检索结果-南通市图书馆

Hydrodechlorination of trifluoro-trichloroethane to chlorotrifluoroethylene:Revealing the deactivation mechanism and regeneration strategy of Pd-Cu/AC catalyst

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第6期70卷 261-268页

作者： Song Tian Yicheng Chen Xiaoyu Wen Bingcheng Li jian Lu Zile Li feng feng Qingtao Wang Qunfeng Zhang Xiaonian Li State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology Institute of Industrial Catalysis of Zhejiang University of TechnologyHangzhou 310014China State Key Laboratory of Fluorine&Nitrogen Chemicals Xi'an Modern Chemistry Research InstituteXi'an 710065China

Chlorotrifluoroethylene(CTFE)is a vital fluorinated olefinic monomer produced through the catalytic hydrodechlorination of trichlorotrifluoroethane(CFC-113),an eco-friendly ***,hydrodechlorination catalysts for olefin production often suffer from poor *** Pd/AC catalyst and Pd-Cu/AC catalyst prepared by co-impregnation method exhibited poor stability,Pd-Cu/AC catalyst with CFC-113 conversion dropping to around 37%after 50 h of hydrodechlorination ***-Emmett-Teller,transmission electron microscopy,X-ray photoelectron spectroscopy,and X-ray diffraction of fresh and deactivated Pd/AC catalysts indicate that the deactivation of Pd/AC catalysts is due to high-temperature agglomeration of *** analysis of fresh and deactivated Pd-Cu/AC catalysts using Brunauer-Emmett-Teller,transmission electron microscopy,and thermogravimetric analysis techniques revealed decreased dispersion of active sites,reduced surface area,catalyst aggregation deactivation,and a significant decrease in Cu ***,the results of NH3-TPD revealed that the acid sites of the catalyst increased significantly.X-ray diffraction spectra indicated the formation of new species,basic copper chloride(Cu_(2)(OH)_(3)Cl),during the *** the reaction progressed,these new species agglomerated,leading to a gradual loss of catalyst ***,the deactivated catalyst was successfully reactivated using a simple alkaline washing method.

关键词： CFC-113 Hydrodechlorination Chlorotrifluoroethylene Catalyst deactivation

Water modeling on fluid flow and mixing phenomena in a BOF steelmaking converter

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第3期31卷 595-607页

作者： Xin-yu Cai Hao-jian Duan Ding-han Li Anjun Xu Li-feng Zhang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing 100083China School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China

A 1∶8 physical water model was constructed to investigate the fluid flow and mixing phenomena in the basic oxygen furnace(BOF)*** particle image velocimetry was employed to measure the velocity distribution of the bath and the high-speed camera was applied to capture the cavity shape in the combined blowing BOF *** mixing time for varied operating conditions was measured by the stimulus-response *** cavity depth increased with the decrease in the lance height and the increase in the top gas flow rate while the bottom blowing gas had little influence on the cavity *** minimum cavity depth was obtained under the condition of a 69.8 m^(3)/h top gas flow rate,a 287.5 mm lance height and a 0.93 m^(3)/h bottom blowing gas flow rate,which was 161.2 *** mixing time decreased as the lance height decreased and the top blowing gas flow rate *** mixing time was first decreased and then increased with the increase in the bottom gas flow *** the condition of 69.8 m^(3)/h gas flow rate of top blowing,the 287.5 mm lance height and the 0.93 m^(3)/h gas flow rate of bottom blowing,the mixing time in the converter was 48.65 *** empirical formula between the stirring power and the mixing time in the converter was calculated.

关键词： Water model Fluid flow Particle image velocimetry Mixing time BOF converter

Charge regulation by ferromagnetic metal/LiF spin-polarized interface for high-performance Li metal anodes

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3期43卷 995-1005页

作者： Ming-yang feng Shuang Zhou Yi-Fang Zhang Ya-Ping Wang Chun-Yan Fu jian-Wen Li Yuan-Lang Wan Zhi-Jia Zhang Yong jiang An-Qiang Pan State Key Laboratory of Powder Metallurgy School of Materials Science and EngineeringCentral South UniversityChangsha410083China State Key Laboratory of Separation Membranes and Membrane Processes Tianjin Key Laboratory of Advanced Fibers and Energy StorageSchool of Material Science and EngineeringTiangong UniversityTianjin300387China School of Materials Science and Engineering Hebei University of TechnologyTianjin300130China

