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古生物化学中的凝聚态化学反应

化学进展 2022年第7期34卷 1626-1641页

作者：黄大一中国台湾中兴大学中国台中402

研究古生物学,必须从古生物变“化”之学的方向着手,深入化石骨头和细胞里面,探讨在漫长时间内、该古生物的化学组成、细微构造等起了什么变化?化成了什么?如今保留的是什么?保存这些有机残留物的化学机制(Mechanism)是什么?凝聚态化学... 详细信息

研究古生物学,必须从古生物变“化”之学的方向着手,深入化石骨头和细胞里面,探讨在漫长时间内、该古生物的化学组成、细微构造等起了什么变化?化成了什么?如今保留的是什么?保存这些有机残留物的化学机制(Mechanism)是什么?凝聚态化学在此又扮演了什么关键角色?在此我以个人所知一点点从凝聚态化学的角度,来探讨古生物领域诸多古化学相关的最基本底层奥秘,本文举三个实例说明可能的凝聚态化学反应,肯定在古生物化学中扮演了关键的基本机制,等着我们去揭发;如:一般认为化石就是古代生物变化成为石头,从有机体变成无机的矿物质,有机体不可能保存成千万上亿年;然而,我们团队却在1.95亿年前的禄丰龙胚胎骨头内,发现了被保存下来的原生I型胶原蛋白(Native Collagen I);又在22亿年前化石内发现多种氨基酸,和证明为最早多细胞真核生物的甾烷;这是地球生命演化重大的发现;从这些古生物化石的实例来说,可以看出凝聚态化学绝非仅是个理论化学的旁观者,而是关键角色,它的重要性,非常值得我们投入去深入探讨,揭开从古代生物到你我手中化石无数化学反应最底层化学的奥秘。

关键词：古生物化学古生物学化石第一型胶原蛋白恐龙胚胎多细胞真核生物碳酸盐胶合

dEM Study on the Effects of Micro-parameters of smooth joint model of Synthetic Rock Mass

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DEM Study on the Effects of Micro-parameters of smooth joint...

The 16th Annual Conference of Hong Kong Society of Theoretical and Applied Mechanics 2012、The 1st Mainland-Hong Kong Youth Forum on Mechanics 2012、The 8th Shanghai-Hong Kong Forum on Mechanics and Its Application 2012

作者： d.huang J.F.Wang

The calibration and determination of micro-parameters is a first important step towards the successful establishment of a dEM model for *** this paper,we aim to develop such a model for synthetic rock mass(SRM) using the bonded particle modeling(BPM) approach(Potyondy,dO and Cundall,PA ).A series of simulation parametric studies were performed to investigate the effects of particle-level parameters on the macroscopic strength behavior of a *** is achieved by calibrating the model performance against the laboratory test results on the marble samples extracted

关键词： SRM dEM Study on the Effects of Micro-parameters of smooth joint model of Synthetic Rock Mass

double heterogeneous structures induced excellent strength-ductility synergy in Ni_(40)Co_(30)Cr_(20)Al_(5)Ti_(5) medium-entropy alloy

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Journal of Materials Science & Technology 2024年第14期181卷 176-188页

作者： A.X.Li X.S.Liu R.Li S.B.Yu M.H.Jiang J.S.Zhang C.N.Che d.huang P.F.Yu G.Li State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

The application of single-phase face-centered cubic(FCC)medium entropy alloys(MEAs)in the engi-neering industry is often hindered by the challenge of insufficient *** this study,a novel non-equiatomic ratio Ni_(40)Co_(30)Cr_(20)Al_(5)Ti_(5)MEA was successfully *** the well-designed mechan-ical heat treatment processing,we introduced a heterogeneous grain structure comprising 67.4%fine grain and 32.6%coarse ***,heterogeneous size L12 phases consisting of 18.7%submicron precip-itates and 11.7%nano-sized precipitates,were incorporated into the *** tests conducted at room temperature revealed that the double heterogeneous structure alloy demonstrated remarkable strength–ductility *** exhibited a yield strength of 1200 MPa,an ultimate tensile strength of 1560 MPa and a total elongation of 33.6%.The exceptional strength of the alloy can be primarily attributed to heteroge-neous deformation induced strengthening,grain boundary strengthening and precipitation *** excellent ductility is mainly attributed to the high-density stacking faults and Lomer–Cottrell *** study not only contributes to the clarification of the strengthening and deformation mechanism of double heterogeneous structure alloys but also provides an effective strategy for the development of high-performance alloys with high strength and ductility.

