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Ultrafast dynamics in photo-excited Mott insulator Sr_(3)Ir_(2)O_7 at high pressure
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作者 尹霞 张建波 +6 位作者 王东 Takeshi Nakagawa 夏春生 张曹顺 郭伟程 昌峻 丁阳 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期149-155,共7页
High-pressure ultrafast dynamics,as a new crossed research direction,are sensitive to subtle non-equilibrium state changes that might be unresolved by equilibrium states measurements,providing crucial information for ... High-pressure ultrafast dynamics,as a new crossed research direction,are sensitive to subtle non-equilibrium state changes that might be unresolved by equilibrium states measurements,providing crucial information for studying delicate phase transitions caused by complex interactions in Mott insulators.With time-resolved transient reflectivity measurements,we identified the new phases in the spin–orbit Mott insulator Sr_(3)Ir_(2)O_7 at 300 K that was previously unidentified using conventional approaches such as x-ray diffraction.Significant pressure-dependent variation of the amplitude and lifetime obtained by fitting the reflectivity?R/R reveal the changes of electronic structure caused by lattice distortions,and reflect the critical phenomena of phase transitions.Our findings demonstrate the importance of ultrafast nonequilibrium dynamics under extreme conditions for understanding the phase transition of Mott insulators. 展开更多
关键词 ultrafast dynamics high pressure phase transition Mott insulator
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Emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate obtained by Corolase PP under high hydrostatic pressure 被引量:1
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作者 Haining Guan Chunmei Feng +3 位作者 Min Ren Xiaojun Xu Dengyong Liu Xiaoqin Diao 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1271-1278,共8页
Enzymatic hydrolysis of proteins can enhance their emulsifying properties and antioxidant activities.However,the problem related to the hydrolysis of proteins was the generation of the bitter taste.Recently,high hydro... Enzymatic hydrolysis of proteins can enhance their emulsifying properties and antioxidant activities.However,the problem related to the hydrolysis of proteins was the generation of the bitter taste.Recently,high hydrostatic pressure(HHP)treatment has attracted much interest and has been used in several studies on protein modification.Hence,the study aimed to investigate the effects of enzymatic hydrolysis by Corolase PP under different pressure treatments(0.1,100,200,and 300 MPa for 1-5 h at 50℃)on the emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate(SPIH).As observed,the hydrolysate obtained at 200 MPa for 4 h had the highest emulsifying activity index(47.49 m^(2)/g)and emulsifying stability index(92.98%),and it had higher antioxidant activities(44.77%DPPH free radical scavenging activity,31.12%superoxide anion radical scavenging activity,and 61.50%copper ion chelating activity).At the same time,the enhancement of emulsion stability was related to the increase of zeta potential and the decrease of mean particle size.In addition,the hydrolysate obtained at 200 MPa for 4 h had a lower bitterness value and showed better palatability.This study has a broad application prospect in developing food ingredients and healthy foods. 展开更多
关键词 Soybean protein isolate high hydrostatic pressure EMULSIFICATION ANTIOXIDANT Bitter taste
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First-principles study of structural and electronic properties of multiferroic oxide Mn_(3)TeO_(6) under high pressure
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作者 潘小龙 王豪 +2 位作者 柳雷 陈向荣 耿华运 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期448-454,共7页
Mn_(3)TeO_(6)(MTO) has been experimentally found to adopt a P2_(1)/In structure under high pressure,which exhibits a significantly smaller band gap compared to the atmospheric R3 phase.In this study,we systematically ... Mn_(3)TeO_(6)(MTO) has been experimentally found to adopt a P2_(1)/In structure under high pressure,which exhibits a significantly smaller band gap compared to the atmospheric R3 phase.In this study,we systematically investigate the magnetism,structural phase transition,and electronic properties of MTO under high pressure through first-principles calculations.Both R3 and P2_(1)/n phases of MTO are antiferromagnetic at zero temperature.The R3 phase transforms to the P2_(1)/n phase at 7.5 8 GPa,accompanied by a considerable volume collapse of about 6.47%.Employing the accurate method that combines DFT+U/and GW,the calculated band gap of R3 phase at zero pressure is very close to the experimental values,while that of the P2_(1)/n phase is significantly overestimated.The main reason for this difference is that the experimental study incorrectly used the Kubelka-Munk plot for the indirect band gap to obtain the band gap of the P2_(1)/n phase instead of the Kubelka-Munk plot for the direct band gap.Furthermore,our study reveals that the transition from the R3 phase to the P2_(1)/n phase is accompanied by a slight reduction in the band gap. 展开更多
关键词 MAGNETISM phase transition band gap high pressure
