检索结果-南通市图书馆

Numerical Simulation on Radon Retardation Behavior of Covering Floats in Radon-Containing Water

Biomedical and Environmental Sciences 2024年第4期37卷 406-417页

作者： LIU Shu Yuan ZHANG Li ye Yong Jun DING Ku ke National Institute for Radiological Protection Chinese Center for Disease Control and PreventionBeijing 100088China Office for Public Health Management Chinese Center for Disease Control and PreventionBeijing 102206China key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy University of South ChinaHengyang 421001HunanChina

Objective This study aimed to efficiently reduce the release of radon from water bodies to protect the environment.Methods Based on the sizes of the experimental setup and modular float,computational fluid dynamics(CFD)was used to assess the impact of the area coverage rate,immersion depth,diffusion coefficient,and radon transfer velocity at the gas–liquid interface on radon migration and exhalation of radon-containing water.Based on the numerical simulation results,an estimation model for the radon retardation rate was constructed.The effectiveness of the CFD simulation was evaluated by comparing the experimental and simulated variation values of the radon retardation rate with the coverage area rates.Results The effect of radon transfer velocity on radon retardation in water bodies was minor and insignificant according to the appropriate value;therefore,an estimation model of the radon retardation rate of the coverage of a radon-containing water body was constructed using the synergistic impacts of three factors:area coverage rate,immersion depth,and diffusion coefficient.The deviation between the experimental and simulated results was<4.3%.Conclusion Based on the numerical simulation conditions,an estimation model of the radon retardation rate of covering floats in water bodies under the synergistic effect of multiple factors was obtained,which provides a reference for designing covering floats for radon retardation in radoncontaining water.

关键词： Radon-containing water Radon retardation rate CFD Coverage experiment Optimized design

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Strong Antiferromagnetic Exchange-Coupling Observed in Hydride-Bridged Dimeric Dysprosium(Ⅲ)Single-Molecule Magnet

引用

Chinese Journal of Chemistry 2024年第4期42卷 391-396页

作者： Qian-Cheng Luo ke-Xin Yu Peng-Bo Jin ye-ye Liu Yuan-Qi Zhai Yan-Zhen Zheng Frontier Institute of Science and Technology State Key Laboratory of Electrical Insulation and Power EquipmentXi'an Key Laboratory of Electronic Devices and Materials ChemistrySchool of Chemistry and School of PhysicsXi'an Jiaotong University99 Yanxiang RoadXi'anShaanxi710054 China

One dihydride-bridged dimeric Dy(Ⅲ)guanidinate complex,formulated as[{(Me_(3)Si)_(2)NC(NiPr)_(2)}_(2)Dy(μ-H)]_(2)(1Dy),was successfully isolated and the introduction of hydride bridges significantly reduces the intramolecular Dy(Ⅲ)…Dy(Ⅲ)distance to only 3.688(1)Å.To investigate the effect of such a short Dy(Ⅲ)…Dy(Ⅲ)distance on magnetism,we also prepared its dibromide-bridged analogue[{(Me_(3)Si)_(2)NC(NiPr)_(2)}_(2)Dy(μ-Br)]_(2)(2Dy),which has a much longer Dy(Ⅲ)…Dy(Ⅲ)distance of 4.605(4)Å.Surprisingly,2Dy demonstrates much larger effective energy barrier for magnetization reversal(U_(eff))and higher blocking temperature(T_(B)).The worse performance of 1Dy is attributed to the concerted effect of strong antiferromagnetic interactions between Dy(Ⅲ)ions(J_(total)=–2.683 cm^(–1))and the unparallel arrangement of magnetic principle axes of the Dy(Ⅲ)ions for 1Dy.

关键词： Single-molecule magnets Lanthanides Guanidinate ligand Hydride bridge Magnetic properties Ab initio calculations

来源：

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

Electrochemical Dearomative Spirocyclization of N-Acyl Sulfonamides in a Continuous-Flow Cell

引用

Chinese Journal of Chemistry 2024年第9期42卷 980-984页

作者： Ting Liu Zhaojiang Shi Yaofeng Yuan Yuqi Lin ke-Yin ye key Laboratory of Molecule Synthesis and Function Discovery(Fujian Province University) College of ChemistryFuzhou University FuzhouFujian350108China

The development of efficient and sustainable methods to obtain spirocyclic compounds is of significance as these structures are widely found in pharmaceuticals and agrochemicals.Herein,we disclose an electrochemical dearomative spirocyclization of N-acyl sulfonamides in a continuous-flow cell.The reaction is simple and efficient without external catalysts or supporting electrolytes and could be applied in a decagram-scale synthesis.

