检索结果-南通市图书馆

Spherical Polyelectrolyte Brush Nanoreactor:Preparation of Hollow TiO_(2) Nanospheres and Characterization by Small Angle X-Ray Scattering

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第9期42卷 1393-1400,I0009页

作者： Yu-Hua zhang Zi-Yu zhang Xin liu En-Guang Ma Jiang-Tao Guo li li Xu-hong Guo State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai200237China Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology College of Chemistry and Chemical EngineeringDezhou UniversityDezhou253023China Institute of Bast Fiber Crops&Center of Southern Economic Crops Chinese Academy of Agricultural SciencesChangsha410205China

Titanium dioxide(TiO_(2))hollow nanoparticles present significant potential for photocatalytic applications while their straightforward preparation with precise structure control is still *** work reports the approach to preparing tunable hollow TiO_(2) nanospheres by utilization of spherical polyelectrolyte brushes(SPB)as nanoreactors and *** the preparation,the evolution of the structure was characterized by small angle X-ray scattering(SAXS),and in combination with dynamic light scattering and transmission electron *** formation of TiO_(2) shell within the brush(SPB@TiO_(2))is confirmed by the significant increase of the electron density,and its internal structure has been analyzed by fitting SAXS data,which can be influenced by Titanium precursors and ammonia *** calcining SPB@TiO_(2) in a muffle furnace,hollow TiO_(2) nanospheres are produced,and their transition to the anatase crystal form is triggered,as confirmed by X-ray diffraction *** the advantages of their hollow structure,these TiO_(2) nanospheres exhibit exceptional catalytic degradation efficiency of methylene blue(MB),tetracycline(TC),and 2,4-dichlorophenoxyacetic acid(2,4-D),and also demonstrate excellent recyclability.

关键词： Spherical polyelectrolyte brush Nanoreactor Hollow titanium dioxide X-ray scattering

Prediction for permeability index of blast furnace based on VMD-PSO-BP model

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 573-583页

作者： Xiao-jie liu Yu-jie zhang Xin li Zhi-feng zhang hong-yang li Ran liu Shu-jun Chen School of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210HebeiChina Chengde Branch HBIS Group Co.Ltd.Chengde 067000HebeiChina

The permeability index is one of the important production indicators to monitor the operation of blast *** is crucial to grasp the trends of changes in the new permeability index in *** the complex vibration spectrum of the permeability index,a prediction model of the permeability index based on the VMD-PSO-BP(variational mode decomposition-particle swarm optimization-back propagation)method was ***,the key factors that affect the permeability index of blast furnace were studied from multiple ***,the permeability index was divided into multiple sub-modes based on the difference of frequency bands by the VMD algorithm,and a PSO-BP prediction model was established for each ***,the prediction results of each sub-mode were summed to obtain the final *** results show that the composite prediction accuracy by using the VMD algorithm is 3%higher than that of the traditional prediction method,which has better applicability.

关键词： Big data-Blast furnace Air permeability Variational mode decomposition Particle swarm optimization Back propagation Model prediction

Enhancing flotation recovery of residual carbon from gasification waste by mixing hydrophobic powder with diesel as collector

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第6期89卷 211-217页

作者： Rui Han Ningning zhang Anning Zhou Zhen li Jinzhou Qu hong Wang College of Chemistry and Chemical Engineering Xi’an University of Science and TechnologyXi’anShaanxi 710054China

Coal gasification fine slag(CGFS)is a solid waste containing residual carbon and ash generated during the coal gasification process,and the separation of the two components is the essential way to realize its environmental pollution reduction and resource value *** flotation is the preferred method for separating CGFS,but there is a barrier of low carbon recovery in this process due to the extensive adsorption of collector by the well-developed pores on residual *** this study,a sufficiently simple yet innovative collector,a mixture of hydrophobic powder and diesel,was proposed in an attempt to break the *** experiments with common diesel and this novel collector were performed respectively,and FTIR,XPS,and SEM-EDX were employed to analyze the collector action *** results revealed that the novel collector could significantly improve the residual carbon recovery;test results demonstrated that the novel collector could increase the hydrophobic functional group content on the fine slag surface,and the hydrophobic powders in this novel collector mainly appeared at the pore openings of the flotation *** essence of the mechanism is that the hydrophobic powders play a dual role of blocking pores and providing adsorption sites,thus facilitating the spreading of diesel on the carbon surface and promoting its *** study can provide creative ideas for the efficient disposal of coal gasification waste.

