检索结果-南通市图书馆

Defence Technology（防务技术） 2024年第6期36卷 20-29页

作者： Huixin wang Qiang li Hui ren liangjun Xie Tingting liu zhihong Chen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Inner Mongolia Institute of Synthetic Chemicals Hohhot 010010China

Coating modification is an important way to enhance the reactivity of aluminum *** this paper,ammonium perchlorate and aluminum powder were assembled into energetic microunits by liquid deposition *** particles with AP as shell and ultrafine aluminum powder as the core(Al@AP)were *** micromorphology results show that the coated particles are about 5μm,and the coating layer is evenly distributed on the outer surface of aluminum powder,indicating a complete *** energetic microunits were implanted into the nitrate ester plasticizing adhesive system(NEPE)as solid phase *** effect of filler on the rheological properties,safety,mechanical properties,thermal reaction and energy properties of the system was analyzed by comparing with the raw aluminum *** test results show that the rheological properties,mechanical properties and pressure index of NEPE containing system Al@AP meets the requirements of solid propellant *** with Al based propellant,the mechanical sensitivity and thermal sensitivity are decreased,the safety is better,and the explosion heat of the propellant is increased by 7.8%.The engine test shows that the specific impulse is increased by 1.2 ***@AP can improve the energy output and safety of NEPE propellant,and has potential application prospects in high-energy propellants.

关键词： Aluminum powder Coating NEPE propellant Energy output Applied research

Hybrid ion/electron interfacial regulation stabilizes the cobalt/oxygen redox of ultrahigh-voltage lithium cobalt oxide for fast-charging cyclability

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2024年第13期69卷 2071-2079页

作者： zhihong Bi Anping Zhang Gongrui wang Cong Dong Pratteek Das Xiaoyu shi Zhong-Shuai wu State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory of Clean Energy Chinese Academy of SciencesDalian 116023China

High-voltage and fast-charging liCoO_(2)(LCO)is key to high-energy/power-density li-ion ***,unstable surface structure and unfavorable electronic/ionic conductivity severely hinder its high-voltage fast-charging ***,we construct a li/Na-B-Mg-Si-O-F-rich mixed ion/electron interface network on the 4.65 V LCO electrode to enhance its rate capability and long-term cycling ***,the resulting artificial hybrid conductive network enhances the reversible conversion of Co^(3+)/^(4+)/O_(2)/nredox by the interfacial ion–electron cooperation and suppresses interface side reactions,inducing an ultrathin yet compact cathode electrolyte ***,the derived near-surface Na+/Mg2+/Si^(4+)-pillared local intercalation structure greatly promotes the li^(+)diffusion around the 4.55 V phase transition and stabilizes the cathode ***,excellent 3 C(1 C=274 mA g1)fast charging performance is demonstrated with 73.8%capacity retention over 1000 *** findings shed new insights to the fundamental mechanism of interfacial ion/electron synergy in stabilizing and enhancing fast-charging cathode materials.

关键词： High-voltage Fast-charging liCoO_(2) Interfacial ion-electron cooperation Local intercalation

Reoxidation of liquid steel and evolution of inclusions during protective atmosphere electroslag remelting of Ce-containing heat-resistant stainless steel

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 Iron and Steel Research International 2024年第8期31卷 1923-1935页

作者： Yu Zhao Cheng-bin shi shijun wang Peng ren Jing li State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing(USTB)Beijing 100083China

The evolution of Ce-containing inclusions and its correlation with the reoxidation of liquid steel during protective atmosphere electroslag remelting(ESR)of heat-resistant steel were *** reoxidation of liquid steel took place during the ESR,resulting in the oxygen pickup from 0.0014 to 0.0053 wt.%.The inclusions in the consumable electrode,liquid metal pool and remelted ingot are Ce_(2)O_(2)S and Ce_(2)O,inclusions *** inclusions in the remelted ingot are originated from three ways:(I)the original inclusions from the electrode;(Il)the newly formed Ce_(2)O_(2)S and Ce_(2)O_(3) inclusions in the liquid metal pool by reoxidation remaining still in remelted ingot;(Ili)the newly generated Ce2O2S and Ce_(2)O_(3) inclusions during cooling and solidification of liquid *** relative proportions of Ce_(2)O_(3) inclusions in liquid metal pool and remelted ingot are 41% and 76.5%,*** inclusions ranging from 2 to 5μm in the remelted ingot take up 55%,followed by the inclusions smaller than 2μm(43%of total inclusions).The number proportion of the Ce_(2)0,inclusions in the liquid metal pool which were removed by floating up into slag is 1.96×10-5%.

