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Science China Chemistry 2017年第2期60卷 284-292页

作者： Miao hu Chuang Guo Linzhou Zhang Suoqi Zhao Keng h. chung Chunming Xu Quan Shi State Key Laboratory of heavy Oil Processing China University of Petroleum Beijing 102249 China Daqing Oilfield Limited Corporation Daqing 163159 China North huajin Chemical Industries Group Corporation Panjin 124000 China

Delayed coking is an important petroleum resid conversion *** processability of coking liquids is known to be dependent on the heteroatom compounds present in the coking *** commercial delayed coking liquids were characterized by electrospray ionization(ESI)Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS)and gas chromatographic *** relatively abundant heteroatom compounds in the coking liquids were 1-4 aromatic-ring pyridinic nitrogen compounds,carbazoles,benzocarbazoles,phenols,mercaptans,benzothiophenes,dibenzothiophenes,and *** liquids derived from various feeds had similar compound class types,molecular weight distribution ranges,and double bond equivalents(DBE).however,the concentration of individual compounds and the distribution of DBE versus carbon number of heteroatom compounds varied.A comparison of heteroatom compounds in coker feeds and products revealed the various reaction mechanism of heteroatom compounds occurred during the coking *** results suggested that molecular-level process models can be developed for optimization of unit operation to obtain desirable products that meet the environmental specifications and quality requirements.

关键词： FT-ICR MS molecular composition heteroatom compounds petroleum delayed coking

Subchronic Oral Toxicity of Pyridostigmine Bromide in Rats

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Biomedical and Environmental Sciences 1991年第3期4卷 283-289页

作者： B.S.LEVINE R.LONG h.chung Department of Pharmacology University of Illinois at Chicago Chicago IL 60680Pathology Associates Inc. Chicago IL 60616Walter Reed Army Institute of Research WashingtonDC 20307

This study evaluated the oral toxicity of pyridostigmine bromide in Sprague-Dawley rats when administered for 13 weeks by daily gavage. Groups of 10 rats/sex received doses of 0, 5, 15, 30, or 60 mg/kg/day. Toxicity was limited to exaggerated cholinergic stimulation at doses of 15 mg/kg/day or greater. Significant findings included tremors and inhibition of RBC acetylcholinesterase. Thus, 5 mg/kg/day of pyridostigmine bromide appears to be the no observed toxic effect level under the conditions of the present investigation.

关键词： Subchronic Oral Toxicity of Pyridostigmine Bromide in Rats

Mssbauer spectra of MnFe_(2-2x)Al_(2x)O_4(0≤x≤0.4) ferrites

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Journal of Central South University 2010年第6期17卷 1129-1132页

作者： BATOO K M KUMAR S PRAKASh R ALIMUDDIN SONG J I chung h JEONG h KOO B h LEE C G King Abdullah Institute for Nanotechnology King Saud UniversityRiyadh 11451Saudi Arabia School of Nano and Advanced Materials Engineering Changwon National UniversityChangwon 641773Korea Department of Mechanical Engineering Changwon National UniversityChangwon 641773Korea Department of Applied Physics Aligarh Muslim UniversityAligarh 202002India Department of Precision & Mechanical Engineering and BK21 Eco-Friendly heat & Cooling Energy Mechanical Research Team Gyeongsang National U niversityTongyeong 650160Korea

The effect of non-magnetic Al^3＋ ion doping on the magnetic properties of MnFe2-2x Al2xO4 （0 ≤x≤ 0.4） spinel ferrites was studied using Moessbauer spectroscopy measurements at room temperature. From the Moessbauer study, it is observed that the ：esolved hyperfine sextets are due to the distribution of Fe ions on the two sublattices of the spinel ferrites. The value of the isomer shift obtained from the fitting of the Moessbauer spectra indicates that Fe ions are in ＋3 state. A paramagnetic doublet is observed at ：iegree of inversion x=0.4, superimposed on the hyperfine sextets, indicating that the super-exchange interaction A-B decreases due to ：he dilution of sublattice by Al^3＋ ions. The hyperfine magnetic field decreases at both interstitial sites of tetrahedral （A） and 3ctahedral （B） with the increase in Al concentration.

关键词： ferrites hyperfine interactions Moessbauer spectroscopy isomer shift

Factors that affect heart rate variability following acute resistance exercise:A systematic review and meta-analysis

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Journal of Sport and health Science 2022年第3期11卷 376-392页

作者： Sajith U.Marasingha-Arachchige JacoboÁ.Rubio-Arias Pedro E.Alcaraz Linda h.chung UCAM Research Center for high Performance Sport Catholic University of MurciaMurcia 30107Spain LFE Research Group Department of Health and Human PerformanceFaculty of Physical Activity and Sport Science-INEFUniversidad Politécnica de MadridMadrid 28040Spain Faculty of Sport Catholic University of MurciaMurcia 30107Spain

