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Complementary monogamy and polygamy properties among multipartite systems
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作者 李陶 周静怡 +3 位作者 孙琪 靳志祥 梁登峰 罗婷 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期207-213,共7页
Monogamy and polygamy relations are essential properties of quantum entanglement,which characterize the distributions of entanglement in multipartite systems.In this paper,we establish the general monogamy relations ... Monogamy and polygamy relations are essential properties of quantum entanglement,which characterize the distributions of entanglement in multipartite systems.In this paper,we establish the general monogamy relations forγ-th(0≤γ≤α,α≥1)power of quantum entanglement based on unified-(q,s)entanglement and polygamy relations forδ-th(δ≥β,0≤β≤1)power of entanglement of assistance based on unified-(q,s)entanglement of assistance,which provides a complement to the previous research in terms of different parameter regions ofγandδ.These results are then applied to specific quantum correlations,e.g.,entanglement of formation,Renyi-q entanglement of assistance and Tsallis-q entanglement of assistance to get the corresponding monogamy and polygamy inequalities.Moreover,typical examples are presented for illustration. 展开更多
关键词 monogamy relation polygramy relation
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叔胺型响应表面活性剂的合成及性能研究
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作者 张鑫 张光华 +3 位作者 孙棋 李慧 唐明旋 郭泽华 《日用化学工业(中英文)》 CAS 北大核心 2023年第11期1250-1256,共7页
以油酸和N,N-二甲基-1,3-丙二胺为原料,氟化钠为催化剂,合成了一种具有CO_(2)响应性的长链叔胺(油酸酰胺丙基二甲基叔胺(DMOA)),测定了其通入CO_(2)和N2下的电导率,证实了合成的DMOA溶液具有CO_(2)响应性能。测定了在通入CO_(2)下DMOA... 以油酸和N,N-二甲基-1,3-丙二胺为原料,氟化钠为催化剂,合成了一种具有CO_(2)响应性的长链叔胺(油酸酰胺丙基二甲基叔胺(DMOA)),测定了其通入CO_(2)和N2下的电导率,证实了合成的DMOA溶液具有CO_(2)响应性能。测定了在通入CO_(2)下DMOA与反离子复配的表面张力,发现将DMOA与二元反离子草酸钠复配能显著降低溶液的表面张力。研究了DMOA与草酸钠复配体系的黏度的CO_(2)响应性能,结果表明,复配体系能够显著提高体系的黏度,并具有CO_(2)响应性和循环可逆性。研究了复配体系的起泡性能和在石蜡膜上的接触角,发现在通入了CO_(2)条件下,复配体系能够降低起泡性能和与疏水表面的接触角。 展开更多
关键词 开关表面活性剂 CO_(2)开关 可逆响应 叔胺基 反离子
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Phase separation-hydrogen etching-derived Cu-decorated Cu-Mn bimetallic oxides with oxygen vacancies boosting superior sodium-ion storage kinetics 被引量:1
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作者 Lin Yan Lingshuo Zong +6 位作者 qi sun Junpeng Guo Zhenyang Yu Zhijun qiao Jiuhui Han Zhenyu Cui Jianli Kang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第5期163-173,I0005,共12页
Understanding the crystal phase evolution of bimetallic oxide anodes is the main concern to profoundly reveal the conversion reaction kinetics and sodium-ion storage mechanisms.Herein,an integrated selfsupporting anod... Understanding the crystal phase evolution of bimetallic oxide anodes is the main concern to profoundly reveal the conversion reaction kinetics and sodium-ion storage mechanisms.Herein,an integrated selfsupporting anode of the Cu-decorated Cu-Mn bimetallic oxides with oxygen vacancies(Ov-BMO-Cu)are in-situ generated by phase separation and hydrogen etching using nanoporous Cu-Mn alloy as selfsacrificial templates.On this basis,we have elucidated the relationship between the phase evolution,oxygen vacancies and sodium-ion storage mechanisms,further demonstrating the evolution of oxygen vacancies and the inhibition effect of manganese oxides as an“anchor”on grain aggregation of copper