检索结果-南通市图书馆

Preparation of Calcium Carbonate Nanoparticles with a Continuous Gas-liquid Membrane Contactor： Particles Morphology and Membrane Fouling

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2013年第2期21卷 121-126页

作者： JIA Zhiqian chang qing QIN jin MAMATA Aynur Lab for Membrane Science and Technology College of Chemistry Beijing Normal University Beijing 100875 China

Nanosized calcium carbonate particles were prepared with a continuous gas-liquid membrane contactor. The effects of Ca(OH)2 concentration, CO2 pressure and liquid flow velocity on the particles morphology, pressure drop and membrane fouling were studied. With rising Ca(OH)2 concentrations, the average size of the particles increased. The effects of Ca(OH)2 concentration and CO2 pressure on particles were not apparent under the experimental conditions. When the Ca(OH)2 concentration and liquid flow velocity were high, or the CO2 pressure was low, the fouling on the membrane external surface at the contactor entrance was serious due to liquid leakage, whereas the fouling was slight at exit. The fouling on the membrane inner-surface at entrance was apparent due to adsorption of raw materials. The membrane can be recovered by washing with dilute hydrochloric acid and reused for at least 6 times without performance deterioration.

关键词： membrane contactor gas-liquid reaction CaCO3 nanoparticles two-phase reaction membrane absorption

Low temperature Pmmm and C2/m phases in Sr_2CuO_(3+δ) high temperature superconductor

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第5期28卷 206-209页

作者： Hai-Bo Wang Zhen-Lin Luo Yuan-Jun Yang qing-qing Liu Si-Xia Hu Meng-Meng Yang chang-qing jin Chen Gao Tonghua Normal University National Synchrotron Radiation Laboratory and School of Nuclear Science and Technology University of Science and Technology of China Institute of Physics Chinese Academy of Sciences CAS Key Laboratory of Materials for Energy Conversion and Collaborative Innovation Center of Chemistry for Energy Materials University of Science and Technology of China

A new low temperature Pmmm(120 K) phase was found in high temperature superconductor Sr_2 CuO_(3+δ), which was indicated as a pure electronic phase by resonant x-ray diffraction at Cu K-edge. As shown by x-ray absorption fine structure(EXAFS) and x-ray absorption near edge structure(XANES) at Cu K-edge, the strong charge density redistribution and local lattice fluctuations around Cu site at the onset of phase transition were due to the occurrence of superconductive coherence, the redistribution and fluctuation finished at Tc. Finally, the electron–lattice interaction was mainly elaborated to understand the superconductivity of Sr_2 CuO_(3+δ).

关键词： resonant x-ray diffraction x-ray absorption fine structure modulated phase superconductivity

Constituents from Aerial Parts of Bidens ceruna L. and Their DPPH Radical Scavenging Activity

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2009年第3期25卷 328-331页

作者： ZHU Na LI Xu-wen LIU Gui-ying SHI Xiao-lei GUI Ming-yu SUN chang-qing jin Yong-ri College of Chemistry Jilin University Changchun 130012 P. R. China

A new chalcone glycoside, butein-4-methoxyl-4′-O-（6＂-O-acetyl）-β-D-glucopyranoside（2）, along with seven known compounds, namely, quercitrin（1）, luteolin-7-O-β-D-glucopyranoside（3）, butein-4＇-O-β-D-glucopyranoside（4）, butein-4-methoxyl-4＇-O-β-D-glucopyranoside（5）, butin-7-O-β-D-glucopyranoside（6）, isoquercitrin（7）, and sulfurein（8） was isolated from aerial parts of Bidens ceruna L. Their structures were elucidated on the basis of spectroscopic studies. Compounds 1-8 were tested for their DPPH radical scavenging activity and, except compounds 2 and 5, other compounds showed scavenging activitv.

关键词： Bidens ceruna L. Constituent Flavonoid DPPH radical Scavenging activity

Physical properties and phase diagram of NaFe_(1-x)V_(x)As

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第1期30卷 100-103页

作者： Guang-Yang Dai Xin He Zhi-Wen Li chang-Ling Zhang Lu-Chuan Shi Run-Ze Yu Xian-Cheng Wang chang-qing jin Institute of Physics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China Materials Research Laboratory at Songshan Lake Dongguan 523808China

We grew a series of NaFe_(1-x)V_(x) As(0 ≤ x ≤ 0.03) single crystals and performed the measurements of resistance,magnetic susceptibility, and specific heat to study the superconducting phase diagram by doping V into Na Fe As. Both the structural and the spin-density-wave(SDW) transitions are slightly suppressed by V-doping. While superconducting transition temperature is enhanced to the maximum value of 15 K when the optimal doping level x = 0.007 and then is suppressed rapidly with further V-doping, displaying a small superconducting dome. Our results suggest that V-impurities should act as strong magnetic scattering centers which cause the sharp suppression of superconductivity in NaFe_(1-x)V_(x) As.

