检索结果-南通市图书馆

Graph partitioning algorithm for opportunistic routing in large-scale wireless network

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2009年第4期16卷 42-46页

作者： LI yan-hua liu Yuan-an Wireless Communication Center Beijing University of Posts and Telecommunications Beijing 100876 China

Opportunistic routing takes advantage of the broadcast nature of wireless communications by forwarding data through a set of opportunistic paths instead of one ＇best＇ path in traditional routing. However, using the global scheduling opportunistic scheme like the existing opportunistic routing protocol （ExOR） would consume considerable transmission latency and energy in large-scale wireless topologies. In this article, a graph partitioning algorithm is proposed, namely, minimum cut with laplacians （MCL）, to divide the Ad-hoc network topology into subgraphs with minimized edge cuts across them. Then the existing opportunistic routing can be applied locally in each subgraph. In this way, forwarders in different subgraphs can transmit simultaneously, and each node only needs to maintain a local forwarder list instead of a global one. The simulations show that using MCL scheme in the opportunistic routing can reduce the end-to-end delay by about 49%, and increase the life time of the wireless node by about 39%.

关键词： opportunistic routing graph partitioning wireless routing mobile Ad-hoc network

Comparative efficacy and safety of cognitive enhancers for treating vascular cognitive impairment: systematic review and Bayesian network meta-analysis

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2019年第5期14卷 805-816页

作者： Bo-Ru Jin hua-yan liu Department of Neurology First Affiliated Hospital China Medical University

Objective: To assess and compare the clinical efficacy and safety of cognitive enhancers(donepezil, galantamine, rivastigmine, and memantine) on cognition, behavior, function, and global status in patients with vascular cognitive *** sources: The initial literature search was performed with PubMed, EMBASE, the Cochrane Methodology Register, the Cochrane Central Register of Controlled Trials, and Cumulative Index to Nursing & Allied Health(CINAHL) from inception to January 2018 for studies regarding donepezil, galantamine, rivastigmine, and memantine for treatment of vascular cognitive *** selection: Randomized controlled trials on donepezil, galantamine, rivastigmine, and memantine as monotherapy in the treatment of vascular cognitive impairment were included. A Bayesian network meta-analysis was conducted. Outcome measures: Efficacy was assessed by changes in scores of the Alzheimer's Disease Assessment Scale, cognitive subscale, Mini-Mental State Examination, Neuropsychiatric Inventory scores and Clinician's Interview-Based Impression of Change Scale Plus Caregiver's Input, Activities of Daily Living, the Clinical Dementia Rating scale. Safety was evaluated by mortality, total adverse events(TAEs), serious adverse events(SAEs), nausea, vomiting. diarrhea, or cerebrovascular accidents(CVAs). Results: After screening 1717 citations, 12 randomized controlled trials were included. Donepezil and rivastigmine(mean difference(e) = –0.77, 95% confidence interval(CI): 0.25–1.32; MD = 1.05, 95% CI: 0.18–1.79) were significantly more effective than placebo in reducing Mini-Mental State Examination scores. Donepezil, galantamine, and memantine(MD = –1.30, 95% CI: –2.27 to –0.42; MD = –1.67, 95% CI: –3.36 to –0.06; MD = –2.27, 95% CI: –3.91 to –0.53) showed superior benefits on the Alzheimer's Disease Assessment Scale–cognitive scores compared with placebo. Memantine(MD = 2.71, 95% CI: 1.05–7.29) improved global status(Clinician's Interview-Based Impres

关键词： nerve regeneration vascular cognitive impairment vascular dementia pharmacotherapy cholinesterase inhibitors donepezil galantamine rivastigmine memantine systematic review Bayesian network meta-analysis neural regeneration

Results of the maximum genus of graphs

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2007年第11期50卷 1563-1570页

作者： Guang-hua DONG yan-pei liu Department of Mathematics School of ScienceBeijing Jiaotong UniversityBeijing 100044China Department of MathematicsSchool of ScienceBeijing Jiaotong UniversityBeijing 100044China

In this paper,we provide a new class of up-embeddable graphs,and obtain a tight lower bound on the maximum genus of a class of 2-connected pseudographs of diameter 2 and of a class of diameter 4 *** extends a result o... 详细信息

关键词： maximum genus up-embeddable diameter

Ni-Catalyzed Chelation-Assisted Direct Functionalization of Inert C—H Bonds

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2020年第6期38卷 635-662页

作者： yan-hua liu Yu-Nong Xia Bing-Feng Shi Department of Chemistry Zhejiang UniversityHangzhouZhejiang 310027China

During the last two decades,impressive advancements have been achieved in transition metal-catalyzed chelation-assisted C—H functionalization *** reactions in this field are still dominated by precious 4d or 5d metals(e.g.,Pd,Rh,Ir),the 3d base metals(e.g.,Ni,Co,Cu,Fe)have made significant headway partially due to their relatively large abundance,low cost,low toxicity as well as their occasionally occurred novel reactivity when compared to their noble *** review will give a comprehensive summary on Ni-catalyzed functionalization of inert C—H bonds assisted by chelation *** clarity,the content is classified by the newly formed chemical bonds,namely C—C,C—N,C—chalcogen and C—halogen bond formation.