oxides.The kinetic analyses confirm that the expanded lattice space and increased oxygen vacancies of cycled Ov-BMO-Cu synergistically guarantee effective sodium-ion diffusion and storage mechanisms.Therefore,the Ov-BMO-Cu electrode exhibits higher reversible capacities of 4.04 mA h cm^(-2)at 0.2 mA cm^(-2)after 100 cycles and 2.20 m A h cm^(-2)at 1.0 mA cm^(-2)after 500 cycles.Besides,the presodiated Ov-BMO-Cu anode delivers a considerable reversible capacity of 0.79 m A h cm^(-2)at 1.0 mA cm^(-2)after 60 cycles in full cells with Na_(3)V_(2)(PO_(4))_(3)cathode,confirming its outstanding practicality.Thus,this work is expected to provide enlightenment for designing high-capacity bimetallic oxide anodes. 展开更多
关键词 Sodium-ion storage mechanism Bimetallic oxide anode material Crystal phase evolution Oxygen vacancies Kinetic analyses
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Towards the Deep Convergence of Communication and Computing in RAN: Scenarios, Architecture, Key Technologies, Challenges and Future Trends 被引量:1
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作者 Nan Li qi sun +5 位作者 Xiang Li Fengxian Guo Yuhong Huang Ziqi Chen Yiwei Yan Mugen Peng 《China Communications》 SCIE CSCD 2023年第3期218-235,共18页
To accommodate the diversified emerging use cases in 5G,radio access networks(RAN)is required to be more flexible,open,and versatile.It is evolving towards cloudification,intelligence and openness.By embedding computi... To accommodate the diversified emerging use cases in 5G,radio access networks(RAN)is required to be more flexible,open,and versatile.It is evolving towards cloudification,intelligence and openness.By embedding computing capabilities within RAN,it helps to transform RAN into a natural cost effective radio edge computing platform,offering great opportunity to further enhance RAN agility for diversified services and improve users’quality of experience(Qo E).In this article,a logical architecture enabling deep convergence of communication and computing in RAN is proposed based on O-RAN.The scenarios and potential benefits of sharing RAN computing resources are first analyzed.Then,the requirements,design principles and logical architecture are introduced.Involved key technologies are also discussed,including heterogeneous computing infrastructure,unified computing and communication task modeling,joint communication and computing orchestration and RAN computing data routing.Followed by that,a VR use case is studied to illustrate the superiority of the joint communication and computing optimization.Finally,challenges and future trends are highlighted to provide some insights on the potential future work for researchers in this field. 展开更多
关键词 RAN computing resource sharing com-munication and computing joint design
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Discovery and genome-guided mapping of REN12 from Vitis amurensis, conferring strong, rapid resistance to grapevine powdery mildew 被引量:1
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作者 Surya Sapkota Cheng Zou +4 位作者 Craig Ledbetter Anna Underhill qi sun David Gadoury Lance Cadle-Davidson 《Horticulture Research》 SCIE CSCD 2023年第5期139-149,共11页
