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Cretaceous lacewing larvae with binocular vision demonstrate the convergent evolution of sophisticated simple eyes
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作者 Carolin Haug Florian Braig +7 位作者 Simon J.Linhart Derek E.G.Briggs Roland R.Melzer Alejandro Caballero Yanzhe Fu Gideon T.Haug Marie K.Hörnig Joachim T.Haug 《Insect Science》 2026年第1期441-452,共12页
Many insects and their relatives are renowned for sophisticated compound eyes,which are also preserved in the fossil record.Yet there are other types of eyes,notably the so-called stemmata of holometabolans,such as be... Many insects and their relatives are renowned for sophisticated compound eyes,which are also preserved in the fossil record.Yet there are other types of eyes,notably the so-called stemmata of holometabolans,such as beetles,bees,and butterflies.Stemmata are not as effective as compound eyes,except in some predatory larvae.Here we report three lacewing larvae with large forward-directed stemmata from Cretaceous Kachin amber,Myanmar.The stemmata are large relative to those of other fossil lacewing larvae,comparable to the simple eyes of modern larvae capable of image formation.The head is very wide in one larva,representing a new type of morphology as demonstrated by a quantitative comparison of the head and stylets of over 400 fossil and extant lacewing larvae.The arrangement of the exceptionally large stemmata of the larvae reported here provides stereoscopic vision.These new specimens demonstrate the convergent evolution of highly developed simple eyes in at least two additional lineages of lacewings,showcasing the enormous diversity of lacewing larvae in the Cretaceous. 展开更多
关键词 Burmese amber CRETACEOUS lacewing larvae Myanmar amber NEUROPTERA stemmata
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Seeing amyotrophic lateral sclerosis in a multi-omic perspective
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作者 Natalie Dikwella Paul Lingor Laura Tzeplaeff 《Neural Regeneration Research》 2026年第8期3567-3568,共2页
Amyotrophic lateral sclerosis(ALS)is a rapidly progressing neurodegenerative disease,leading to muscle weakness,paralysis and ultimately death due to respiratory failure.Currently licensed drugs have only very limited... Amyotrophic lateral sclerosis(ALS)is a rapidly progressing neurodegenerative disease,leading to muscle weakness,paralysis and ultimately death due to respiratory failure.Currently licensed drugs have only very limited effects on slowing down disease progression or biomarkers.Despite numerous successful preclinical analyses,most new drugs fail when translated to clinical trials(Petrov et al.,2017).This is believed to be,in part,due to the multilayer heterogeneity of ALS(e.g.,clinical,genetic,and molecular;Tzeplaeff et al.,2024).Studies integrating multi-omic data are still limited,making it difficult to fully understand the biological complexity that characterizes the disease. 展开更多
关键词 amyotrophic lateral sclerosis als clinical trials petrov multi omic PARALYSIS muscle weakness neurodegenerative diseaseleading amyotrophic lateral sclerosis neurodegenerative disease
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Self-propelled biomotors co-deliver doxorubicin liposomes and aPD-1 antibody to fight breast cancer
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作者 Jia Wang Yunxiu Fan +9 位作者 Shilin Xu Zhouxue Wu Tian Hu Yun Lu Yue Li Kang Xiong Hongjun Deng Jingrong Huang Bo Yang Shaozhi Fu 《Chinese Chemical Letters》 2026年第2期375-378,共4页
Although the combination of chemotherapy and immunotherapy can improve the treatment of breast cancer,traditional drugs are highly toxic because they do not specifically target tumors.In this study,we developed a self... Although the combination of chemotherapy and immunotherapy can improve the treatment of breast cancer,traditional drugs are highly toxic because they do not specifically target tumors.In this study,we developed a self-driving bacteria/nanoparticle biohybrid called Bif@PDA-aPD1/DOX-Lip by attaching polydopamine(PDA)coated doxorubicin(DOX)liposomes and the immune checkpoint inhibitor anti-programmed cell death protein 1 antibody(aPD-1)to Bifidobacterium infantis(B.infantis,Bif).Using the homing