检索结果-南通市图书馆

Emerging progress:photochemical transformation of nitroso compounds

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期68卷 118-133页

作者： ze-Le chen Qiang-Qiang Li Armido Studer Jun Xuan Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials School of Chemistry&Chemical EngineeringAnhui UniversityHefei 230601China Organisch-Chemisches Institut Universitat MünsterMunster 48149Germany

Nitroso compounds have emerged as highly valuable reaction partners or reagents in organic synthesis due to their rich *** versatile profile of these compounds allows them to function as electrophiles,nucleophiles,diradicals,and radical acceptors in diverse *** recent years,notable progress has been made in harnessing photochemical reactions with nitroso compounds to prepare N,O-containing structures using mild and eco-friendly *** nitroso compounds like nitrosoarenes,acyloxy nitroso compounds,N-nitrosoamines and nitrites have received significant attention for their ability to introduce NO moieties into complex molecules that are otherwise difficult to *** this review,we provide an overview of the recent advancements in the visible light-induced conversion of nitroso compounds,with particular emphasis on their role as bifunctional reagents and acceptors of radicals,carbenes and nitrenes.

关键词： nitroso compounds photochemistry radical reaction carbene transformation nitrosoarenes

A Correntropy-Based Echo State Network With Application to Time Series Prediction

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2025年第2期12卷 425-435页

作者： Xiufang chen Zhenming Su long Jin Shuai Li the School of Information Science and Engineering Lanzhou University IEEE the Hangzhou Institute for Advanced Study University of Chinese Academy of Science

As a category of recurrent neural networks, echo state networks(ESNs) have been the topic of in-depth investigations and extensive applications in a diverse array of fields, with spectacular triumphs achieved. Nevertheless, the traditional ESN and the majority of its variants are devised in the light of the second-order statistical information of data(e.g., variance and covariance), while more information is neglected. In the context of information theoretic learning, correntropy demonstrates the capacity to grab more information from data. Therefore, under the guidelines of the maximum correntropy criterion, this paper proposes a correntropy-based echo state network(CESN) in which the first-order and higher-order information of data is captured, promoting robustness to noise. Furthermore, an incremental learning algorithm for the CESN is presented, which has the expertise to update the CESN when new data arrives, eliminating the need to retrain the network from scratch. Finally, experiments on benchmark problems and comparisons with existing works are provided to verify the effectiveness and superiority of the proposed CESN.

关键词： Correntropy echo state network (ESN) noise time series prediction

Impact of Various Silicon Sources on the Synthesis of Mordenite and Differences in the Carbonylation Reaction of Dimethyl Ether

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2025年第1期41卷 59-65页

作者： chen long WANG Yunzheng LV Jiangang YANG Weimin School of Chemical Engineering East China University of Science and TechnologyShanghai200237P.R.China Sinopec Shanghai Research Institute of Petrochemical Technology Co. Ltd.Shanghai201208P.R.China

This study introduces an innovative method for synthesizing mordenite(MOR)by employing a combination of water glass and fumed silica as the silica *** zeolite produced through this method exhibits a smaller grain size,a larger specific surface area,and a greater number of Brønsted acid sites compared to the conventionally synthesized mordenite using silica ***,the chemical environment of framework Al in MOR zeolites is influenced by different silica sources,leading to varied acid properties between the two MOR zeolites,which results in an enhanced activity of dimethyl ether carbonylation from 50%to over 83%.

关键词： Mordenite Silica source DME carbonylation

Optical signature of flat bands in topological hourglass semimetal Nb_(3)SiTe_(6)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2025年第2期34卷 388-392页

作者： Shize Cao Cuiwei Zhang Yueshan Xu Jianzhou Zhao Youguo Shi Yun-ze long Jianlin Luo Zhi-Guo chen Collaborative Innovation Center for Nanomaterials&Devices College of PhysicsQingdao UniversityQingdao 266071China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Co-Innovation Center for New Energetic Materials Southwest University of Science and TechnologyMianyang 621010China Songshan Lake Materials Laboratory Dongguan 523808China

Flat electronic bands in condensed matter provide a rich avenue for exploring novel quantum phenomena. Here, we report an optical spectroscopy study of a topological hourglass semimetal Nb_(3)SiTe_(6) with the electric field of the incident light parallel to its crystalline ab-plane. The ab-plane optical conductivity spectra of Nb_(3)SiTe_(6) single crystals exhibit a remarkable peak-like feature around 1.20 eV, which is mainly contributed by the direct optical transitions between the two ab-initio-calculation-derived flat bands along the momentum direction Z–U. Our results pave the way for investigating exotic quantum phenomena based on the flat bands in topological hourglass semimetals.