Powdery mildew resistance genes restrict infection attempts at different stages of pathogenesis.Here,a strong and rapid powdery mildew resistance phenotype was discovered from Vitis amurensis‘PI 588631’that rapidly ... Powdery mildew resistance genes restrict infection attempts at different stages of pathogenesis.Here,a strong and rapid powdery mildew resistance phenotype was discovered from Vitis amurensis‘PI 588631’that rapidly stopped over 97%of Erysiphe necator conidia,before or immediately after emergence of a secondary hypha from appressoria.This resistance was effective across multiple years of vineyard evaluation on leaves,stems,rachises,and fruit and against a diverse array of E.necator laboratory isolates.Using core genome rhAmpSeq markers,resistance mapped to a single dominant locus(here named REN12)on chromosome 13 near 22.8–27.0 Mb,irrespective of tissue type,explaining up to 86.9%of the phenotypic variation observed on leaves.Shotgun sequencing of recombinant vines using skim-seq technology enabled the locus to be further resolved to a 780 kb region,from 25.15 to 25.93 Mb.RNASeq analysis indicated the allele-specific expression of four resistance genes(NLRs)from the resistant parent.REN12 is one of the strongest powdery mildew resistance loci in grapevine yet documented,and the rhAmpSeq sequences presented here can be directly used for marker-assisted selection or converted to other genotyping platforms.While no virulent isolates were identified among the genetically diverse isolates and wild populations of E.necator tested here,NLR loci like REN12 are often race-specific.Thus,stacking of multiple resistance genes and minimal use of fungicides should enhance the durability of resistance and could enable a 90%reduction in fungicides in low-rainfall climates where few other pathogens attack the foliage or fruit. 展开更多
关键词 VITIS RESISTANCE durability
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Convenient design of anti-wetting nano-Al/WO_(3)metastable intermolecular composites(MICs)with an enhanced exothermic life-span
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作者 Xiaogang Guo Taotao Liang +5 位作者 Junfeng Guo Huisheng Huang Shuying Kong Jianwei Shi Binfang Yuan qi sun 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第2期84-92,共9页
For solving the dilemma of the short exothermic life-span of WO_(3)based metastable interstitial composites(MICs)with extensive application prospect,this paper has firstly designed the promising antiwetting Al/WO_(3)M... For solving the dilemma of the short exothermic life-span of WO_(3)based metastable interstitial composites(MICs)with extensive application prospect,this paper has firstly designed the promising antiwetting Al/WO_(3)MICs via electrophoresis assembly of nano-Al and WO_(3)particles fabricated by hydrothermal synthesis method,followed by the subsequent fluorination treatment.A combination of X ray diffraction(XRD),field emission scanning electron microscope(FESEM),energy dispersive X-ray spectroscopy(EDX),and Fourier transform infrared spectroscopy(FT-IR)techniques were utilized in order to characterize the crystal structure,microstructure,and elemental composition distribution of target films after different natural exposure tests.The product with uniform distribution and high purity possesses a high contact angle of~170°and a minute sliding angle of~1°,and displays the outstanding anti-wetting property using droplets with different surface tensions.It also shows great moisture stability in high relative-humidity circumstances after one year of the natural exposure experiment.Notably,the heat output of a fresh sample can reach up to 2.3 kJ/g and retain 96%after the whole exposure test,showing outstanding thermo-stability for at least one year.This work further proposed the mechanism of antiwetting Al/WO_(3)MICs considering the variation tendency of their DSC curve,providing a valuable theoretical reference for designing other self-protected MICs with a long exothermic life-span applied in wide fields of national defense,military industry,etc. 展开更多