abilities of bacteria,Bif@PDA-aPD1/DOX-Lip could actively accumulate in tumor tissue,releasing DOX and aPD-1 in the acidic environment to have a synergistic anti-tumor effect.Results show that the concentration of DOX in tumors of the Bif@PDA-aPD1/DOX-Lip group was 6.31 times higher than in the free DOX group.The combination of DOX and aPD-1 not only killed tumor cells but also promoted immune normalization by maturing dendritic cells(DCs),increasing M1 macrophage ratio,and enhancing infiltration of CD8^(+) and CD4^(+)T cells in tumors and spleen.Therefore,Bif@PDA-aPD1/DOX-Lip therapy significantly inhibited tumor growth and increased the average survival time of mice to over 80 days.The Bif@PDA-aPD1/DOX-Lip biomotors offer a highly effective method for enhancing chemo-immunotherapy in solid tumors. 展开更多
关键词 Anaerobic bacteria Liposome Doxorubicin Anti-PD-1 antibody CHEMO-IMMUNOTHERAPY Breast cancer
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Pile installation effects in natural soft clays:A semi-analytical solution using strain path method
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作者 Liang Li Pan Zhou +3 位作者 Jingpei Li Seyedmohsen Miraei Peng Feng Mingdong Wei 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期728-744,共17页
This paper develops a semi-analytical solution for pile penetration in natural soft clays using the strain path method(SPM).The stress-strain behavior of soils is characterized by the S-CLAY1S model,which can capture ... This paper develops a semi-analytical solution for pile penetration in natural soft clays using the strain path method(SPM).The stress-strain behavior of soils is characterized by the S-CLAY1S model,which can capture the anisotropic evolution and destructuring nature of soft clays.By integrating the S-CLAY1S model into the theoretical framework of the SPM,a set of ordinary differential equations is formulated with respect to the vertical coordinate of soil particles.The distribution of excess pore water pressure(EPWP)following pile installation is approximated through one-dimensional(1D)radial integration around the pile shaft.The distribution of stresses and EPWP,along with the evolution of fabric anisotropy within the soil surrounding the pile,is presented to illustrate the response of pile penetration in natural soft clays.The proposed solution is validated against existing theoretical solutions using the SPM and cavity expansion method(CEM),along with experimental data.The findings demonstrate that the SPM reveals lower radial effective stresses and EPWP at the pile shaft than that of CEM.Pile penetration alters the soil's anisotropic properties,inducing rotational hardening and affecting post-installation stress distribution.Soil destructuration eliminates bonding among particles near the pile,resulting in a complete disruption of soil structure at the pile surface,which is particularly pronounced for higher initial soil structure ratios.Minimal variation was observed in the three principal stresses and shear stress on the cone side surface as the angle increased from 18°to 60°,except for a slight reduction in EPWP. 展开更多
关键词 Pile penetration Strain path method Natural soft clays Anisotropy evolution Destructuration
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Reconstruction of the macrophage and myelin debris ecosystem following spinal cord injury:a dual-matrix hydrogel/polycaprolactone platform
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作者 Tao Xu Yuchen Zhou +7 位作者 Wei Han Xiaohui Ni Mengke Liu Renyue Hu Wei Shi Yahong Zhao Yumin Yang Xiaoqing Chen 《Bio-Design and Manufacturing》 2026年第2期335-356,I0028-I0068,共63页
