期刊文献+
共找到28篇文章
< 1 2 >
每页显示 20 50 100
Impacts of Defoliation on Morphological Characteristics and Non-Structural Carbohydrates of Populus talassica × Populus euphratica Seedlings
1
作者 Mengxu Su Zhanjiang Han +2 位作者 Zhen Zhao xiaofeng wu Jiaju wu 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第7期1689-1703,共15页
Leaves are important‘source’organs that synthesize organic matter,providing carbon sources for plant growth.Here,we used Populus talassica×Populus euphratica,the dominant species in ecological and timber forest... Leaves are important‘source’organs that synthesize organic matter,providing carbon sources for plant growth.Here,we used Populus talassica×Populus euphratica,the dominant species in ecological and timber forests,to simulate carbon limitation through artificial 25%,50%,and 75%defoliation treatments and explore the effects on root,stem,and leaf morphology,biomass accumulation,and carbon allocation strategies.At the 60th d after treat-ment,under 25%defoliation treatment,the plant height,specific leaf weight,root surface area and volume,and concentrations of non-structural carbohydrates in stem and root were significantly increased by 9.13%,20.00%,16.60%,31.95%,5.12%,and 9.34%,respectively,relative to the control.There was no significant change in the growth indicators under 50%defoliation treatment,but the concentrations of non-structural carbohydrates in the leaf and stem significantly decreased,showing mostly a negative correlation between them.The opposite was observed in the root.Under 75%defoliation treatment,the plant height,ground diameter,leaf number,single leaf area,root,stem,and total biomass were significantly reduced by 14.15%,10.24%,14.86%,11.31%,11.56%,21.87%,and 16.82%,respectively,relative to the control.The concentrations of non-structural carbohydrates in various organs were significantly reduced,particularly in the consumption of the starch concentrations in the stem and root.These results indicated that carbon allocation strategies can be adjusted to increase the con-centration of non-structural carbohydrates in root and meet plant growth needs under 25%and 50%defoliation.However,75%defoliation significantly limited the distribution of non-structural carbohydrates to roots and stems,reduced carbon storage,and thus inhibited plant growth.Defoliation-induced carbon limitation altered the carbon allocation pattern of P.talassica×P.euphratica,and the relationship between carbon reserves in roots and tree growth recovery after defoliation was greater.This study provides a theoretical basis for the comprehen-sive management of P.talassica×P.euphratica plantations,as well as a reference for the study of plantation car-bon allocation strategies in the desert and semi-desert regions of Xinjiang under carbon-limitation conditions. 展开更多
关键词 Populus talassica×Populus euphratica DEFOLIATION carbon limitation carbon allocation non-structural carbohydrates
下载PDF
TDERS,an exosome RNA-derived signature predicts prognosis and immunotherapeutic response in clear cell renal cell cancer:a multicohort study
2
作者 Aimin Jiang Ying Liu +12 位作者 Ziwei He Wenqiang Liu Qiwei Yang Yu Fang Baohua Zhu xiaofeng wu Huamao Ye Bicheng Ye Shunxiang Gao Le Qu Wenhao Xu Peng Luo Linhui Wang 《Journal of the National Cancer Center》 2024年第4期382-394,共13页
Background:Tumor-derived exosomes are involved in tumor progression and immune invasion and might func-tion as promising noninvasive approaches for clinical management.However,there are few reports on exosom-based mar... Background:Tumor-derived exosomes are involved in tumor progression and immune invasion and might func-tion as promising noninvasive approaches for clinical management.However,there are few reports on exosom-based markers for predicting the progression and adjuvant therapy response rate among patients with clear cell renal cell carcinoma(ccRCC).Methods:The signatures differentially expressed in exosomes from tumor and normal tissues from ccRCC pa-tients were correspondingly deregulated in ccRCC tissues.We adopted a two-step strategy,including Lasso and bootstrapping,to construct a novel risk stratification system termed the TDERS(Tumor-Derived Exosome-Related Risk Score).During the testing and validation phases,we leveraged multiple external datasets containing over 2000 RCC cases from eight cohorts and one inhouse cohort to evaluate the accuracy of the TDERS.In addition,enrichment analysis,immune infiltration signatures,mutation landscape and therapy sensitivity between the high and