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In-situ Investigation of BBr_3/benzene Solution by Fourier Transformation Infrared Spectroscopy

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Chemical Research in Chinese Universities 2009年第5期25卷 733-737页

作者： YU Li-li GAI Li-gang CUI de-liang WANG Qi-long State Key Laboratory of Crystal Materials Shandong University Jinan 250100 P. R. China School of Chemical Engineering Shandong Institute of Light Industry Jinan 250353 P. R. China

By means of the in-situ Fourier transformation infrared spectroscopy（FTIR）, the properties of BBr3/ benzene solution, which is usually used as the reactant and solution to synthesize BN by benzene-thermal method, have been investigated. The results show that there are some side reactions between BBr3 and benzene：（1） BBr3 as an electron-deficient molecule reacts with benzene at room temperature; （2） below 100℃, substitution of Br atom for H atom of benzene（ring-H） dominates in BBr3/benzene solution; （3） cracking of benzene ring occurs at a temperature above 100℃; （4） decomposition of benzene molecules and formation of long-chain aliphatic compounds feature the spectra of BBr3/benzene solution collected at above 160℃, They are unfavor for BN to form when BBr3 is excessive in the synthesis of BN by benzene-thermal route. On the basis of the experimental results, a coordination reaction mechanism via a η^2-C6H6 binding mode in BBr3/benzene solution is suggested.

关键词： In-situ FTIR technique BBr3 Benzene Boron nitride Reaction mechanism

Movement initiation of millimeter particles on a rotating rough surface: The role of adhesion

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Particuology 2020年第6期18卷 92-99页

作者： Karina de los Angeles Valenzuela Aracena Rodolfo O.Unac Irene Ippolito Ana M.Vidales INFAP CONICETDepartamento de FisicaFacultad de Ciencias Fisico Matematicas y NaturalesUniversidad Nacional de San LuisEjercito de los Andes 950D5700HHWSan LuisArgentina Universidad de Buenos Aires Facultad de IngenieriaGrupo de Medios PorososPaseo Colon 850C1063ACV Buenos AiresArgentina

We performed experiments to determine the critical moment for movement initiation of a millimeter bead on a rotating rough *** corresponding critical angular velocities were measured for glass and stainless-steel ball bearings over two different rough surfaces with glued glass beads.A basic theoretical analysis was developed to explain the observed *** the expectation of a simple approach with the presence of the obstacles offered by a rough surface could be sufficient to describe the problem,we prove here that the sole con sideration of these obstacles,and even friction,are insufficient to explain the results in the range of a few-millimeter glass *** the thermodynamic work of adhesion between surfaces is significant,the adhesion forces must be considered in the force balance for particle detachment:.This effect is a determinant for describing theoretically and numerically the dynamics of millimeter particles.

关键词： detachment Adhesion Centrifugation

Facile and efficient synthesis of 2-substituted-Nl-carbethoxy-2,3-dihydro-4(1H)-quinazolinones in fluorous solvent

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Chinese Chemical Letters 2008年第5期19卷 537-540页

作者： Bai Ling Xu Jin Ping Chen Rong Zhang Qiao de Cai Fu lnstitute of Materia Medica Chinese Academy of Medical Sciences Peking Union Medical College Beijing 100050 China Hebei University of Science and Technology Shijiazhuang 050018 China department of Life Science and Technology Beijing University of Chemical Technology Beijing 100029 China

A facile, efficient and novel approach to access 2-substituted-N1-carbethoxy-2,3-dihydro-4（1H）-quinazolinones was developed by condensation of substituted N-carbethoxyanthranilamide with alkyl, aromatic or heteroaromatic aldehydes in the refluxing 2,2,2- trifluoroethanol or hexafluoroisopropanol using p-toluenesulfonic acid as catalyst.

关键词： Quinazolinones Trifluoroethanol Hexafluoroisopropanol Fluorous solvent Solvent effect

Preparation and Characterization of UV-absorbing PVDF Membranes via Pre-irradiation Induced Graft Polymerization

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Chinese Journal of Polymer Science 2019年第5期37卷 493-499页

作者： Li Dong Xiang-Dong Liu Zheng-Rong Xiong de-Kun Sheng Yan Zhou Yu-Ming Yang Changchun Institute of Applied Chemistry Chinese Academy of Sciences University of Science and Technology of China

Herein, excellent UV-absorbing poly(vinylidene fluoride)(PVDF) membranes were fabricated through the pre-irradiation induced graft polymerization method. The PVDF chains irradiated with ^(60)Co γ-ray were modified with the polymerizable UV absorber 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2 H-benzotriazole(RUVA-93). The influences of irradiation dose and monomer concentration on the prepared PVDF-g-PRUVA-93 membranes were investigated, and the optimal condition was eventually obtained. The chemical structures of the films were studied by ~1H-NMR, FTIR, and XRD. UV light transmittance and DSC tests were used to characterize the UV-absorbing performance and thermal property of the PVDF films before and after modification. The results proved that the PRUVA-93 side chains were successfully incorporated into the PVDF main chains and the obtained PVDF-g-PRUVA-93 films possessed remarkable UV-absorbing property. The modified membrane made under the optimized experiment condition could completely block the UV light in the range of 200-387 nm. Additionally, the transmittance of the PVDF-g-PRUVA-93 film could be reduced to0.04% in 280-320 nm, where the light irradiation could damage polymer materials most seriously.

关键词： PVDF membrane Modification Irradiation Grafting UV-absorbing

Estimating Change in Sedimentary Organic Carbon Content During Mangrove Restoration in Southern China Using Carbon Isotopic Measurements

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Pedosphere 2012年第1期22卷 58-66页

作者： ZHANG Jin-Ping SHEN Cheng-de REN Hai WANG Jun HAN Wei-Dong Key Laboratory of Vegetation Restoration and Management of degraded Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou 510650(China) Graduate University of Chinese Academy of Sciences Beijing 100039(China) Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640(China) Guangdong Ocean University Zhanjiang 524088(China)

Based on total carbon(C) and C isotopes in sediment cores,sedimentary organic carbon(SOC) was quantified in three types of mangrove sites(barren flat sites without mangroves,mangrove plantations,and natural mangrove forests),which were considered to represent a continuum from least restored to most restored sites in southern *** densities in the barren sites,plantations,and natural forests were 90,170 and 288 Mg ha 1,*** inferred that mangrove restoration increased SOC accumulation in coastal *** 0-70 cm depth,SOC δ 13 C values in both mangrove sites ranged from 27.37‰ to 23.07‰ and exhibited gradual enrichment with *** contrast,the values in the barren flat sites remained around 22.19‰ and fluctuated slightly with *** 0-60 cm,the 14 C ages of the SOC in the barren flat site,the natural mangrove site,and the artificial mangrove site ranged from 1 397 to 2 608,255 to 2 453,and 391 to 2 512 years BP,*** both types of mangrove sites but not in the barren flat sites,the enrichment of δ 13 C with depth was related to increases in SOC decay and SOC age with *** to analysis of 14 C age,much of the mangrove-derived C was transported and stored at 0-60 cm depth under anaerobic conditions in both mangrove *** sediments of mangrove forests in southern China sequester large quantities of SOC during mangrove restoration.

关键词： artificial mangrove 14C age δ13C value natural mangrove radiocarbon

Severe delayed complication after percutaneous endoscopic colostomy for chronic intestinal pseudo-obstruction: A case report and review of the literature

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World Journal of Gastroenterology 2007年第15期13卷 2255-2257页

作者： David Bertolini Philippe de Saussure Michael Chilcott Marc Girardin Jean-Marc Dumonceau Divisions of Gastroenterology and Hepatology Geneva University Hospitals GenevaSwitzerland department of Digestive Surgery Geneva University Hospitals GenevaSwitzerland

Percutaneous endoscopic colostomy （PEC） is increasingly proposed as an alternative to surgery to treat various disorders, including acute colonic pseudo-obstruction, chronic intestinal pseudo-obstruction and relapsing sigmoid volvulus. We report on a severe complication that occurred two months after PEC placement. A 74-year-old man with a history of chronic intestinal pseudo-obstruction evolving since 8 years was readmitted to our hospital and received PEC to provide long-standing relief. The procedure was uneventful and greatly improved the patient＇s quality of life. Two months later, the patient developed acute stercoral peritonitis. At laparotomy, the colostomy flange was embedded in the abdominal wall but no pressure necrosis was found at the level of the colonic wall. This complication was likely related to inadvertent traction of the colostomy tube. Subtotal colectomy with terminal ileostomy was performed. We review the major features of 60 cases of PEC reported to date, including indications and complications.