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Stability and melting behavior of boron phosphide under high pressure
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作者 梁文嘉 向晓君 +2 位作者 李倩 梁浩 彭放 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期579-584,共6页
Boron phosphide(BP)has gained significant research attention due to its unique photoelectric and mechanical properties.In this work,we investigated the stability of BP under high pressure using x-ray diffraction and s... Boron phosphide(BP)has gained significant research attention due to its unique photoelectric and mechanical properties.In this work,we investigated the stability of BP under high pressure using x-ray diffraction and scanning electron microscope.The phase diagram of BP was explored in both B-rich and P-rich environments,revealing crucial insight into its behavior at 5.0 GPa.Additionally,we measured the melting curve of BP from 8.0 GPa to 15.0 GPa.Our findings indicate that the stability of BP under high pressure is improved within B-rich and P-rich environments.Furthermore,we report a remarkable observation of melting curve frustration at 10.0 GPa.This study will enhance our understanding of stability of BP under high pressure,shedding light on its potential application in semiconductor,thermal,and light-transmitting devices. 展开更多
关键词 boron phosphide STABILITY melting curve high pressure
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High-pressure study on calcium azide(Ca(N_(3))_(2)):Bending of azide ions stabilizes the structure
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作者 武晓鑫 王颖健 +7 位作者 李思琪 吕俊呈 王婧姝 杨丽华 张旗 刘艳清 张俊凯 贾洪声 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期542-548,共7页
The high-pressure structure and elastic properties of calcium azide(Ca(N_(3))_(2))were investigated using in-situ highpressure x-ray diffraction and Raman scattering up to 54 GPa and 19 GPa,respectively.The compressib... The high-pressure structure and elastic properties of calcium azide(Ca(N_(3))_(2))were investigated using in-situ highpressure x-ray diffraction and Raman scattering up to 54 GPa and 19 GPa,respectively.The compressibility of Ca(N_(3))_(2)changed as the pressure increased,and no phase transition occurred within the pressure from ambient pressure up to 54 GPa.The measured zero-pressure bulk modulus of Ca(N_(3))_(2)is higher than that of other alkali metal azides,due to differences in the ionic character of their metal-azide bonds.Using CASTEP,all vibration modes of Ca(N_(3))_(2)were accurately identified in the vibrational spectrum at ambient pressure.In the high-pressure vibration study,several external modes(ext.)and internal bending modes(ν_(2))of azide anions(N_(3)^(-))softened up to~7 GPa and then hardened beyond that pressure.This evidence is consistent with the variation observed in the F_(E)–f_(E)data analyzed from the XRD result,where the slope of the curve changes at 7.1 GPa.The main behaviors under pressure are the alternating compression,rotation,and bending of N_(3)^(-)ions.The bending behavior makes the structure of Ca(N_(3))_(2)more stable under pressure. 展开更多
关键词 high pressure calcium azide azide anions
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Recension of boron nitride phase diagram based on high-pressure and high-temperature experiments
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作者 Ruike Zhang Ruiang Guo +3 位作者 Qian Li Shuaiqi Li Haidong Long Duanwei He 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期450-457,共8页
Cubic boron nitride and hexagonal boron nitride are the two predominant crystalline structures of boron nitride.They can interconvert under varying pressure and temperature conditions.However,this transformation requi... Cubic boron nitride and hexagonal boron nitride are the two predominant crystalline structures of boron nitride.They can interconvert under varying pressure and temperature conditions.However,this transformation requires overcoming significant potential barriers in dynamics,which poses great difficulty in determining the c-BN/h-BN phase boundary.This study used high-pressure in situ differential thermal measurements to ascertain the temperature of h-BN/c-BN conversion within the commonly used pressure range(3-6 GPa)for the industrial synthesis of c-BN to constrain the P-T phase boundary of h-BN/c-BN in the pressure-temperature range as much as possible.Based on the analysis of the experimental data,it is determined that the relationship between pressure and temperature conforms to the following equation:P=a+1/bT.Here,P denotes the pressure(GPa)and T is the temperature(K).The coefficients are a=-3.8±0.8 GPa and b=229.8±17.1 GPa/K.These findings call into question existing high-pressure and high-temperature phase diagrams of boron nitride,which seem to overstate the phase boundary temperature between c-BN and h-BN.The BN phase diagram obtained from this study can provide critical temperature and pressure condition guidance for the industrial synthesis of c-BN,thus optimizing synthesis efficiency and product performance. 展开更多
关键词 hexagonal boron nitride phase diagram high temperature and high pressure cubic boron nitride phase transition differential thermal analysis