关键词 Electrophoresis assembly Al/WO_(3)MICs Fluorination treatment Anti-wetting property Exothermic life-span
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Multi-dimensional size effects and representative elements for nonpersistent fractured rock masses: A perspective of geometric parameter distribution
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作者 Jia Wang Wen Zhang +4 位作者 Chun Tan Zhenbang Nie Wenliang Ma Donghui Chen qi sun 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第9期2339-2354,共16页
This study takes a fractured rock mass in the Datengxia Hydropower Station,China as an example to analyze the size effects and determine the representative elementary sizes.A novel method considering geometric paramet... This study takes a fractured rock mass in the Datengxia Hydropower Station,China as an example to analyze the size effects and determine the representative elementary sizes.A novel method considering geometric parameter distributions is proposed in this work.The proposed method can quickly and simply determine the size effects and representative elementary sizes.Specifically,geometric parameter distributions,including fracture frequency,size and orientation,are generated on the basis of the Bernoulli trial and Monte Carlo simulation.The distributions are assessed using the coefficient of variation(CV),and the acceptable variations for CV(5%,10%and 20%)are used to determine representative elementary sizes.Generally,the representative element of rock masses is the representative elementary volume(REV).The present study extends the representative element to other dimensions,i.e.representative elementary length(REL)and representative elementary area(REA)for one and two dimensions,respectively.REL and REA are useful in studying the size effects of one-(1D)and twodimensional(2D)characteristics of rock masses.The relationships among multi-dimensional representative elementary sizes are established.The representative elementary sizes reduce with the increase in the dimensions,and REA and REV can be deduced by REL.Therefore,the proposed method can quickly and simply determine REL and further estimate REA and REV,which considerably improves the efficiency of rock mass analysis. 展开更多
关键词 Size effect Discrete fracture network(DFN) Stochastic mathematics ANISOTROPY Coefficient of variation(CV)
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Recent advances in solid-state metal-air batteries
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作者 qi sun Lei Dai +3 位作者 Tingting Luo Ling Wang Feng Liang Shan Liu 《Carbon Energy》 SCIE CSCD 2023年第2期148-170,共23页