Background:There is controversial evidence regarding the effect of acute resistance exercise(ARE) on heart rate variability(hRV) parameters,which indicates the activities of the cardiac autonomic nervous *** aim of this study was to perform a systematic review and meta-analysis of the literature on the effect of ARE on hRV parameters and identify its possible moderating ***:The PubMed-Medline,Web of Science,SPORTDiscus,and Cochrane Library databases were *** Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA) declaration was followed,and the methodological quality of the studies was *** level of significance was set at p≤***-six studies met the inclusion *** effect analyses between pre-and post-test interventions demonstrated an increase in normalized units low frequency(p high frequency ratio(p he normal-to-normal(NN)interval(p he successive differences(p high frequency(p healthy individuals range:15 ± 1 to 48 ± 2 years;mean ± SD).Results:There were differences between the subgroups in the number of sets used in an exercise(p=0.05) for root mean square of the successive differences,as well as for exercise intensity(p=0.01) and rest between sets(p=0.05) for normalized units high ***,there were differences between the subgroups in training volume for root mean square of the successive differences(p=0.01),normalized units high frequency(p=0.003) and normalized units low frequency(p=0.02).Conclusion:Overall,there was a withdrawal of cardiac parasympathetic and activation of cardiac sympathetic modulations following ARE,and th

关键词： Cardiac Parasympathetic Sympathetic

Features of extrahepatic metastasis after radiofrequency ablation for hepatocellular carcinoma

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World Journal of Gastroenterology 2020年第32期26卷 4833-4845页

作者： Jae h Yoon Young J Goo Chae-Jun Lim Sung K Choi Sung B Cho Sang S Shin chung h Jun Department of Gastroenterology Chonnam National University Hospital and Medical SchoolGwangju 61469South Korea Department of Gastroenterology Hwasun Chonnam National University Hospital and Medical SchoolHwasun 58128South Korea Department of Radiology Chonnam National University Hospital and Medical SchoolGwangju 61469South Korea Department of Internal Medicine Mokpo Hankook HospitalMokpo 58643South Korea

BACKGROUND Extrahepatic metastasis(EhM)of hepatocellular carcinoma(hCC)is associated with poor ***,the clinical features and risk factors of EhM of hCC after radiofrequency ablation(RFA)remain *** To elucidate the characteristics and risk factors of EhM after RFA for *** From January 2008 to December 2017,we retrospectively enrolled 661 patients who underwent RFA as first-line treatment for hCC at 2 tertiary *** inclusion criteria were age≥18 years,a diagnosis of hCC,and *** computed tomography(CT)or magnetic resonance imaging(MRI)and alpha-fetoprotein measurements were routinely performed at 1 mo after RFA and followed-up at intervals of 3-6 *** analyses were performed using the chi-squared test or Student’s t-test,and univariate and multivariate analyses were performed via logistic regression,as *** EhM was diagnosed in 44 patients(6.7%)during a median follow-up period of 1204 *** 10-year cumulative rate of hCC recurrence and EhM was 92.7%and 33.7%,*** recurrence was most often intrahepatic,and the rate of extrahepatic recurrence at initial recurrence was only 1.2%.The median time to the diagnosis of EhM was 2.68 years,and 68.2%of patients developed EhM within 2 years of the first recurrence,regardless of recurrence-free survival and 75.0%of patients developed EhM within 5 years after first *** was mostly diagnosed via abdominal CT/MRI in 33(75.0%)and 38 of 44 patients(86.4%)with EhM had either positive abdominal CT scan results or serum AFP level *** multivariate analysis,recurrence-free survivalha-fetoprotein level>400 IU/mL were associated with a high EhM *** EhM occurs following multiple intrahepatic recurrences after RFA and combined contrast-enhanced abdominal CT and serum AFP were useful for *** especially with high-risk factors require close follow-up for

关键词： hepatocellular carcinoma Metastasis Radiofrequency ablation Surveillance Risk factor

Characterization of heavy petroleum fraction by positive-ion electrospray ionization FT-ICR mass spectrometry and collision induced dissociation: Bond dissociation behavior and aromatic ring architecture of basic nitrogen compounds

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Science China Chemistry 2013年第7期56卷 874-882页

作者： ZhANG LinZhou ZhANG Yahe ZhAO SuoQi XU ChunMing chung Keng h. ShI Quan State Key Laboratory of heavy Oil Processing China University of Petroleum

This paper examined the bond dissociation behavior and aromatic ring architecture of basic nitrogen compounds in Sudan heavy petroleum fraction. Both broadband and quadrupole isolation modes positive-ion electrospray ionization （ESI） Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS） coupled with collision induced dissociation （CID） tech- niques were used to characterize a low sulfur crude oil derived vacuum residuum （VR）. The appropriate CID operating condi- tion was selected by comparing the molecular weight distributions of the basic nitrogen compounds under various CID operat- ing conditions. Both odd- and even-electron fragment ions were observed from the mass spectrum, indicating that the hetero- lyric and homolytic bond cleavages occurred simultaneously during the CID process. The odd-electron fragment ions were predominant in each class species, indicating preferential heterolytic bond cleavages. At the optimal CID condition, the alkyl groups decomposed deeply and just left the aromatic cores of the nitrogen compounds. No Significant variation in double bond equivalent （DBE） value was observed between the fragment and parent ions, revealing that the domination of single core structure.