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High Hydrostatic Pressure Exacerbates Bladder Fibrosis through Activating Piezo1
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作者 Bo-lang DENG Dong-xu LIN +7 位作者 Zhi-peng LI Kang LI Peng-yu WEI Chang-cheng LUO Meng-yang ZHANG Quan ZHOU Zheng-long YANG Zhong CHEN 《Current Medical Science》 SCIE CAS 2024年第4期718-725,共8页
Objective Bladder outlet obstruction(BOO)results in significant fibrosis in the chronic stage and elevated bladder pressure.Piezo1 is a type of mechanosensitive(MS)channel that directly responds to mechanical stimuli.... Objective Bladder outlet obstruction(BOO)results in significant fibrosis in the chronic stage and elevated bladder pressure.Piezo1 is a type of mechanosensitive(MS)channel that directly responds to mechanical stimuli.To identify new targets for intervention in the treatment of BOO-induced fibrosis,this study investigated the impact of high hydrostatic pressure(HHP)on Piezo1 activity and the progression of bladder fibrosis.Methods Immunofluorescence staining was conducted to assess the protein abundance of Piezo1 in fibroblasts from obstructed rat bladders.Bladder fibroblasts were cultured under normal atmospheric conditions(0 cmH_(2)O)or exposed to HHP(50 cmH_(2)O or 100 cmH_(2)O).Agonists or inhibitors of Piezo1,YAP1,and ROCK1 were used to determine the underlying mechanism.Results The Piezo1 protein levels in fibroblasts from the obstructed bladder exhibited an elevation compared to the control group.HHP significantly promoted the expression of various pro-fibrotic factors and induced proliferation of fibroblasts.Additionally,the protein expression levels of Piezo1,YAP1,ROCK1 were elevated,and calcium influx was increased as the pressure increased.These effects were attenuated by the Piezo1 inhibitor Dooku1.The Piezo1 activator Yoda1 induced the expression of pro-fibrotic factors and the proliferation of fibroblasts,and elevated the protein levels of YAP1 and ROCK1 under normal atmospheric conditions in vitro.However,these effects could be partially inhibited by YAP1 or ROCK inhibitors. 展开更多
关键词 high hydrostatic pressure bladder outlet obstruction FIBROSIS Piezo1
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NMI,POLR3G and APIP are the key molecules connecting glaucoma with high intraocular pressure:a clue for early diagnostic biomarker candidates
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作者 Nawaf Almarzouki 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第11期1987-1994,共8页
AIM:To understand the molecular connectivity between the intraocular pressure(IOP)and glaucoma which will provide possible clues for biomarker candidates.METHODS:The current study uncovers the important genes connecti... AIM:To understand the molecular connectivity between the intraocular pressure(IOP)and glaucoma which will provide possible clues for biomarker candidates.METHODS:The current study uncovers the important genes connecting IOP with the core functional modules of glaucoma.An integrated analysis was performed using glaucoma and IOP microarray datasets to screen for differentially expressed genes(DEGs)in both conditions.To the selected DEGs,the protein interaction network was constructed and dissected to determine the core functional clusters of glaucoma.For the clusters,the connectivity of IOP DEGs was determined.Further,enrichment analyses were performed to assess the functional annotation and potential pathways of the crucial clusters.RESULTS:The gene expression analysis of glaucoma and IOP with normal control showed that 408 DEGs(277 glaucoma and 131 IOP genes)were discovered from two GEO datasets.The 290 DEGs of glaucoma were extended to form a network containing 1495 proteins with 9462 edges.Using ClusterONE,the network was dissected to have 12 clusters.Among them,three clusters were linked with three IOP DEGs[N-Myc and STAT Interactor(NMI),POLR3G(RNA Polymerase Ⅲ Subunit G),and APAF1-interacting protein(APIP)].In the clusters,ontology analysis revealed that RNA processing and transport,p53 class mediators resulting in cell cycle arrest,cellular response to cytokine stimulus,regulation of phosphorylation,regulation of type Ⅰ interferon production,DNA deamination,and cellular response to hypoxia were significantly enriched to be implicated in the development of glaucoma.Finally,NMI,POLR3G,and APIP may have roles that were noticed altered in glaucoma and IOP conditions.CONCLUSION:Our findings could help to discover new potential biomarkers,elucidate the underlying pathophysiology,and identify new therapeutic targets for glaucoma. 展开更多
关键词 GLAUCOMA high intraocular pressure biomarkers gene expression protein interaction molecular pathways
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Characteristics and distribution of microstructures in high pressure die cast alloys with X-ray microtomography:A review
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作者 Hai-dong Zhao Xue-ling Wang +2 位作者 Qian Wan Wen-hui Bai Fei Liu 《China Foundry》 SCIE EI CAS CSCD 2024年第5期427-444,共18页