The interfacial characteristics of the Li metal anode(LMA)play a crucial role in its overall *** various materials being applied to modify the interface,a comprehensive understanding of their specific mechanisms remains to be ***,we have prepared carbon cloth(CC)frameworks with their surfaces modified using ferromagnetic metal/LiF heterogeneous films(T^(M)-LiF-CC)as the substrate for LMA,which exhibit superior electrochemical *** ferromagnetic Co as a representative example,our study demonstrates that the enhanced performance of Co-LiF-CC,compared to bare CC,is attributed to the spinpolarized interface contributed by the Co/LiF *** and LiF play individual roles in redistributing electrons and Li^(+)to promote homogeneous Li *** nanoparticles play a crucial role in generating strong surface capacitance by storing electrons in spin-split bands,while LiF,with low surface diffusion barriers,ensures fast transportation of Li^(+).The Co-LiF-CC@Li electrodes deliver long lives of 7400 and 3600 h at 1 and 2 mA·cm^(-2)in symmetric cells,respectively;moreover,they enable full batteries with high and durable capacities,particularly when the N/P ratios are low(3.3 or even 1.7).

关键词： Lithium metal anode Interfacial charge Ferromagnetic metal Lithium fluoride Spin polarization

Suppression of low-frequency ultrasound broadband vibration using star-shaped single-phase metamaterials

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第4期34卷 217-224页

作者： Rui Zhao jian Zheng Jin Guo Yunbo Shi Hengzhen feng Jun Tang Jun Liu Science and Technology on Electronic Test&Measurement Laboratory North University of ChinaTaiyuan 030051ShanxiChina School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

In order to suppress the low-frequency ultrasound vibration in the broadband range of 20 k Hz—100 k Hz,this paper proposes and discusses an acoustic metamaterial with low-frequency ultrasound vibration attenuation properties,which is configured by hybrid arc and sharp-angle convergent star-shaped *** effect of the dispersion relation and the bandgap characteristic for the scatterers in star-shaped are simulated and *** target bandgap width is extended by optimizing the geometry parameters of arc and sharp-angle convergent *** proposed metamaterial configured by optimized hybrid lattices exhibits remarkable broad bandgap characteristics by bandgap complementarity,and the simulation results verify a 99%vibration attenuation amplitude can be obtained in the frequency of20 k Hz—100 k *** the fabrication of the proposed hybrid configurational star-shaped metamaterial by 3D printing technique,the transmission loss experiments are performed,and the experimental results indicate that the fabricated metamaterial has the characteristics of broadband vibration attenuation and an amplitude greater than 85%attenuation for the target *** results demonstrate that the hybrid configurational star-shaped metamaterials can effectively widen the bandgap and realize high efficiency attenuation,which has capability for the vibration attenuation in the application of highprecise equipment.

关键词： Star-shaped metamaterials Broadband Vibration attenuation Low-frequency ultrasound vibration Transmission loss

Mucosa color and size may indicate malignant transformation of chicken skin mucosa-positive colorectal neoplastic polyps

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第3期16卷 750-760页

作者： Ying-Jie Zhang Meng-Xia Yuan Wu Wen Fan Li Yi jian Chuan-Ming Zhang Ye yang feng-Lin Chen Department of Digestive Diseases Chengdu Second People’s HospitalChengdu 610000Sichuan ProvinceChina Graduate School Chengdu Medical CollegeChengdu 610000Sichuan ProvinceChina

BACKGROUND Lipid metabolism reprogramming is suspected to exist in pre-cancerous lesions,including colorectal *** colonoscopy frequently reveals chicken skin mucosa(CSM;white or yellow-white speckled mucosa)surrounding colo-rectal polyps,caused by macrophages engulfing and accumulating the lipids decomposed by colon cells or adjacent ***-positive colorectal polyps are associated with various diseases;however,their prognosis varies *** snare polypectomy is commonly used to resect lesions up to 10 to 15 mm in diameter without signs of submucosal invasion but is controversial for CSM-positive colorectal *** imaging is required to diagnose and treat CSM-positive colorectal *** This retrospective cohort study included 177 patients with CSM-positive colorectal polyps diagnosed using *** patient-related information was extracted from the Goldisc soft-clinic DICOM system or electronic medical record *** on the pathological results,patients were classified as non-neoplastic polyps(five juvenile polyps),neoplastic polyps,non-invasive high-grade neoplasia(NHGN),or submucosal invasive carcinoma(SM stage cancer).We analyzed and compared the clinical features,suspected risk factors for malignant transformation of neoplastic polyps,and early infiltration of sub-mucosal *** The diameters of NHGN and SM polyps were much smaller than those of neoplastic *** NHGN polyps had a deeper red mucosal *** logistic regression analyses,diameter and deeper red mucosal color were independent risk factors for malignant transformation of neoplastic *** 1 CSM was more common in high-grade intraepithelial neoplasia and SM;type 2 CSM was more common in neoplastic *** regression analyses revealed no significant differences in the malignant transformation of neoplastic polyps or early submucosal invasion of CSM-positive colorectal *** in the CSM mucosa surrounding neoplastic

