Noise-free frequency conversion of quantum states

In this paper, the frequency conversion of quantum states based on the intracavity nonlinear interaction is proposed. The fidelity of an input state after frequency conversion is calculated, and it is shown the noise-free frequency conversion of a quantum state can be achieved by injecting a strong signal field. The dependences of conversion efficiency on the pump parameter, extra losses and input state amplitude are also analysed.

Instability, adiabaticity, and controlling effects of external fields for the dark state in a homonuclear atom tetramer conversion system

In the present paper, we investigate the instability, adiabaticity, and controlling effects of external fields for a dark state in a homonuclear atom-tetramer conversion that is implemented by a generalized stimulated Raman adiabatic passage. We analytically obtain the regions for the appearance of dynamical instability and study the adiabatic evolution by a newly defined adiabatic fidelity. Moreover, the effects of the external field parameters and the spontaneous emissions on the conversion efficiency are also investigated.

Linear instability and adiabaticity of a dark state during conversion of two species of fermionic atoms to stable molecules

In the present paper, we investigate the linear instability and adiabaticity of a dark state during conversion of two species of fermionic atoms to stable molecules through the stimulated Raman adiabatic passage aided by Feshbach resonance. We analytically obtain the regions for the appearance of linear instability. Moreover, taking 40K and 6Li atom molecule conversion systems as examples, we give the unstable regions numerically. We also attempt to obtain the adiabatic criterion for this nonlinear system with classical adiabatic dynamics and study the adibaticity of the dark state with the adiabatic condition.

Highly efficient conversion from classical guided waves to topological chiral edge states

Electromagnetic topological chiral edge states mimicking the quantum Hall effect have attracted a great deal of attention due to their unique features of free backscattering and immunity against sharp bends and defects.However,the matching techniques between classical waveguides and the topological one-way waveguide deserve more attention for real-world applications.In this paper,a highly efficient conversion structure between a classical rectangular waveguide and a topological one-way waveguide is proposed and demonstrated at the microwave frequency,which efficiently converts classical guided waves to topological one-way edge states.A tapered transition is designed to match both the momentum and impedance of the classical guided waves and the topological one-way edge states.With the conversion structure,the waves generated by a point excitation source can be coupled to the topological one-way waveguide with very high coupling efficiency,which can ensure high transmission of the whole system(i.e.,from the source and the receiver).Simulation and measurement results demonstrate the proposed method.This investigation is beneficial to the applications of topological one-way waveguides and opens up a new avenue for advanced topological and classical integrated functional devices and systems.

Two-photon Up-conversion Luminescent Properties of HMASPS and HEASPS in Three Different Polymer Matrices

Three dye-doped polymer rods in different matrices were synthesized in which weak hydrogen bond, strong hydrogen bond and covalent bond existed between the dye and the polymer chain. And the two-photon up-conversion luminescent properties of HMASPS and HEASPS1 in three different microenvironments were studied.

使固态化学反应100%完成的方法

无溶液形成的固态化学反应具有“一旦发生,就必完全”的特质,但因为固体的非流动性,它常常会因严重的传质困难而有始无终。为了克服这个困难,作者提出了少溶剂固态化学反应(LSR)的概念,即通过使用少量的溶剂赋予固体流动性,使反应物固体部分溶解,再使用搅拌反应器解决其“三传”问题,使之完全反应,从而达到使一些化学工业过程绿色化的目的。本文用平衡热力学数值计算的方法图解了几种代表性LSR的Gibbs自由能随反应进度的关系,进而指出:LSR的中间阶段如同没有溶液形成的固态化学反应,两端像溶液化学反应,因此,LSR虽继承了混合自由能导致的化学平衡,但其平衡点比溶液化学反应更接近100%完全。特别地,在LSR即将结束时,通过逐步移除溶剂以使反应物和产物固体持续存在而延长中段,能推动反应达到100%完全;对于连串反应,LSR仍有可能通过控制反应物的物质的量之比来获得中间产物;对于Δ_rG_m~?略小于零的反应,可以通过使用较多的溶剂跨越可能的早期平衡态,或者使用大量的产物固体“种子”使所有的产物一直与其饱和溶液平衡,最终通过逐渐蒸发溶剂推动反应进行到底;LSR的反应速度与反应物或产物的溶解度关系不大,但与反应物的溶解速度、化学反应速度和产物的结晶速度紧密相关。本文还讨论了使一些竞争反应、非自发反应进行到底的方法,获得高度的反应控制能力。