Al and Mg alloy high pressure die castings(HPDC)are increasingly used in automotive industries.The microstructures in the castings have decisive effect on the casting mechanical properties,in which the microstructure ... Al and Mg alloy high pressure die castings(HPDC)are increasingly used in automotive industries.The microstructures in the castings have decisive effect on the casting mechanical properties,in which the microstructure characteristics are fundamental for the investigation of the microstructure-property relation.During the past decade,the microstructure characteristics of HPDC Al and Mg alloys,especially micro-pores andα-Fe,have been investigated from two-dimensional(2D)to threedimensional with X-ray micro-computed tomography(μ-CT).This paper provides an overview of the current understanding regarding the 3D characteristics and formation mechanisms of microstructures in HPDC alloys,their spatial distributions,and the impact on mechanical properties.Additionally,it outlines future research directions for the formation and control of heterogeneous microstructures in HPDC alloys. 展开更多
关键词 high pressure die casting microstructure three-dimensional characteristics DISTRIBUTION Al and Mg alloys
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Screening, Treatment and Control of High Blood Pressure on Five Sites in Mali
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作者 Mamadou Touré Sagara Ibrahima +19 位作者 Youssouf Camara Hamidou Oumar Bâ Ibrahima Sangaré Djénébou Traoré Noumou Sidibé Fousseyni Samassékou Massama Konaté Coumba Thiam Doumbia Asmaou Maiga Réné-Marie Dakouo Hamidou Camara Sako Mariam Sidibé Samba Adama Sogodogo Boubacar Diarra Boubacar Sonfo Aladji Traoré Mamadou Diakité Ilo Bella Diall Ichaka Menta 《World Journal of Cardiovascular Diseases》 CAS 2024年第5期322-332,共11页
Introduction: High blood pressure is defined as blood pressure greater than or equal to 140 mm Hg for systolic and or 90 mm Hg for diastolic. It constitutes a major public health problem, the leading chronic disease i... Introduction: High blood pressure is defined as blood pressure greater than or equal to 140 mm Hg for systolic and or 90 mm Hg for diastolic. It constitutes a major public health problem, the leading chronic disease in the world. The objective was to determine the prevalence, treatment rate and control of hypertension. Methods: This was a cross-sectional and descriptive study which took place over a period of 6 months in a hospital environment and in the general population. Results: Of the 1000 participants, 637 had hypertension, giving a prevalence of 63.70% with a female predominance. Thirty-three percent (33%) were unaware of their high blood pressure. The age group 60 and more was the most represented (44%). A proportion of 33 and 23.20 were overweight and obese participants, respectively. Male subjects were more overweight than female, unlike obesity which was more common among female subjects. Sixty-two percent (62%) of hypertensives were treated, of whom 44% were non-compliant. The excessively high cost and consumption of medications as needed were the main factors in therapeutic non-compliance. Twenty-two percent (22%) of all hypertensive patients and 35% of treated hypertensive patients were controlled. Women were more treated but less observant and less controlled than men. Therapeutic coverage and combination therapy rates were lower in rural areas. Hypertensives who had a high level of education were better treated and controlled than those who had no level. Conclusion: High blood pressure remains a real public health problem in Mali. It is more common in people aged 60 and over and in females. One in three hypertensives were unaware of their hypertension. The majority received antihypertensive treatments, but only a minority of them had their hypertension controlled. 展开更多
关键词 high Blood pressure SCREENING Control Rate MALI
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Economic Stress, Precariousness and Risk of High Blood Pressure: A Descriptive Survey of Life Models within Households of the Central Region of Cameroon
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作者 Jean Ndibi Abanda Ulrich Dama +5 位作者 Viviane Foussouo Ndoungue Anicet Onana Akoa Melkior Fobasso Dzeuta Alphonse Tedonge Asobochia Arsène Emilien Messi Ndzengue Désiré Tchoffo 《Health》 2024年第2期118-130,共13页
Context/Objective: High blood pressure (HBP) currently represents the most widespread chronic non-communicable disease in Cameroon. The increase in its prevalence in the country is the result of multiple factors inclu... Context/Objective: High blood pressure (HBP) currently represents the most widespread chronic non-communicable disease in Cameroon. The increase in its prevalence in the country is the result of multiple factors including economic stress imposed by precariousness, poor living conditions, sources of anxiety, anguish, depression and other behavioral disorders. Economic stress is a globalizing concept that integrates into a purely hermeneutic approach, a particular functioning of the nervous system of an individual who faces employment problems and precarious remuneration conditions. The non-satisfaction by an individual of his basic needs due to insufficient financial means can cause him to become irritable, aggressive, and socially and symbolically isolated, thereby