关键词： Coal gasification fine slag Carbon recovery Collector Fotation Hydrophobic powder

Giant negative electrocaloric effect measured by indirect method in X-ray irradiated P(VDF-TrFE)films

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 Materiomics 2024年第3期10卷 624-631页

作者： Bo li Bin Yang hong zhang Jiajia zhang Qianjin Wang Weishu liu Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhenGuangdong 518055China Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices Southern University of Science and TechnologyShenzhenChina College of Physics and Electronic Information Yunnan Normal UniversityYunnan Kunming 650500China The Science and Technology on Reliability Physics and Application of Electronic Component Laboratory China Electronic Product Reliability and Environmental Testing Research InstituteGuangzhou 510610China

Flexible solid-state cooling devices with high efficiency are attracted to ferroelectric polymers with excellent negative electrocaloric(EC)*** is challenging to obtain a large negative EC effect in ferroelectric polymers due to the lack of tunable techniques.A giant negative EC response was obtained in the poly(vinylidene fluoride-trifluoroethylene)copolymers(P(VDF-TrFE),70/30,in mole ratio)irra-diated with high-energy *** irradiated P(VDF-TrFE)films showed an adiabatic temperature change of-13.5 K at 40 MV/m under a dose of 5 Mrad(1 Mrad=10^(4) J/kg)obtained by the indirect *** significant negative EC effect is attributed to the enhancement of crystalline due to the entry of polymer molecules into the amorphous to crystalline structure and the reduction of heat ca-pacity due to the increase of *** addition,X-ray irradiation improves the dielectric coefficient from 15 to *** research indicates that irradiation can modify the negative EC properties of ferro-electric polymers for solid-state cooling.

关键词： Negative electrocaloric effects X-rays radiation P(VDF-TrFE)films

农村面源污染强度与生态非敏感性强度的空间耦合协调性分析——以鲹鱼河流域会东段为例

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

安徽农业科学 2024年第4期52卷 62-70页

作者：王世忠张利红王晓庆袁建明黄程璐浙江财经大学公共管理学院浙江杭州310018 华东勘测设计研究院浙江杭州311122

农村面源污染问题是当前研究的热点和难点问题。以鲹鱼河流域会东段为例,构建了农村面源污染强度与生态非敏感性强度的空间耦合协调度模型,并对各斑块的农村面源污染强度、生态非敏感性强度和空间耦合协调度进行了计算和空间分析。结果... 详细信息

农村面源污染问题是当前研究的热点和难点问题。以鲹鱼河流域会东段为例,构建了农村面源污染强度与生态非敏感性强度的空间耦合协调度模型,并对各斑块的农村面源污染强度、生态非敏感性强度和空间耦合协调度进行了计算和空间分析。结果表明:鲹鱼河流域会东段虽然有60.55%的土地处于优质耦合协调区和良好耦合协调区,但仍然有11.96%的土地处于极度失调区,农村面源污染带来的生态环境问题依然非常严峻;耦合协调度的热点区和冷点区的空间分布非常明显,99%置信区间的热点区面积占56.08%,99%置信区间的冷点区面积占21.21%;养殖业污染是鲹鱼河流域会东段农村主要的面源污染源,是影响空间耦合协调性的主要因素。建议各乡镇科学地划定畜牧业的禁养限养区,合理确定养殖规模,推行种养结合和生态养殖模式;科学布设生态田埂、生态沟渠和生态池塘等系统,以防止农业尾水和农村生活污水未经任何处理直接排入河道;逐步降低和减少农村经济社会活动对生态环境尤其是生态高敏感区的农村生态环境的影响和干扰。