关键词： flat band topological semimetal optical spectroscopy

Recurrent corneal erosion after buried-suture doubleeyelid blepharoplasty using barbed thread

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2025年第1期18卷 178-180页

作者： Tian-ze Huang Jiu-Zuo Huang Di chen Department of Ophthalmology Peking Union Medical College HospitalPeking Union Medical College&Chinese Academy of Medical SciencesBeijing 100730China Department of Plastic and Reconstructive Surgery Peking Union Medical College HospitalPeking Union Medical College&Chinese Academy of Medical SciencesBeijing 100730China

Dear Editor,Recurrent corneal erosion(RCE)is a common clinical condition characterized by repeated episodes of eye redness,pain,foreign-body sensation,photophobia,and tearing[1].The causes of RCE include trauma,chemical and thermal injuries,previous herpetic keratitis,epithelial basement membrane dystrophy,and systemic conditions like epidermolysis bullosa[2-3].

关键词： injuries sensation corneal

Decellularized amniotic membrane promotes the anti-inflammatory response of macrophages via PI3K/AKT/HIF-1α pathway

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2025年第1期36卷 403-407页

作者： Xiongbo Song Jinwen Xiao Juan Wu Li Sun long chen Department of Orthopedics Guizhou Provincial People’s HospitalGuiyang 550000China The Lab of Tissue Engineering and Translational Medicine College of MedicineGuizhou UniversityGuiyang 550000China Wuhan Kangchuang Biotechnology Wuhan 430074China

Macrophages undergo dynamic transitions between M1 and M2 states,exerting profound influences on both inflammatory and regenerative *** biocompatible and wound-healing properties of decellularized amniotic membrane(d AM)make it a subject of exploration for its potential impact on the anti-inflammatory response of *** findings unequivocally demonstrate that d AM promotes anti-inflammatory M2 polarization of macrophage,with its cytokine-rich content posited as a potential *** application of RNA sequencing unveils differential gene expression,implicating the hypoxia inducible factor-1α(HIF-1α)signaling pathway in this intricate *** investigation further demonstrates that d AM facilitates anti-inflammatory M2 polarization of macrophage through the upregulation of epidermal growth factor(EGF),which,in turn,activates the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)pathway and stabilizes HIF-1α.This cascade results in a noteworthy augmentation of anti-inflammatory gene *** study significantly contributes to advancing our comprehension of d AM's immunomodulatory role in tissue repair,thereby suggesting promising therapeutic potential.

关键词： Macrophage Decellularized amniotic membrane Anti-inflammatory response Hypoxia inducible factor-1α Epidermal growth factor

Hausdorff Measure of Space Anisotropic Gaussian Processes with Non-stationary Increments

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2025年第1期41卷 114-132页

作者： Jun WANG Zhen-long chen Wei-jie YUAN Guang-jun SHEN School of Mathematics and Physics Anhui Polytechnic UniversityWuhu 241000China School of Statistics and Mathematics Zhejiang Gongshang UniversityHangzhou 310018China Department of Mathematics Anhui Normal UniversityWuhu 241000China

Let X={X(t),t∈R+} be a centered space anisotropic Gaussian process values in R^(d) with non-stationary increments,whose components are independent but may not be identically *** certain conditions,then almost surely c_(1)≤ϕ-m(X([0,1]))≤c_(2),where ϕ denotes the exact Hausdorff measure associated with function ϕ(s)=s1/α_(k)+Σ_(i=1)k(1-αi/αk)log log 1/s for some 1≤k≤d,(α_(1),…,α_(d))∈(0,1]^(d).We also obtain the exact Hausdorff measure of the graph of X on[0,1].