increasing the desire to resort to morbid life models such as excessive consumption of narcotics and other psychoactive substances often associated with high blood pressure. The fight against the emergence of BPH is a complex, multifaceted and multifactorial reality that requires taking into account economic stress. The main objective of this survey is to describe the situation of economic stress within the Cameroonian population, which imposes precariousness and life models at risk of high blood pressure. Specifically, we determined the level of household income and the sources of income. Methods: A cross-sectional survey with a descriptive aim among five hundred households in the Central Region of Cameroon was conducted. A probabilistic technique called simple randomness was used. The number of households to be surveyed was determined indirectly using the Cochrane formula. Data collection in face-to-face mode using a physical questionnaire took place from July 1 to August 31, 2023, after obtaining ethical clearance from the Regional Health Research Ethics Committee, Human from the Center and an administrative authorization for data collection. Regarding their processing, the data was grouped during processing in Excel sheets. Normality and reliability tests of the collected data were carried out. For this, the Chi-square test was used for data with a qualitative value and that of Kolmogorov-Sminorf for data with a quantitative value. Descriptive analysis was possible using R software version 3.2, SPSS version 25.0, XLSTAT 2016, PAST and EXCEL programs from Microsoft Office 2013. Results: The main results highlight economic stress, with 45.60% of households surveyed earning less than US$154 per month;55% of household heads were women in single-parent families;14% of household heads were unemployed, 22% worked in the private sector and 19% were self-employed. This general economic situation leads to precarious living conditions, thereby increasing the risk of high blood pressure among the Cameroonian population. 展开更多
关键词 Economic Stress PRECARIOUSNESS high Blood pressure Life Models Households
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Effect of slow shot speed on externally solidified crystal,porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy
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作者 Wen-ning Liu Wei Zhang +6 位作者 Peng-yue Wang Yi-xian Liu Xiang-yi Jiao Ao-xiang Wan Cheng-gang Wang Guo-dong Tong Shou-mei Xiong 《China Foundry》 SCIE EI CAS CSCD 2024年第1期11-19,共9页
The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron mi... The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron microscopy(SEM)and laboratory computed tomography(CT).Results showed that the newly developed AlSi9MnMoV alloy exhibited improved mechanical properties when compared to the AlSi10MnMg alloy.The AlSi9MnMoV alloy,which was designed with trace multicomponent additions,displays a notable grain refining effect in comparison to the AlSi10MnMg alloy.Refining elements Ti,Zr,V,Nb,B promote heterogeneous nucleation and reduce the grain size of primaryα-Al.At a lower slow shot speed,the large ESCs are easier to form and gather,developing into the dendrite net and net-shrinkage.With an increase in slow shot speed,the size and number of ESCs and porosities significantly reduce.In addition,the distribution of ESCs is more dispersed and the net-shrinkage disappears.The tensile property is greatly improved by adopting a higher slow shot speed.The ultimate tensile strength is enhanced from 260.31 MPa to 290.31 MPa(increased by 11.52%),and the elongation is enhanced from 3.72%to 6.34%(increased by 70.52%). 展开更多
关键词 hypoeutectic Al-Si alloy high pressure die casting POROSITY externally solidified crystal tensile property
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Analysis of the Flow Field and Impact Force in High-Pressure Water Descaling
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作者 Yue Cui Liyuan Wang +2 位作者 Jian Wu Haisheng Liu Di Wu 《Fluid Dynamics & Materials Processing》 EI 2024年第1期165-177,共13页
This study aims to improve the performances of the high-pressure water descaling technology used in steel hot rolling processes.In particular,a 2050 mm hot rolling line is considered,and the problem is investigated by... This study aims to improve the performances of the high-pressure water descaling technology used in steel hot rolling processes.In particular,a 2050 mm hot rolling line is considered,and the problem is investigated by means of a fluid–structure interaction(FSI)method by which the descaling effect produced by rolling coils with different section sizes is examined.Assuming a flat fan-shaped nozzle at the entrance of the R1R2 roughing mill,the outflow field characteristics and the velocity distribution curve on the strike line(at a target distance of 30–120 mm)are determined.It is found that the velocity in the center region of the water jet with different target distances is higher than that in the boundary region.As the target distance increases,the velocity of the water jet in the central region decreases.Through comparison with experimental results,it is shown that the simulation model can accurately predict the impact position of the high-pressure water on the impact plate,thereby providing a computational scheme that can be used to optimize the nozzle space layout and improve the slabs’descent effect for different rolling specifications. 展开更多
