检索结果-南通市图书馆

Preparation and characterization of Fe_(2)O_(3)/Bi_(2)WO_(6)composite and photocatalytic degradation mechanism of microcystin-LR

引用

Water Science and Engineering 2021年第2期14卷 109-118页

作者： Li-xiao Ni cun-hao du Han-qi Wu Yan Li Xiang-lan Li Chu Xu Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes Ministry of EducationHohai UniversityNanjing 210098China College of Environment Hohai UniversityNanjing 210098China

The long-standing popularity of semiconductor photocatalysis,due to its great potential in a variety of applications,has resulted in the creation of numerous semiconductor photocatalysts,and it stimulated the development of various characterization *** this study,Fe_(2)O_(3)/Bi_(2)WO_(6)composite with a flower-like microsphere and hierarchical structure was synthesized with the facile hydrothermal-impregnation method without any surfactants.X-ray diffraction(XRD),scanning electron microscopy(SEM),ultravioletevisible(UV-Vis)diffuse reflectance spectroscopy,and photoluminescence spectroscopy were used to characterize the structures of the *** specific surface area was estimated with the Brunauer-Emmett-Teller(BET)method,and pore size distribution was determined using the Barrett-Joyner-Halenda(BJH)*** synthesized Fe_(2)O_(3)/Bi_(2)WO_(6)composite had an average diameter of approximately 4 nm,with smaller specific surface area and larger pore diameter than those of pristine Bi_(2)WO_(6).The results of XRD and SEM analyses confirmed that the composite was composed of Fe_(2)O_(3)and Bi_(2)WO_(6).The absorption edge of Bi_(2)WO_(6)was at a wavelength of 460 *** contrast,the absorption edge of Fe_(2)O_(3)/Bi_(2)WO_(6)to visible light was redshifted to 520 nm,with narrower bandgap width and stronger visible light *** was also found that the main active substances in the degradation of microcystin-LR(MC-LR)were hydroxyl radicals(·OH)and electron holes(h^(+)).Consequently,the results further showed that the heterojunction between Fe_(2)O_(3)and Bi_(2)WO_(6)can improve the charge transfer rate and effectively separate the photoinduced electrons and *** with Bi_(2)WO_(6),Fe_(2)O_(3)/Bi_(2)WO_(6)had no significant difference in the adsorption capacity of MC-LR and had more efficient photocatalytic degradation activity of *** degradation rates of MC-LR by Fe_(2)O_(3)/Bi_(2)WO_(6)and Bi_(2)WO_(6)reached 80%and 56%,*** d

关键词： Photocatalysis Composite photocatalyst Fe_(2)O_(3)/Bi_(2)WO_(6) Bi_(2)WO_(6) MC-LR

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

The Completeness of Accreting Neutron Star Binary Candidates from the Chinese Space Station Telescope

引用

Research in Astronomy and Astrophysics 2024年第9期24卷 28-36页

作者： hao Shen Shun-Yi Lan Xiang-cun Meng Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China International Centre of Supernovae Yunnan Key LaboratoryKunming 650216China

A neutron star(NS)has many extreme physical conditions,and one may obtain some important information about an NS via accreting neutron star binary(ANSB)*** upcoming Chinese Space Station Telescope(CSST)provides an opportunity to search for a large sample of ANSB *** goal is to check the completeness of the potential ANSB samples from CSST *** this paper,we generate some ANSBs and normal binaries under the CSST photometric system by binary evolution and binary population synthesis method and use a machine learning method to train a classification *** the Precision(94.56%)of our machine learning model is as high as before study,the Recall is only about 63.29%.The Precision/Recall is mainly determined by the mass transfer rate between the NSs and their *** addition,we also find that the completeness of ANSB samples from CSST photometric data by the machine learning method also depends on the companion mass and the age of the *** candidates with a low initial mass companion star(0.1 M_(⊙)to 1 M_(⊙))have a relatively high Precision(94.94%)and high Recall(86.32%),whereas ANSB candidates with a higher initial mass companion star(1.1 M_(⊙)to 3 M_(⊙))have similar Precision(93.88%)and quite low Recall(42.67%).Our results indicate that although the machine learning method may obtain a relatively pure sample of ANSBs,a completeness correction is necessary for one to obtain a complete sample.