Solid-state metal-air batteries have emerged as a research hotspot due to their high energy density and high safety.Moreover,side reactions caused by infiltrated gases(O_(2),H_(2)O,or CO_(2))and safety issues caused b... Solid-state metal-air batteries have emerged as a research hotspot due to their high energy density and high safety.Moreover,side reactions caused by infiltrated gases(O_(2),H_(2)O,or CO_(2))and safety issues caused by liquid electrolyte leakage will be eliminated radically.However,the solid-state metal–air battery is still in its infancy,and many thorny problems still need to be solved,such as the large resistance of the metal/electrolyte interface and catalyst design.This review will summarize some important progress and key issues for solid-state metal-air batteries,especially the lithium-,sodium-,and zinc-based metal-air batteries,clarify some core issues,and forecast the future direction of the solid-state metal-air batteries. 展开更多
关键词 cathode structure interface stability metal anode metal-air batteries solid electrolyte
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Unified entropy entanglement with tighter constraints on multipartite systems
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作者 孙琪 李陶 +1 位作者 靳志祥 梁登峰 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期96-101,共6页
Monogamy and polygamy relations characterize the distributions of entanglement in multipartite systems.We provide a characterization of multiqubit entanglement constraints in terms of unified-(q,s)entropy.A class of t... Monogamy and polygamy relations characterize the distributions of entanglement in multipartite systems.We provide a characterization of multiqubit entanglement constraints in terms of unified-(q,s)entropy.A class of tighter monogamy inequalities of multiqubit entanglement based on theα-th power of unified-(q,s)entanglement forα≥1 and a class of polygamy inequalities in terms of theβ-th power of unified-(q,s)entanglement of assistance are established in this paper.Our results present a general class of the monogamy and polygamy relations for bipartite entanglement measures based on unified-(q,s)entropy,which are tighter than the existing ones.What is more,some usual monogamy and polygamy relations,such as monogamy and polygamy relations based on entanglement of formation,Renyi-q entanglement of assistance and Tsallis-q entanglement of assistance,can be obtained from these results by choosing appropriate parameters(q,s)in unified-(q,s)entropy entanglement.Typical examples are also presented for illustration. 展开更多
关键词 ENTANGLEMENT monogamy relations polygamy relations
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Neutralization of excessive levels of active TGF-β1 reduces MSC recruitment and differentiation to mitigate peritendinous adhesion
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作者 Yu Sheng Li Xiao Wang +5 位作者 Bo Hu qi sun Mei Wan Andrew Carr Shen Liu Xu Cao 《Bone Research》 SCIE CAS CSCD 2023年第2期368-383,共16页
PPeritendinous adhesion formation(PAF)can substantially limit the range of motion of digits.However,the origin of myofibroblasts in PAF tissues is still unclear.In this study,we found that the concentration of active ... PPeritendinous adhesion formation(PAF)can substantially limit the range of motion of digits.However,the origin of myofibroblasts in PAF tissues is still unclear.In this study,we found that the concentration of active TGF-β1 and the numbers of macrophages,mesenchymal stromal cells(MSCs),and myofibroblasts in human and mouse adhesion tissues were increased.Furthermore,knockout of TGF-β1 in macrophages or TGF-β1R2 in MSCs inhibited PAF by reducing MSC and myofibroblast