Experimental investigation on the invert stability of operating railway tunnels with different drainage systems using 3D printing technology

In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently,which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor to ensure the invert stability by regulating the external water pressure(EWP). By means of a threedimensional(3D) printing model, this paper experimentally investigates the deformation behavior of the invert for the tunnels with the traditional drainage system(TDS) widely used in China and its optimized drainage system(ODS) with bottom drainage function. Six test groups with a total of 110 test conditions were designed to consider the design factors and environmental factors in engineering practice,including layout of the drainage system, blockage of the drainage system and groundwater level fluctuation. It was found that there are significant differences in the water discharge, EWP and invert stability for the tunnels with the two drainage systems. Even with a dense arrangement of the external blind tubes, TDS was still difficult to eliminate the excessive EWP below the invert, which is the main cause for the invert instability. Blockage of drainage system further increased the invert uplift and aggravated the track irregularity, especially when the blockage degree is more than 50%. However, ODS can prevent these invert anomalies by reasonably controlling the EWP at tunnel bottom. Even when the groundwater level reached 60 m and the blind tubes were fully blocked, the invert stability can still be maintained and the railway track experienced a settlement of only 1.8 mm. Meanwhile, the on-site monitoring under several rainstorms further showed that the average EWP of the invert was controlled within 84 k Pa, while the maximum settlement of the track slab was only 0.92 mm, which also was in good agreement with the results of model test.

Characterization of a 3-Phase a.c. Free Burning Arc Plasma

A 3-phase a.c. arc plasma reactor with large volume plasma has been developed for the synthesis of new carbon nano-structures. One of the main characteristics of the plasma system is related to the absence of a fixed neutral point. This gives rise to a rich and complex phenomenology related to instabilities and arc motion since the arcs are ＂burning＂ freely in the gas flow between the three electrodes. This paper is dedicated to the analysis of the behavior of such a system under typical conditions using argon and nitrogen as plasma gases. A classification of are configuration, arc commutating, arc interaction, arc motion and arc instabilities are discussed based on ultra high-speed cine camera analysis. A simple model describing the time evolution of the system is also presented and compared with the experimental measurements. The results show that an adequate control could allow the improvement of the overall system.

Ecofriendly Hydroxyalkyl Cellulose Additives for Efficient and Stable MAPbI_(3)-Based Inverted Perovskite Solar Cells

Perovskite solar cells(PSCs)have been demonstrated to be one of the most promising technologies in the field of renewable energy.However,the presence of the defects in the perovskite films greatly limits the efficiency and the stability of the PSCs.The additive engineering is one of the most effective approaches to overcome this problem.Most of the successful additives are extracted from the petroleum-based materials,while the research on the biomass-based additives is still lagging behind.In this paper,two ecofriendly hydroxyalkyl cellulose additives,i.e.,hydroxyethyl cellulose(HEC)and hydroxylpropyl cellulose(HPC),are investigated on the performance of the MAPbl_(3)-based inverted PSCs.Due to the strong interaction between the hydroxyl groups of the cellulose and the divalent cations of the perovskite,these additives enhance the crystal grain orientation and significantly repair the defects of the perovskite films.Working as the additives,these two cellulose derivatives show a strong passivation ability,which significantly reduces the trap density and improves the optoelectronic feature of the PSCs.Compared with the average power conversion efficiency(PCE)of the control device(19.19%),an enhancement of~10%is achieved after the addition of HEC.The optimized device(PCE=21.25%)with a long-term stability(10:80 h,PCE=20.93%)is achieved by the incorporation of the HEC additives into the precursor solution.It is the best performance among the PSCs with the cellulose additives up to now.This research provides a novel choice to develop a cost-effective and renewable additive for the PSCs with high efficiency and excellent long-term stability.

A new design of stator magnetic system for 3-phase & 12-pole HB stepper

A new design of stato magnetic System is Proposed for 3-phase & 12-pole HB stepper, and it features bet-ter distribution of magntic lield to incare Pullou tope and bopmve Operaonal stability of moor and minimummutual inductance between phase windimp to make design of control circuit easier, and application proved it is as good as expected.

Improvement of β-phase crystal formation in a BaTiO3-modified PVDF membrane

In this paper,low temperature plasma is used to modify the surface of barium titanate（BaTiO3）nanoparticles in order to enhance the interfacial compatibility between ferroelectric poly（vinylidene fluoride）（PVDF） and BaTiO3 nanoparticles.The results demonstrate that oxygenic groups are successfully attached to the BaTiO3 surface,and the quantity of the functional groups increases with the treatment voltage.Furthermore,the effect of modified BaTiO3 nanoparticles on the morphology and crystal structure of the PVDF/BaTiO3 membrane is investigated.The results reveal that the dispersion of BaTiO3 nanoparticles in the PVDF matrix was greatly improved due to the modification of the BaTiO3 nanoparticles by air plasma.It is worth noting that the formation of a β-phase in a PVDF/modified BaTiO3 membrane is observably promoted,which results from the strong interaction between PVDF chains and oxygenic groups fixed on the BaTiO3 surface and the better dispersion of BaTiO3 nanoparticles in the PVDF matrix.Besides,the PVDF/modified BaTiO3 membrane at the treatment voltage of 24 k V exhibits a lower water contact angle（≈68.4°） compared with the unmodified one（≈86.7°）.Meanwhile,the dielectric constant of PVDF/BaTiO3 nanocomposites increases with the increase of working voltage.