关键词： Electrochemistry Continuous-flow Dearomatization Spirocyclization Sulfonamides Cyclization Methodology and reactions

来源：

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

Oxygen‑Coordinated Single Mn Sites for Efficient Electrocatalytic Nitrate Reduction to Ammonia

引用

Nano-Micro Letters 2024年第1期16卷 147-159页

作者： Shengbo Zhang Yuankang Zha Yixing ye ke Li Yue Lin Lirong Zheng Guozhong Wang Yunxia Zhang Huajie Yin Tongfei Shi Haimin Zhang Laboratory of Materials Physics Centre for Environmental and Energy NanomaterialsAnhui Key Laboratory of Nanomaterials and NanotechnologyCAS Center for Excellence in NanoscienceInstitute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031People’s Republic of China University of Science and Technology of China Hefei 230026People’s Republic of China key Laboratory of Agricultural Sensors Ministry of AgricultureSchool of Information and ComputerAnhui Agricultural UniversityHefei 230026People’s Republic of China Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026People’s Republic of China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of Sciences19B Yuquan RoadBeijing 100049People’s Republic of China

Electrocatalytic nitrate reduction reaction has attracted increasing attention due to its goal of low carbon emission and environmental protection.Here,we report an efficient NitRR catalyst composed of single Mn sites with atomically dispersed oxygen(O)coordination on bacterial cellulose-converted graphitic carbon(Mn-O-C).Evidence of the atomically dispersed Mn-(O-C_(2))_(4)moieties embedding in the exposed basal plane of carbon surface is confirmed by X-ray absorption spectroscopy.As a result,the as-synthesized Mn-O-C catalyst exhibits superior NitRR activity with an NH_(3)yield rate(RNH_(3))of 1476.9±62.6μg h^(−1)cm^(−2)at−0.7 V(vs.reversible hydrogen electrode,RHE)and a faradaic efficiency(FE)of 89.0±3.8%at−0.5 V(vs.RHE)under ambient conditions.Further,when evaluated with a practical flow cell,Mn-O-C shows a high RNH_(3)of 3706.7±552.0μg h^(−1)cm^(−2)at a current density of 100 mA cm−2,2.5 times of that in the H cell.The in situ FT-IR and Raman spectroscopic studies combined with theoretical calculations indicate that the Mn-(O-C_(2))_(4)sites not only effectively inhibit the competitive hydrogen evolution reaction,but also greatly promote the adsorption and activation of nitrate(NO_(3)^(−)),thus boosting both the FE and selectivity of NH_(3)over Mn-(O-C_(2))_(4)sites.

关键词： Atomically dispersed Oxygen coordination Nitrate reduction reaction In situ spectroscopic studies Hydrogen evolution reaction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Enemies atpeace:Recentprogressin Agrobacterium-mediated cereal transformation

引用

The Crop Journal 2024年第2期12卷 321-329页

作者： Shaoshuai Liu ke Wang Shuaifeng Geng Moammar Hossain Xingguo ye Aili Li Long Mao Karl-Heinz Kogel State key Laboratory of Crop Gene Resources and Breeding Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijing 100081China Institute of Phytopathology Centre for BioSystemsLand Use and NutritionJustus Liebig UniversityHeinrich Buff-Ring 26-32D-35392GiessenGermany

Agrobacterium tumefaciens mediated plant transformation is a versatile tool for plant genetic engineering following its discovery nearly half a century ago.Numerous modifications were made in its application to increase efficiency,especially in the recalcitrant major cereals plants.Recent breakthroughs in transformation efficiency continue its role as a mainstream technique in CRISPR/Cas-based genome editing and gene stacking.These modifications led to higher transformation frequency and lower but more stable transgene copies with the capability to revolutionize modern agriculture.In this review,we provide a brief overview of the history of Agrobacterium-mediated plant transformation and focus on the most recent progress to improve the system in both the Agrobacterium and the host recipient.A promising future for transformation in biotechnology and agriculture is predicted.

关键词： Agrobacterium tumefaciens Cereal species Genome editing Genetic engineering Plant breeding

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A sequential continuous flow synthesis and purification process of calcium dibutyryladenosine cyclophosphate

引用

Chinese Chemical Letters 2024年第2期35卷 402-406页

作者： Liming Cao Maolin Sun Chaoming Liang Lei Yang Yueyue Ma Ruihua Cheng Yanxiong ke Wei Yu Jinxing ye Engineering Research Center of Pharmaceutical Process Chemistry Ministry of EducationSchool of PharmacyEast China University of Science and TechnologyShanghai 200237China School of Biomedical and Pharmaceutical Sciences Guangdong University of TechnologyGuangzhou 510006China Shanghai No.1 Biochemical& Pharmaceutical Co. Ltd.Shanghai 200080China

Calcium dibutyryladenosine cyclophosphate is a widely used cardiovascular drug.The traditional batch synthesis process suffers from long reaction times,tedious operations,and unstable yields.Herein,a sequential continuous flow synthesis combined with a multistage in-line purification process of calcium dibutyryladenosine cyclophosphate was developed.The acylation reaction was completed in a continuous coil reactor at 160℃ in 20 min.And the high toxic solvent pyridine was replaced by acetonitrile.Furthermore,the multistage in-line purification process was integrated into the homemade 3D circular cyclone-type micromixer chip.Combining with the membrane phase separators,the residence time of the purification step was 30 s.The isolated yield of this sequential continuous process was 92%with 99%purity.