关键词： reaction. metals Functional

Interleukin-4 affects microglial autophagic flux

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

Neural Regeneration Research 2019年第9期14卷 1594-1602页

作者： Run-Hong Tang Rui-Qun Qi hua-yan liu Department of Neurology the First Hospital of China Medical UniversityShenyangLiaoning ProvinceChina Department of Dermatology Key Laboratory of Immunodermatologythe First Hospital of China Medical UniversityShenyangLiaoning ProvinceChina

Interleukin-4 plays an important protective role in Alzheimer’s disease by regulating microglial phenotype,phagocytosis of amyloid-β,and secretion of anti-inflammatory and neurotrophic ***,increasing evidence has suggested that autophagy regulates innate immunity by affecting M1/M2 polarization of microglia/***,the role of interleukin-4 in microglial autophagy is *** view of this,BV2 microglia were treated with 0,10,20 or 50 ng/mL interleukin-4 for 24,48,or 72 ***,light chain 3-II and p62 protein expression levels were detected by western blot ***2 microglia were incubated with interleukin-4(20 ng/mL,experimental group),3-methyladenine(500μM,autophagy inhibitor,negative control group),rapamycin(100 nM,autophagy inductor,positive control group),3-methyladenine+interleukin-4(rescue group),or without treatment for 24 hours,and then exposed to amyloid-β(1μM,model group)or vehicle control(control)for 24 ***3-II and p62 protein expression levels were again detected by western blot *** addition,expression levels of multiple markers of M1 and M2 phenotype were assessed by real-time fluorescence quantitative polymerase chain reaction,while intracellular and supernatant amyloid-βprotein levels were measured by enzyme-linked immunosorbent *** results showed that interleukin-4 induced microglial autophagic flux,most significantly at 20 ng/mL for 48 ***-4 pretreated microglia inhibited blockade of amyloid-β-induced autophagic flux,and promoted amyloid-βuptake and degradation partly through autophagic flux,but inhibited switching of amyloid-β-induced M1 phenotype independent on autophagic *** results indicate that interleukin-4 pretreated microglia increases uptake and degradation of amyloid-βin a process partly mediated by autophagy,which may play a protective role against Alzheimer’s disease.

关键词： nerve regeneration Alzheimer’s disease interleukin-4 amyloid-β microglial autophagy microglial polarization microglia M1 phenotype M2 phenotype peptide degradation neural regeneration

A new process of extracting vanadium from stone coal

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2010年第4期17卷 381-388页

作者： yan-hua liu Chao yang Pei-you Li Shi-qi Li Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China Beijing Nengtai Environmental Protection Group Corp Beijing 100022 China

A new process of extracting vanadium from the stone coal vanadium ore in Fangshankou, Dtmhuang area of Gansu Province, China was introduced. Various leaching experiments were carried out, and the results show that the vanadium ore in Fangshankou is difficult to process due to its high consumption of acid and the high leaching rate of impurities. However, the leaching rate can be up to 80% and the content of V2O5 in the residue can be between 0.22%-0.25% in the process of ore fme grinding→oxidation roasting→mixing and ripening→aqueous leaching→P2O4 solvent extraction→sulfuric acid stripping→oxidation and precipitation→decomposition by heat. Also, the quality of flaky V205 produced by this process can meet the requirements of GB3283--87. The total leaching rate of vanadium is 70%. Also, three types of wastes are easy to treat. The vanadium extraction process is better in relation to the aspect of environmental protection than the sodium method.