关键词： Chicken skin mucosa Colorectal cancer Colorectal polyps Endoscopic resection Malignant transformation White light endoscopy

Knockout of a rice K5.2 gene increases Ca accumulation in the grain

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

Journal of Integrative Plant Biology 2024年第2期66卷 252-264页

作者： Peitong Wang Naoki Yamaji Namiki Mitani-Ueno Jun Ge jian feng Ma National Key Laboratory of Crop Genetics&Germplasm Enhancement and Utilization College of Resources and Environmental SciencesNanjing Agricultural UniversityNanjing 210095China Institute of Plant Science and Resources Okayama UniversityKurashiki 710-0046Japan

Rice is a staple food for half of the world’s population,but it is a poor dietary source of calcium(Ca)due to the low *** is an important issue to boost Ca concentration in this grain to improve Ca deficiency risk,but the mechanisms underlying Ca accumulation are poorly ***,we obtained a rice(Oryza sativa)mutant with high shoot Ca *** mutant exhibited 26%-53% higher Ca in shoots than did wild-type rice(WT)at different Ca *** concentration in the xylem sap was 36% higher in the mutant than in the *** was no difference in agronomic traits between the WT and mutant,but the mutant showed 25% higher Ca in the polished grain compared with the ***-based cloning combined with a complementation test revealed that the mutant phenotype was caused by an 18-bp deletion of a gene,OsK5.2,belonging to the Shaker-like K+channel ***5.2 was highly expressed in the mature region of the roots and its expression in the roots was not affected by Ca levels,but upregulated by low *** showed that OsK5.2 was mainly expressed in the pericycle of the *** together,our results revealed a novel role for OsK5.2 in Ca translocation in rice,and will be a good target for Ca biofortification in rice.

关键词： accumulation biofortification calcium OsK5.2 pericycle rice translocation

Trend of Storm Surge Induced by Typical Landfall Super Typhoons During 1975–2021 in the Eastern China Sea

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2024年第2期23卷 277-286页

作者： LUO feng WANG Yi TAO Aifeng SHI jian WANG Yongzhi ZHANG Chi College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210098China Nantong Ocean and Coastal Engineering Research Institute Hohai UniversityNantong 226000China Key Laboratory of Ministry of Education for Coastal Disaster and Protection Hohai UniversityNanjing 210098China College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China The First Institute of Oceanography MNRQingdao 266061China

Climate change affects the activity of global and regional tropical cyclones(TCs).Among all TCs,typical super typhoons(STYs)are particularly devastating because they maintain their intensity when landing on the coast and thus cause casualties,economic losses,and environmental *** a 3D tidal model,we reconstructed the typhoon(TY)wind field to simulate the storm surge induced by typical *** TY activity was then analyzed using historical *** showed a downtrend of varying degrees in the annual frequency of STYs and TCs in the Western North Pacific(WNP)Basin,with a significant trend change observed for TCs from 1949 to 2021.A large difference in the interannual change in frequency was found between STYs and TCs in the WNP and Eastern China Sea(ECS).Along the coast of EC,the frequency of landfall TCs showed a weak downtrend,and the typical STYs showed reverse micro growth with peak activity in ***,Fujian,and Taiwan were highly vulnerable to the frontal hits of typical *** by climate change,the average lifetime maximum intensity(LMI)locations and landfall locations of typical STYs in the ECS basin showed a significant poleward migration *** addition,the annual average LMI and accumulated cyclone energy showed an uptrend,indicating the increasing severity of the disaster *** by the typical STY activity in the ECS,the maximum storm surge area also showed poleward migration,and the coast of North China faced potential growth in high storm surge risks.