关键词 high pressure water descaling flow field analysis FSI target distance strike range
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Ethics of Human Resources Management in the Cameroonian Health System, Medical Nomadism and the Ineffectiveness of the Fight against High Blood Pressure
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作者 Jean Ndibi Abanda Anicet Onana Akoa +2 位作者 Désiré Tchoffo Ulrich Dama Pierre Yassa Yoniene 《Health》 2024年第1期9-21,共13页
Context/objectives: The fight against Chronic Non-Communicable Diseases (NCDs) is a long-term undertaking, which requires available, motivated and well-managed human resources (HR). The administrative management of sk... Context/objectives: The fight against Chronic Non-Communicable Diseases (NCDs) is a long-term undertaking, which requires available, motivated and well-managed human resources (HR). The administrative management of skills on both qualitative and quantitative levels is one of the essential functions of a health system. To better implement policies of fight against High Blood Pressure (HBP) and other chronic diseases, it is important to establish strategies to retain health personnel. This loyalty requires favorable working conditions and consideration of the contribution-reward couple. Good working conditions are likely to reduce the phenomenon of medical nomadism;conversely, poor HR management can contribute to their exodus towards exotic “green pastures”, thus leading to an additional crisis in the Cameroonian health system. The fight against HBP is a complex, multifaceted and multifactorial reality that requires appropriate management model for all types of resources mainly HR. The main objective of this research is to show the impact of poor management of human resources in Cameroon health system on medical nomadism and the ineffectiveness of the fight against High Blood Pressure. Method: A cross-sectional descriptive survey among five hundred (500) health facilities in the center region of Cameroon has been conducted. A stratified probabilistic technique has been used, and the number of health facilities to be surveyed has been determined using the “sample size estimation table” of Depelteau. The physical questionnaires have been printed and then distributed to data collectors. After data collection, the latter were grouped during processing in Excel sheets. The Chi-square test was used for data with a qualitative value and that of Kolmogorov-Sminorf for data with a quantitative value to assess the normality and reliability of data. The Crochach’s Alpha reliability test allowed us to have a summary of the means and variances and then to search for intragroup correlations between variables. Descriptive analysis was possible with the XLSTAT 2016 software. Results: 43.60% of Health Facilities (HF) managers were unqualified. 82.20% of HF managers have staff in a situation of professional insecurity. They are mainly contractual (49.00), decision-making agents (24.40%), casual agents (08.80). The proportion of unstable personnel is average of 22.00% and very unstable, 12.00%. 展开更多
关键词 ETHICS Human Resources Management Cameroonian Health System Medical Nomadism Ineffectiveness high Blood pressure
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Determination of critical state line(CSL)for silty-sandy iron ore tailings subjected to low-high confining pressures
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作者 Nilo Cesar Consoli João Vítor de Azambuja Carvalho +4 位作者 Alexia Cindy Wagner Hugo Carlos Scheuermann Filho Inácio Carvalho Pedro Pazzoto Cacciari João Paulo de Sousa Silva 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1684-1695,共12页
The disposal of filtered tailings in high dry stacks can induce particle breakage,changing the material's behaviour during the structure's lifetime.The grading changes influence material properties at the crit... The disposal of filtered tailings in high dry stacks can induce particle breakage,changing the material's behaviour during the structure's lifetime.The grading changes influence material properties at the critical state,and this is not mature for intermediate artificial soils(tailings)in a broad range of confining pressures.In this paper,it aims to describe the behaviour of iron ore tailings in a spectrum of confining pressures broader than the reported in previous studies.A series of consolidated drained(CD)triaxial tests was carried out with confining pressures ranging from 0.075 MPa to 120 MPa.These results show that the amount of breakage plays an essential role in the response of iron ore tailings.The existence of curved critical state line(CSL)in both specific volume(ν)-logarithm of mean effective stress(p′)and deviatoric stress(q)-mean effective stress(p′)planes,and different responses in the deviatoric stress-axial strain-volumetric strain curves were verified.An inverse S-shaped equation was proposed to represent the silty-sandy tailings'behaviour up to high pressures onν-lnp′plane.The proposed equation provides a basis for enhancing constitutive models and considers the evolution of the grading up to severe loading conditions.The adjustment considered three regions with different responses associated with particle breakage at different pressure levels. 展开更多