infiltration and collagenⅠandⅢdeposition,respectively.Moreover,we found that MSCs differentiated into myofibroblasts to form adhesion tissues.Systemic injection of the TGF-β–neutralizing antibody 1D11 during the granulation formation stage of PAF significantly reduced the infiltration of MSCs and myofibroblasts and,subsequently,PAF.These results suggest that macrophage-derived TGF-β1 recruits MSCs to form myofibroblasts in peritendinous adhesions.An improved understanding of PAF mechanisms could help identify a potential therapeutic strategy. 展开更多
关键词 inhibited INJECTION MSC
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Straight-Path Following and Formation Control of USVs Using Distributed Deep Reinforcement Learning and Adaptive Neural Network
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作者 Zhengqing Han Yintao Wang qi sun 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第2期572-574,共3页
Dear Editor,This letter presents a distributed deep reinforcement learning(DRL) based approach to deal with the path following and formation control problems for underactuated unmanned surface vehicles(USVs). By const... Dear Editor,This letter presents a distributed deep reinforcement learning(DRL) based approach to deal with the path following and formation control problems for underactuated unmanned surface vehicles(USVs). By constructing two independent actor-critic architectures,the deep deterministic policy gradient(DDPG) method is proposed to determine the desired heading and speed command for each USV. 展开更多
关键词 DEEP POLICY HEADING
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Intelligent acupuncture:data-driven revolution of traditional Chinese medicine
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作者 Yunfan Bao Haokang Ding +4 位作者 Zhihan Zhang Kunhuan Yang Queena Tran qi sun Tiancheng Xu 《Acupuncture and Herbal Medicine》 2023年第4期271-284,共14页
Acupuncture,a form of traditional Chinese medicine with a history of 2,000 years in China,has gained wider acceptance worldwide as a complementary therapy.Studies have examined its effectiveness in various health cond... Acupuncture,a form of traditional Chinese medicine with a history of 2,000 years in China,has gained wider acceptance worldwide as a complementary therapy.Studies have examined its effectiveness in various health conditions and it is commonly used alongside conventional medical treatments.With the development of artificial intelligence(AI)technology,new possibilities for improving the efficacy and precision of acupuncture have emerged.This study explored the combination of traditional acupuncture and AI technology from three perspectives:acupuncture diagnosis,prescription,and treatment evaluation.The study aimed to provide cutting-edge direction and theoretical assistance for the development of an acupuncture robot. 展开更多
关键词 ACUPUNCTURE Artificial intelligence Knowledge graph Graphical abstract:http://links.lww.com/AHM/A68
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氮掺杂多孔石墨烯对硝基和偶氮化合物的催化还原性能——化学相关专业综合实验的设计与实践
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作者 奚江波 孙琦 +1 位作者 王刚 陈伟 《大学化学》 CAS 2023年第5期220-226,共7页
针对溶有常见含硝基和偶氮化合物废水处理的问题,设计了无金属碳基催化剂制备及其对此类化合物催化还原的综合实验。实验以氧化石墨烯为原料,经水热法合成碳基催化剂氮掺杂多孔石墨烯或氮掺杂石墨烯,通过扫描电子显微镜、透射电子显微... 针对溶有常见含硝基和偶氮化合物废水处理的问题,设计了无金属碳基催化剂制备及其对此类化合物催化还原的综合实验。实验以氧化石墨烯为原料,经水热法合成碳基催化剂氮掺杂多孔石墨烯或氮掺杂石墨烯,通过扫描电子显微镜、透射电子显微镜、比表面分析仪、X射线光电子能谱等对其结构、形貌和元素组成等进行表征,并研究其对硼氢化钠还原硝基和偶氮化合物的性能。该实验涉及碳基催化剂制备、表征和废水处理等多个实验环节,涵盖了物理化学、材料化学和环境化学等多个学科领域。通过该实验可以培养学生的科研思维,提高学生的科研动手能力和用化学知识解决实际问题的能力。 展开更多