3-Phase Modeling for the Origin of Chinese Lithium-Rich Brines

There are significantly different origins and mineralizations among various lithium-rich brines of the world.As for Clayton Valley,Nevada,the data and interpretations recently presented suggest that the model

Fault diagnosis algorithm for 3-phase passive rectifiers based on frequency-domain analysis for acceleration grid power supply in CFETR NBI system

The acceleration grid power supply(AGPS) is a crucial part of the Negative-ion Neutral Beam Injection system in the China Fusion Engineering Test Reactor,which includes a 3-phase passive(diode) rectifier.To diagnose and localize faults in the rectifier,this paper proposes a frequencydomain analysis-based fault diagnosis algorithm for the rectifier in AGPS.First,time-domain expressions and spectral characteristics of the output voltage of the TPTL-NPC inverter-based power supply are analyzed.Then,frequency-domain analysis-based fault diagnosis and frequency-domain analysis-based sub-fault diagnosis algorithms are proposed to diagnose open circuit(OC) faults of diode(s),which benefit from the analysis of harmonics magnitude and phase-angle of the output voltage.Only a fundamental period is needed to diagnose and localize exact faults,and a strong Variable-duration Fault Detection Method is proposed to identify acceptable ripple from OC faults.Detailed simulations and experimental results demonstrate the effectiveness,quickness,and robustness of the proposed algorithms,and the diagnosis algorithms proposed in this article provide a significant method for the fault diagnosis of other rectifiers and converters.

A Device for Measuring 3-Phase Alternating Current at a Distance

We have made a preliminary study on a possibility to build a device, which could measure three-phase alternating current at a distance. This report gives a brief look at the theoretical background related with such a device and derives several mathematical results associated with the theory and the structure of the device. Our results suggest that such a device can be built, assuming the distances between the three current-carrying wires and the two sensors of the device are known accurately enough. There are ways to measure these distances, but this article does not concentrate on them.

RWNeRF:Robust Watermarking Scheme for Neural Radiance Fields Based on Invertible Neural Networks

As neural radiance fields continue to advance in 3D content representation,the copyright issues surrounding 3D models oriented towards implicit representation become increasingly pressing.In response to this challenge,this paper treats the embedding and extraction of neural radiance field watermarks as inverse problems of image transformations and proposes a scheme for protecting neural radiance field copyrights using invertible neural network watermarking.Leveraging 2D image watermarking technology for 3D scene protection,the scheme embeds watermarks within the training images of neural radiance fields through the forward process in invertible neural networks and extracts them from images rendered by neural radiance fields through the reverse process,thereby ensuring copyright protection for both the neural radiance fields and associated 3D scenes.However,challenges such as information loss during rendering processes and deliberate tampering necessitate the design of an image quality enhancement module to increase the scheme’s robustness.This module restores distorted images through neural network processing before watermark extraction.Additionally,embedding watermarks in each training image enables watermark information extraction from multiple viewpoints.Our proposed watermarking method achieves a PSNR(Peak Signal-to-Noise Ratio)value exceeding 37 dB for images containing watermarks and 22 dB for recovered watermarked images,as evaluated on the Lego,Hotdog,and Chair datasets,respectively.These results demonstrate the efficacy of our scheme in enhancing copyright protection.

Non-destructive buffer enabling near-infrared-transparent inverted inorganic perovskite solar cells toward 1400 h light-soaking stable perovskite/Cu(In,Ga)Se_(2) tandem solar cells

Near-infrared(NIR)transparent inverted all-inorganic perovskite solar cells(PSCs)are excellent top cell candidates in tandem applications.An essential challenge is the replacement of metal contacts with transparent conductive oxide(TCO)electrodes,which requires the introduction of a buffer layer to prevent sputtering damage.In this study,we show that the conventional buffers(i.e.,small organic molecules and atomic layer deposited metal oxides)used for organic-inorganic hybrid perovskites are not applicable to all-inorganic perovskites,due to non-uniform coverage of the vulnerable layers underneath,deterioration upon ion bombardment and moisture induced perovskite phase transition,A thin film of metal oxide nanoparticles by the spin-coating method serves as a non-destructive buffer layer for inorganic PSCs.All-inorganic inverted near-infrared-transparent PSCs deliver a PCE of 17.46%and an average transmittance of 73.7%between 780 and 1200 nm.In combination with an 18.56%Cu(In,Ga)Se_(2) bottom cell,we further demonstrate the first all-inorganic perovskite/CIGS 4-T tandem solar cell with a PCE of 24.75%,which exhibits excellent illumination stability by maintaining 86.7%of its initial efficiency after 1400 h.The non-destructive buffer lays the foundation for efficient and stable NIR-transparent inverted inorganic perovskite solar cells and perovskite-based tandems.