low TDERS groups were compared.Finally,the impact of TDERS on the tumor microenvironment(TME)was also analysed in our single-cell datasets.Results:TDERS consisted of 12 mRNAs deregulated in both exosomes and tissues from patients with ccRCC.TDERS achieved satisfactory performance in both prognosis and immune checkpoint inhibitor(ICI)response across all ccRCC cohorts and other pathological types,since the average area under the curve(AUC)to predict 5-year overall survival(OS)was larger than 0.8 across the four cohorts.Patients in the TDERS high group were resistant to ICIs,while mercaptopurine might function as a promising agent for those patients.Patients with a high TDERS were characterized by coagulation and hypoxia,which induced hampered tumor antigen presentation and relative resistance to ICIs.In addition,single cells from 12 advanced samples validated this phenomenon since the interaction between dendritic cells and macrophages was limited.Finally,PLOD2,which is highly expressed in fibro-and epi-tissue,could be a potential therapeutic target for ccRCC patients since inhibiting PLOD2 altered the malignant phenotype of ccRCC in vitro.Conclusion:As a novel,non-invasive,and repeatable monitoring tool,the TDERS could work as a robust risk stratification system for patients with ccRCC and precisely inform treatment decisions about ICI therapy. 展开更多
关键词 Renal cell carcinoma EXOSOME Non-invasive biopsy Immunotherapy response Multiomics PLOD2
下载PDF
Initial experience of laparoendoscopic single-site radical prostatectomy with a novel purpose-built robotic system 被引量:1
3
作者 Zheng Wang Chao Zhang +13 位作者 Chengwu Xiao Yang Wang Yu Fang Baohua Zhu Shouyan Tang xiaofeng wu Hong Xu Yi Zhou Lingfen wu Zhenjie wu Bo Yang Yi He Yi Liu Linhui Wang 《Asian Journal of Urology》 CSCD 2023年第4期467-474,共8页
Objective This prospective single-arm clinical trial aimed to evaluated the feasibility and safety of the application of the SHURUI system(Beijing Surgerii Technology Co.,Ltd.,Beijing,China),a novel purpose-built robo... Objective This prospective single-arm clinical trial aimed to evaluated the feasibility and safety of the application of the SHURUI system(Beijing Surgerii Technology Co.,Ltd.,Beijing,China),a novel purpose-built robotic system,in single-port robotic radical prostatectomy.Methods Sixteen patients diagnosed with prostate cancer were prospectively enrolled in and underwent robotic radical prostatectomy from October 2021 to August 2022 by the SHURUI single-port robotic surgical system.The demographic and baseline data,surgical,oncological,and functional outcomes as well as follow-up data were recorded.Results The mean operative time was 226.3(standard deviation[SD]52.0)min,and the mean console time was 183.4(SD 48.3)min,with the mean estimated blood loss of 116.3(SD 90.0)mL.The mean length of postoperative hospital stay was 4.50(SD 0.97)days.Two patients had postoperative complications(Clavien-Dindo Grade II),and both patients improved after conservative treatment.All patients’postoperative prostate-specific antigen levels decreased to below 0.2 ng/mL 1 month after discharge.The mean prostate-specific antigen level further decreased to a mean of 0.0219(SD 0.0641)ng/mL 6 months after surgery.Thirty days postoperatively,12 out of 16 patients reported using no more than one urinary pad per day,and all patients reported satisfactory urinary control without the need for pads 6 months after surgery.Conclusion The SHURUI system is safe and feasible in performing radical prostatectomy via both transperitoneal and extraperitoneal approaches.Tumor control and urinary continence were satisfying for patients enrolled in.The next phase involves conducting a large-scale,multicenter randomized controlled trial to thoroughly assess the effectiveness and safety of the new technology in a broader population. 展开更多
关键词 Laparoendoscopic single-site surgery Robotic surgical procedure Prostatectomy Prostatic cancer
下载PDF
Building a Neural Network Model to Analyze Teachers’ Satisfaction with Online Teaching during the COVID-19 Ravages
4
作者 Gangxin Wen Quanlong Guan +1 位作者 xiaofeng wu Weiqi Luo 《Journal of Computer and Communications》 2022年第1期91-114,共24页