Spinal cord injury(SCI)causes severe trauma to the central nervous system(CNS),involving complex pathological processes such as oxidative stress,inflammation,demyelination,and scar formation.During SCI progression,ong... Spinal cord injury(SCI)causes severe trauma to the central nervous system(CNS),involving complex pathological processes such as oxidative stress,inflammation,demyelination,and scar formation.During SCI progression,ongoing myelin degeneration leads to the release of myelin debris,which directly inhibits neural regeneration and impairs functional recovery following the injury.Moreover,bone marrow-derived macrophages(BMDMs)infiltrate the injured site and extensively phagocytose myelin debris,transforming into lipid-laden foam cells.These foam cells accumulate at the lesion core,significantly promoting fibrotic scar formation.To address these challenges,we developed a composite scaffold consisting of a foam cell membrane-coated polycaprolactone(PCL)nanofiber membrane that was integrated with a dual-matrix human acellular amniotic membrane(HAAM)hydrogel.A comprehensive evaluation combining material characterization,in vitro assays,and in vivo assessment using a Sprague-Dawley rat spinal cord defect model demonstrated that the scaffold retains the bioactive properties of HAAM,effectively clearing myelin debris and mitigating foam cell accumulation while concurrently promoting neural regeneration following SCI.The proposed novel biomaterial-based strategy offers a promising approach to addressing the persistent accumulation of myelin debris after SCI. 展开更多
关键词 Spinal cord injury(SCI) Nerve regeneration Foam cell Biomaterials
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贝叶斯方法在地质学和地球化学中的应用 被引量:1
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作者 钱航 张南 田猛 《北京大学学报(自然科学版)》 北大核心 2025年第6期1201-1217,共17页
从反演模型的角度,阐述贝叶斯方法的基本原理、计算手段、发展历程和研究现状。详细介绍各种贝叶斯方法及其在地质学与地球化学各领域的应用,并探讨未来发展方向以及需要解决的难点。
关键词 贝叶斯方法 模型反演 随机模拟 先验概率 后验概率 似然函数
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Alkali metal cations change the hydrogen evolution reaction mechanisms at Pt electrodes in alkaline media 被引量:1
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作者 Yamen Taji Alexandra Zagalskaya +8 位作者 Iman Evazzade Sebastian Watzele Kunting Song Song Xue Christian Schott Batyr Garlyyev Vitaly Alexandrov Elena Gubanova Aliaksandr S.Bandarenka 《Nano Materials Science》 2025年第6期729-734,共6页
The effects of seemingly inert alkali metal(AM)cations on the electrocatalytic activity of electrode materials towards reactions essential for energy provision have become the emphasis of substantial research efforts ... The effects of seemingly inert alkali metal(AM)cations on the electrocatalytic activity of electrode materials towards reactions essential for energy provision have become the emphasis of substantial research efforts in recent years.The hydrogen and oxygen evolution reactions during alkaline water electrolysis and the oxygen electro-reduction taking place in fuel cells are of particular importance.There is no universal theory explaining all the details of the AM cation effect in electrocatalysis.For example,it remains unclear how“spectator”AM-cations can change the kinetics of electrocatalytic reactions often more significantly than the modifications of the elec-trode structure and composition.This situation originates partly from a lack of systematic experimental and theoretical studies of this phenomenon.The present work exploits impedance spectroscopy to investigate the influence of the AM cations on the mechanism of the hydrogen evolution reaction at Pt microelectrodes.The activity follows the trend:Li^(+)≥Na^(+)≥K^(+)≥Cs^(+),where the highest activity corresponds to 0.1 M LiOH electrolytes at low overpotentials.We demonstrate that the nature of the AM cations also changes the relative contribution of the Volmer–Heyrovsky and Volmer–Tafel mechanisms to the overall reaction,with the former being more important for LiOH electrolytes.Our density functional theory-based thermodynamics and molecular dynamics calculations support these findings. 展开更多
关键词 Hydrogen evolution reaction Electrolyte effect Reaction mechanism ELECTROCATALYSIS PLATINUM Density functional theory calculations
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Translocator protein and neurodegeneration: insights from Alzheimer’s disease
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作者 Arpit Kumar Pradhan Rainer Rupprecht Gerhard Rammes 《Neural Regeneration Research》 SCIE CAS 2025年第4期1090-1091,共2页