基于滑模自抗扰的储能变流器控制策略

为了提高储能变流器(PCS)的动态性能,设计基于降阶级联扩张状态观测器(ESO)和互补滑模控制(CSMC)的改进自抗扰控制(ADRC)策略,将改进ADRC策略应用于PCS的双向DC/AC变流器电压外环.改进ESO为降阶级联ESO以提高状态变量和系统总扰动的估计速度,增加扰动估计能力;更改PD控制为CSMC以设计状态误差反馈律,提升PCS的系统鲁棒性;设计改进指数趋近律以抑制抖振现象.为了证明改进ADRC策略相较于PI控制和传统ADRC的优越性,建立仿真模型并搭建相关实验平台.仿真与实验结果表明,改进ADRC策略减小了PCS暂态时直流母线电压波动,提高了PCS交流侧功率响应速度,改善了交流侧的输出电能质量.

TBAI辅助三嗪聚合物催化CO_(2)与环氧氯丙烷环加成反应机理的理论研究

二氧化碳排放量的增加对环境造成了重大威胁。利用含氮和卤素的有机催化剂可以催化CO_(2)与环氧化物的环加成反应。用ωB97X-D/def2-TZVP//ωB97X-D/def2-SVP方法,结合SMD溶剂化模型,计算了三嗪骨架聚合物催化剂与四丁基碘化铵(TBAI)助催化剂的复合催化体系(Cat-I)催化CO_(2)与环氧氯丙烷(ECH)加成为环碳酸酯的详细反应机理。计算结果显示,在Cat-I的催化作用下,ECH先活化的路径为最低能量路径。亚胺基氢键供体活化ECH中的C-O键,I-的强亲核性和离去能力协同作用促进反应的进行。其决速中间体(TDI)为起始反应物,决速过渡态(TDTS)为碳酸半酯的闭环步骤的过渡态,表观自由能垒为33.54 kcal/mol,比无助催化剂时的能垒低16.55 kcal/mol。这与105℃、常压下、TBAI为助催化剂时三嗪骨架聚合物催化目标反应的转化率为100%,而无助催化剂时转化率仅为70%的实验事实相符。

结合对话状态信息的个性化对话回复生成

尽管个性化回复生成模型取得了显著成功,但这些研究都未能很好地考虑到对话状态信息对于个性化对话回复的影响。针对此问题,基于预训练生成模型提出了结合对话状态的自监督对话回复生成模型,该模型可以有效地对结合对话状态生成个性化的回复。首先,将对话状态纳入情景喜剧数据集中,以增强模型对上下文信息的理解能力。其次,采用自监督的训练技术,赋予预训练语言生成模型独特的对话文本特征知识,并采用多种掩码策略合并对话文本和对话状态,进一步提升模型性能。最后,基于历史对话,使用自监督生成模型生成个性化回复。在自行收集的情景喜剧数据集上进行性实验,结果表明,结合对话状态的对话回复生成模型在多项指标上优于一些强基准,进而证明了对话状态和个性化回复生成模型的有效性。

团簇NiPS_(3)异构转化热力学与动力学分析

为了探究团簇NiPS_(3)的稳定性和异构转化机理,本文利用密度泛函理论,在B3LYP/def2-tzvp的量化水平下,对团簇NiPS_(3)的初始构型进行优化分析和异构化计算,得到了10种优化构型和7种异构转化类型.从化学反应的热力学和动力学对异构转化反应进行讨论分析,得出了以下结论:团簇NiPS_(3)的异构转化反应依赖于非金属-金属和非金属-非金属之间的成键与断键;反应物与产物稳定性差别越大,反应进行的越彻底;除反应2((2))→1((4))外,其他的异构化反应在低温下更加易于自发进行;异构化反应趋向于正向进行,即能量高的构型向能量低的构型转换更容易;构型1((2))、构型2((2))和构型1((4))是团簇NiPS_(3)异构转化的最终产物,进行相关材料的研究、开发和生产时,可优先考虑.