关键词 TAILINGS Iron ore tailings dry stacking Silty-sandy material Critical state soil mechanics high confining pressures Particle breakage
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Single-cell RNA sequencing analysis of the retina under acute high intraocular pressure
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作者 Shaojun Wang Siti Tong +5 位作者 Xin Jin Na Li Pingxiu Dang Yang Sui Ying Liu Dajiang Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第11期2522-2531,共10页
High intraocular pressure causes retinal ganglion cell injury in primary and secondary glaucoma diseases,yet the molecular landscape characteristics of retinal cells under high intraocular pressure remain unknown.Rat ... High intraocular pressure causes retinal ganglion cell injury in primary and secondary glaucoma diseases,yet the molecular landscape characteristics of retinal cells under high intraocular pressure remain unknown.Rat models of acute hypertension ocular pressure were established by injection of cross-linked hyaluronic acid hydrogel(Healaflow■).Single-cell RNA sequencing was then used to describe the cellular composition and molecular profile of the retina following high intraocular pressure.Our results identified a total of 12 cell types,namely retinal pigment epithelial cells,rod-photoreceptor cells,bipolar cells,Müller cells,microglia,cone-photoreceptor cells,retinal ganglion cells,endothelial cells,retinal progenitor cells,oligodendrocytes,pericytes,and fibroblasts.The single-cell RNA sequencing analysis of the retina under acute high intraocular pressure revealed obvious changes in the proportions of various retinal cells,with ganglion cells decreased by 23%.Hematoxylin and eosin staining and TUNEL staining confirmed the damage to retinal ganglion cells under high intraocular pressure.We extracted data from retinal ganglion cells and analyzed the retinal ganglion cell cluster with the most distinct expression.We found upregulation of the B3gat2 gene,which is associated with neuronal migration and adhesion,and downregulation of the Tsc22d gene,which participates in inhibition of inflammation.This study is the first to reveal molecular changes and intercellular interactions in the retina under high intraocular pressure.These data contribute to understanding of the molecular mechanism of retinal injury induced by high intraocular pressure and will benefit the development of novel therapies. 展开更多
关键词 APOPTOSIS axon degeneration high intraocular pressure MICROGLIA ocular hypertension photoreceptor cells RETINA retinal degeneration retinal ganglion cells single-cell RNA sequencing
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An ultrafast spectroscopy system for studying dynamic properties of superconductors under high pressure and low temperature conditions
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作者 朱健 李叶西 +9 位作者 冯登满 苏德鹏 范东牛 杨松 赵辰晓 赵高扬 李亮 李芳菲 王英惠 周强 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期608-613,共6页
An ultrafast pump-probe spectroscopy system combined with a cryogenic diamond anvil cell(DAC) instrument is developed to investigate the photo-excitation dynamic properties of condensed materials under low temperature... An ultrafast pump-probe spectroscopy system combined with a cryogenic diamond anvil cell(DAC) instrument is developed to investigate the photo-excitation dynamic properties of condensed materials under low temperature and high pressure(LTHP) conditions.The ultrafast dynamics study is performed on Bi_(2)Sr_(2)CaCu_(2)O_(8+δ)(Bi-2212) thin film under LTHP conditions.The superconducting(SC) phase transition has been observed by analyzing the ultrafast dynamics of Bi-2212 as a function of pressure and temperature.Our results suggest that the pump-probe spectroscopy system combined with a cryogenic DAC instrument is an effective method to study the physical mechanism of condensed matter physics at extreme conditions,especially for the SC phase transition. 展开更多
关键词 high pressure ultrafast spectroscopy SUPERCONDUCTING phase transition
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An adaptive physics-informed deep learning method for pore pressure prediction using seismic data 被引量:2
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作者 Xin Zhang Yun-Hu Lu +2 位作者 Yan Jin Mian Chen Bo Zhou 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期885-902,共18页