关键词： Hausdorff measure self-similar Gaussian processes non-stationary increment Lamperti theorem

MXene Hybridized Polymer with Enhanced Electromagnetic Energy Harvest for Sensitized Microwave Actuation and Self‑Powered Motion Sensing

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第3期17卷 265-279页

作者： Yu‑ze Wang Yu‑Chang Wang Ting‑Ting Liu Quan‑Liang Zhao chen‑Sha Li Mao‑Sheng Cao School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China School of Materials Science and Engineering Peking UniversityBeijing 100871People’s Republic of China School of Mechanical and Material Engineering North China University of TechnologyBeijing 100144People’s Republic of China Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education of the People’s Republic of ChinaHeilongjiang UniversityHarbin 150080People’s Republic of China

Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is challenged by restricted electromagneticsensitivity and intricate sensing coupling. In this study, a sensitized polymericmicrowave actuator is fabricated by hybridizing a liquid crystal polymer with Ti3C2Tx(MXene). Compared to the initial counterpart, the hybrid polymer exhibits unique spacechargepolarization and interfacial polarization, resulting in significant improvements of230% in the dielectric loss factor and 830% in the apparent efficiency of electromagneticenergy harvest. The sensitized microwave actuation demonstrates as the shortenedresponse time of nearly 10 s, which is merely 13% of that for the initial shape memory polymer. Moreover, the ultra-low content of MXene (upto 0.15 wt%) benefits for maintaining the actuation potential of the hybrid polymer. An innovative self-powered sensing prototype that combinesdriving and piezoelectric polymers is developed, which generates real-time electric potential feedback (open-circuit potential of ~ 3 mV) duringactuation. The polarization-dominant energy conversion mechanism observed in the MXene-polymer hybrid structure furnishes a new approachfor developing efficient electromagnetic dissipative structures and shows potential for advancing polymeric electromagnetic intelligent devices.

关键词： Microwave absorption Electromagnetic response Energy harvest Self-sensing Soft actuator

Controlling segregation and hardenability of gear steel based on as-cast structure

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2025年第1期32卷 144-158页

作者： Hai-jie Wang ze Zhang Peng Lan Gang chen Pu Wang Chuan-hui Jiang Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Weifang Iron and Steel Group Co. Ltd.Weifang 261000ShandongChina

Hardenability significantly impacts the distortion of gear during heat treatment,correlated to the uniformity of solute distribution in steel *** experimental analysis was conducted on the macrostructure,solute distribution,dendrite structure,and rod hardenability of 20CrMnTiH gear steel in continuously cast blooms and hot roller *** evaluation approach by the standards for the hardenability of gear steel rods and the corresponding blooms was analyzed,and the inheritance mechanism from solidification segregation to hardenability fluctuation of gear steel was *** results indicate that semi-macroscopic spot segregation located in the equiaxed zone exhibits larger size,higher solute enrichment,and worse solute homogeneity,leading to significant solute fluctuations in the blooms and hardenability fluctuation in the *** increasing the liquid steel superheat from 35 to 40℃,reducing the mold electromagnetic stirring from 300 to 100 A,and implementing the soft reduction(SR)of 7 mm at the solidification end,the equiaxed ratio of the strand decreased from 26.42%to 6.69%.Consequently,the solute fluctuation range and standard deviation decrease significantly in the transverse section,while the maximum segregation ratio,average fluctuation range,and average standard deviation of solutes C,Cr,and Mn in the spot segregation decrease at the same *** the meanwhile,the equiaxed ratio of the rod decreased from 24.89%to 4.09%,and the structure of the hardenability detection zone was transformed from equiaxed crystals to columnar ***,the solute fluctuation range and standard deviation in the transverse section decreased,while the homogeneity in spot segregation was also *** hardness difference of A and B surfaces at J9 and J15 positions was smaller than 2 HRC,meeting the qualification standard for hardenability.

关键词： Gear steel Continuous casting Solute distribution Dendritic structure Hardenability