关键词： stars:neutron X-rays:binaries methods:analytical

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-optimized single-nanowire photoluminescence thermometry

引用

Light(Science & Applications) 2023年第2期12卷 259-271页

作者： Zhang Liang Jinhua Wu Ying Cui hao Sun cun-Zheng Ning Department of Electronic Engineering Tsinghua University100084 BeijingChina College of Integrated Circuits and Optoelectronic Chips Shenzhen Technology University518118 ShenzhenGuangdongChina

Nanomaterials-based photoluminescence thermometry(PLT)is a new contact-free photonic approach for temperature sensing,important for applications ranging from quantum technology to biomedical imaging and *** though numerous new materials have been explored,great challenges and deficiencies remain that hamper many *** contrast to most of the existing approaches that use large ensembles of rare-earth-doped nanomaterials with large volumes and unavoidable inhomogeneity,we demonstrate the ultimate size reduction and simplicity of PLT by using only a single erbium-chloride-silicate(ECS)***,we propose and demonstrate a novel strategy that contains a self-optimization or "smart"procedure to automatically identify the best PL intensity ratio for temperature *** automated procedure is used to self-optimize key sensing metrics,such as sensitivity,precision,or resolution to achieve an all-around superior PLT including several record-setting metrics including the first sensitivity exceeding 100%K^(-1)(~138%K^(-1)),the highest resolution of 0.01 K,and the largest range of sensible temperatures 4-500 K operating completely within 1500-1800 nm(an important biological window).The high-quality ECS nanowire enables the use of well-resolved Stark-sublevels to construct a series of PL intensity ratios for optimization in infrared,allowing the completely Boltzmann-based sensing at cryogenic temperature for the frst *** single-nanowire PLT and the proposed optimization strategy overcome many existing challenges and could fundamentally impact PL nano-thermometry and related applications such as single-cell thermometry.

关键词： optimization exceeding simplicity

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

Efficient molecular model for squeeze-film damping in rarefied air

引用

Chinese Physics B 2019年第9期28卷 367-372页

作者： cun-hao Lu Pu Li Yu-Ming Fang School of Mechanical Engineering Southeast UniversityNanjing 211100China College of Electronic Science and Engineering Nanjing University of Posts and TelecommunicationsNanjing 211100China

Based on the energy transfer model(ETM) proposed by Bao et *** the Monte Carlo(MC) model proposed by Hutcherson and Ye, this paper proposes an efficient molecular model(MC-S) for squeeze-film damping(SQFD) in rarefied air by releasing the assumption of constant molecular velocity in the *** with the experiment data, the MC-S model is more efficient than the MC model and more accurate than ***, by using the MC-S model, the feasibility of the empirical model proposed by Sumali for SQFD of different plate sizes is *** is proved that, for various plate sizes, the accuracy of the empirical model is relatively *** last, the SQFD of various vibration frequencies is discussed, and it shows that, for low vibration frequency, the MC-S model is reduced to ETM.

关键词： micro-electro-mechanical system(MEMS) squeeze-film air damping rarefied air molecular model

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

Microstructural evolution and mechanical properties of Alloy 718 fabricated by selective laser melting following different post-treatments

引用

Rare Metals 2021年第11期40卷 3222-3234页

作者： hao Luo Xiao-Qiang Li cun-Liang Pan Peng-Jiang He Ke-Li Zeng National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510640China Institute of Materials and Processing Guangdong Academy of SciencesGuangzhou 510650China Dongguan Hyperpowder Co.Ltd. Dongguan 523808China

In this study,Alloy 718 specimens were fabricated via selective laser melting(SLM),and the effects of different post-treatments on microstructures and mechanical properties of the alloy were systematically *** post-treatment techniques investigated were solid solution+dual aging(SA) and hot isostatic pressing+solid solution+dual aging treatment(HIP+SA).The results indicate that the specimens treated using SA have a columnar crystal structure similar to the as-built sample,the microstructure is partially recrystallized,and the grain size increases ***,the grain morphology is dominated by equiaxed crystals in samples treated using HIP+SA,and the microstructure is completely recrystallized,with distinct grain coarsening and a large number of twins *** treated using SA and HIP+SA show high tensile strength and yield strength and excellent elongation at room temperature,which can be primarily attributed to the strengthening of the γ’ and γ "precipitated *** number of γ" precipitated phases are reduced due to the consumption of Nb to form a large amounts of δ phase and(Ti,Nb)C carbides,resulting in the strength of HIP+SA specimens being lower than that of SA specimens.

