP Business School LondonU.K. Pittsburg State University PittsburgUSA

The boom of innovative and new technology-oriented companies that provide products and services to customers in recent years has given rise to a new class of firms called New Economy Companies,or *** valuation of these companies throughout their life cycles can be challenging because most of them have massive amount of debt and have a long history of losses since inception,and their principal assets are mostly intangible with no clear ***,the COVID-19 pandemic has added even more obstacles for valuation providers to determine the value of this new type of *** paper examines the characteristics of NECs,valuation methods,and the impact of COVID-19 on the valuation of these companies.

关键词： New Economy Companies(NECs) valuation of New Economy Companies techniques used by New Economy Companies

Multimodality management of resectable gastric cancer: A review

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World Journal of Gastrointestinal Oncology 2014年第10期6卷 393-402页

作者： Helen shum Lakshmi Rajdev Department of Oncology Montefiore Medical Center Albert Einstein College of MedicineBronx NY 10461 United States

Adenocarcinoma of the stomach carries a poor prognosis and is the second most common cause of cancer death worldwide. It is recommended that surgical resection with a D1 or a modified D2 gastrectomy(with at least 15 lymph nodes removed for examination), be performed in the United States, though D2 lymphadenectomies should be performed at experienced centers. A D2 lymphadenectomy is the recommended procedure in Asia. although surgical resection is considered the definitive treatment, rates of recurrences are high, necessitating the need for neoadjuvant or adjuvant therapy. This review article aims to outline and summarize some of the pivotal trials that have defined optimal treatment options for non-metastatic non-cardia gastric cancer. Some of the most notable trials include the INT-0116 trial, which established a benefit in concurrent chemoradiation and adjuvant chemotherapy. This was again confirmed in the ARTIST trial, especially in patients with nodal involvement. Later, the Medical Research Council Adjuvant Gastric Infusional Chemotherapy trial provided evidence for the use of perioperative chemotherapy. Targeted agents such as ramucirumab and trastuzumab are also being investigated for use in locally advanced gastric cancers after demonstrating a benefit in the metastatic setting. Given the poor response rate of this difficult disease to various treatment modalities, numerous studies are currently ongoing in an attempt to define a more effective therapy, some of which are briefly introduced in this review as well.

关键词： Neoadjuvant chemotherapy Adjuvant che-motherapy Adjuvant chemoradiation Gastric cancer Gastric adenocarcinoma

Storage and repair bandwidth tradeoff for heterogeneous cluster distributed storage systems

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Science China(Information Sciences) 2020年第2期63卷 131-145页

作者： Jingzhao WANG Yuan LUO Kenneth W.shum Department of Computer Science and Engineering Shanghai Jiao Tong University Institute of Network Coding The Chinese University of Hong Kong

The storage and repair bandwidth tradeoff is an important issue in distributed storage systems(DSSs) where large scale data are stored in multiple nodes with erasure coding to ensure reliability. There are lots of studies on the DSS model with multiple clusters where the repair bandwidths from intra-cluster and cross-cluster nodes are differentiated to improve repair efficiency based on the realistic network topological structures. At the same time, separate nodes are also prevalent due to the variety of practical networks, but the work on the cluster DSS model with multiple separate nodes is insufficient, which is a main motivation of this paper. We formulate the tradeoff bound between storage repair bandwidth for a heterogeneous DSS model consisting of clusters and separate nodes by analyzing the min-cuts of heterogeneous information flow graphs corresponding to the orders of failed nodes. Additionally, the tradeoff bounds are investigated in multiple aspects when the repair bandwidth constraints and the amount of separate nodes vary, ***, a class of regenerating codes are illustrated to achieve the tradeoff in the heterogeneous cases.

关键词： distributed storage system cluster separate node repair bandwidth information flow graph

SOME REMARKS ON (L)-GREEN’S RELATIONS AND STRONGLY RPP SEMIGROUPS

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Acta Mathematica Scientia 2011年第4期31卷 1591-1599页

作者：杜兰郭聿琦 K.P. shum Department of Mathematics Ningxia University Department of Mathematics Southwest University Department of Mathematics Hong Kong University

In order to study rpp semigroups, in particular, some special cases, several facts on （l）-Green’s relations and strongly rpp semigroups are given as some remarks.

关键词： (l)-Green’s relations strongly rpp semigroups semilattice congruences Dprimitive idempotents

Natural sediment at a dam and its inorganic materials as adsorbents of praseodymium(Pr(Ⅲ))

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International Journal of Sediment Research 2023年第4期38卷 566-575页

作者： Melania Jiménez-Reyes Jaime Jiménez-Becerril Marcos Solache-Ríos Perla Tatiana almazán-Sánchez Departamento de Química Instituto Nacional de Investigaciones Nucleares Carretera México-Toluca S/N CONACy T-Instituto Nacional de Investigaciones Nucleares