The ravages of COVID-19 have forced schools in countries around the world to make a temporary shift from traditional, face-to-face teaching to online teaching. Are teachers in schools prepared to deal with this change... The ravages of COVID-19 have forced schools in countries around the world to make a temporary shift from traditional, face-to-face teaching to online teaching. Are teachers in schools prepared to deal with this change? We conducted a survey in which we distributed questionnaires to primary and secondary school teachers in Guangdong Province, China, asking them about their views on various aspects of online education. We received 498,481 questionnaires back, and over 80% of teachers were satisfied with the online resources, and over 68% of teachers were satisfied with the online platform and software. Immediately afterward, we analyzed the differences between urban and rural teachers on specific issues using cross-sectional analysis and chi-square tests and built a neural network model to achieve predictions of teacher satisfaction with an accuracy of nearly 90%. Finally, we analyzed the features that influence the decisions of the neural network. This epidemic has prompted the widespread use of online learning, and the insights we gain today will be helpful in the future. 展开更多
关键词 COVID-19 Online Education Neural Networks SATISFACTION
下载PDF
SPR effect of bismuth enhanced visible photoreactivity of Bi_2WO_6 for NO abatement 被引量:10
5
作者 Li Zhang Chao Yang +7 位作者 Kangle Lv Yachao Lu Qin Li xiaofeng wu Yuhan Li Xiaofang Li Jiajie Fan Mei Li 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第5期755-764,共10页
Bi2WO6 is a typical visible-light-responsive semiconductor photocatalyst with a layered structure.However,the relatively large bandgap(2.6–2.8 eV)and quick recombination of photo-generated carriers result in its low ... Bi2WO6 is a typical visible-light-responsive semiconductor photocatalyst with a layered structure.However,the relatively large bandgap(2.6–2.8 eV)and quick recombination of photo-generated carriers result in its low quantum efficiency.In this paper,Bi-nanospheres-modified flower-like Bi2WO6 was successfully prepared by solvothermal treatment of Bi2WO6 powders in Bi(NO3)3 solution using ethylene glycol as reductant.The photoreactivity of this photocatalyst was evaluated by the oxidation of NO in a continuous-flow reactor under irradiation by a visible LED lamp(λ>400 nm).It was found that both Bi nanospheres and flower-like Bi2WO6 precursor exhibit very poor photocatalytic activity with NO removal rates of only 7.7%and 8.6%,respectively.The photoreactivity of Bi/Bi2WO6 was found to steadily increase from 12.3%to 53.1%with increase in the amount of Bi nanospheres from 0 to 10 wt%.However,with further increase in the loading amount of Bi nanospheres,the photoreactivity of Bi/Bi2WO6 hybridized photocatalyst begins to decrease,possibly due to the light filtering by the Bi nanospheres.The enhanced visible photoreactivity of Bi/Bi2WO6 towards NO abatement was attributed to surface plasmon resonance driven interfacial charge separation.The excellent stability of Bi/Bi2WO6 hybridized photocatalyst towards NO oxidation demonstrates its potential for applications such as air purification. 展开更多
关键词 BISMUTH Bi2WO6 Surface plasmon resonance PHOTOCATALYSIS NO
下载PDF
Recent advance on VOCs oxidation over layered double hydroxides derived mixed metal oxides 被引量:9
6
作者 Shuangde Li Dongdong Wang +1 位作者 xiaofeng wu Yunfa Chen 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第4期550-560,共11页
Catalytic oxidation is regarded as one of the most promising strategies for volatile organic compounds(VOCs)purification.Mixed metal oxides(MMOs),after topological transformation using layered double hydroxides(LDHs)a... Catalytic oxidation is regarded as one of the most promising strategies for volatile organic compounds(VOCs)purification.Mixed metal oxides(MMOs),after topological transformation using layered double hydroxides(LDHs)as precursors,are extensively used as catalysts for VOCs oxidation due to their uniformity advantage.This review summarizes the developments in the LDH-derived VOCs heterogeneous catalytic oxidation over the last 10 years.Particularly,it addresses the VOCs abatement performance over MMO,noble metal/MMO,core-shell structured MMO,and integral MMO film catalysts originating from LDHs.Moreover,it highlights the water vapor effect and oxidation mechanism.This review indicates that LDH-based catalysts are a category of important VOCs oxidation materials. 展开更多
关键词 Volatile organic compounds oxidation Layered double hydroxides Mixed metal oxides Water vapor Oxidation mechanism
下载PDF
Effects of fluorine on photocatalysis 被引量:4
7
作者 Xiaofang Li xiaofeng wu +3 位作者 Shengwei Liu Yuhan Li Jiajie Fan Kangle Lv 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第10期1451-1467,共17页