关键词： FT-ICR MS CID heavy oil molecular structure

hetero-deformation promoted strengthening and toughening in BCC rich eutectic and near eutectic high entropy alloys

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Journal of Materials Science & Technology 2023年第15期146卷 1-9页

作者： D.h.chung J.Lee Q.F.he Y.K.Kim K.R.Lim h.S.Kim Y.Yang Y.S.Na Department of Special Alloys Extreme Materials Research InstituteKorea Institute of Materials ScienceChangwonThe Republic of Korea Department of Mechanical Engineering City University of Hong KongKowloon TongKowloonHong KongChina Graduate Institute of Ferrous Technology Pohang University of Science and TechnologyPohangThe Republic of Korea Center for heterogenic Metal Additive Manufacturing Pohang University of Science and TechnologyPohangThe Republic of Korea Department of Materials Science and Engineering City University of Hong KongKowloon TongKowloonHong KongChina

heterostructured eutectic high-entropy alloys(EhEAs)have attracted significant attention owing to their novel properties,such as balanced combinations of strength and fracture ***,the toughening/strengthening mechanisms of these EhEAs have not been thoroughly *** this study,we developed a series of dual-phase Al_((18–2x))Co_(30)Cr_((11+x))Fe_((11+x))Ni_(3)0(x=-1,0,1)eutectic and neareutectic hEAs containing face-centered cubic(FCC)and body-centered cubic(BCC)*** the high amount of BCC,which is referred to as the brittle phase,newly developed EhEAs exhibited superior fracture ***,we discovered that a fully eutectic hEA exhibited further improvements in both yield stress and fracture toughness,outperforming our off-eutectic and other previously reported *** combining experiments and theoretical models,we demonstrated that the synergistic increase in both strength and toughness in our fully eutectic hEA was derived from the high hetero-deformationinduced(hDI)strengthening/toughening associated with a high misorientation angle at the grain/phase boundaries.

关键词： Eutectic high entropy alloy Fracture toughness heterogeneous structure hetero deformation induced strengthening Misorientation angle

A Wavelength Monitoring System Using Tunable MEMS Filter Calibrated by F-P Laser

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光学学报 2003年第S1期23卷 615-616页

作者： h. Y. Tam P. K. A. Wai W. h. chung Photonics Research Center Department of Electrical Engineering The Hong Kong Polytechnic University Hong Kong SAR ChinaPhotonics Research Center Department of Electronic and Information Engineering The Hong Kong Polytechnic University Hong Kong SAR ChinaPhotonics Research Center Department of Electrical Engineering The Hong Kong Polytechnic University Hong Kong SAR China

We report a wavelength and power monitoring system based on a scanning MEMS filter as wavelength discriminator and a near threshold-biased Fabry-Perot diode laser as wavelength reference. This system is capable of mon... 详细信息

关键词： DWDM FP LD MEMS A Wavelength Monitoring System Using Tunable MEMS Filter Calibrated by F-P Laser by

Thermal transformation of acid compounds in high TAN crude oil

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Science China Chemistry 2013年第7期56卷 848-855页

作者： YANG BaiBing XU ChunMing ZhAO SuoQi hSU Chang Samuel chung Keng h. ShI Quan State Key Laboratory of heavy Oil Processing China University of Petroleum

The Liaohe crude oil with high total acid number （TAN） was subjected to thermal reaction at 300 ℃ to 500℃. Reaction products were collected and analyzed by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry （ESI FT-ICR MS） to determine acid compounds in the crude oil. The double-bond equivalence （DBE） versus carbon number was used to characterize the oxygenated components in the feed and reaction products. The 02 class which mainly corresponds to naphthenic acids decarboxylated at 350-400℃, resulting in a sharply decrease in TAN. Phenols （O1 class） are more thermally stable than carboxylic acids. Carboxylic acids were also thermally cracked into smaller molecular size acids, evidenced by the presence of acetic acid, propanoic acid, and butyric acid in the liquid product. These small acid species are strong acids likely responsible for corrosion problems in refineries.

关键词： naphthenic acid TAN ESI FT-ICR MS thermal cracking

A Chinese Information Processing System

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Journal of Computer Science and Technology 1986年第2期1卷 15-24页

作者： C.Y.chung 华宣仁 Basser Department of Computer Science University of Sydney

The Chinese information processing system(CIPS)introduced in this paper can producegraphs,tables,flowcharts,mathematical equations,forms and also provides *** system can process not only Chinese text but also English text or a mixture *** is written in C language and runs on VAX Ⅱ/780 under Unix operating *** system is very easy to use and provides user-defined macro which allows abbreviationsof commonly used Chinese phrases and reduce the complexity of Chinese characters coding.

关键词： CIPS data A Chinese Information Processing System