关键词： stone coal vanadium extraction leaching solvent extraction V2O5

Copper-Catalyzed Modular Access to N-Fused Polycyclic Indoles and 5-Aroyl-pyrrol-2-ones via Intramolecular N-H/C-H Annulation with Alkynes:Scope and Mechanism Probes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2020年第12期38卷 1545-1552页

作者： yan-hua liu Hong Song Chi Zhang Yue-Jin liu Bing-Feng Shi Department of Chemistry Zhejiang UniversityHangzhouZhejiang 310027China

of main observation and concusion Copper-catalyzed intramolecular N-H/C-H annulation with alkynes has been developed.A vaniety ofdensely functionalized heterocycles,such as pyrrolo[1,2-a]indoles,indolo[1,2-c]quinazolin-2-ones,oxazolo[3,4-o]indoles,and imidazo[1.5-o]indoles,eresynthesized in an atom-and step-economical manner,owing to the high modularized feature of aniline moiety te linker moiety,as well as the *** simply changing the oxidant from di-tert-butyl peroxide(DTBP)to 2,2,6.6-tetramethylpiperidine-1-oxyl(TEMPo)the reacton could readily betransformed to the aminooxygenation pathway,which grabs one oxygen atom from the TEMPO to generate 5-aroy'-*** experi-ments indicate that viny radical is involved in this reaction and an amidyl-radical-initiated radical cascade might be responsible for this transformation.

关键词： moiety Copper radical

Advancing pressure sensors performance through a flexible MXene embedded interlocking structure in a microlens array

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

Nano Research 2023年第7期16卷 10493-10499页

作者： Tong Li Zhenzong Xu Ben Bin Xu Zhanhu Guo Yunhong Jiang Xuehua Zhang Maryam Bayati Terence Xiaoteng liu yan-hua liu School of Optoelectronic Science and Engineering Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province&Key Lab of Modern Optical Technologies of Education Ministry of ChinaSoochow UniversitySuzhou 215006China Department of Mechanical and Construction Engineering Faculty of Engineering and EnvironmentNorthumbria UniversityNewcastle upon TyneNE18STUK Hub for Biotechnology in the Built Environment Department of Applied SciencesNorthumbria University at NewcastleNE18STUK Department of Chemical and Materials Engineering University of AlbertaEdmontonAlberta T6G 1H9Canada

Piezoresistive composite elastomers have shown great potentials for wearable and flexible electronic applications due to their high sensitivity,excellent frequency response,and easy signal detection.A composition membrane sensor with an interlocked structure has been developed and demonstrated outstanding pressure sensitivity,fast response time,and low temperature drift *** with a flexible MXene-based flat sensor(Ti_(3)C_(2)),the interlocked sensor exhibits a significantly improved pressure sensitivity of two magnitudes higher(21.04 kPa^(-1)),a fast reaction speed of 31 ms,and an excellent cycle life of 5000 test *** viability of sensor in responding to various external stimuli with high deformation capacity has been confirmed by calculating the force distribution of a polydimethylsiloxane(PDMS)film model with a microlens structure using the solid mechanics module in *** conventional process,we utilized three-dimensional(3D)laser-direct writing lithography equipment to directly transform high-precision 3D data into a micro-nano structure morphology through variable exposure doses,which reduces the hot melting ***,the flexible pressure device is capable of detecting and distinguishing signals ranging from finger movements to human pulses,even for speech *** simple,convenient,and large-format lithographic method offers new opportunities for developing novel human-computer interaction devices.

关键词： three-dimensional(3D)lithography microlens array flexible electronics pizoresistive pressure sensors MXene

Improvement of pitting corrosion resistance for Al-Cu alloy in sodium chloride solution through equal-channel angular pressing

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

Progress in Natural Science:Materials International 2011年第4期21卷 307-313页

作者： Dan SONG,Ai-bin MA,Jing-hua JIANG,Ping-hua LIN,liu-yan ZHANG College of Mechanics and Materials,Hohai University,Nanjing 210098,China College of Mechanics and Materials Hohai University Nanjing 210098 China

Significant corrosion resistance improvement was achieved in solid-solution treated(T4) Al-Cu alloy after severe grain refinement through equal-channel angular *** bulk ultrafine-grained Al-Cu alloy with grain sizes of 200-300 nm has higher pitting potential(elevated by about 34 mV,SCE) and lower corrosion current density(decreased by about 3.88μA/cm~2) in polarization tests than the as-T4 alloy,and increased polarization resistance(increased by about 5.7 kΩ·cm~2) in electrochemical impendence spectrum tests,along with alleviated corrosion damage in immersion *** factors responds to the improved corrosion resistance of the alloy:the first is the refinement of residualθ-phase(Al2Cu) particles leading to the lower micro-galvanic currents and reduced susceptibilities to pitting corrosion,the second is the mass of strain-induced crystalline defects providing more nucleation sites for the formation of more volume fractions of stable oxide film.

关键词： Al-Cu alloy equal-channel angular pressing pitting corrosion resistance ultrafine-grained particle