关键词： iron based superconductor "111"type NaFeAs V doping phase diagram

Generic Modeling and Control Framework for Power Systems Dominated by Power Converters Connected Through a Passive Transmission and Distribution Grid

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第1期10卷 292-301页

作者： qing-chang Zhong Marcio Stefanello Department of Electrical and Computer Engineering Illinois Institute of TechnologyChicagoIL 60616USA Syndem LLC USA.M.Stefanello is with the Fundacao Universidade Federal do Pampa at AlegreteRS97546-550Brazil

In this paper,a compact mathematical model having an elegant structure,together with a generic control framework,are proposed for generic power systems dominated by power converters that are interconnected through a passive transmission and distribution(T&D)grid,by adopting the port-Hamiltonian(pH)systems theory and the fundamental circuit *** models of generic T&D lines are developed and then the model of a generic T&D grid is *** the proposed control framework,the controlled converters are proven to be passive and Input-to-State Stable(ISS).The compact mathematical model is scalable and can be applied to power systems with multiple power electronic converters with generic passive controllers,passive local loads,and different types of passive T&D lines connected in a meshed configuration without self-loops,so it is very ***,the resulting power system is proven to be ISS as *** analysis is carried out without assumptions on constant frequency/voltage,constant loads,and/or lossless networks,except the need of passivity for all parts involved,and without using the Clarke/Park transformations or the graph *** simplify the presentation,three-phase balanced systems are adopted but the results can be easily adapted for single-phase or unbalanced three-phase systems.

关键词： Input-to-State Stable(ISS) passivity,portHamiltonian(pH)systems Power electronic converters dominated power systems Synchronized and Democratized(SYNDEM)grid architecture

Dual modification of LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2) cathode materials by K^(+) doping and Li_(3)PO_(4) coating for lithium ions batteries

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第7期43卷 3007-3018页

作者： Wei Xiao Jia-Le Wang Zhi-Cheng Yi Cheng-jin Liu chang Miao Yu Xin Shu-qing Nie College of Chemistry and Environmental Engineering Yangtze UniversityJingzhou 434023China

Li_(3)PO_(4)@Li_(0.99)K_(0.01)Ni_(0.83)Co_(0.11)Mn_(O.06)O_(2)(NCM-KP) cathode powders are synthesized via K^(+)doping in calcination processes and H_3PO_4 coating in sol-gel processes.K^(+) precisely enters into the lattice to widen the(003) plane to 0.4746 nm with a lower cationic disordered degree of 1.87%.Moreover,the surface residual lithium salts are treated by H_3PO_4 to generate a uniform Li_(3)PO_(4) coating layer of approximately 11.41 nm,which completely covers on the surface of secondary spherical particles to improve the interfacial *** 25℃,the NCM-KP electrode delivers a discharge specific capacity of 148.9 mAh·g^(-1) with a remarkable capacity retention ratio of 84.1% after 200 cycles at 1.0C and retains a high reversible specific capacity of 154.4 mAh·g^(-1) at *** at 1.0C and 60℃,it can maintain a reversible discharge specific capacity of 114.6 mAh·g^(-1) with 0.21% of capacity decay per cycle after 200 cycles,which is significantly lower than 0.40% for the pristine NCM ***,the charge transfer resistance of 238.89 Ω for the NCM-KP electrode is significantly lower than 947.41 Ω for the pristine NCM one by restricting the interfacial side ***,combining K+doping and Li_(3)PO_(4) coating is an effective strategy to enable the significant improvement of the electrochemical property of high-nickel cathode materials,which may be mainly attributed to the widened diffusion pathway and the formed Li_(3)PO_(4) protective layer,thus promoting Li~+diffusion rate and preventing the erosion of HF.

关键词： High-nickel cathode material Residual lithium K^(+)doping Li_(3)PO_(4)coating Lithium ions battery

Early results of reverse less invasive stabilization system plating in treating elderly intertrochanteric fractures： a prospective study compared to proximal femoral nail

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2011年第14期124卷 2150-2157页

作者： YAO Chen ZHANG chang-qing jin Dong-xu CHEN Yun-feng Department of Orthopaedics Shanghai No. 6 People's HospitalShanghai Jiao Tong University School of Medicine Shanghai 200233 China