关键词：面源污染强度生态非敏感性强度空间耦合协调模型耦合协调度

人工血管动静脉内瘘慢性血栓形成腔内治疗的可行性探索

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

临床肾脏病杂志 2024年第5期24卷 353-358页

作者：郭燕张丽红詹申苏晓美王玉柱首都医科大学石景山教学医院(北京市石景山医院)肾内科北京100043 北京市海淀医院(北京大学第三医院海淀院区)肾内科北京100080

目的观察腔内改良药物机械溶栓治疗人工血管动静脉内瘘(arteriovenous graft,AVG)慢性血栓形成的可行性、安全性及疗效。方法回顾性分析2020年1月1日至2022年12月31日在北京市海淀医院因AVG血栓形成且血栓时间大于3 d接受腔内治疗的患者... 详细信息

目的观察腔内改良药物机械溶栓治疗人工血管动静脉内瘘(arteriovenous graft,AVG)慢性血栓形成的可行性、安全性及疗效。方法回顾性分析2020年1月1日至2022年12月31日在北京市海淀医院因AVG血栓形成且血栓时间大于3 d接受腔内治疗的患者,并将入组患者根据血栓形成时间长短分为2组,3~7 d的分为A组,>7 d的分为B组,比较两组患者基线特征包括人口学特征、内瘘特征、血栓的特点,观察两组患者腔内治疗成功率、并发症发生率、通路干预后通畅率等。结果本研究共纳入81例患者,血栓时间分别为A组4(3,5)d,B组14(10,23)d。腔内治疗技术成功率98.77%(80/81)、临床成功率98.77%(80/81),无严重并发症发生。其中两组的技术成功率分别为A组98.48%(65/66)、B组100%(15/15)。两组的临床成功率分别为A组98.48%(65/66);B组100%(15/15),差异无统计学意义。共随访1年,干预后30 d、90 d、180 d、270 d、360 d时原发通畅率分别为A组89.39%(59/66)、69.70%(46/66)、50.00%(22/66)、33.33%(22/66)、21.21%(12/66);B组86.67%(13/15)、80.00%(12/15)、46.67%(7/15)、26.67%(4/15)、20.00%(3/15)。两组患者均保持较好的1年累积通畅率,分别为A组78.79%,B组80.00%,两组比较均差异无统计学意义。结论改良药物机械溶栓治疗AVG慢性血栓可行、有效、安全,可进一步延长AVG使用时间,值得临床推广。

关键词：人工血管内瘘慢性血栓腔内技术通畅率

A 23 GHz high-temperature superconducting microstrip filter for radio astronomy

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2009年第19期54卷 3485-3488页

作者： GAO Lu GUO Jin WANG YueHui YU Tao zhang Qiang li ChunGuang zhang XueQiang li hong li JunJie li WuXia GU ChangZhi MENG JiBao FENG Ji HE YuSheng Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China

This paper reports a 6-pole high-temperature superconducting (HTS) microstrip bandpass filter for radio astronomy applications. The filter has a center frequency of 23 GHz and a bandwidth the 2 GHz. We have made many efforts, such as adopting 0.25-mm-thick substrate, carefully designing the housing box and filter layout, to solve the problems in realizing a K-band planar filter. A special straight-line half-wavelength resonator (center-widen resonator) was also designed to reduce the insertion loss of the filter. The measured results showed a midband insertion loss of 0.11 dB with a ripple of 0.4 dB, and a return loss better than 11.5 dB. Good agreement was obtained between simulated and measured results.

关键词：微波传输带无线电通信电波天文学超导

Formulation of dried lignans nanosuspension with high redispersibility to enhance stability,dissolution,and oral bioavailability

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Natural Medicines 2016年第10期14卷 757-768页

作者： SHEN Gang CHENG ling WANG li-Qiang zhang li-hong SHEN Bao-De liAO Wei-Bo li Juan-Juan ZHENG Juan XU Rong YUAN Hai-Long Department of Pharmacy Air Force General Hospital of PLABeijing 100142China Pharmacy College Chengdu University of Traditional Chinese MedicineChengdu 611137China School of Biomedical Sciences Huaqiao UniversityQuanzhou 362021China

Herpetospermum caudigerum lignans(HTL), one of the potential drugs with anti-hepatitis B virus and hepatoprotective effects, has limited clinical applications because of poor aqueous solubility and low bioavailability. Both herpetrione(HPE) and herpetin(HPN) are the most abundant ingredients in HTL and exhibit weak acidity. The purpose of the present study was to produce dried preparations of HTL(composed of HPE and HPN) nanosuspensions(HTL-NS) with high redispersibility using lyophilization technology. The HTL-NS was prepared by utilizing precipitation-combined homogenization technology based on acid-base neutralization reactions, and critical formulation and process parameters affecting the characteristics of HTL-NS were optimized. The resultant products were characterized by particle size analysis, SEM, XRD, stability, solubility, dissolution and in vivo bioavailability. HTL-NS showed near-spherical-shaped morphology and the size was 243 nm with a narrow PDI value of 0.187. The dried preparations with a relatively large particle size of 286 nm and a PDI of 0.215 were achieved by using 4%(W/V) mannitol as cryoprotectants, and had a better stability at 4 or 25 oC for 2 months, compared to HTL-NS. In the in vitro test, the dried preparations showed markedly increased solubility and dissolution velocity. Besides, in the in vivo evaluation, it exhibited significant increases in AUC0–t, C_(max), MRT and a decrease in T_(max), compared to the raw drug.. In conclusion, our results provide a basis for the development of a drug delivery system for poorly water-soluble ingredients with p H-dependent solubility.

关键词： Herpetospermum caudigerum lignans Nanosuspensions Acid-base neutralization Saturation solubility Dissolution Oral bioavailability

BSTFNet:An Encrypted Malicious Traffic Classification Method Integrating Global Semantic and Spatiotemporal Features

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第3期78卷 3929-3951页

作者： hong Huang Xingxing zhang Ye Lu Ze li Shaohua Zhou School of Computer Science and Engineering Sichuan University of Science&EngineeringYibin644002China School of Mathematics and Statistics Sichuan University of Science&EngineeringYibin644002China

While encryption technology safeguards the security of network communications,malicious traffic also uses encryption protocols to obscure its malicious *** address the issues of traditional machine learning methods relying on expert experience and the insufficient representation capabilities of existing deep learning methods for encrypted malicious traffic,we propose an encrypted malicious traffic classification method that integrates global semantic features with local spatiotemporal features,called BERT-based Spatio-Temporal Features Network(BSTFNet).At the packet-level granularity,the model captures the global semantic features of packets through the attention mechanism of the Bidirectional Encoder Representations from Transformers(BERT)*** the byte-level granularity,we initially employ the Bidirectional Gated Recurrent Unit(BiGRU)model to extract temporal features from bytes,followed by the utilization of the Text Convolutional Neural Network(TextCNN)model with multi-sized convolution kernels to extract local multi-receptive field spatial *** fusion of features from both granularities serves as the ultimate multidimensional representation of malicious *** approach achieves accuracy and F1-score of 99.39%and 99.40%,respectively,on the publicly available USTC-TFC2016 dataset,and effectively reduces sample confusion within the Neris and Virut *** experimental results demonstrate that our method has outstanding representation and classification capabilities for encrypted malicious traffic.

关键词： Encrypted malicious traffic classification bidirectional encoder representations from transformers text convolutional neural network bidirectional gated recurrent unit