The 18 kDa translocator protein(TSPO)located on the outer mitochondrial membrane regulates several key cellular processes including mitochondrial homeostasis,cholesterol transport,apoptosis,cell proliferation,and main... The 18 kDa translocator protein(TSPO)located on the outer mitochondrial membrane regulates several key cellular processes including mitochondrial homeostasis,cholesterol transport,apoptosis,cell proliferation,and maintenance of mitochondrial health(Rupprecht et al.,2022,2023).TSPO is expressed in both peripheral organs and the central nervous system,with a more pronounced expression in tissues that produce steroids.The main reason why TSPO has garnered so much attention is because it plays a key role in neurosteroidogenesis by transferring cholesterol from the outer to the inner mitochondrial membrane,which is the rate-limiting step in neurosteroid synthesis.A cholesterol-recognizing amino acid consensus domain has been identified in the cytosolic C terminus of the TSPO protein by both in vitro and site-directed mutagenesis experiments(Li et al.,2001).However,the role of TSPO in the process of neurosteroid synthesis has been challenged by several studies,particularly TSPO knockout models,which suggest that TSPO removal does not affect the phenotype or the system’s viability(Tu et al.,2014).However,ligands targeting TSPO have been shown to enhance levels of neurosteroids which suggests that neurosteroidogenesis is one of the major functional roles mediated by the TSPO protein. 展开更多
关键词 CHOLESTEROL ORGANS
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Oxidation Resistance of Mg-Ca Alloys with Protective Coating Under Flame Exposure
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作者 Ming Yue You Guoqiang +2 位作者 Zhang Jun Wang Xiaoxi Yang Feng 《稀有金属材料与工程》 北大核心 2025年第10期2440-2444,共5页
To further expand the application of Mg alloys at high temperatures,the oxidation resistance of Mg-0.3Ca and Mg-3.6Ca alloys with protective coating under flame exposure was studied.Results show that the oxidation res... To further expand the application of Mg alloys at high temperatures,the oxidation resistance of Mg-0.3Ca and Mg-3.6Ca alloys with protective coating under flame exposure was studied.Results show that the oxidation resistance of Mg-Ca alloys under flame exposure is significantly improved by the protective coating,and Mg-3.6Ca alloy shows better oxidation resistance performance.The surface temperature of Mg-Ca alloys is reduced by the coating,therefore improving the oxidation resistance under flame exposure.However,the thermal insulation effect of the coating on Mg-3.6Ca alloy is better,which can be attributed to the Ca accumulation on the surface film.In addition,the surface film with Ca accumulation layer plays a crucial role in protecting the alloy.No obvious Ca accumulation layer exists on the Mg-0.3Ca alloy surface,presenting a restricted protective effect.Nevertheless,the surface film containing Ca accumulation layer is formed on Mg-3.6 Ca alloy,which shows an excellent protective effect. 展开更多
关键词 Mg-Ca alloy OXIDATION flame exposure COATING
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Prevalence and risk of progression of pancreatic cystic lesions in immunosuppressed patients:A systematic review and meta-analysis
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作者 Maximilian Kießler Helmut Friess Volker Assfalg 《World Journal of Transplantation》 2025年第2期320-327,共8页
BACKGROUND Pancreatic cystic lesions are common in patients eligible for solid organ transplan-tation.It has been shown that the need for immunosuppression after organ transplantation increases the rate of malignancie... BACKGROUND Pancreatic cystic lesions are common in patients eligible for solid organ transplan-tation.It has been shown that the need for immunosuppression after organ transplantation increases the rate of malignancies in organ recipients.However,the impact of immunosuppression on pancreatic cystic lesions is yet unknown.AIM To evaluate the prevalence of pancreatic cystic lesions and the risk of cyst progression in immunosuppressed patients.METHODS A systematic literature search was performed in relevant databases.Studies reporting either on the prevalence and/or the incidence of pancreatic cyst progression compared to a control group were implemented in the first systematic review and meta-analysis on this topic.RESULTS The prevalence of pancreatic cystic lesions was comparable with 7%(95%CI:5%-11%)in the immunosuppressed cohort and 9%(95%CI:5%-16%)in the control cohort.The mean cyst size increase in the immunosuppression group was 3.2 mm(range 