Background Intertrochanteric femur fracture is common in elderly population. Though multiple treatment options are available, the choice of implant remains controversial. The reverse less invasive stabilization system （LISS） plating was introduced for treatment of a patient with ipsilateral intertrochanteric and midshaft femoral fractures. The aim of this research was to compare such technique to intramedullary nailing （proximal femoral nail, PFN） for intertrochanteric *** Fifty-six patients with an age of at least sixty-five years and an AO/OTA type-A1 or A2 fractures were included and divided into LISS and PFN treatment group. Background parameters, fracture and surgery details were documented. Follow-up time was at least 12 months. Radiology, complication, Harris Hip Score and Rapid Disability Rating Score （RDRS） were recorded to evaluate fixation status and hip function for each patient during *** There was no significant difference between the two groups in surgical time （（48.0±8.6） minutes, vs.（51.8±10.8） minutes, P=0.3836） and intraoperative blood loss （（149.1±45.1） ml vs. （176.4±25.4） ml, P=0.0712）. The LISS group had less postoperative haemoglobin （Hb） reduction （（10.2±4.5） g/L Hb, vs. （15.1-5.9） g/L Hb, P=0.0475）. There was no complication observed in PFN group. All 31A1 type fracture in LISS group showed 100% maintenance of reduction. One nonunion with locking screw breakage and 2 varus union were found in the LISS group. Postoperative hip function was similar between the two *** Though reverse LISS plating may not be recommended as a routine fixation method for elderly unstable intertrochanteric fractures compared to PFN, it may possibly be reserved for rapid fixation and damage control in polytrauma patients and ORIF of subtrochanteric and reverse oblique intertrochanteric fractures.

关键词： less invasive stabilization system intertrochanteric femur fracture proximal femoral nail osteoporosis unstable fracture

Preoperative blood markers and intra-abdominal infection after colorectal cancer resection

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第2期16卷 451-462页

作者： chang-qing Liu Zhong-Bei Yu jin-Xian Gan Tian-Ming Mei Department of Gastrointestinal Anorectal Surgery Suzhou Hospital Affiliated to Anhui Medical UniversitySuzhou 234000Anhui ProvinceChina

BACKGROUND Colorectal cancer(CRC)has one of the highest morbidity and mortality rates among digestive tract ***-abdominal infection(IAI)is a common postoperative complication that affects the clinical outcomes of patients with CRC and hinders their rehabilitation ***,the factors influencing abdominal infection after CRC surgery remain unclear;further,prediction models are rarely used to analyze preoperative laboratory indicators and postoperative *** To explore the predictive value of preoperative blood markers for IAI after radical resection of *** The data of 80 patients who underwent radical resection of CRC in the Anorectal Surgery Department of Suzhou Hospital affiliated with Anhui Medical University were *** patients were categorized into IAI(n=15)and non-IAI groups(n=65)based on whether IAI *** factors were compared;general data and laboratory indices of both groups were *** relationship between the indicators was ***,a nomogram prediction model was developed and evaluated;its utility and clinical applic-ability were *** The risk factors for IAI after radical resection of CRC were neutrophil-lymphocyte ratio(NLR),platelet-lymphocyte ratio(PLR),systemic immune-inflammation index(SII),and carcinoembryonic antigen(CEA)*** was correlated with PLR and SII(r=0.604,0.925,and 0.305,respectively),while PLR was correlated with SII(r=0.787).The nomogram prediction model demonstrated an area under the curve of 0.968[95%confidence interval(CI):0.948-0.988]in the training set(n=60)and 0.926(95%CI:0.906-0.980)in the validation set(n=20).The average absolute errors of the calibration curves for the training and validation sets were 0.032 and 0.048,respectively,indicating a good model *** decision curve analysis curves demonstrated high net income above the 5%threshold,indicating the clinical practicality of the *** The nomogram model constructed

关键词： Radical resection of colorectal cancer Inflammatory factors Intra-abdominal infection Predictive model Blood markers

Thickening progression mechanism of silica fume-oil well cement composite system at high temperatures

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2793-2805页

作者： Hang Zhang Miao-Miao Hu Peng-Peng Li Guo-qing Liu qing-Lu chang Jie Cao Ming Liu Wen-Hua Xu Xiu-Jian Xia jin-Tang Guo School of Chemical Engineering and Technology Tianjin University Zhejiang Institute of Tianjin University Haihe Laboratory of Sustainable Chemical Transformations CNPC Engineering Technology R&D Company Limited

This work studied the thickening progression mechanism of the silica fume-oil well cement composite system at high temperatures(110-180.C) in order to provide a theoretical guidance for the rational application of silica fume in the cementing engineering. Results showed that silica fume seldom affected the thickening progression of oil well cement slurry at 110-120.C, but when temperature reached above130.C, it would aggravate the bulging degree of thickening curves and significantly extend the thickening time, meanwhile causing the abnormal “temperature-based thickening time reversal” and“dosage-based thickening time reversal” phenomena in the range of 130-160.C and 170-180.C respectively. At 130-160.C, the thickening time of oil well cement slurry was mainly associated with the generation rate of calcium hydroxide(CH) crystal. The introduced silica fume would be attracted to the cement minerals' surface that were hydrating to produce CH and agglomerate together to form an“adsorptive barrier” to hinder further hydration of the inner cement minerals. This “adsorptive barrier”effect strengthened with the rising temperature which extended the thickening time and caused the occurrence of the “temperature-based thickening time reversal” phenomenon. At 170-180.C, the pozzolanic activity of silica fume significantly enhanced and considerable amount of C-S-H was generated, thus the “temperature-based thickening time reversal” vanished and the “dosage-based thickening time reversal” was presented.

关键词： Silica fume Oil well cement Thickening time reversal Pozzolanic reaction Adsorptive barrier CH and C−S−H