新型硅酸盐型荧光粉K_(3)(Y_(0.88)Yb_(0.10)Ho_(0.02))Si_(2)O_(7)的上转换光致发光及光学测温性能研究

本文采用普适的固相法合成一种新型硅酸盐K_(3)(Y_(0.88)Yb_(0.10)Ho_(0.02))Si_(2)O_(7)荧光粉,并系统研究样品的上转换光致发光和光学测温性能。研究表明,在980 nm激发下,K_(3)(Y_(0.88)Yb_(0.10)Ho_(0.02))Si_(2)O_(7)荧光粉表现出红光发射,主发射峰位于665 nm,归属于Ho^(3+)的^(5)F_(5)→^(5)I_(8)跃迁。通过对发光强度和激发功率的对数变换,研究荧光粉的上转换机制和可能导致的上转换的光子反应,证明(5S4,5F2)→5I8跃迁上转换发光机制为三光子机制,^(5)F_(5)→^(5)I_(8)跃迁则为双光子机制。K_(3)(Y_(0.88)Yb_(0.10)Ho_(0.02))Si_(2)O_(7)荧光粉的^(5)F_(5)/(^(5)F_(4),^(5)S_(2))的非热耦合能级的荧光强度比结果表现出其良好的光学测温潜力,经计算其最大灵敏度约为0.17 K^(-1)(423 K)。

城郊融合背景下京津冀中小城镇中心城区地域范围识别及应用研究——以河北省宁晋县为例

中心城区地域范围(以下简称“城区地域范围”)识别是新时代国土空间规划体系建构的前提与基础。在以县城占据主导地位的京津冀地区,绝大多数中小城镇具有“城村交织”“城乡互嵌”的空间特征,面对推进实施以县城为主要引擎和重要载体的新型城镇化战略的发展趋势,科学界定该地区中小城镇中心城区的地域空间,成为开展市县国土空间规划编制工作的第一环节。文章分析了传统土地调查以城镇村属性为“202及202A”用地图斑识别作为城区地域范围的局限性,以河北省宁晋县为例,对比在城镇基数转换、城市体检评估等不同工作思路中确定的城区地域范围的划定情况,提出适用于京津冀地区中小城镇城区地域范围识别的方法和途径,为支撑城镇开发边界优化调整、判断城郊融合类村庄、推进城乡一体化发展提供重要依据。

Self-enhancing photothermal conversion of 2D Weyl semimetal WTe_(2)with topological surface states for efficient solar vapor generation

To improve the performance of solar energy-driven water generation,two-dimensional(2D)photothermal materials requisite to be optimized by some strategies such as alloying,combination of plasmonic and defect modulation.However,the challenges faced in practical utilization are the complex preparation process and insufficient solar spectrum absorption.Herein,we propose a strategy of self-enhancing photothermal performance induced by topological surface states(TSSs).2D WTe_(2)is fabricated on the mixed cellulose ester(MCE)for photothermal device.Compared to the MCE and pure water,WTe_(2)@MCE has an excellent photothermal evaporation rate of 1.09 kg·m^(−2)·h^(−1)upon 1 sun irradiation,promoting 6.1 and 3.1 times,respectively.It can be attributed to the characteristics of 2D Weyl semimetal WTe_(2)with TSSs bringing about high optical absorption capacity,low thermal diffusivity,specific heat capacity,and high carrier density,which are strongly proved by experiments and calculation.More importantly,the contribution of TSSs to the enhancement of optical absorption for efficient solar water generation is revealed by the comparative experiment between 2D WTe_(2)with TSSs and that without TSSs.Furthermore,photothermal conversion mechanism is explored in-depth understanding that the photoexcited electrons recombinate with the holes through nonradiative mode for releasing thermal energy by phonons emission via multiple pathway.This work promotes the application of Weyl semimetal material with TSSs in solar water evaporation.

基于SMART模型构建国有企业消防安全管理体系

在数字时代日新月异的今天,国有企业在消防安全管理方面也面临着新的挑战与广阔的机遇。本文以SMART模型与数字化转型战略相结合的方式进行深入剖析,为构建既高效智能又具备可持续发展潜力的国有企业消防安全标准化管理体系提供理论支撑和实践指导。在分析当前形势的基础上,提出以技术创新为引擎以管理创新为动力的相关解决方案和实战案例,以帮助国有企业在消防安全管理工作上取得长足的进步。

Experimentally testing Hardy's theorem on nonlocality with entangled mixed states

Hardy＇s theorem on nonlocality has been verified by a series of experiments with two-qubit entangled pure states.However,in this paper we demonstrate the experimental test of the theorem by using the two-photon entangled mixed states.We first investigate the generic logic in Hardy＇s proof of nonlocality,which can be applied for arbitrary two-qubit mixed polarization entangled states and can be reduced naturally to the well-known logic tested successfully by the previous pure state experiments.Then,the optimized violations of locality for various experimental parameters are delivered by the numerical method.Finally,the logic argued above for testing Hardy＇s theorem on nonlocality is demonstrated experimentally by using the mixed entangled-photon pairs generated via pumping two type-I BBO crystals.Our experimental results shows that Hardy＇s proof of nonlocality can also be verified with two-qubit polarization entangled mixed states,with a violation of about 3.4 standard deviations.