关键词： Flow chemistry Calcium dibutyryladenosine cyclophosphate Continuous flow synthesis In-line purification 3D circular cyclone-type micromixer chip

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Self-powered stimuli responsive material for dual stimulation of heat and guest molecules

引用

Chinese Chemical Letters 2024年第2期35卷 590-593页

作者： Jintao Men ke Xu Taiting Sha Lei He Yan Xu Jie Mu Tijian Yin Qiong ye Jiangsu key Laboratory for Science and Applications of Molecular Ferroelectrics and School of Chemistry and Chemical Engineering Southeast UniversityNanjing 211189China

Stimuli-responsive smart materials exhibit reverse chemical/physical changes in response to external stimuli and research on stimuli-responsive smart materials with self-powered properties is still uncultivated ground.Here,we report perovskite crystalline self-powered multiple stimuli-responsive materials triggered by chemical and thermal stimuli.[HMEP]PbI_(3)·(H_(2)O)(1;HMEP is a hydroxytris(1-methylethyl)phosphorus cation)crystallizes in a chiral space group P 21 at 293 K and has the piezoelectric reaction(d_(33)=10 pC/N and output voltage=1 V)of self-powered modes,this value is larger than the value of 3 pC/N for the classical piezoelectric material ZnO.Piezoelectric materials can generate energy due to mechanical deformation,and using thermal heating to lose water,[HMEP]PbI_(3)(2)can be obtained.2 crystallizes in the non-centrosymmetric space group,undergoes two reversible phase transitions at 243/255 K and 315/348 K,and shows second harmonic generation switching.Interestingly,2 can return to the hydrated form 1 after absorbing water.This work will lay the foundation for self-powered stimuli-responsive compounds and contribute to the construction of novel organic-inorganic hybrid materials with second harmonic generation switching.

关键词： Self-powered Dual stimulation reactive Phase transition SHG switch Organic-inorganic hybrid perovskite

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

High-yield and rapid isolation of extracellular vesicles by flocculation via orbital acoustic trapping:FLOAT

引用

Microsystems & Nanoengineering 2024年第1期10卷 313-323页

作者： Joseph Rufo Peiran Zhang Zeyu Wang Yuyang Gu Kaichun Yang Joseph Rich Chuyi Chen Ruoyu Zhong ke Jin ye He Jianping Xia ke Li Jiarong Wu Yingshi Ouyang Yoel Sadovsky Luke P.Lee Tony Jun Huang Department of Mechanical Engineering and Materials Science Duke UniversityDurhamNCUSA Department of Biomedical Engineering Duke UniversityDurhamNCUSA Department of Obstetrics Gynecologyand Reproductive SciencesMagee-Womens Research InstituteUniversity of PittsburghPittsburghPAUSA Department of Microbiology and Molecular Genetics School of MedicineUniversity of PittsburghPittsburghPAUSA Renal Division and Division of Engineering in Medicine Department of MedicineBrigham and Women’s HospitalHarvard Medical SchoolBostonMAUSA Department of Bioengineering Department of Electrical Engineering and Computer ScienceUniversity of CaliforniaBerkeleyBerkeleyCAUSA Department of Biophysics Institute of Quantum BiophysicsSungkyunkwan UniversitySuwonKorea

Extracellular vesicles(EVs)have been identified as promising biomarkers for the noninvasive diagnosis of various diseases.However,challenges in separating EVs from soluble proteins have resulted in variable EV recovery rates and low purities.Here,we report a high-yield(>90%)and rapid(<10 min)EV isolation method called FLocculation via Orbital Acoustic Trapping(FLOAT).The FLOAT approach utilizes an acoustofluidic droplet centrifuge to rotate and controllably heat liquid droplets.By adding a thermoresponsive polymer flocculant,nanoparticles as small as 20 nm can be rapidly and selectively concentrated at the center of the droplet.We demonstrate the ability of FLOAT to separate urinary EVs from the highly abundant Tamm-Horsfall protein,addressing a significant obstacle in the development of EV-based liquid biopsies.Due to its high-yield nature,FLOAT reduces biofluid starting volume requirements by a factor of 100(from 20 mL to 200µL),demonstrating its promising potential in point-of-care diagnostics.

