气压及流速可调的气动夹头控制器

本发明公开了气压及流速可调的气动夹头控制器， 包括壳体、压力表、调压阀、控制开关组、限流阀组、总进气嘴、第一夹头进气嘴组和第二夹头进气嘴组， 壳体包括前侧板和后侧板， 压力表、调压阀和控制开关组分别嵌接于前侧板；限流阀组、总进气嘴、第一夹头进气嘴组和第二夹头进气嘴组嵌接于后侧板；调压阀包括调压阀体和调节旋钮， 调压阀体上连接有调压进气嘴和调压出气接头， 调压进气嘴与总进气嘴连接， 调压出气接头连接有压力表和限流阀组；控制开关组上连接有控制进气接头组和控制出气接头组。本发明将压力表、调压阀、控制开关组、限流阀组、总进气嘴、第一夹头进气嘴组和第二夹头进气嘴组集成于壳体， 即该壳体具备高集成度和完善的功能

The failure behavior of syntactic foams as buoyancy materials for deepsea applications

Syntactic foams made of hollow particles embedded in a matrix material are widely used as buoyancy materials for underwater marine structures, where both low density and high mechanical properties are desired. In most engineering materials, however, the reduction in density is often accompanied with the decrease in stiffness and strength. Such a dilemma forces us to strike a balance between them for different application scenarios, which necessitates a profound understanding of the structure -property correlations in syntactic foams. In this paper, we investigated the mechanical properties of syntactic foams subjected to triaxial compressive loading. Taking particle crushing as the primary failure mode, we develop an analytical analysis on the compressive strength of syntactic foams. For syntactic foams with high strength under hydrostatic pressure, they may fail readily in the presence of deviatoric stress. In addition, we identify the critical conditions associated with other failure modes, including particle -matrix interface delamination and particle buckling. This study not only sheds light on the structure -property relationship in syntactic foams for deepsea usage, but also provides guideline for the design and optimization of syntactic foams, which would be of great value for the development of high-performance underwater structures

固体浮力材料研究前沿

固体浮力材料是深海开发中普遍应用的一种功能材料,利用其密度小于海水的特点,实现往返式深潜器的无动力上浮和海底生产系统的浮力补偿与保温.随着海洋资源开发及科考向深海的挺进,装备作业模式向长时间坐底、连续往返方向发展,因此对固体浮力材料提出了更为苛刻的要求.低密度、抗高静水压的能力以及长时间深水服役环境下的可靠性是固体浮力材料的核心目标.文章以这三方面要素为牵引,分类阐述了两相、三相和混杂强化浮力材料的微结构与性能之间的关系.同时结合深远海探测装备长期服役的需求,从物理老化、吸水和降解等方面着重论述了浮力材料在不同环境中的耐久性研究.最后文章就浮力材料和构件设计中的问题和挑战以及固体浮力材料技术的未来发展提供了建议和讨论

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies