An inversely designed integrated spectrometer with reconfigurable performance and ultra-low power consumption

Despite the pressing demand for integrated spectrometers,a solution that deliver high-performance while being practically operated is still missing.Furthermore,current integrated spectrometers lack reconfigurability in their performance,which is highly desirable for dynamic working scenarios.This study presents a viable solution by demonstrating a userfriendly,reconfigurable spectrometer on silicon.At the core of this innovative spectrometer is a programmable photonic circuit capable of exhibiting diverse spectral responses,which can be significantly adjusted using on-chip phase shifters.The distinguishing feature of our spectrometer lies in its inverse design approach,facilitating effortless control and efficient manipulation of the programmable circuit.By eliminating the need for intricate configuration,our design reduces power consumption and mitigates control complexity.Additionally,our reconfigurable spectrometer offers two distinct operating conditions.In the Ultra-High-Performance mode,it is activated by multiple phase-shifters and achieves exceptional spectral resolution in the picometer scale while maintaining broad bandwidth.On the other hand,the Ease-of-Use mode further simplifies the control logic and reduces power consumption by actuating a single-phase shifter.Although this mode provides a slightly degraded spectral resolution of approximately 0.3 nm,it prioritizes ease of use and is wellsuited for applications where ultra-fine spectral reconstruction is not a primary requirement.

Optimized online filter stack spectrometer for ultrashort X-ray pulses

Currently,with the advent of high-repetition-rate laser-plasma experiments,the demand for online diagnosis for the X-ray spectrum is increasing because the laser-plasma-generated X-ray spectrum is very important for characterizing electron dynamics and applications.In this study,scintillators and silicon PIN(P-type–intrinsic-N-type semiconductor)diodes were used to construct a wideband online filter stack spectrometer.The X-ray sensor and filter arrangement was optimized using a genetic algorithm to minimize the condition number of the response matrix.Consequently,the unfolding error was significantly reduced based on numerical experiments.The detector responses were quantitatively calibrated by irradiating the scintillator and PIN diode with various nuclides and comparing the measuredγ-ray peaks.A prototype 15-channel spectrometer was developed by integrating an X-ray detector with front-and back-end electronics.The prototype spectrometer could record X-ray pulse signals at a repetition rate of 1 kHz.Furthermore,an optimized spectrometer was employed to record the real-time spectra of laser-driven bremsstrahlung sources.This optimized spectrometer offers a compact solution for spectrum diagnostics of ultrashort X-ray pulses,exhibiting improved accuracy in terms of spectrum measurements and repetition rates,and could be widely used in next-generation high-repetition-rate high-power laser facilities.

Design and implementation of the monochromator shielding for the cold neutron spectrometers XINGZHI and BOYA

An innovative monochromator shielding is designed and implemented for the cold neutron spectrometers XINGZHI and BOYA operated by Renmin University of China at China Advanced Research Reactor.Via Monte Carlo simulations and careful mechanical designs,a shielding configuration has been successfully developed to satisfy safety requirements of below 3μSv/h dose rate at its exterior,meanwhile fulfilling space,floor load and nonmagnetic requirements.Composite materials are utilized to form the sandwich-type shielding walls:the inner layer of boron carbide rubber,the middle layer of steel-encased lead and the outer layer of borated polyethylene.Special-shaped liftable shielding blocks are incorporated to facilitate a continuous adjustment of the neutron energy while preventing radiation leakage.Our work has demonstrated that by utilizing composite shielding materials,along with the sandwich structure and liftable shielding blocks,a compact and lightweight shielding solution can be achieved.This enables the realization of advanced neutron scattering instruments that provide expanded space of measurement,larger energy and momentum coverage,and higher flux on the sample.This shielding represents the first of its kind in neutron scattering instruments in China.Following its successful operation,it has been subsequently employed by other neutron instruments across the country.

A seven-crystal spectrometer for high-energy resolution X-ray spectroscopy at Shanghai Synchrotron Radiation Facility

A Johann-type X-ray spectrometer was successfully developed at the hard X-ray branch(in-vacuum undulator with a 24-mm periodic length)of the energy material beamline(E-line)at the Shanghai Synchrotron Radiation Facility(SSRF).This spectrometer was utilized to implement X-ray emission spectroscopy(XES),high-energy resolution fluorescence-detected X-ray absorption spectroscopy(HERFD-XAS),and resonant inelastic X-ray scattering.Seven spherically bent crystals were positioned on the respective vertical 500-mm-diameter Rowland circles,adopting an area detector to increase the solid angle to 1.75%of 4πsr,facilitating the study of low-concentrate systems under complex reaction conditions.Operated under the atmosphere pressure,the spectrometer covers the energy region from 3.5 to 18 keV,with the Bragg angle ranging from 73°to 86°during vertical scanning.It offers a promised energy resolution of sub-eV(XES)and super-eV(HERFD-XAS).Generally,these comprehensive core-level spectroscopy methods based on hard X-rays at the E-line with an extremely high photon flux can meet the crucial requirements of a green energy strategy.Moreover,they provide substantial support for scientific advances in fundamental research.