Accurate prediction of formation pore pressure is essential to predict fluid flow and manage hydrocarbon production in petroleum engineering.Recent deep learning technique has been receiving more interest due to the g... Accurate prediction of formation pore pressure is essential to predict fluid flow and manage hydrocarbon production in petroleum engineering.Recent deep learning technique has been receiving more interest due to the great potential to deal with pore pressure prediction.However,most of the traditional deep learning models are less efficient to address generalization problems.To fill this technical gap,in this work,we developed a new adaptive physics-informed deep learning model with high generalization capability to predict pore pressure values directly from seismic data.Specifically,the new model,named CGP-NN,consists of a novel parametric features extraction approach(1DCPP),a stacked multilayer gated recurrent model(multilayer GRU),and an adaptive physics-informed loss function.Through machine training,the developed model can automatically select the optimal physical model to constrain the results for each pore pressure prediction.The CGP-NN model has the best generalization when the physicsrelated metricλ=0.5.A hybrid approach combining Eaton and Bowers methods is also proposed to build machine-learnable labels for solving the problem of few labels.To validate the developed model and methodology,a case study on a complex reservoir in Tarim Basin was further performed to demonstrate the high accuracy on the pore pressure prediction of new wells along with the strong generalization ability.The adaptive physics-informed deep learning approach presented here has potential application in the prediction of pore pressures coupled with multiple genesis mechanisms using seismic data. 展开更多
关键词 Pore pressure prediction Seismic data 1D convolution pyramid pooling Adaptive physics-informed loss function high generalization capability
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ULTRASTRUCTURE OF THE VEGETATIVE CELLS OF NOSTOC FLAGELLIFORME PREPARED WITH HIGH PRESSURE FREEZING AND FREEZE SUBSTITUTION TECHNIQUE 被引量:8
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作者 祝建 王俊 +1 位作者 华振基 马丁.米勒 《Acta Botanica Sinica》 CSCD 1998年第10期901-905,共5页
The ultrastructure of the vegetative cells of Nostoc flagelliforme Born. et Flah. was investigated with high pressure freezing and freeze substitution technique and compared with the results obtained by using conv... The ultrastructure of the vegetative cells of Nostoc flagelliforme Born. et Flah. was investigated with high pressure freezing and freeze substitution technique and compared with the results obtained by using conventional preparation methods. During the processes of chemical fixation, dehydration and embedding, the cell structures might be more artificially modified than that obtained from high pressure freezing and freeze substitution. With the present method, the sheath of N. flagelliforme could be well penetrated and no extra big space could exist between the cell and the sheath. The cell protoplasm rarely shrinked. Some fine structures of cell inclusions and unit membranes became visualized. Many bacteria were harbored in the sheath. In addition, the presence of big vacuoles in the cell of N. flagelliforme as well as the presence of bacteria in the sheath shown in the present preparation for cyanobacteria has not been described so far in the literature. 展开更多
关键词 ultraSTRUCTURE Nostoc flagelliforme Vegetative cell high pressure freezing Freeze substitution
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Pressure generation under deformation in a large-volume press
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作者 Saisai Wang Xinyu Zhao +8 位作者 Kuo Hu Bingtao Feng Xuyuan Hou Yiming Zhang Shucheng Liu Yuchen Shang Zhaodong Liu Mingguang Yao Bingbing Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期622-626,共5页
Deformation can change the transition pathway of materials under high pressure,thus significantly affects physical and chemical properties of matters.However,accurate pressure calibration under deformation is challeng... Deformation can change the transition pathway of materials under high pressure,thus significantly affects physical and chemical properties of matters.However,accurate pressure calibration under deformation is challenging and thereby causes relatively large pressure uncertainties in deformation experiments,resulting in the synthesis of complex multiphase materials.Here,pressure generations of three types of deformation assemblies were well calibrated in a Walker-type largevolume press(LVP)by electrical resistance measurements combined with finite element simulations(FESs).Hard Al_(2)O_(3) or diamond pistons in shear and uniaxial deformation assemblies significantly increase the efficiency of pressure generation compared with the conventional quasi-hydrostatic assembly.The uniaxial deformation assembly using flat diamond pistons possesses the highest efficiency in these deformation assemblies.This finding is further confirmed by stress distribution analysis based on FESs.With this deformation assembly,we found shear can effectively promote the transformation of C60 into diamond under high pressure and realized the synthesis of phase-pure diamond at relatively moderate pressure and temperature conditions.The present developed techniques will help improve pressure efficiencies in LVP and explore the new physical and chemical properties of materials under deformation in both science and technology. 展开更多
关键词 shear/uniaxial DEFORMATION pressure calibration finite element simulations large- VOLUME PRESS high pressure
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