关键词： Selective laser melting Alloy 718 Post-treatments Microstructural evolution Mechanical properties

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

Excitonic complexes and optical gain in two-dimensional molybdenum ditelluride well below the Mott transition

引用

Light(Science & Applications) 2020年第1期9卷 1647-1656页

作者： Zhen Wang hao Sun Qiyao Zhang Jiabin Feng Jianxing Zhang Yongzhuo Li cun-Zheng Ning Department of Electronic Engineering Tsinghua University100084 BeijingChina Frontier Science Center for Quantum Information 100084 BeijingChina Beijing National Research Center for Information Science and Technology 100084 BeijingChina School of Electrical Computerand Energy EngineeringArizona State UniversityTempeAZ 85287USA

Semiconductors that can provide optical gain at extremely low carrier density levels are critically important for applications such as energy efficient ***,all current semiconductor lasers are based on traditional semiconductor materials that require extremely high density levels above the so-called Mott transition to realize optical *** new emerging 2D materials provide unprecedented opportunities for studying new excitonic physics and exploring new optical gain mechanisms at much lower density levels due to the strong Coulomb interaction and co-existence and mutual conversion of excitonic ***,we report a new gain mechanism involving charged excitons or trions in electrically gated 2D molybdenum ditelluride well below the Mott *** combined experimental and modelling study not only reveals the complex interplay of excitonic complexes well below the Mott transition but also establishes 2D materials as a new class of gain materials at densities 4-5 orders of magnitude lower than those of conventional semiconductors and provides a foundation for lasing at ultralow injection levels for future energy efficient photonic ***,our study could help reconcile recent conflicting results on 2D materials:While 2D material-based lasers have been demonstrated at extremely low densities with spectral features dominated by various excitonic complexes,optical gain was only observed in experiments at densities several orders of magnitude higher,beyond the Mott *** believe that our results could lead to more systematic studies on the relationship between the mutual conversion of excitonic species and the existence of optical gain well below the Mott transition.

关键词： optical complexes transition

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

Neighbor Distinguishing Total Choice Number of Sparse Graphs via the Combinatorial Nullstellensatz

引用

Acta Mathematicae Applicatae Sinica 2016年第2期32卷 537-548页

作者： cun-quan QU Lai-hao DING Guang-hui WANG Gui-ying YAN School of Mathematics Shandong University Academy of Mathematics and Systems Science Chinese Academy of Sciences

Let G =（V, E） be a graph and Ф ： V tA E → {1, 2,..., k） be a total-k-coloring of G. Let f（v）（S（v）） denote the sum（set） of the color of vertex v and the colors of the edges incident with v. The total coloring Ф is called neighbor sum distinguishing if （f（u） ≠ f（v）） for each edge uv∈ E（G）. We say that Фis neighbor set distinguishing or adjacent vertex distinguishing if S（u） ≠ S（v） for each edge uv ∈ E（G）. For both problems, we have conjectures that such colorings exist for any graph G if k 〉 △（G）＋ 3. The maximum average degree of G is the maximum of the average degree of its non-empty subgraphs, which is denoted by mad （G）. In this paper, by using the Combinatorial Nullstellensatz and the discharging method, we prove that these two conjectures hold for sparse graphs in their list versions. More precisely, we prove that every graph G with maximum degree A（G） and maximum average degree mad（G） has ch＇＇∑（G）〈 △（G）＋ 3 （where ch＇＇∑（G） is the neighbor sum distinguishing total choice number of G） if there exists a pair （k, m） ∈ {（6, 4）, （5, 18/5）, （4, 16）} such that △（G）〉 k and mad （G）〈 m.