Tailoring the microstructure of pristine TiO2 is essential to narrow its band gap and prolong the charge lifetime. In particular, strategies involving fluorine have been used successfully to tune the surface chemistry... Tailoring the microstructure of pristine TiO2 is essential to narrow its band gap and prolong the charge lifetime. In particular, strategies involving fluorine have been used successfully to tune the surface chemistry, electronic structure, and morphology of TiO2 photocatalysts to improve their photocatalytic activity based on the strong complexation between fluoride ions and TiO2 and the high electronegativity of fluorine. In this review, we summarize the strategies involving fluorine to establish highly efficient TiO2 photocatalytic systems or fabricate highly efficient TiO2 photocatalysts. The main fluorine effects(i.e. the effects of fluorine on photocatalysis) include the following four aspects:(1) Surface effects of fluoride on TiO2 photocatalysis,(2) effects of fluorine doping on TiO2 photocatalysis,(3) fluoride-mediated tailoring of the morphology of TiO2 photocatalysts, and(4) the effects of fluorine on non-TiO2 photocatalysis. Additionally, the unique applications of these fluorine effects in photocatalysis, including selective degradation of pollutants, selective oxidation of chemicals, water-splitting to produce H2, reduction of CO2 to produce solar fuels, and improvement of the thermostability of TiO2 photocatalysts, are reviewed. 展开更多
关键词 TIO2 FLUORINE PHOTOCATALYSIS DOPING Surface modification
下载PDF
In-situ transformation of Bi_2WO_6 to highly photoreactive Bi_2WO_6@Bi_2S_3 nanoplate via ion exchange 被引量:4
8
作者 Tingting Huang Yuhan Li +5 位作者 xiaofeng wu Kangle Lv Qin Li Mei Li Dongyun Du Hengpeng Ye 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第4期718-727,共10页
As a two dimensional(2D)visible‐light‐responsive semiconductor photocatalyst,the photoreactivity of Bi2WO6 is not high enough for practical application owing to its limited response to visible light and rapid recomb... As a two dimensional(2D)visible‐light‐responsive semiconductor photocatalyst,the photoreactivity of Bi2WO6 is not high enough for practical application owing to its limited response to visible light and rapid recombination of photogenerated electron‐hole pairs.In this paper,2D core‐shell structured Bi2WO6@Bi2S3 nanoplates were prepared by calcination of a mixture of Bi2WO6(1.3 g)and a certain amount of Na2S·9H2O(0–3.0 g)at 350°C for 2 h.The reactivity of the resulting photocatalyst materials was evaluated by photocatalytic degradation of Brilliant Red X‐3B(X3B),an anionic dye,under visible light irradiation(?>420 nm).As the amount of Na2S·9H2O was increased from 0 to 1.5 g,the degradation rate constant of X3B sharply increased from 0.40×10?3 to 6.6×10?3 min?1.The enhanced photocatalytic activity of Bi2WO6@Bi2S3 was attributed to the photosensitization of Bi2S3,which greatly extended the light‐responsive range from the visible to the NIR,and the formation of a heterojunction,which retarded the recombination rate of photogenerated electron‐hole pairs.However,further increases in the amount of Na2S·9H2O(from 1.5 to 3.0 g)resulted in a decrease of the photocatalytic activity of the Bi2WO6@Bi2S3 nanoplates owing to the formation of a photo‐inactive NaBiS2 layer covering the Bi2WO6 surface. 展开更多
关键词 BI2S3 Bi2WO6 Ion exchange Photocatalytic degradation NANOPLATE
下载PDF
Factors Research on the Influence of Leaching Rate of Nickel and Cobalt from Waste Superalloys with Sulfuric Acid 被引量:4
9
作者 Xingxiang Fan Weidong Xing +5 位作者 Haigang Dong Jiachun Zhao Yuedong wu Bojie Li Weifeng Tong xiaofeng wu 《International Journal of Nonferrous Metallurgy》 2013年第2期63-67,共5页
Unlike the reported leaching technologies of waste superalloys, the process of the “atomized spray-sulfuric acid leaching nickel and cobalt” technology was put forward in the present work according to the compositio... Unlike the reported leaching technologies of waste superalloys, the process of the “atomized spray-sulfuric acid leaching nickel and cobalt” technology was put forward in the present work according to the compositions of waste superalloys. The effects of sulfuric acid temperature, concentration, leaching time, stirring speed and size of superalloys on leaching of Ni and Co from waste superalloys have been mainly investigated, and the optimum leaching conditions were determined and reported. The leaching rates for nickel and cobalt were 96.68% and 96.63%, respectively, and the contents of nickel and cobalt in leaching slag were 6.77% and 0.96%, respectively. The obtained leaching solution containing Ni and Co could be used for production of Ni and Co products after removal. 展开更多