关键词： Non-metallic inclusion Electroslag remelting Rare earth cerium Reoxidation Inclusion evolution

C2-phenyl-substituted benzimidazolium-based covalent organic framework as efficient catalyst for CO_(2) conversion without solvents,metals,and cocatalysts

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第2期67卷 551-557页

作者： Zhenzhen wu Jing wang lili liu Shang Guo Juan li Xianming Zhang Shanxi Institute for Functional Food Shanxi Agricultural UniversityTaiyuan030031China Institute of Crystalline Materials Shanxi UniversityTaiyuan030006China Key Laboratory of Interface Science and Engineering in Advanced Materials College of ChemistryTaiyuan University of TechnologyTaiyuan030024China

Covalent organic frameworks(COFs) are a potential platform for carbon dioxide(CO_(2)) conversion owing to their periodic permanent porosity,adjustable structure,and chemical *** good catalytic performance in CO_(2) conversion,collaborative multifunctions should be strategically integrated into the catalytic system design and *** this study,a four-in-one high-efficiency catalyst was synthesized and tested for CO_(2) cycloaddition to form cyclic *** obtained Tp-MPB-BrCOF had a high nitrogen content,which enhanced its CO_(2) affinity through substantial Lewis acid-base or dipole-quadrupole interactions;moreover,the acid(protons transferring from oxygen(–OH) to nitrogen(–NH)),hydrogen bond donor(hydroxyl group),and Br-(nucleophile group) served as three active sites,further improving the catalyst *** results provide a basis for designing efficient and stable CO_(2)-conversion catalysts.

关键词： covalent organic framework C2-phenyl-substituted benzimidazolium CO_(2)conversion four-in-one catalyst

Simplified quantitative analysis method and its application in the insitu synthesized copper-based azide chips

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 309-316页

作者： Jie ren Yunfeng li Mingyu li Xingyu wu Jiabao wang Qingxuan Zeng State Key Laboratory of Explosion and Technology Beijing Institute of TechnologyBeijing 100081China

Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent ***,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA *** aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition *** this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through *** spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test *** optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content *** with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory ***,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was *** study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.

关键词： Copper-based azide chips Spectrophotometry Separation method Quantitative analysis Ignition ability

Effects of anterior sciatic nerve acupuncture on lower limb paralysis after cerebral infarction:study protocol for a randomized controlled trial

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2024年第1期44卷 205-211页

作者： li Menghan wang Yu RAN Dawei YANG Xinming DENG shizhe shi Lei MENG zhihong Department of Acupuncture First Teaching Hospital of Tianjin University of Traditional Chinese MedicineTianjin 300193China National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion Tianjin 300193China Graduate department Tianjin University of Traditional Chinese MedicineTianjin 301617China Department of Massage and Rehabilitation Second Affiliated Hospital of Tianjin University of Traditional Chinese MedicineTianjin 300250China

Stroke is the main cause of disability in the middle and old ***,especially lower limb paralysis,often leads to the loss of self-care ability and a series of secondary *** main method to improve hemiplegic limb movement is exercise therapy,but there are still many patients with disabilities after rehabilitation *** one of the non-pharmacological therapies for stroke,acupuncture has been recognized to improve motor function in ***,we propose a new method,anterior sciatic nerve acupuncture,which can stimulate both the femoral nerve and the sciatic *** designed this study to determine the effect of this method on lower limb motor *** participants recruited with hemiplegia after cerebral infarction will be randomly assigned to the test group or control group in a 1:1 *** control group will receive Xingnao Kaiqiao acupuncture,and the test group will receive anterior sciatic nerve acupuncture on this *** participants will get acupuncture treatment once a day,6 times a week for 2 *** primary outcome is Fugl-Meyer Assessment of Lower Extremity and the secondary outcomes are Modified Ashworth Scale and Modified Barthel *** will be collected before treatment,1week after treatment,and 2 weeks after treatment,and then statistical analysis will be *** study can preliminarily verify the effect of anterior sciatic nerve acupuncture on improving lower limb motor function in patients with cerebral infarction,which may provide an alternative approach for clinical treatment of hemiplegia.

关键词： anterior sciatic nerve acupuncture paralysis cerebral infarction Xingnao Kaiqiao clinical protocols

Reduced magma generation and its implications for the Pulang giant porphyry Cu-polymetallic deposit in Northwest Yunnan,China

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第4期43卷 802-813页

作者： Jingwei Guan Tao ren Lei wang Shenjin Guan lianrong wu Baosheng shi Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming 650093People’s Republic of China Diqing Nonferrous Metals Co. LtdShangri-La 674400People’s Republic of China