关键词： neighbor sum distinguishing total coloring Combinatorial Nullstellensatz neighbor sum distin-guishing total choice number

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-dose vs low-dose proton pump inhibitors for upper gastrointestinal bleeding:A meta-analysis

引用

World Journal of Gastroenterology 2010年第20期16卷 2558-2565页

作者： Wu, Liu-Cheng Cao, Yun-Fei Huang, Jia-hao Liao, cun Gao, Feng Guangxi Med Univ Dept Colorectal & Anal Surg Affiliated Hosp 1 Nanning 530021 Guangxi Zhuang Peoples R China

AIM:To evaluate the efficacy of high-dose proton pump inhibitors(PPIs)vs low-dose PPIs for patients with upper gastrointestinal ***:PubMed,Embase,the Cochrane Library,and Web of Science were searched to identify relevant randomized controlled trials(RCTs).Eligible trials were RCTs that compared high-dose PPI with low-dose PPI following endoscopic *** primary endpoint was rebleeding;secondary endpoints were patient numbers that needed surgery,and *** meta-analysis was performed with a fixed effects model or random effects ***:Nine eligible RCTs including 1342 patients were *** results showed that high-dose intravenous PPI was not superior to low-dose intra-venous PPI in reducing rebleeding[odds ratio(OR)= 1.091,95%confidential interval(CI):0.777-1.532],need for surgery(OR=1.522,95%CI:0.643-3.605) and mortality(OR=1.022,95%CI:0.476-2.196).Subgroup analysis according to different region revealed no difference in rebleeding rate between Asian patients(OR=0.831,95%CI,0.467-1.480)and European patients(OR=1.263,95%CI:0.827-1.929).CONCLUSION:Low-dose intravenous PPI can achieve the same efficacy as high-dose PPI following endoscopic hemostasis.

关键词： Meta-analysis High-dose Low-dose Proton pump inhibitors Gastrointestinal bleeding

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

HIGH RESOLUTION LASER SPECTROSCOPY STUDY OF THE l(2,-1)TYPE RESONANCE IN CH_3Fv_5 BAND

引用

Chinese Physics Letters 1984年第2期1卷 69-72页

作者： Zhao Yao SHEN Zhiye ZHU Qing-shi ZHANG cun-hao Dalian Institute of Chemical Physics Academia SinicaDalian

The high resolution laser spectroscopy study on the l(2,-1)type Coriolis resonance in CH_(3)Fv_(5)RQO and pp_(3)was carried *** improved value of E5 is obtained,E_(5)=2.3892(9)x10^(-3)cm^(-1).

关键词： CH3F LASER value

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

Microstructure evolution and performance improvement of powder metallurgy stainless steel with P addition

引用

Journal of Iron and Steel Research International 2023年第10期30卷 2055-2066页

作者： Qian Qin Dao-qing Zhang Fang Yang cun-guang Chen Jun-jie hao Zhi-meng Guo Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China Shunde Innovation School University of Science and Technology BeijingGuangzhou 528399GuangdongChina

P-containing 316L stainless steel was prepared by powder metallurgy technology using gas atomized alloy powder and phosphorus-iron alloy powder as raw materials.P addition was beneficial to sintering *** 0.6 wt.%P addition,the density increased from 7.60 to 7.82 g/cm^(3).In such case,the samples with 0.6 wt.%P addition should be sintered at a lower temperature of 1200℃.Otherwise,there were coarse grain boundary precipitates,which would seriously deteriorate the performance of stainless *** the case of suppressing the formation of coarse precipitates,appropriate P content had a beneficial effect on apparent morphology,hardness and strength of stainless *** 316L-0.6 wt.%P sample was sintered at 1200℃,the hardness and tensile strength were increased to 86.3 HRB and 672.8 MPa,respectively,and the elongation still reached 38.1%.Besides,it also had good corrosion resistance.

关键词： Phosphorus Stainless steel Powder metallurgy Precipitate phase Performance

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

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：