关键词 WASTE SUPERALLOYS ACID LEACHING NICKEL COBALT LEACHING Rate
下载PDF
Optimizing the electronic spin state and delocalized electron of NiCo_(2)(OH)_(x)/MXene composite by interface engineering and plasma boosting oxygen evolution reaction
10
作者 Jingyao Xu Xia Zhong +2 位作者 xiaofeng wu Ying Wang Shouhua Feng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第8期129-140,I0004,共13页
The electrocatalytic activity of transition-metal-based compounds is closely related to the electronic configuration.However,optimizing the surface electron spin state of catalysts remains a challenge.Here,we develope... The electrocatalytic activity of transition-metal-based compounds is closely related to the electronic configuration.However,optimizing the surface electron spin state of catalysts remains a challenge.Here,we developed a spin-state and delocalized electron regulation method to optimize oxygen evolution reaction(OER)performance by in-situ growth of NiCo_(2)(OH)_(x) using Oswald ripening and coordinating etching process on MXene and plasma treatment.X-ray absorption spectroscopy,magnetic tests and electron paramagnetic resonance reveal that the coupling of NiCo_(2)(OH)_(x) and MXene can induce remarkable spin-state transition of Co^(3+)and transition metal ions electron delocalization,plasma treatment further optimizes the 3 d orbital structure and delocalized electron density.The unique Jahn-Teller phenomenon can be brought by the intermediate spin state(t2 _(g)^(5) e_(g)^(1))of Co^(3+),which benefits from the partial electron occupied egorbitals.This distinct electron configuration(t2_(g)^(5) e_(g)^(1))with unpaired electrons leads to orbital degeneracy,that the adsorption free energy of intermediate species and conductivity were further optimized.The optimized electrocatalyst exhibits excellent OER activity with an overpotential of 268 m V at 10 m A cm^(-2).DFT calculations show that plasma treatment can effectively regulate the d-band center of TMs to optimize the adsorption and improve the OER activity.This approach could guide the rational design and discovery of electrocatalysts with ideal electron configurations in the future. 展开更多
关键词 Transition metal compounds Electronic state control of surface/interface Electron spin state Delocalized electron Electrocatalytic material
下载PDF
Mechanized Grafting Technology for Apple Seedlings
11
作者 Zhiru LI xiaofeng wu +2 位作者 Lizhi HAN Quangang LI Beihang ZHANG 《Asian Agricultural Research》 2019年第2期100-101,105,共3页
The current cultivation of apple trees mainly relies on grafted seedlings to achieve seedling regeneration of apple trees. The commonly used splice grafting,V-shaped grafting and tongue grafting mostly use plastic fil... The current cultivation of apple trees mainly relies on grafted seedlings to achieve seedling regeneration of apple trees. The commonly used splice grafting,V-shaped grafting and tongue grafting mostly use plastic film for fixation and sealing. After one year,the wrapped plastic film needs to be removed to avoid affecting the growth of the seedlings. This paper introduces a brand new grafting technology which uses tongue grafting iron nails for fixation and growth fixation wax for sealing( SDRG). The process of mechanized grafting for apple nursery stock is determined,and the fixation and sealing problems with the grafting parts of seedlings are solved. The technology is characterized by quick speed,high efficiency,improved seedling survival rate lower labor cost and great significance to the promotion of industrialized nursery and mechanized grafting. 展开更多
关键词 GRAFTING FIXATION with IRON NAILS Process program Industrialized NURSERY
下载PDF
Application of three dimensional conformal radiation therapy combined with high-intensity focused ultrasound for prostate cancer
12
作者 Hui Yao Jinlan Gong +2 位作者 Li Li xiaofeng wu Jianjun Yu 《The Chinese-German Journal of Clinical Oncology》 CAS 2012年第3期164-167,共4页