The Pulang giant porphyry Cu-Mo polymetallic deposit is located in the Zhongdian area in the center of the Sanjiang Tethys tectonic domain,which was formed by the westward subduction of the Garze-litang oceanic slab beneath the Zhongza ***-pyrrhotite-pyritemolybdenite occurs as disseminations,veins,veinlets,and stockworks distributed in the K-silicate alteration zone in the monzonite porphyry,which is superimposed by *** chemical compositions of biotite and amphibole analyzed by electron probe microanalysis(EPMA)indicate that the ore-forming magma and exsolved fluids experienced a continuous decrease in the oxygen fugacity(fO_(2)).Primary amphibolite and biotite(type I)crystallized at relatively high temperatures(744-827°C)and low fO_(2)(log fO_(2)=−12.26 to−11.91)during the magmatic *** fluids exsolved from the magma have a relatively lower temperature(621-711°C)and fO_(2)(log fO_(2)=−14.36 to−13.32)than the original *** addition,the presence of a high abundance of pyrrhotite and an insufficiency of primary magnetite and sulfate in the ore(i.e.,anhydrite and gypsum)indicate that the deposit may be a reduced porphyry *** and fluid fO_(2)results,combined with previous research on magmatic fO_(2)at the Pulang deposit,indicate that the magma associated with the reduced Pulang ore assemblages was initially generated as a highly oxidized magma that was subsequently reduced by sedimentary rocks of the Tumugou Formation.

关键词： Porphyry deposit Oxygen fugacity(fO_(2)) Contamination of surrounding rock Pulang Zhongdian arc

Dynamics and data fitting of a time-delayed SIRS hepatitis B model with psychological inhibition factor and limited medical resources

在线全文

学校读者我要写书评

暂无评论

International Journal of Biomathematics 2024年第2期17卷 263-298页

作者： Ximei wang Xinzhi ren Yan wu Yong li School of Information and Mathematics Yangtze University Jingzhou 434023 P.R.China School of Mathematics and Statistics Southwest University Chongqing 400715 P.R.China School of Mathematics and Statistics Lanzhou University Lanzhou 734000 P.R.China

Hepatitis B is an infectious disease worthy of *** the incubation period,psychological inhibition factor,vaccine,limited medical resources and horizontal transmission,an SIRS model is proposed to describe hepatitis B transmission *** order to describe the behavior changes caused by people's psychological changes,the non-monotonic incidence rate is adopted in the *** use the saturated treatment rate to describe the limited medical *** analysis shows the existence conditions of the equilibria,forward or backward bifurcation,Hopf bifurcation and the Bogdanov-Takens *** the observation of the case data of hepatitis B in China,it is found that there are mainly three features,periodic outbreaks,aperiodic outbreaks,and periodic outbreaks turns to aperiodic *** to the above features,we select three different representative regions,Jiangxi,Zhejiang province and Beijing,and then use our model to fit the actual monthly hepatitis B case *** basic reproduction numbers that we estimated are 1.7712,1.4805 and 1.4132,*** results of data fitting are consistent with those of theoretical *** to the sensitivity analysis of Ro,we conclude that reducing contact,increasing treatment rate,strengthening vaccination and revaccinating can effectively prevent and control the prevalence of hepatitis B.

关键词： Hepatitis B SIRS model psychological inhibition factor limited medical resources bifurcation data fitting

Analog spatiotemporal feature extraction for cognitive radio-frequency sensing with integrated photonics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

light(Science & Applications) 2024年第3期13卷 478-487页

作者： shaofu Xu Binshuo liu Sicheng Yi Jing wang Weiwen Zou State Key Laboratory of Advanced Optical Communication Systems and Networks Intelligent Microwave Lightwave Integration Innovation Center(imLic)Department of Electronic EngineeringShanghai Jiao Tong UniversityShanghaiChina

Analog feature extraction(AFE)is an appealing strategy for low-latency and efficient cognitive sensing systems since key features are much sparser than the Nyquist-sampled ***,applying AFE to broadband radio-frequency(RF)scenarios is challenging due to the bandwidth and programmability bottlenecks of analog electronic ***,we introduce a photonics-based scheme that extracts spatiotemporal features from broadband RF signals in the analog *** feature extractor structure inspired by convolutional neural networks is implemented on integrated photonic circuits to process RF signals from multiple antennas,extracting valid features from both temporal and spatial *** of the tunability of the photonic devices,the photonic spatiotemporal feature extractor is trainable,which enhances the validity of the extracted ***,a digital-analog-hybrid transfer learning method is proposed for the effective and low-cost training of the photonic feature *** validate our scheme,we demonstrate a radar target recognition task with a 4-GHz instantaneous *** results indicate that the photonic analog feature extractor tackles broadband RF signals and reduces the sampling rate of analog-to-digital converters to 1/4 of the Nyquist sampling while maintaining a high target recognition accuracy of 97.5%.Our scheme offers a promising path for exploiting the AFE strategy in the realm of cognitive RF sensing,with the potential to contribute to the efficient signal processing involved in applications such as autonomous driving,robotics,and smart factories.

关键词： scheme driving smart