Artificial neural network-based method for discriminating Compton scattering events in high-purity germaniumγ-ray spectrometer

To detect radioactive substances with low activity levels,an anticoincidence detector and a high-purity germanium(HPGe)detector are typically used simultaneously to suppress Compton scattering background,thereby resulting in an extremely low detection limit and improving the measurement accuracy.However,the complex and expensive hardware required does not facilitate the application or promotion of this method.Thus,a method is proposed in this study to discriminate the digital waveform of pulse signals output using an HPGe detector,whereby Compton scattering background is suppressed and a low minimum detectable activity(MDA)is achieved without using an expensive and complex anticoincidence detector and device.The electric-field-strength and energy-deposition distributions of the detector are simulated to determine the relationship between pulse shape and energy-deposition location,as well as the characteristics of energy-deposition distributions for fulland partial-energy deposition events.This relationship is used to develop a pulse-shape-discrimination algorithm based on an artificial neural network for pulse-feature identification.To accurately determine the relationship between the deposited energy of gamma(γ)rays in the detector and the deposition location,we extract four shape parameters from the pulse signals output by the detector.Machine learning is used to input the four shape parameters into the detector.Subsequently,the pulse signals are identified and classified to discriminate between partial-and full-energy deposition events.Some partial-energy deposition events are removed to suppress Compton scattering.The proposed method effectively decreases the MDA of an HPGeγ-energy dispersive spectrometer.Test results show that the Compton suppression factors for energy spectra obtained from measurements on ^(152)Eu,^(137)Cs,and ^(60)Co radioactive sources are 1.13(344 keV),1.11(662 keV),and 1.08(1332 keV),respectively,and that the corresponding MDAs are 1.4%,5.3%,and 21.6%lower,respectively.

An empirical method for joint inversion of wave and wind parameters based on SAR and wave spectrometer data

Synthetic aperture radar(SAR)and wave spectrometers,crucial in microwave remote sensing,play an essential role in monitoring sea surface wind and wave conditions.However,they face inherent limitations in observing sea surface phenomena.SAR systems,for instance,are hindered by an azimuth cut-off phenomenon in sea surface wind field observation.Wave spectrometers,while unaffected by the azimuth cutoff phenomenon,struggle with low azimuth resolution,impacting the capture of detailed wave and wind field data.This study utilizes SAR and surface wave investigation and monitoring(SWIM)data to initially extract key feature parameters,which are then prioritized using the extreme gradient boosting(XGBoost)algorithm.The research further addresses feature collinearity through a combined analysis of feature importance and correlation,leading to the development of an inversion model for wave and wind parameters based on XGBoost.A comparative analysis of this model with ERA5 reanalysis and buoy data for of significant wave height,mean wave period,wind direction,and wind speed reveals root mean square errors of 0.212 m,0.525 s,27.446°,and 1.092 m/s,compared to 0.314 m,0.888 s,27.698°,and 1.315 m/s from buoy data,respectively.These results demonstrate the model’s effective retrieval of wave and wind parameters.Finally,the model,incorporating altimeter and scatterometer data,is evaluated against SAR/SWIM single and dual payload inversion methods across different wind speeds.This comparison highlights the model’s superior inversion accuracy over other methods.

造纸机械生产线的CIMS研究

随着信息技术的飞速发展和制造业的转型升级,计算机集成制造系统(Computer Integrated Manufacturing System,CIMS)在现代制造业中扮演着核心角色。文章旨在深入探讨造纸机械生产线中CIMS的应用,分析其系统构成、关键技术及实施效果。通过引入CIMS,造纸机械生产线能够实现对设计、工艺、生产、管理等活动的全面集成,以提高生产效率、产品质量和市场竞争力。

CIMS环境下产品信息编码原理的研究与应用

对产品信息进行统一编码 ,是企业实施 CIMS过程中需要研究和解决的关键问题之一。分析了产品信息及其分类、特性与结构 ;讨论了 CIMS对产品信息编码的基本要求 ;详细论述了 CIMS环境下产品信息编码原理和方法 ;基于该原理 ,在 i MAN(UGS的 PDM系统 )中开发了一个空调器产品信息编码工具 ;介绍了通过统一的产品信息代码、产品零部件主属性和信息关联技术 。