Objective:Prostate cancer is a form of cancer that develops in the prostate,a gland in the male reproductive system.Prostate cancer tends to develop in men over the age of fifty;it is one of the most prevalent types o... Objective:Prostate cancer is a form of cancer that develops in the prostate,a gland in the male reproductive system.Prostate cancer tends to develop in men over the age of fifty;it is one of the most prevalent types of cancer in men.This article introduced a new method of prostate cancer treatment with the combination of three dimensional conformal radiation therapy (3D-CRT) and high-intensity focused ultrasound (HIFU),its efficacy was evaluated.Methods:From January 2004 to December 2009,95 patients were diagnosed with prostate cancer,among them,48 patients were received combined therapy with total irradiation of TD 60 Gy/30 Fx and 5 fractions of HIFU treatment,while 47 patients were received with pure 3D-CRT with total irradiation of TD (66-72) Gy/(33-36) Fx.Various indicators were evaluated,such as the local control rate and distant metastasis rate,the changes in blood PSA and fPSA,changes in T-lymphocyte subsets and NK cells,as well as acute adverse reaction of normal tissue.Results:The local response rate difference between the two groups had statistical significance (P < 0.05);the changes in blood PSA and fPSA were significant (P < 0.05);CD3+,CD4+,CD8+,CD4+/CD8+ and NK cells of the combined group increased obviously (P < 0.01),while the latter group had no increase (P > 0.05);the combined group had lower blood cells reduction and II-level acute adverse reaction of rectum,bladder and caput humeri than the pure group,but the II-level acute adverse reaction of urogenital canal in the combined group was higher (P < 0.05).Conclusion:The combined therapy with 3D-CRT and HIFU is a good way for the treatment of aged-related prostate cancer.It can ease the symptoms,control the disease and lengthen the survival time. 展开更多
关键词 prostate cancer three dimensional conformal radiotherapy (3D-CRT) high-intensity focused ultrasound (HIFU)
下载PDF
Naked-eye visualization of lymph nodes using fluorescence nanoprobes in non-human primate-animal models
13
作者 Xiaoyuan Ji Binbin Chu +13 位作者 xiaofeng wu Zhiming Xia Airui Jiang Chenyu Wang Zhiming Chen Danni Zhong Qiaolin Wei Bin Song Wanlin Li Yiling Zhong Houyu Wang Fenglin Dong Min Zhou Yao He 《Nano Research》 SCIE EI CSCD 2024年第8期7404-7414,共11页
Despite sufficient studies performed in non-primate animal models,there exists scanty information obtained from pilot trials in non-human primate animal models,severely hindering nanomaterials moving from basic resear... Despite sufficient studies performed in non-primate animal models,there exists scanty information obtained from pilot trials in non-human primate animal models,severely hindering nanomaterials moving from basic research into clinical practice.We herein present a pioneering demonstration of nanomaterials based optical imaging-guided surgical operation by using macaques as a typical kind of non-human primate-animal models.Typically,taking advantages of strong and stable fluorescence of the small-sized(diameter:~5 nm)silicon-based nanoparticles(SiNPs),lymphatic drainage patterns can be vividly visualized in a real-time manner,and lymph nodes(LN)are able to be sensitively detected and precisely excised from small animal models(e.g.,rats and rabbits)to non-human primate animal models(e.g.,cynomolgus macaque(Macaca fascicularis)and rhesus macaque(Macaca mulatta)).Compared to clinically used invisible near-infrared(NIR)lymphatic tracers(i.e.,indocyanine green(ICG);etc.),we fully indicate that the SiNPs feature unique advantages for naked-eye visible fluorescence-guided surgical operation in long-term manners.Thorough toxicological analysis in macaque models further provides confirming evidence of favorable biocompatibility of the SiNPs probes.We expect that our findings would facilitate the translation of nanomaterials from the laboratory to the clinic,especially in the field of cancer treatment. 展开更多
关键词 fluorescent silicon nanoparticles lymph node REAL-TIME naked-eye visualization macaque models
原文传递
亚临界或超临界反应的凝聚态化学
14
作者 张媛 郑贝宁 +2 位作者 吴小峰 黄科科 冯守华 《化学进展》 SCIE CAS CSCD 北大核心 2023年第6期968-982,共15页
通过化学反应形成确定的和复杂的原子分子凝聚态,其原子分子间相互作用的多维度复合与协同,拓展了物质结构模式,体系性能发生突变,表现出凝聚态化学的某些特性。在特定条件下或在超临界条件下的歧化反应,产生锰金属离子以三种氧化态的... 通过化学反应形成确定的和复杂的原子分子凝聚态,其原子分子间相互作用的多维度复合与协同,拓展了物质结构模式,体系性能发生突变,表现出凝聚态化学的某些特性。在特定条件下或在超临界条件下的歧化反应,产生锰金属离子以三种氧化态的形式聚集成的复杂调制结构。本文从凝聚态化学角度出发,详细介绍了在亚/超临界水热条件下,原子尺度pn结固体的生成,量子IV特性与电场诱导超流现象,讨论了化学反应驱动的凝聚态转变问题。本文同时介绍了凝聚态流体的基本性质和各级凝聚尺度中气体分子参与的化学反应,包括化学键修复反应、水热反应、人工降雨和肿瘤的消退,以及超临界条件下凝聚态化学反应的机理和潜在应用。 展开更多
关键词 超临界 水热歧化反应 原子尺度pn结 玻色爱因斯坦凝聚 肿瘤消退
原文传递
Reinforcement learning based dynamic distributed routing scheme for mega LEO satellite networks 被引量:2
15