Study on Free Amino Acid and Short Peptide Fertilizer Production by Solid State Fermented Castor Bean Meal

Using microbial fermentation to increase the content of free amino acids and short peptides in the organic fertilizer for castor bean meal can effectively promote plant growth and improve fruit quality.Using free amino acid and short peptide content as an indicator,through single factor and response surface optimization experiments,the process parameters(moisture content,fermentation time and inoculum quantity)of castor meal solid-state fermentation were optimized.The best process parameters for the solid-state fermentation were:the moisture content 62%,the fermentation time 20 d,and the inoculum quantity 0.23%.The moisture content had the greatest impact on the conversion rate of free amino acids and short peptides,and the protein conversion rate reached 65.6%.The scale-up experiment under the optimal conditions showed that the solid-state fermentation using the inoculum had a significant beneficial effect compared with other fermentation methods.The fermentation of castor cake fertilizer provides a theoretical and practical basis for production feasibility,and has important guiding significance for the effective utilization of castor bean meal.

An optical scheme for conditional generation of W state and photon-added coherent state

We propose a simple scheme to generate an arbitrary photon-added coherent state of a travelling optical field by combining an array of degenerate parametric amplifiers and corresponding single-photon detectors. Particularly, when the single-photon-added coherent state is observed by developing the novel technique of Zavatta et al （2004 Science 306 660）, we can simultar/eously obtain the generalized N-qubit W state.

STEADY-STATE AND IDLE OPTIMIZA-TION OF INTERNAL COMBUSTION ENGINE CONTROL STRATEGIES FOR HYBRID ELECTRIC VEHICLES

A novel steady-state optimization （SSO） of internal combustion engine （ICE） strategy is proposed to maximize the efficiency of the overall powertrain for hybrid electric vehicles, in which the ICE efficiency, the efficiencies of the electric motor （EM） and the energy storage device are all explicitly taken into account. In addition, a novel idle optimization of ICE strategy is implemented to obtain the optimal idle operating point of the ICE and corresponding optimal parking generation power of the EM using the view of the novel SSO of ICE strategy. Simulations results show that potential fuel economy improvement is achieved relative to the conventional one which only optimized the ICE efficiency by the novel SSO of ICE strategy, and fuel consumption per voltage increment decreases a lot during the parking charge by the novel idle optimization of ICE strategy.

高亮度固态照明用LuYAG∶Ce荧光陶瓷

实现高发光效率、高亮度和良好的热稳定性是固态照明的迫切要求。因此,用于高功率发光二极管或激光二极管(LED/LD)的高性能荧光转换材料具有重要的研究意义。在这项工作中,通过将Lu^(3+)离子引入YAG∶Ce荧光陶瓷中方法作为有效策略来改善YAG∶Ce荧光材料的发光性能。采用固相反应和真空烧结法制Article ID:1000-7032(2023)06-0964^(-1)1收稿日期:2022^(-1)2-31;修订日期:2023-01-30基金项目:中国科学院战略性先导科技专项(XDA22010301)Supported by The Strategic Priority Research Program of The Chinese Academy of Sciences(XDA22010301)第6 HUANG Xinyou期,et al.:LuYAG∶Ce Transparent Ceramic Phosphors for High-brightness Solid-state…备了不同Lu^(3+)含量的(Lu,Y)_(3)Al_(5)O_(12)∶Ce荧光陶瓷(LuYAG∶Ce荧光陶瓷)。随着Lu^(3+)含量的增加,LuYAG∶Ce荧光陶瓷中的Y^(3+)位点被Lu^(3+)位点取代,Ce^(3+)的发射峰呈现从573 nm到563 nm的蓝移现象。当Lu^(3+)含量为60%时,通过将LuYAG∶Ce荧光陶瓷与蓝光LED组合,其发光强度达到最大值,流明效率达到114 lm∙W^(-1)。使用450 nm激光源与LuYAG∶Ce荧光陶瓷构建了透射模式下的激光驱动照明装置。随着功率密度从2.2 W·mm^(-2)增加到39 W·mm^(-2),Lu^(3+)含量为60%的荧光陶瓷光通量从128 lm增加到1874 lm,且没有发光饱和的迹象,最佳发光效率达到128 lm·W^(-1)。因此,LuYAG∶Ce荧光陶瓷有望成为高功率LED/LD照明的潜在荧光转换材料。