关键词 氮掺杂多孔石墨烯 无金属催化 硝基和偶氮化合物 还原反应 综合实验
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新一代微测序基因芯片的设计及其耐药性检测效果的初步研究 被引量:6
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作者 孙照刚 张洪静 +7 位作者 李自慧 孙琦 吕琳娜 潘丽萍 Sandy Gilbert 张宗德 许绍发 James Xia 《中国防痨杂志》 CAS CSCD 2019年第6期609-615,共7页
目的设计和评价微测序基因芯片检测结核分枝杆菌(MTB)耐药性的价值。方法于北京结核病临床数据和样本资源库选取MTB实验室标准菌株(H37Rv)和109株MTB临床分离株,采用绝对浓度法进行表型药物敏感性试验(简称“表型药敏试验”)和基因测序... 目的设计和评价微测序基因芯片检测结核分枝杆菌(MTB)耐药性的价值。方法于北京结核病临床数据和样本资源库选取MTB实验室标准菌株(H37Rv)和109株MTB临床分离株,采用绝对浓度法进行表型药物敏感性试验(简称“表型药敏试验”)和基因测序法检测MTB耐药相关基因突变(包括inhA、katG、rpsL、gyrA、rrs、eis、rpoB和embB基因)。以荧光标记探针为基本检测原理设计制备微测序基因芯片,检测109株MTB临床分离株耐药基因突变,分析微测序基因芯片的检测效能。结果通过表型药敏试验及基因测序检测,明确了109株MTB临床分离株耐药相关基因(inhA、katG、rpsL、gyrA、rrs、eis、rpoB和embB基因)突变位点及突变形式。微测序耐药检测基因芯片初期设计包含了katG、inhA、rpoB、gyrA、embB、rpsL、rrs和eis基因的目前已报道的所有突变位点的全部已知突变形式,共计220条探针,并确认出67条优秀探针。采用包含67条探针的微测序耐药检测基因芯片对109株MTB临床分离株进行检测。结果发现,与测序结果相比,除检测embB基因突变的2条探针外,其余65条探针检测碱基突变形式的符合率均超过95%,其中42条探针检测的符合率达到100.00%。以测序结果为参照标准,基因芯片检测对embB基因、gyrA基因、inhA基因、katG基因、rpoB基因、rpsL基因、eis基因和rrs基因突变检测的敏感度分别为64.21%(61/95)、80.00%(8/10)、95.83%(23/24)、98.55%(68/69)、92.63%(88/95)、93.85%(61/65)、75.00%(3/4)和94.44%(17/18);特异度分别为92.86%(13/14)、100.00%(99/99)、97.65%(83/85)、87.50%(35/40)、85.71%(12/14)、63.64%(28/44)、100.00%(105/105)和98.90%(90/91);Kappa值分别为0.29、0.88、0.92、0.88、0.68、0.60、0.85、0.93。结论本研究研发设计了一套包含67条探针微测序耐药基因检测芯片,经过初步验证后证明其检测MTB耐药相关基因突变的效能较好,对embB基因的耐药检测探针还需进一步优化,使之更好的满足临床需求。 展开更多
关键词 分枝杆菌 结核 结核 抗多种药物性 微生物敏感性试验 基因 突变 芯片分析技术 技术评估 生物医学
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基于Kriging模型的快速拆装叶轮轮盘多目标优化设计 被引量:11
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作者 冀春俊 徐浩 +1 位作者 孙琦 孙淼 《风机技术》 2017年第3期44-48,共5页
为了降低叶轮安装端面变形量以及减轻叶轮质量,对快速拆装形式的叶轮轮盘结构进行多目标优化设计,使用拉丁超立方试验设计和有限元分析生成初始样本数据并构造出Kriging近似模型,运用遗传算法对近似模型进行寻优。对优化后的参数值进行... 为了降低叶轮安装端面变形量以及减轻叶轮质量,对快速拆装形式的叶轮轮盘结构进行多目标优化设计,使用拉丁超立方试验设计和有限元分析生成初始样本数据并构造出Kriging近似模型,运用遗传算法对近似模型进行寻优。对优化后的参数值进行工程取整并进行有限元分析得出叶轮轮盘结构设计模型,最终优化结果显示叶轮质量减小了15%,叶轮摩擦端面轴向变形量降低了29%。优化后的叶轮模型可提高拉杆螺栓连接转子结构的可靠性。 展开更多
关键词 快速拆装叶轮 优化设计 KRIGING模型
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离心压缩机扩压器进口流动研究
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作者 冀春俊 孙淼 +2 位作者 孙琦 徐浩 卜庆团 《风机技术》 2017年第5期26-31,共6页
以某制冷用离心压缩机模型级为研究对象,利用数值模拟的方法,对其扩压器进口真实模型进行了详细分析,考察其形状对间隙泄漏量与主流道流动的影响。建立了主流道与密封腔的真实模型,分析发现密封腔的存在对流动造成了很大影响,且扩压器... 以某制冷用离心压缩机模型级为研究对象,利用数值模拟的方法,对其扩压器进口真实模型进行了详细分析,考察其形状对间隙泄漏量与主流道流动的影响。建立了主流道与密封腔的真实模型,分析发现密封腔的存在对流动造成了很大影响,且扩压器进口形状对内部流动有一定扰动作用。在此基础上,进行了扩压器进口的改进设计。通过分析改进前后结果发现,减小扩压器进口面积能有效减小密封腔对主流道流动的影响,提高模型级效率与压比,但同时也会造成密封泄漏量的增加。 展开更多
关键词 离心压缩机 扩压器进口 数值模拟 优化设计
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双中心多孔聚合物作为多相催化剂实现CO_(2)在温和条件下高效转化 被引量:2
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作者 戴志锋 唐永铨 +7 位作者 张飞 熊玉兵 王赛 孙琦 王亮 孟祥举 赵雷洪 肖丰收 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第4期618-626,共9页