CIMS中的信息分类编码技术及其发展

从CIMS对信息集成的要求出发 ,探讨了CIMS中的信息分类编码问题。在分析国内外一些主要分类编码系统的基础上 ,指出了它们的不足之处 ,并结合实际应用系统 ,提出了两个适合CIMS信息集成的分类编码系统 :一个是具有分级柔性的分类编码系统模型 ,另一个是功能强大、基于面向对象思想构造的分类编码系统模型。

流程工业CIMS中生产调度研究进展

针对当前流程工业ＣＩＭＳ的关键问题，分析了流程工业ＣＩＭＳ中生产调度系统的结构和特点，介绍了流程工业生产调度的主要方法及其研究进展。

面向CIMS的覆盖件模具CAD/CAM技术

目前计算机集成制造系统（CIMS）已成为制造工业应用计算机技术的主要发展方向。从产品定义模型、系统的集成方案、系统信息流的特点等方面，介绍东风汽车公司冲模厂应用CIMS哲理进行的覆盖件模具CAD／CAM技术的研究与实现方法。

CIMS技术的进展与复合信息模型

本文根据国内外ＣＩＭＳ发展的概况，首先介绍了基本概念和定义，然后对ＣＩＭＳ的体系结构、模型、方法与工具进行了较为全面的介绍，指出了它们的特点。最后对复合信息模型及其应用进行了论述，并对存在的问题和发展方向进行了讨论。

关于在我国企业中实施CIMS的研究

本文根据我们近几年来对ＣＩＭＳ实施的理论和实践的研究，围绕“ＣＩＭＳ的实施目标、ＣＩＭＳ实施的几个阶段和ＣＩＭＳ的实施过程中企业结构的变化模式”等方面进行了讨论，并结合我国目前实施ＣＩＭＳ企业的现状，探讨了它们普遍存在的问题，以及克服这些问题的对策。

CIMS体系结构研究

CIMS是计算机应用新潮流，它的开发问题引发了一些新的重大课题。从体系结构方面入手，文中讨论了CIMS的开发问题，分析了CIMS的静态结构与动态结构，提出动态结构的面向对象化与协议化（模型化）的路线，并说明了以协议化为基础的系统划分与集成方法。

国家CIMS工程技术研究中心的虚拟制造基地及研究进展

介绍了国家ＣＩＭＳ中心开展虚拟制造研究的最近进展，包括所建立的虚拟制造基地的体系结构，解决的关键技术，以及结合典型产品进行虚拟制造研究所取得的初步成果。

CIMS网管的智能配置分析

本文在分析传统 CIMS网管的不足时提出了新型 CIMS网管体系结构 ,剖析了智能配置在网管中的作用和地位并详细描述了智能配置向 CIMS网络提供的管理功能 .

CIMS环境中的集成化工艺过程设计

介绍一个CIMS或FMS环境下的集成化CAPP系统——THCAPP,该系统以非回转体零件为加工对象,利用IGES实现与CAD/CAPP/CAM的信息集成。工艺路线生成核心是创成式专家系统,推理机的控制策略以启发式搜索的估价函数为主,可自动选择定位夹紧面。工艺知识库为独立的、可维护的形式,根据CIMS车间的实际环境可获得多种工艺方案。

MES——流程工业CIMS发展的关键

生产执行 (ManufacturingExecutionSystem ,MES)是CIMS信息集成的中心环节 ,是流程工业CIMS发展的关键。首先介绍了MES的一般功能模型及其与CIMS的关系 ,进而基于流程工业特点对流程工业MES的体系结构和功能模块进行了探讨 。

MAS和CSCW在CIMS中的新应用

在实现ＣＩＭＳ的有效集成方面，多智能体系统（ＭＡＳ）、计算机支持的协同工作（ＣＳＣＷ）提供了一种全新的理念与有效的手段。ＣＩＭＳ中的ＭＡＳ、ＣＳＣＷ研究正日益得到人们的关注，其应用领域主要涉及制造系统、协同设计、工作流管理、供应链管理、并行工程等方面。本文综述了有关研究与应用现状，并提出了深入研究ＣＩＭＳ中ＭＡＳ。

CIMS工程中的加工过程仿真技术

基于ＣＩＭＳ对仿真技术的需求，研究开发了协同ＣＩＭＳ工程各环节和完成ＣＩＭＳ工程设计必不可少的支持环境──加工过程仿真器ＭＰＳ。介绍了ＭＰＳ的结构、关键技术和主要算法（包括几何及运动建模、数控代码翻译、碰撞和干涉检验、材料切除以及加工动画等），提出了实体Ｒａｙ－Ｒｅｐ表达方法（简化了实体间的布尔运算过程，大大提高了材料切除过程的仿真速度）和Ｖｏｘｅｌ十Ｂ－Ｒｅｐ算法（解决了加工过程碰撞和干涉仿真的快速检测问题）。最后给出了ＭＰＳ的应用实例。