关键词： Medium entropy alloy double heterogeneous structure HdI strengthening Remarkable tensile properties

Continuous-variable quantum key distribution using orbital angular momenta

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Continuous-variable quantum key distribution using orbital a...

第十八届全国量子光学学术会议

作者：金迪 Y.Guo L.Zhang d.huang 中南大学 School of Information Science & Engineering Central South University

Orbital angular momentum（OAM） is an important physical quantity of photons. If a photon of a helically phased beam with an azimuthal phase dependence of the form exp（ilθ）, the photon can carry an OAM of l?. In principle, there is no theoretical upper limit on the azimuthal quantum numbers l, which could greatly increase information capacity. In this paper, we propose a scheme for continuous-variable quantum key distribution（CV-QKd） using OAM. Results indicate that increasing the dimension of OAM leads to an increased information capacity as well as higher the total secret key rate. Additionally, as a result of the existence of turbulence, the power of OAM beams will diffuse to beams with neighboring topological charges, resulting in the decrease of received power and impairing channel capacity. In order to mitigate the influence of atmospheric turbulence, a special coherent detection is used. It is found that both of the distorted orbital angular momentum and the distorted wavefront of a beam due to turbulence can be compensated. The normalized power spectrum of the detected OAMs also shows a significant improvement.

关键词：

Secret information reconciliation based on check-node-based globally coupled low-density parity-check codes for continuous-variable quantum key distribution

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Secret information reconciliation based on check-node-based ...

第十八届全国量子光学学术会议

作者：李伯鹏 Y.Guo L.Zhang d.huang 中南大学 School of Information Science & Engineering Central South University

Check-node-based globally coupled low-density parity-check(CN-GC-LdPC) is a special type of LdPC codes. The CN-GC-LdPC’s Tanner graph comprises a set of disjoint Tanner graphs which are connected together by a group of overall check-nodes(CNs), called global CNs. Reconciliation is a significant procedure in a continuous-variable quantum key distribution(CV-QKd) system. In this paper, we propose a high performance reconciliation scheme through employing a modified two-phase local/global iterative decoding scheme based on CN-GC-LdPC. By using this reconciliation scheme, the CV-QKd system’s reconciliation efficiency can reach 98.48%. The gaps between the iterative decoding thresholds and the Shannon limits are very small. The proposed scheme has lower encoding complexity compared to the conventional reconciliation scheme. By using a graphics processing unit(GPU), the reconciliation scheme can reach a high speed for a CV-QKd system.

关键词：

Continuous-variable quantum key distribution based on faster-than-Nyquist

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Continuous-variable quantum key distribution based on faster...

第十八届全国量子光学学术会议

作者：潘雅茜 L.Zhang Y.Guo d.huang 中南大学 School of Information Science & Engineering Central South University

In previous continuous-variable quantum key distribution（CV-QKd） systems, the transmission rate is limited by Nyquist criterion. Under this limitation, the data symbols transmit without inter symbol interference（ISI）, but the spectra of the system are not efficient. Faster-than-Nyquist（FTN） technology has been view as a potential technique in future communication systems because of its higher spectrum efficiency and faster symbol rate. In this paper, a CV-QKd system based on FTN is proposed. To eliminate ISI caused by FTN and further boost the system performance, we conceive a low-complexity frequency domain equalization（FdE）-aided receiver structure and use an efficient 1 GHz homodyne detector at Bob’s side. Our proposed scheme is especially beneficial for the long-tap and long-distance scenario. Simulation results demonstrate such an CV-QKd system can reduce demodulating complexity, decrease the excess noise caused by pulse overlap and enhance key rate.

关键词：

Compressive sensing based channel parameter estimation for continuous-variable quantum key distribution

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Compressive sensing based channel parameter estimation for c...

第十八届全国量子光学学术会议

作者：何哲 Y.Su L.Zhang Y.Guo G.H.Zeng d.huang 中南大学 School of Information Science & Engineering Central South University State Key Laboratory of Advanced Optical Communication Systems and Networks and Center of Quantum Information Sensing and ProcessingShanghai Jiao Tong University

Parameter estimation is one of the crucial procedure in continuous-variable quantum key distribution（CVQKd）, aiming at acquiring the real paramaters values that are relevant for the system performance in the composable security framework. In general, almost half of the raw key are used for parameter estimation to guarantee the accuracy, leading to the decline in key rate. This introduces a tradeoff between the secret key rate and the accuracy or parameter estimation in the finite-size regime. In this paper, a compressvie sensing（CS） based channel parameter estimation approach is proposed. Utilizing beam extinction and a variety of turbulence effects in the atmospheric channel, the CS framework is modeled to estimate the transmittance, which can achieve accurate parameter estimation. We apply CS for measuring the initial state of a subsystem and predicting the remaining state in parameter estimation procedure. Simulation results illustrate that our purposed approach of CS based channel parameter estimation has a superior performance which can provide higher secret key rate.

关键词：

Rare Earth Elements in dinosaur bones across the embryo-adult spectrum

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Rare Earth Elements in Dinosaur bones across the embryo-adul...

第十七届全国稀土分析化学学术研讨会

作者： Shuanglong Wang Runhan Yan Huanwen Chen Shitao Zhang Xiaobo Li László Kótai Timothy d.huang Robert R.Reisz Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation East China University of Technology International Center of Future Science Jilin University Kunming Science and Technology University Hungarian Academy of Science department of Life Sciences National Chung Hsing University University of Toronto Mississauga

There is broad consensus that many bones of extinct vertebrates contain Rare Earth Elements(REE)and other trace minerals that have been incorporated and enriched into the fossil during *** fossilization,apatite minerals in vertebrate bones recrystallize from metastable biogenic forms to thermodynamically more stable inorganic apatite minerals while incorporating REEs from their *** than-95% of the REE in fossil bones are diagenetically incorporated postmortem and bones in different environments have different and distinct REE signatures,generally viewed to be controlled by sedimentological and taphonomic *** REE pattern in fossils is generally stable and the normalized concentration patterns provide unique "fingerprints" or signatures that have been used for various geological and paleontological *** we compare REE patterns in bones from two distinct sites in Yunnan,China,both preserving embryonic and adult bones of Early Jurassic sauropodomorph *** discovery of embryos and their adults at the same site,a rare occurrence in the fossil record,allowed us to compare for the first time the relationship between REE concentrations in the same taxon at widely differing ontogenetic *** dinosaurs are closely related to each other and close in geological age,and their bones show similar REE ***,the embryonic bones have significantly lower levels of total REEs when compared to their adult *** attribute the tenfold difference to the level of ossification of the bones and the dramatically lower concentration of apatites in the embryonic than in the adult *** conclude that the ontogenetic stage of fossil materials can have a significant impact on REE concentrations,and discuss the impact of these results on future work.

关键词： Rare Earth Elements fossils Early Jurassic dinosaurs

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新的炼铁工艺中炉膛的形状和移动

鞍钢技术 2004年第2期 48-51页

作者： d.huang W.K.Lu 胡俊鸽

新技术提出铁矿石与煤制成的球团在完全燃烧气氛下还原可产生高金属化率的直接还原铁。

关键词：铁矿石直接还原铁炼铁炉膛回转窑转底式炉膛式炉