1.0-5.2mm)compared to 3.5 mm(1.0-6.9)in the control group(standar-dized mean difference 0.0 mm,95%CI:-0.3-0.2 mm,P=0.72).There was also no significant increase in the development of resection criteria or worrisome features under immunosuppression either[relative risk 1.1(fixed effect model),1.2(ran-dom effects model),P=0.61].CONCLUSION Immunosuppression does not increase the prevalence of pancreatic cystic lesions,nor does it increase the risk of cyst progression in terms of cyst size and development of resection criteria.Therefore,pancreatic cystic lesions in transplant candidates should not be a contraindication for solid organ transplantation. 展开更多
关键词 Pancreatic cystic lesions Intraductal papillary mucinous neoplasm IMMUNOSUPPRESSION Organ transplantation Systematic review
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Needle detection and localisation for robot-assisted subretinal injection using deep learning
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作者 Mingchuan Zhou Xiangyu Guo +7 位作者 Matthias Grimm Elias Lochner Zhongliang Jiang Abouzar Eslami Juan Ye Nassir Navab Alois Knoll Mohammad Ali Nasseri 《CAAI Transactions on Intelligence Technology》 2025年第3期703-715,共13页
Subretinal injection is a complicated task for retinal surgeons to operate manually.In this paper we demonstrate a robust framework for needle detection and localisation in robotassisted subretinal injection using mic... Subretinal injection is a complicated task for retinal surgeons to operate manually.In this paper we demonstrate a robust framework for needle detection and localisation in robotassisted subretinal injection using microscope-integrated Optical Coherence Tomography with deep learning.Five convolutional neural networks with different architectures were evaluated.The main differences between the architectures are the amount of information they receive at the input layer.When evaluated on ex-vivo pig eyes,the top performing network successfully detected all needles in the dataset and localised them with an Intersection over Union value of 0.55.The algorithm was evaluated by comparing the depth of the top and bottom edge of the predicted bounding box to the ground truth.This analysis showed that the top edge can be used to predict the depth of the needle with a maximum error of 8.5μm. 展开更多
关键词 deep learning optical coherence tomography robot-assisted surgery subretinal injection
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vip Editorial:Special Issue on Al Technologies and Applications in Medical Robots
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作者 Xiaozhi Qi Zhongliang Jiang +1 位作者 Ying Hu Jianwei Zhang 《CAAI Transactions on Intelligence Technology》 2025年第3期635-637,共3页
The integration of artificial intelligence(AI)into medical robotics has emerged as a cornerstone of modern healthcare,driving transformative advancements in precision,adaptability and patient outcomes.Although computa... The integration of artificial intelligence(AI)into medical robotics has emerged as a cornerstone of modern healthcare,driving transformative advancements in precision,adaptability and patient outcomes.Although computational tools have long supported diagnostic processes,their role is evolving beyond passive assistance to become active collaborators in therapeutic decision-making.In this paradigm,knowledge-driven deep learning systems are redefining possibilities-enabling robots to interpret complex data,adapt to dynamic clinical environments and execute tasks with human-like contextual awareness. 展开更多
关键词 diagnostic processestheir medicalrobotics artificial intelligence ai interpret complex dataadapt medical robotics deeplearning computational tools precisionmedicine
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State-Space Reduction Techniques Exploiting Specific Constraints for Quantum Search Initialization,Application to an Outage Planning Problem
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作者 Rodolphe Griset Ioannis Lavdas Jiri Guth Jarkovsky 《Journal of Quantum Computing》 2025年第1期81-105,共25页
Quantum search has emerged as one of the most promising fields in quantum computing.Stateof-the-art quantum search algorithms enable the search for specific elements in a distribution by monotonically increasing the d... Quantum search has emerged as one of the most promising fields in quantum computing.Stateof-the-art quantum search algorithms enable the search for specific elements in a distribution by monotonically increasing the density of these elements relative to the rest of the distribution.These kinds of algorithms demonstrate a theoretical quadratic speed-up on the number of queries compared to classical search algorithms in unstructured spaces.Unfortunately,the major part of the existing literature applies quantum search to problems whose size grows exponentially with the input size without exploiting any specific problem structure,rendering this kind of approach not exploitable in real industrial problems.In contrast,this work proposes exploiting specific constraints of an outage planning problem,consisting in setting outage dates of production units under specific fuel management constraints and resource constraints limiting the number of outages in parallel,to build an initial superposition of states with size almost quadratically increasing as a function of the problem size.This state space reduction,inspired by the quantum walk algorithm,constructs a state superposition corresponding to all paths in a state-graph,embedding spacing constraints between outages.Our numerical results on quantum emulators highlight the potential of the statespace reduction approach.In our simplified use case,the number of iterations required to reach a 90% probability of measuring a feasible solution is reduced by a factor between 2 and 4.More importantly,the squared ratio between the number of possible configurations and the number of valid solutions shifts from exponential to linear behavior,demonstrating that the quadratic speedup offered by Grover-based algorithms becomes sufficient in this setting.While these results are based on a simplified scenario and further investigation is needed to generalize them to large-scale industrial problems,they illustrate the promise of structure-aware initialization in significantly improving the efficiency of quantum search by focusing on a smaller,more relevant solution space. 展开更多
关键词 Quantum search amplitude amplification quantum walk scheduling planning problem
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A low-cost and high-energy aqueous potassium-ion battery
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作者 Raphael L.Streng Tim Steeger +10 位作者 Anatoliy Senyshyn Steffen Abel Peter Schneider Christine Benning Bernardo Miller Naranjo David Gryc Mian Zahid Hussain Oliver Lieleg Martin Elsner Aliaksandr S.Bandarenka Katarina Cicvaric 《Journal of Energy Chemistry》 2025年第7期523-531,共9页
To address challenges related to the intermittency of renewable energy sources,aqueous potassium-ion batteries(AKIBs)are a promising and sustainable alternative to conventional systems for large-scale energy storage.T... To address challenges related to the intermittency of renewable energy sources,aqueous potassium-ion batteries(AKIBs)are a promising and sustainable alternative to conventional systems for large-scale energy storage.To enable their practical application,maximizing energy density and longevity while minimizing production and material costs is a key goal.In this work,we propose an AKIB consisting only of abundant and cost-efficient materials,which delivers a high energy density of more than 70 Wh kg^(-1).We combine simple strategies to stabilize the Mn-rich Prussian blue analog cathode by Fe-doping,improving the crystallinity,and tuning the electrolyte composition without employing expensive water-in-salt electrolytes.Using a mixed 2.5 M Ca(NO_(3))_(2)+1.5 M KNO_(3)electrolyte,we assemble a novel AKIB with a Fe-doped manganese hexacyanoferrate cathode and an organic poly(naphthalene-4-formylethylenediamine)anode.Besides a high energy density,the full cell delivers a specific capacity of approximately 60 mAhg^(-1),a power density of 5000 W kg^(-1),and 80% capacity retention after 600 cycles. 展开更多
关键词 Aqueous Battery ELECTROLYTE POTASSIUM CALCIUM
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Probing the Warm and Hot Absorbers along the Sightline of PG 0052+251