关键词： storm surge super typhoons tropical cyclones eastern China Sea poleward migration

Hemorrhagic transformation in patients with large-artery atherosclerotic stroke is associated with the gut microbiota and lipopolysaccharide

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第7期19卷 1532-1540页

作者： Qin Huang Minping Wei Xianjing feng Yunfang Luo Yunhai Liu jian Xia Department of Neurology Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina Department of Neurology Peking University People’s HospitalBeijingChina Clinical Research Center for Cerebrovascular Disease of Hunan Province Central South UniversityChangshaHunan ProvinceChina National Clinical Research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina

Hemorrhagic transformation is a major complication of large-artery atheroscle rotic stroke(a major ischemic stro ke subtype)that wo rsens outcomes and increases *** of the gut microbiota is an important feature of stroke,and some specific bacteria and bacterial metabolites may contribute to hemorrhagic transformation *** aimed to investigate the relationship between the gut microbiota and hemorrhagic transformation in largearte ry atheroscle rotic stro *** observational retrospective study was *** May 2020 to September 2021,blood and fecal samples were obtained upon admission from 32 patients with first-ever acute ischemic stroke and not undergoing intravenous thrombolysis or endovascular thrombectomy,as well as 16 healthy *** with stro ke who developed hemorrhagic transfo rmation(n=15)were compared to those who did not develop hemorrhagic transformation(n=17)and with healthy *** gut microbiota was assessed through 16S ribosomal ribonucleic acid *** also examined key components of the lipopolysaccharide pathway:lipopolysaccharide,lipopolysaccharide-binding protein,and soluble *** observed that bacterial diversity was decreased in both the hemorrhagic transformation and non-hemorrhagic transfo rmation group compared with the healthy *** patients with ischemic stro ke who developed hemorrhagic transfo rmation exhibited altered gut micro biota composition,in particular an increase in the relative abundance and dive rsity of members belonging to the Enterobacteriaceae *** lipopolysaccharide and lipopolysaccharide-binding protein levels were higher in the hemorrhagic transformation group compared with the non-hemorrhagic transfo rmation ***,lipopolysaccharide-binding protein,and soluble CD14 concentrations were associated with increased abundance of Enterobacte ***,the role of the gut microbiota in hemorrhagic transformation was evaluated using

关键词： gut microbiota hemorrhagic transformation inflammation lipopolysaccharide stroke

Downregulation of Serum PTEN Expression in Mercury-Exposed Population and PI3K/AKT Pathway-Induced Inflammation

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2024年第4期37卷 354-366页

作者： MEI Peng DING En Min YIN Hao yang DING Xue Xue WANG Huan WANG jian feng HAN Lei ZHANG Heng Dong ZHU Bao Li School of Public Health Nanjing Medical UniversityNanjing 210000JiangsuChina Institute of Occupational Disease Prevention Jiangsu Province Center for Disease Prevention and ControlNanjing 21000JiangsuChina Suzhou Center for Disease Prevention and Control Suzhou 215004JiangsuChina Center for Global Health School of Public HealthNanjing Medical UniversityNanjing 210000JiangsuChina

Objective This study investigated the impact of occupational mercury(Hg) exposure on human gene transcription and expression, and its potential biological *** Differentially expressed genes related to Hg exposure were identified and validated using gene expression microarray analysis and extended validation. Hg-exposed cell models and PTEN lowexpression models were established in vitro using 293T cells. PTEN gene expression was assessed using qRT-PCR, and Western blotting was used to measure PTEN, AKT, and PI3K protein levels. IL-6 expression was determined by *** Combined findings from gene expression microarray analysis, bioinformatics, and population expansion validation indicated significant downregulation of the PTEN gene in the high-concentration Hg exposure group. In the Hg-exposed cell model(25 and 10 μmol/L), a significant decrease in PTEN expression was observed, accompanied by a significant increase in PI3K, AKT, and IL-6 ***, a low-expression cell model demonstrated that PTEN gene knockdown led to a significant decrease in PTEN protein expression and a substantial increase in PI3K, AKT, and IL-6 *** This is the first study to report that Hg exposure downregulates the PTEN gene, activates the PI3K/AKT regulatory pathway, and increases the expression of inflammatory factors, ultimately resulting in kidney inflammation.

关键词： PTEN Occupational mercury exposure Occupational health PI3K/AKT pathway 293T cell IL-6