关键词： trapping utilize separating

来源：

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

T2-weighted imaging-based radiomic-clinical machine learning model for predicting the differentiation of colorectal adenocarcinoma

引用

World Journal of Gastrointestinal Oncology 2024年第3期16卷 819-832页

作者： Hui-Da Zheng Qiao-Yi Huang Qi-Ming Huang Xiao-Ting ke Kai ye Shu Lin Jian-Hua Xu Department of Gastrointestinal Surgery The Second Affiliated Hospital of Fujian Medical UniversityQuanzhou 362000Fujian ProvinceChina Department of Gynaecology and Obstetrics The Second Affiliated Hospital of Fujian Medical UniversityQuanzhou 362000Fujian ProvinceChina Department of Computed Tomography/Magnetic Resonance Imaging The Second Affiliated Hospital of Fujian Medical UniversityQuanzhou 362000Fujian ProvinceChina Centre of Neurological and Metabolic Research The Second Affiliated Hospital of Fujian Medical UniversityQuanzhou 362000Fujian ProvinceChina Group of Neuroendocrinology Garvan Institute of Medical ResearchSydneyNSW 2010Australia

BACKGROUND The study on predicting the differentiation grade of colorectal cancer(CRC)based on magnetic resonance imaging(MRI)has not been reported yet.Developing a non-invasive model to predict the differentiation grade of CRC is of great value.AIM To develop and validate machine learning-based models for predicting the differ-entiation grade of CRC based on T2-weighted images(T2WI).METHODS We retrospectively collected the preoperative imaging and clinical data of 315 patients with CRC who underwent surgery from March 2018 to July 2023.Patients were randomly assigned to a training cohort(n=220)or a validation cohort(n=95)at a 7:3 ratio.Lesions were delineated layer by layer on high-resolution T2WI.Least absolute shrinkage and selection operator regression was applied to screen for radiomic features.Radiomics and clinical models were constructed using the multilayer perceptron(MLP)algorithm.These radiomic features and clinically relevant variables(selected based on a significance level of P<0.05 in the training set)were used to construct radiomics-clinical models.The performance of the three models(clinical,radiomic,and radiomic-clinical model)were evaluated using the area under the curve(AUC),calibration curve and decision curve analysis(DCA).RESULTS After feature selection,eight radiomic features were retained from the initial 1781 features to construct the radiomic model.Eight different classifiers,including logistic regression,support vector machine,k-nearest neighbours,random forest,extreme trees,extreme gradient boosting,light gradient boosting machine,and MLP,were used to construct the model,with MLP demonstrating the best diagnostic performance.The AUC of the radiomic-clinical model was 0.862(95%CI:0.796-0.927)in the training cohort and 0.761(95%CI:0.635-0.887)in the validation cohort.The AUC for the radiomic model was 0.796(95%CI:0.723-0.869)in the training cohort and 0.735(95%CI:0.604-0.866)in the validation cohort.The clinical model achieved an AUC of 0.751(95%CI:0.661-0.842)in the training cohort and

关键词： Radiomics Colorectal cancer Differentiation grade Machine learning T2-weighted imaging

来源：

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

A hybrid WUDT-NAFnet for simultaneous source data deblending

引用

Petroleum Science 2024年第3期21卷 1649-1659页

作者： Chao-Fan ke Shao-Huan Zu Jun-Xing Cao Xu-Dong Jiang Chao Li Xing-ye Liu key Laboratory of Earth Exploration and Information Technology of Ministry of Education Chengdu University of Technology State key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of Technology College of Geophysics Chengdu University of Technology

Simultaneous source technology, which reduces seismic survey time and improves the quality of seismic data by firing more than one source with a narrow time interval, is compromised by the massive blended interference. Therefore, deblending algorithms have been developed to separate this interference.Recently, deep learning(DL) has been proved its great potential in suppressing the interference. The most popular DL method employs neural network as a filter to attenuate the blended noise in an iterative estimation and subtraction framework(IESF). However, there are still amplitude distortion and blended noise residual problems, especially when dealing with weak signal submerged in strong interference. To address these problems, we propose a hybrid WUDT-NAFnet, which contains two sub-networks. The first network is a wavelet based U-shape deblending transformer network(WUDTnet), incorporated into IESF as a robust regularization term to iteratively separate the blended interference. The second network is a nonlinear activate free network(NAFnet) designed to recover the event amplitude and further suppress the weak noise residual in IESF. With the hybrid network, the blended noise can be separated purposefully and accurately. Examples using synthetic and field seismic data demonstrate that the WUDTNAFnet outperforms traditional curvelet transform(CT) based method and the deblending transformer(DT) model in terms of deblending. Additionally, for field applications, the data augmentation method of bicubic interpolation is applied to mitigate the feature difference between synthetic and field data.Consequently, the trained network exhibits strong signal preservation ability in numerical field example without requiring additional training.

关键词： Simultaneous-source Deblending Deep learning Transformer

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：