关键词： Percutaneous endoscopic colostomy Complications Colonic pseudo-obstruction Ileus Peritonitis

Fault Location Approach to Distribution Networks Based on Custom State Estimator

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Journal of Modern Power Systems and Clean Energy 2023年第6期11卷 1878-1889页

作者： Luis F.Ugarte Madson C.de Almeida Luís H.T.Bandória IEEE department of Systems and Energy State University of CampinasSão Paulo 13083-970Brazil

This paper presents a properly designed branchcurrent based state estimator(BCBSE)used as the main core ofan accurate fault location approach(FLA)devoted to distribution *** to the approaches available in the literature,it uses only a limited set of conventional measurementsobtained from smart meters to accurately locate faults at busesor branches without requiring measurements provided by phasor measurement units(PMUs).This is possible due to themethods used to model the angular reference and the faultedbus,in addition to the proper choice of the weights in the stateestimator(SE).The proposed approach is based on a searchingprocedure composed of up to three stages:①the identificationof the faulted zones;②the identification of the bus closest tothe fault;and③the location of the fault itself,searching onbranches connected to the bus closest to the ***,this paper presents a comprehensive assessment of the proposedapproach,even considering the presence of distributed generation,and a sensitivity study on the proper weights required bythe SE for fault location purposes,which can not be found inthe *** show that the proposed BCBSE-basedFLA is robust,accurate,and aligned with the requirements ofthe traditional and active distribution networks.

关键词： Active distribution network branch current based state estimator fault location smart meter

Isochamaejasmin induces apoptosis in leukemia cells through inhibiting Bcl-2 family proteins

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Chinese Journal of Natural Medicines 2015年第9期13卷 660-666页

作者： ZHANG Shou-de SHAN Lei LI Wei LI Hong-Lin ZHANG Wei-Dong Shanghai Key Laboratory of New Drug design State Key Laboratory of Bioreactor Engineering School of Pharmacy East China University of Science and Technology School of Pharmacy Second Military Medical University Qinghai Academy of Agriculture and Forestry Science

The biflavonoid isochamaejasmin is mainly distributed in the root of Stellera chamaejasme L.(Thymelaeaceae) that is used in traditional Chinese medicine(TCM) to treat tumors, tuberculosis, and psoriasis. Herein, isochamaejasmin was found to show similar bioactivity against Bcl-2 family proteins to the reference Bcl-2 ligand(–)-gossypol through 3D similarity search. It selectively bound to Bcl-xL and Mcl-1 with Ki values being 1.93 ± 0.13 μmol·L-1 and 9.98 ± 0.21 μmol·L-1, respectively. In addition, isochamaejasmin showed slight growth inhibitory activity against HL-60 with IC50 value being 50.40 ± 1.21 μmol·L-1 and moderate growth inhibitory activity against K562 cells with IC50 value being 24.51 ± 1.62 μmol·L-1. Furthermore, isochamaejasmin induced apoptosis of K562 cells by increasing the intracellular expression levels of proteins of the cleavage of caspase-9, caspase-3, and PARP which involved in the Bcl-2-induced apoptosis pathway. These results indicated that isochamaejasmin induces apoptosis in leukemia cells by inhibiting the activity of Bcl-2 family proteins, providing evidence for further studying the underlying anti-cancer mechanism of S. chamaejasme L..

关键词： Stellera chamaejasme L. Isochamaejasmin Bcl-2 3D Similarity search (–)-Gossypol Apoptosis

Prevalence and Predictors of Hypertension in the Labor Force Population in China:Results from a Cross-sectional Survey in Xinjiang Uygur Autonomous Region

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Biomedical and Environmental Sciences 2016年第4期29卷 290-294页

作者： XU de Min LI Xue Feng GOAN Daniel YANG de Min LI Jun Mei WANG Xia HUANG Yu Lian CHEN Yuan Sheng Karamay Center for Disease Control and Prevention The Graduate School of Biomedical Sciences University of North Texas Health Science Center Fort Worth The central hospital of Karamay Chinese Center for Disease Control and Prevention

The objective of this study was to examine the prevalence of hypertension and identify its contributory factors in the labor force population in Karamay.A total of 2819 adults(55.9%male adults)were interviewed and *** overall crude prevalence of hypertension was 32.4%.Among 914hypertensive patients,34.8%were aware of their diagnosis,22.1%received treatment,and 5.6%

关键词： Prevalence and Predictors of Hypertension in the Labor Force Population in China