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作者 Zheng Zhou Junjie Mao +5 位作者 Taotao Fang Yijun Wang Jiayi Chen Fabrizio Nicastro Kaile Wang Yi Zhang 《Research in Astronomy and Astrophysics》 2025年第7期102-110,共9页
We analyze the absorption features in the public 73 ks XMM-Newton spectra of the Seyfert 1 galaxy PG 0052+251.Our analysis reveals the presence of a warm absorber(WA)intrinsic to the source and the hot circumgalactic ... We analyze the absorption features in the public 73 ks XMM-Newton spectra of the Seyfert 1 galaxy PG 0052+251.Our analysis reveals the presence of a warm absorber(WA)intrinsic to the source and the hot circumgalactic medium at zero redshift.The identified WA is inflowing toward the central black hole,with a velocity shift of■.The ionization parameter of the WA is■,showing strong O II and O III absorption lines,along with a significant absorption of the spectral continuum at?10?.The line of sight toward PG 0052+251 intersects the halo of M31 at an impact parameter of approximately 218 kpc.Several local(z~0)absorption lines,like O VII,O VIII,and Ne IX,were detected.The derived hydrogen column density of the local hot gas is 2.2–2.6σhigher than those estimated by several models of the Galactic hot halo,suggesting a likely contribution from the M31 halo.We also find two absorption features at24.305?and 21.410?,which are unlikely to be associated with the hot halos or the warm-hot intergalactic medium but imply the presence of an additional WA component with an outflow velocity of approximately-7000 km s^(-1). 展开更多
关键词 (galaxies:)quasars:individual(PG 0052+251) (galaxies:)quasars:absorption lines galaxies:halos galaxies:individual(M31) X-rays:galaxies
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霸姬蜂属(膜翅目,姬蜂科)一新种 被引量:4
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作者 盛茂领 Klaus SCHNITZER 《动物分类学报》 CSCD 北大核心 2008年第2期391-394,共4页
报道采自宁夏六盘山的霸姬蜂属Barytarbes Frster,18691新种,褐霸姬蜂Barytarbes fulvus Sheng&Schnitzer,sp.nov.。
关键词 膜翅目 姬蜂科 栉足姬蜂亚科 霸姬蜂属 新种
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基于光纤温度测量的土石坝渗漏监测技术 被引量:11
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作者 孙东亚 Markus Aufleger 《水利水电科技进展》 CSCD 2000年第4期29-31,共3页
采用具有高信息密度的分布式光纤温度传感测量系统进行土石坝渗漏监测技术研究 .经过理论研究和室内、现场试验 ,已取得了初步研究成果 .实践表明 ,该传感系统可以埋置于防渗体的下游排水或反滤层内 ,不会因机械施工而损伤 ,具有施工干... 采用具有高信息密度的分布式光纤温度传感测量系统进行土石坝渗漏监测技术研究 .经过理论研究和室内、现场试验 ,已取得了初步研究成果 .实践表明 ,该传感系统可以埋置于防渗体的下游排水或反滤层内 ,不会因机械施工而损伤 ,具有施工干扰小 ,抗电磁干扰等特点 ,系统测量精度能满足工程应用的要求 .该项测量技术还可用于混凝土坝的温度场测量 . 展开更多
关键词 渗漏 土石坝 监测 光纤温度传感测量系统
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小尺寸Si/Ge量子点内应变和组分的拉曼光谱表征 被引量:2
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作者 谭平恒 周霞 +3 位作者 杨富华 K.Brunner D.Bougeard G.Abstreiter 《光散射学报》 2004年第3期203-207,共5页
本文详细地研究了原始生长和退火处理后的Si/Ge量子点的拉曼光谱。我们观测到了Si/Ge量子点的一系列本征的拉曼振动模以及Ge-Ge模的LO和TO声子峰间4.2cm-1的频率劈裂。通过这些参数,我们自洽地确定了原始生长的平面直径为20nm和高为2nm... 本文详细地研究了原始生长和退火处理后的Si/Ge量子点的拉曼光谱。我们观测到了Si/Ge量子点的一系列本征的拉曼振动模以及Ge-Ge模的LO和TO声子峰间4.2cm-1的频率劈裂。通过这些参数,我们自洽地确定了原始生长的平面直径为20nm和高为2nm的Si/Ge量子点内Ge的平均组分为80%,平均应变为-3.4%。分析清楚地表明了这种小尺寸的Si/Ge量子点内的应变仍遵从双轴应变,并且应变的释放主要由量子点和Si隔离层间Si-Ge原子互扩散决定。 展开更多
关键词 量子点 拉曼光谱 应变 组分 Si—Ge原子互扩散
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HgGdTe子能带电子的磁光共振
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作者 褚君浩 沈学础 +1 位作者 R.Sizmann F.Koch 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 1991年第1期44-50,共7页
报道P-Hg_(1-x)Cd_xTe(x=0.234、N_A=4×10^(17)cm^(-3))MIS结构样品在电量子限条件下电子子能带朗道能级间磁光共振光跃迁实验结果。测量了不同光子能量和样品在不同表面电子浓度时子能带朗道能级间和自旋能级间的回旋共振和自旋... 报道P-Hg_(1-x)Cd_xTe(x=0.234、N_A=4×10^(17)cm^(-3))MIS结构样品在电量子限条件下电子子能带朗道能级间磁光共振光跃迁实验结果。测量了不同光子能量和样品在不同表面电子浓度时子能带朗道能级间和自旋能级间的回旋共振和自旋共振。定量地证明了窄禁带半导体量子阱子能带朗道能级的移动和交叉效应,这一效应起源于表面势的反演不对称所导致的较强的表面电子自旋轨道相互作用。 展开更多
关键词 碲镉汞 子能带 电子 磁光效应
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HgCdTe共振缺陷态的电容谱研究
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作者 褚君浩 R.Sizmann +3 位作者 R.Wollrab F.Koch J.Ziegler H.Maier 《红外研究》 CSCD 北大核心 1989年第5期327-334,共8页
提出一种测量HgCdTe量子电容谱、研究共振缺陷态的方法.利用高精度差分电容测量方法,在4.2K下测量了一系列受主浓度为3×10^(16)~4×10^(17)cm^(-3)的P型HgCdTe MIS样品的C-V曲线.对浓度约10^(17)cm^(-3)的强P型Hg_0.79Cd_0.2... 提出一种测量HgCdTe量子电容谱、研究共振缺陷态的方法.利用高精度差分电容测量方法,在4.2K下测量了一系列受主浓度为3×10^(16)~4×10^(17)cm^(-3)的P型HgCdTe MIS样品的C-V曲线.对浓度约10^(17)cm^(-3)的强P型Hg_0.79Cd_0.21Te体材料样品,在C-V曲线上耗尽区和反型层交界的偏压区域观察到一个附加峰,该峰起源于导带底以上45meV的一个共振缺陷态,分析表明是氧占据Hg空位的杂质缺陷态. 展开更多
关键词 碲镉汞 共振缺陷态 电容谱 半导体
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