作者 Yixin HUANG Shufan wu +5 位作者 Zeyu KANG Zhongcheng MU Hai HUANG xiaofeng wu Andrew Jack TANG Xuebin CHENG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第2期284-291,共8页
Recently,mega Low Earth Orbit(LEO)Satellite Network(LSN)systems have gained more and more attention due to low latency,broadband communications and global coverage for ground users.One of the primary challenges for LS... Recently,mega Low Earth Orbit(LEO)Satellite Network(LSN)systems have gained more and more attention due to low latency,broadband communications and global coverage for ground users.One of the primary challenges for LSN systems with inter-satellite links is the routing strategy calculation and maintenance,due to LSN constellation scale and dynamic network topology feature.In order to seek an efficient routing strategy,a Q-learning-based dynamic distributed Routing scheme for LSNs(QRLSN)is proposed in this paper.To achieve low end-toend delay and low network traffic overhead load in LSNs,QRLSN adopts a multi-objective optimization method to find the optimal next hop for forwarding data packets.Experimental results demonstrate that the proposed scheme can effectively discover the initial routing strategy and provide long-term Quality of Service(QoS)optimization during the routing maintenance process.In addition,comparison results demonstrate that QRLSN is superior to the virtual-topology-based shortest path routing algorithm. 展开更多
关键词 LEO satellite networks Mega constellation Multi-objective optimization Routing algorithm Reinforcement learning
原文传递
Inductive effect of Ti-doping in Fe_(2)O_(3)enhances the photoelectrochemical water oxidation 被引量:1
16
作者 Yumei Lin Yan Wang +7 位作者 Hongxia Wang Jingjing Wang xiaofeng wu Jan P.Hofmann Giulio Gorni Victor A.de la Pena O'Shea Freddy E.Oropeza Kelvin H.L.Zhang 《Science China Chemistry》 SCIE EI CAS CSCD 2023年第7期2091-2097,共7页
Hematite(α-Fe_(2)O_(3))is an ideal oxide semiconductor candidate for photoelectrochemical(PEC)water splitting.Doping of Fe_(2)O_(3)is known to benefit the PEC water oxidation efficiency,but despite extensive research... Hematite(α-Fe_(2)O_(3))is an ideal oxide semiconductor candidate for photoelectrochemical(PEC)water splitting.Doping of Fe_(2)O_(3)is known to benefit the PEC water oxidation efficiency,but despite extensive research efforts,the underlying mechanism still remains elusive.In this work,we report a comprehensive study on the relationship between the electronic structure,interfacial reaction kinetics and PEC activity of Ti-doped Fe_(2)O_(3)photoanodes.The results show that the interfacial charge transfer efficiency at the Fe_(2)O_(3)/electrolyte interface is the main factor in the significant increase of the PEC activity of doped Fe_(2)O_(3).Electrochemical impedance spectroscopy reveals that the interfacial charge transfer efficiency is determined by energy overlap between the water oxidation potential and energy distribution of an intermediate surface state that has been identified as Fe^(IV)=O groups on Fe_(2)O_(3)surface generated during PEC process.Interestingly,the potential energy distribution of this intermediate surface state can be modulated by Ti doping,and a shift towards a more positive potential of the intermediate surface state increases the overlap with the water oxidation potential and thus enhances the kinetics of charge transfer for PEC water splitting.The origin of such potential energy modulation is traced to the inductive effect from Ti-doping on the Fe^(3+)/Fe^(4+)redox transition and the Fe-O bond covalency.Our results provide new insight into the mechanism for the doping effect on the PEC water splitting,introducing new strategies to optimize the PEC activity by tuning the redox properties of active metal oxides. 展开更多
关键词 HEMATITE surface states DOPING photoelectrochemical water splitting electronic structure
原文传递
Fluorinated Covalent Organic Frameworks Coupled with Molecular Cobalt Cocatalysts for Efficient Photocatalytic CO_(2)Reduction 被引量:1
17
作者 Zhiwei Fu Chang Shu +8 位作者 Xiaoyan Wang Linjiang Chen Xue Wang Lunjie Liu Kewei Wang Rob Clowes Samantha Y.Chong xiaofeng wu Andrew I.Cooper 《CCS Chemistry》 CSCD 2023年第10期2290-2300,共11页
The combination of covalent organic framework(COF)photosensitizers with molecular cocatalysts is a promising avenue for photocatalytic carbon dioxide(CO_(2))reduction.Here,a series of isostructural COFs was synthesize... The combination of covalent organic framework(COF)photosensitizers with molecular cocatalysts is a promising avenue for photocatalytic carbon dioxide(CO_(2))reduction.Here,a series of isostructural COFs was synthesized using linkers of different lengths,with or without partial fluorination.These COFs were investigated for photocatalytic CO_(2)reduction under visible-light irradiation when combined with cobalt(II)bipyridine complexes as a cocatalyst.Fluorination was found to enhance both CO_(2)affinity and catalytic activity,and a partially fluorinated COF,FBP-COF,achieved the highest CO_(2)-to-CO conversion efficiency,showing a carbon monoxide(CO)generation rate of 2.08 mmol h−1 g−1 and a 90%CO selectivity.FBP-COF also showed good stability under sacrificial conditions,generating CO for 50 h with a turnover number of 91.5.This activity is much higher than a homogeneous system using ruthenium bipyridine complexes as the photosensitizer combined with the same cobalt bipyridine complexes. 展开更多
关键词 carbon dioxide conversion PHOTOCATALYSIS covalent organic frameworks FLUORINATED solar energy conversion
原文传递
Manipulation and observation of atomic-scale superlattices in perovskite manganate
18
作者 Xiyang Wang Keke Huang +4 位作者 xiaofeng wu Long Yuan Liping Li Guangshe Li Shouhua Feng 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第12期481-485,共5页
Superlattices in crystals,particularly in perovskite oxides with strong correlation effects,can create new states of matter and produce peculiar physicochemical phenomena.However,the newfangled perovskite superlattice... Superlattices in crystals,particularly in perovskite oxides with strong correlation effects,can create new states of matter and produce peculiar physicochemical phenomena.However,the newfangled perovskite superlattices depend on physical deposition with unit-cell precision.It has been challenging to explore a new suitable chemical method to tailor perovskite superlattices.Herein,we present a new bottomup strategy to precisely prepare atomic-scale oxide superlattices of(LaMnO_(3))_(1)-(La_(1-x-y)Ca_(x)K_(y)MnO_(3))_(2)in a monodispersed perovskite La_(0.66)Ca_(0.29)K_(0.05)MnO_(3)(LCKMO).The special atomic-scale perovskite superlattices are demonstrated using SAED,HAADF-STEM,XRD,and atomic-resolution elemental mapping.Our experiments reveal that the perovskite superlattices can be fabricated under extreme hydrothermal conditions utilizing ultra-high concentrations of KOH.An approximate molten salt system in the hydrothermal process can induce the disproportionation reaction of MnO_(2)solids,which is vital to the growth of ordered perovskite superlattices.This work not only clarifies the hydrothermal growth process of perovskite oxides in extreme conditions,but also proposes a novel engineering route toward perovskite superlattices. 展开更多
关键词 Perovskite oxides Hydrothermal Ordered superstructure Perovskite superlattice Disproportionation reaction
原文传递
Learning curve and analysis of curative effects after balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension
19
作者 Cheng Hong Linna Hu +8 位作者 Haimin Liu xiaofeng wu Jianmin Lu Jiangpeng Lin Wenliang Guo Xishi Sun Jielong Lin Riken Chen Zhenzhen Zheng 《Chinese Medical Journal》 SCIE CAS CSCD 2023年第1期99-101,共3页
To the Editor:Chronic thromboembolic pulmonary hypertension(CTEPH)is a chronic progressive disease in which pulmonary artery pressure(PAP)increases and eventually leads to right heart failure and death.Balloon pulmona... To the Editor:Chronic thromboembolic pulmonary hypertension(CTEPH)is a chronic progressive disease in which pulmonary artery pressure(PAP)increases and eventually leads to right heart failure and death.Balloon pulmonary angioplasty(BPA)is a new and effective treatment for CTEPH patients who are unsuitable for surgery or who develop recurrent or persistent pulmonary hypertension after pulmonary endarterectomy(PEA).In recent years,major medical centers at home and abroad have been gradually developing and improving BPA,but overall,a unified treatment process and complication control strategy is lacking. 展开更多
关键词 HYPERTENSION BALLOON ANGIOPLASTY
原文传递
碳纳米管-膨胀石墨/环氧树脂复合材料的导热性能 被引量:1
20
作者 刘艳杰 陆江银 +2 位作者 李玲 武晓峰 崔彦斌 《过程工程学报》 CAS CSCD 北大核心 2018年第3期563-569,共7页
在环氧树脂中添加多壁碳纳米管和膨胀石墨作为填料,以提高环氧树脂的导热性能.结果表明,添加0.5wt%多壁碳纳米管时,环氧树脂的最佳导热系数为0.3448 W/(m×K),比不添加时提高30%;添加0.75wt%羧基改性多壁碳纳米管时,环氧树脂的最... 在环氧树脂中添加多壁碳纳米管和膨胀石墨作为填料,以提高环氧树脂的导热性能.结果表明,添加0.5wt%多壁碳纳米管时,环氧树脂的最佳导热系数为0.3448 W/(m×K),比不添加时提高30%;添加0.75wt%羧基改性多壁碳纳米管时,环氧树脂的最佳导热系数为0.3813 W/(m·K),比添不加时提高40%;同时添加多壁碳纳米管和膨胀石墨后,环氧树脂导热系数可进一步提高到0.4039 W/(m·K),表明在环氧树脂中添加混合填料,二者可在环氧树脂中形成有效的导热网络,能进一步提高聚合物的导热性能. 展开更多
关键词 聚合物 多壁碳纳米管 膨胀石墨 复合材料 导热系数
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部