由于对化石燃料的高度依赖和二氧化碳(CO_(2))的过度排放,大气中CO_(2)浓度从280 ppm上升到400 ppm左右,导致全球变暖和其他气候问题.在这种情况下,如何有效降低空气中的CO_(2)浓度成为近年来最迫切的研究领域之一.另一方面,作为一种无... 由于对化石燃料的高度依赖和二氧化碳(CO_(2))的过度排放,大气中CO_(2)浓度从280 ppm上升到400 ppm左右,导致全球变暖和其他气候问题.在这种情况下,如何有效降低空气中的CO_(2)浓度成为近年来最迫切的研究领域之一.另一方面,作为一种无毒、廉价且丰富的C1资源,CO_(2)也可以转化为各种高附加值的工业产品,如甲酸、一氧化碳、甲烷、甲醇以及碳酸酯等.其中CO_(2)与环氧化物转化生成环碳酸酯的环加成反应具有良好原子经济性,在近年来引起了人们的广泛关注.尽管已有多种多相和均相催化剂应用于该反应,但已有的催化剂特别是多相催化剂往往具有反应条件苛刻、催化剂易损失以及需要可溶性的共催化剂等缺点,从而限制了它们的进一步实际应用.因此,发展多相催化剂实现在温和和无共催化剂条件下的CO_(2)环加成转化仍是一个挑战.本文通过自由基共聚的方法,以乙烯基功能化的金属卟啉和季膦盐作为单体制备了一种新型多孔有机聚合物(POP-PBnCl-TPPMg-x).考虑到金属卟啉和季膦盐常作为CO_(2)环加成反应中的Lewis酸和Lewis碱活性中心,我们通过自由基共聚实现了这两种活性中心在分子水平上的结合与协同.所得的催化剂的组成和结构通过固体核磁、X射线光电子能谱、氮气吸附、扫描电子显微镜、透射式电子显微镜等手段进行了表征.值得指出的是,所得多相催化剂具有良好的CO_(2)吸附与富集效应,十分有利于CO_(2)的催化转化.我们以温和(40℃和1 atm CO_(2))并没有任何无可溶性共催化剂存在条件下,进行CO_(2)与环氧化物的环加成作为探针反应,测试了不同催化剂的催化活性.以催化剂POP-PBnCl-TPPMg-12为例,其催化活性远超过单组分的POP-PBnCl和POP-TPPMg多相催化剂,也超过了二者机械混合的POP-PBnCl+POP-TPPMg-12催化剂,接近均相催化剂PBnCl+TPPMg-12的水平.这表明通过共聚合方法所得到的催化剂可以实现Lewis酸和Lewis碱两种活性中心的分子水平的结合.本文进一步研究了多相催化剂POP-PBnCl-TPPMg-12和均相催化剂PBnCl+TPPMg-12在低浓度CO_(2)(15%N2 v/v,工业废气中CO_(2)的浓度)条件下的催化活性,发现在该条件下多相催化剂表现出比均相催化剂更为优异的催化转化性能,且展现出良好的稳定性和循环使用性能,在循环使用5次后仍无明显的活性损失.该催化剂所具有的多相特点和优良的催化性能,因而有望成为实现工业CO_(2)脱除并转化成高附加值产品的潜在高效催化剂. 展开更多
关键词 共聚 多孔有机聚合物 双活性中心 CO_(2)固定 多相催化
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内镜切除治疗食管神经鞘瘤的效果 被引量:1
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作者 姜经伟 孙琦 +7 位作者 倪牧含 许真真 曹守莉 凌亭生 王雷 邹晓平 吕瑛 徐桂芳 《中国内镜杂志》 2021年第7期65-70,共6页
目的探讨食管神经鞘瘤的临床病理特点,以及内镜黏膜下剥离术(ESD)和内镜经黏膜下隧道肿瘤切除术(STER)切除食管神经鞘瘤的效果。方法回顾性分析2007年8月-2019年7月南京大学医学院附属鼓楼医院消化科收治的11例食管神经鞘瘤患者的临床... 目的探讨食管神经鞘瘤的临床病理特点,以及内镜黏膜下剥离术(ESD)和内镜经黏膜下隧道肿瘤切除术(STER)切除食管神经鞘瘤的效果。方法回顾性分析2007年8月-2019年7月南京大学医学院附属鼓楼医院消化科收治的11例食管神经鞘瘤患者的临床特征、内镜下表现、术后并发症和病理特点。结果男患者占54.5%;年龄40~81岁,平均(57.5±12.4)岁;食管神经鞘瘤多位于胸上段(45.5%,5/11)和胸中段(27.3%,3/11);11例(100.0%)病灶的白光内镜分型均为隆起型,表面黏膜光滑、无溃疡。肿瘤直径为0.3~5.0 cm,平均(2.5±1.8)cm;超声内镜(EUS)显示10例(90.9%)起源于固有肌层,11例均为低回声,9例(81.8%)回声均匀;11例EUS下均无血流信号,6例(54.5%)为腔内生长,5例(45.5%)腔内外生长。完整切除率为100.0%(11/11),中位手术时间41 min,11例患者(100.0%)均未出现穿孔、迟发性出血和感染等并发症;术后首次进流食时间为(1.2±0.6)d;平均住院时间为(6.9±2.5)d。所有组织标本中S100均为阳性;中位随访时间为53个月,期间未发生局部复发、远处转移和死亡。结论ESD和STER用于诊断和治疗食管神经鞘瘤是安全、有效的。 展开更多
关键词 食管神经鞘瘤 内镜黏膜下剥离术 内镜经黏膜下隧道肿瘤切除术 超声内镜 S100
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离心压气机不同进气方案的数值计算验证 被引量:2
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作者 房骏翌 冀春俊 +2 位作者 孙琦 刘君男 张雪薇 《风机技术》 2020年第3期15-21,共7页
通过数值模拟将一台径向进气的离心压气机,重新设计流道改为轴向进气且增加了回流器,使之同现有的轴向进气实验台进行匹配连接,并进行实验验证。通过对比计算,表明轴向进气方案比原始的径向进气方案设计点的等熵效率降低0.27%,压比降低0... 通过数值模拟将一台径向进气的离心压气机,重新设计流道改为轴向进气且增加了回流器,使之同现有的轴向进气实验台进行匹配连接,并进行实验验证。通过对比计算,表明轴向进气方案比原始的径向进气方案设计点的等熵效率降低0.27%,压比降低0.48%,喘振点基本一致,阻塞流量减小0.18%,整体特性曲线基本吻合,实验结果符合设计预期。证明了通过改变流道使径向进气压气机与轴向进气的实验台直接连接的实验方案是可靠的,为后续的实验提供参考依据。此外,还分析了两种方案结果差异的产生机理,为其他压气机设计提供参考思路。 展开更多
关键词 数值模拟 离心压气机 实验 特性曲线 喘振 阻塞
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改性钛基PbO_(2)电极的制备及其对COD的快速检测 被引量:2
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作者 孙齐 韩严和 付晓璐 《电化学》 CAS CSCD 北大核心 2021年第5期558-569,共12页
通过制备Ti/α/β-PbO_(2)、Ti/Ag/β-PbO_(2)这两种含有不同中间层的钛基二氧化铅电极来探究电催化氧化技术快速测定葡萄糖模拟废水中有机物(COD)含量的可行性。为了评估两种电极的各项性能,首先采用扫描电镜(SEM)、X射线衍射(XRD)对... 通过制备Ti/α/β-PbO_(2)、Ti/Ag/β-PbO_(2)这两种含有不同中间层的钛基二氧化铅电极来探究电催化氧化技术快速测定葡萄糖模拟废水中有机物(COD)含量的可行性。为了评估两种电极的各项性能,首先采用扫描电镜(SEM)、X射线衍射(XRD)对电极进行形貌表征,其次进行电化学性能测试包括线性伏安曲线(LSV)、塔菲尔曲线(Tafel)、循环伏安曲线(CV)以及交流阻抗测量分析。结果表明,Ti/α/β-PbO_(2)电极表面晶体结构更加均匀,晶粒尺寸偏小,具有更大的电活性表面积。Ti/α/β-PbO_(2)电极的析氧电位为1.77 V,为·OH的产生提供良好条件。在Tafel、CV测试中,Ti/α/β-PbO_(2)电极的交换电流密度i0及比电容Cp分别为0.0995 A·cm^(-1)、0.004098 F·cm^(-1)均高于Ti/Ag/β-PbO_(2)电极,说明Ti/α/β-PbO_(2)电极的耐腐蚀性以及释放电子的能力优异。最终选用Ti/α/β-PbO_(2)电极为工作电极。Ti/α/β-PbO_(2)电极检测COD的最佳条件为:氧化电位1.30 V、电解时间150 s、电解液浓度0.03 mol·L^(-1)硝酸钠(NaNO3)。电化学法与比色消解法测定COD的相关系数可达0.9909,同时具有良好的重现性与相关性,COD的检测范围为0 mg·L^(-1)~500 mg·L^(-1)。在误差允许的范围内可以替代标准的重铬酸钾法,为实现COD的在线快速检测提供参考价值。 展开更多
关键词 二氧化铅电极 COD检测 电催化氧化 电极制备与表征
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