The sediment deposited behind a dam(DS) and its inorganic materials(IM-DS) were characterized and used for the removal of praseodymium(Pr) from aqueous solutions. Quartz, albite, and kaolinite were found in the sediment by X-ray diffraction. Kinetic data fit well to a pseudo second-order model, the equilibrium time for DS and IM-DS was 2 h and 3 min, respectively, and the adsorption capacity was higher for Pr/DS(qe= 4.91 mg/g) than for Pr/IM-DS(qe= 3.01 mg/g) in these conditions. Pr/DS and Pr/IM-DS data isotherms were in agreement with the Langmuir-Freundlich model and the maximum adsorption capacities were 4.95 and 4.01 mg/g, respectively. Both processes are exothermic(enthalpy change, ΔH0=-22.8 and-21.8 k J/mol for DS and IM-DS, respectively), the increase of the randomness is small, and the feasibility and spontaneity are low. Praseodymium was desorbed by ethylenediaminetetraacetic acid disodium(EDTA-Na2), sodium chloride, nitric, citric, and humic acids solutions, and one hundred percent of praseodymium was desorbed by the EDTA-Na2solution. The Pr2(EDTA)3(praseodymium ethylenediaminetetraacetate) complex was completely desorbed from both materials(DS and IM-DS). Distribution coefficients(KD) depend upon praseodymium concentration,temperature, p H, and the kind of adsorbent. Chemical reactions of praseodymium with kaolinite and iron minerals could explain the adsorption.

关键词： Praseodymium Sediment Adsorption process parameters Desorption

Correction of CT Burst Array Errors in the Generalized-Lee-RT Spaces

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Acta Mathematica Sinica,English Series 2010年第8期26卷 1475-1484页

作者： Sapna JAIN K.P.shum Department of Mathematics University of Delhi Department of Mathematics The University of Hong Kong

In [Jain, S.： Array codes in the generalized-Lee-RT-pseudo-metric （the GLRTP-metric）, to appear in algebra Colloq.], Jain introduced a new pseudo-metric on the space Matm×s（Zq）, the module space of all m × s matrices with entries from the finite ring Zq, generalized the classical Lee metric [Lee, C. Y.： Some properties of non-binary error correcting codes. IEEE Trans. Inform. Theory, IT-4, 77- 82 （1958）] and array RT-metric [Rosenbloom, M. Y., Tsfasman, M. A.： Codes for m-metric. Prob. Inf. Transm., 33, 45-52 （1997）] and named this pseudo-metric as the Generalized-Lee-RT-Pseudo-Metric （or the GLRTP-Metric）. In this paper, we obtain some lower bounds for two-dimensional array codes correcting CT burst array errors [Jain, S.： CT bursts from classical to array coding. Discrete Math., 308-309, 1489-1499 （2008）] with weight constraints under the GLRTP-metric.

关键词： Linear array codes Lee metric RT metric CT burst array errors

A Versatile Flow-Profile Engineering Method in the Stokes Flow Regime for Complex-Shaped Flows

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Engineering 2021年第5期7卷 655-662页

作者： Zhenyu Yang Lang Nan Ho Cheung shum Department of Mechanical Engineering The University of Hong KongHong Kong 999077China

Flow profiles are frequently engineered in microfluidic channels for enhanced mixing,reaction control,and material ***,flow profiles are engineered by inducing inertial secondary flow to redistribute the streams,which can hardly be reproduced in microfluidic environments with negligible inertial *** employed symmetric channel structures also limit the variety of achievable flow ***,each of the flow profiles specifically corresponds to a strictly defined flow condition and cannot be generalized to other flow *** address these issues,we present a systematic method to engineer the flow profile using inertialess secondary *** flow is manipulated in the Stokes regime by deploying a cascaded series of microsteps with various morphologies inside a microchannel to shape the flow *** tuning the shapes of the microsteps,arbitrary outflow profiles can be customized.A numerical profile-transformation program is developed for rapid prediction of the output profiles of arbitrary sequences of predefined *** proposed method allows the engineering of stable flow profiles,including asymmetric ones,over a wide range of flow conditions for complex microfluidic environmental prediction and design.

关键词： Microfluidics Flow profile Stokes flow Hydrodynamic focusing Flow shaping

From Eliza to XiaoIce：challenges and opportunities with social chatbots

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Frontiers of Information Technology & Electronic Engineering 2018年第1期19卷 10-26页

作者： Heung-yeung shum Xiao-dong HE Di LI Microsoft Corporation Redmond WA 98052 USA

Conversational systems have come a long way since their inception in the 1960 *** decades of research and development,we have seen progress from Eliza and Parry in the 1960 s and 1970 s,to task-completion systems as in the Defense Advanced Research Projects Agency(DARPA) communicator program in the 2000 s,to intelligent personal assistants such as Siri,in the 2010 s,to today's social chatbots like Xiao *** chatbots' appeal lies not only in their ability to respond to users' diverse requests,but also in being able to establish an emotional connection with *** latter is done by satisfying users' need for communication,affection,as well as social *** further the advancement and adoption of social chatbots,their design must focus on user engagement and take both intellectual quotient(IQ) and emotional quotient(EQ) into *** should want to engage with a social chatbot;as such,we define the success metric for social chatbots as conversation-turns per session(CPS).Using Xiao Ice as an illustrative example,we discuss key technologies in building social chatbots from core chat to visual awareness to *** also show how Xiao Ice can dynamically recognize emotion and engage the user throughout long conversations with appropriate interpersonal *** we become the first generation of humans ever living with artificial intelligenc(AI),we have a responsibility to design social chatbots to be both useful and empathetic,so they will become ubiquitous and help society as a whole.

关键词：社会 DARPA 工程机构系统通信