基于超级电容储能的HL-3装置中性束逆变型高压电源模块设计

高压电源是中性束注入加热系统的重要组成部分,决定着束能量和引出束流的品质。随着电压等级的逐步提高,脉冲阶梯调制(Pulse Step Modulation,PSM)高压电源无法满足实验要求。为了实现中性束调制注入功率的快速切换,提出一种基于超级电容储能的逆变型高压电源。采用超级电容储能方式,降低所需电网容量,减小对电网的冲击。采用软开关技术的直流(DC)-直流(DC)谐振变换器结构,提高电源的响应速度,减小开关器件的开关损耗。设计电源模块电路拓扑,根据电源性能指标要求完成系统建模计算。建立充电电路和主回路的电力仿真软件PSIM(Power SIMulation)仿真模型,对电源性能指标进行仿真验证。最后搭建了逆变电源模块测试样机,进行了阶跃响应、电压纹波和软开关性能指标测试。仿真及实验验证结果表明:设计的电源模块能够实现1 600 V/50 A的稳定输出,满足6 MW/120 kV设计要求。

葡萄籽提取物对前列腺癌PC-3细胞形态结构的影响

目的：观察葡萄籽提取物（GSE）对前列腺癌PC-3细胞形态结构的影响。方法：采用相差显微镜、HE染色和透射电镜观察不同浓度（100、200、300μg／ml）GSE与PC-3细胞作用24、48和72h后细胞形态结构的改变。结果：对照组PC-3细胞在相差显微镜下可观察到细胞呈不规则梭形爬壁生长，贴壁牢固，折光性强；HE染色后光镜下观察显示细胞呈梭形，核规整，染成均一蓝色；透射电镜观察结果显示对照组PC-3细胞有丰富的微绒毛，细胞质内线粒体完整，线粒体嵴清晰，内质网无明显扩张，胞质、胞核无水肿，核膜、质膜完整。采用不同浓度的GSE作用24—72h后，相差显微镜下可见PC-3细胞变圆、变小，细胞膜透亮，高浓度组（300μg／mlGSE作用72h）出现悬浮细胞，表明细胞分裂减少，生长受到抑制；光镜下见PC-3细胞核质比增大，呈多核、巨核，异染色质增多，细胞轮廓模糊。电镜显示GSE作用后PC-3细胞微绒毛结构多数消失，细胞萎缩，胞内出现大量的空泡、染色质凝集、核膜皱缩和核下出现微小空泡等坏死和凋亡的形态特征。结论：GSE可造成PC-3细胞形态结构改变，并诱导PC-3细胞凋亡与坏死，其具体作用机制有待进一步研究。

Gamma 3髓内钉固定与倒置LISS钢板固定治疗股骨转子下骨折的临床比较

目的 比较Gamma 3髓内钉固定与倒置LISS钢板固定对股骨转子下骨折的临床疗效。方法 将2014年1月-2015年10月浙江省嘉兴市第一医院骨科收治的92例股骨转子下骨折患者纳入研究对象,按照手术方案差异分为A组（n=46）与B组（n=46）,A组予Gamma 3髓内钉固定术,B组予倒置LISS钢板固定术。对比两组术中相关指标、住院时间、骨折愈合时间、临床疗效以及术后并发症情况。结果 A组手术时间（89.58±9.82）min、出血量（305.53±54.27）m L、切口长度（10.47±1.58）cm、住院时间（10.36±5.27）d,明显小于B组（109.38±11.36）min、（395.32±52.45）m L、（14.92±1.41）cm、（12.61±4.85）d;两组骨折愈合时间、治疗总优良率、术后并发症总发生率比较差异不具显著性（P〉0.05）。结论 Gamma 3髓内钉固定与倒置LISS钢板固定均能对股骨转子下骨折产生良好疗效,Gamma 3髓内钉固定术在手术时间、术中出血量、切口长度及住院时间等方面有一定优势。

猪蛋白编码基因3’UTR中IRPRE1元件的鉴定及其基因特征分析

为鉴定猪全基因组范围内蛋白编码基因3’UTR(3’-untranslated region)中反向重复PRE1(inverted repeated PRE1,IRPRE1)元件,对猪全基因组的22342个蛋白编码基因的3’UTR序列进行重复序列元件的生物信息学分析。结果表明:猪蛋白编码基因的3’UTR序列中短散在重复序列与简单重复序列在重复序列的类别中所占比例较高,分别为27.58%与31.08%;在SINE/t RNA的重复元件中,Pre0_SS和PRE1x元件所占的比例较高,分别为41.83%和37.51%;共有1 094个候选蛋白编码基因的3’UTR中含有IRPRE1元件;GO分析发现这些候选基因主要参与m RNA经由剪接体的剪接、细胞分裂、RNA通过酯交换反应发生的剪接、T细胞激活、RNA剪接、T细胞受体信号通路、对糖苷反应、甘油三酯稳态、外源性凋亡信号通路的正调节及胆固醇合成等生物过程;KEGG pathway分析发现这些候选基因参与了缬草碱、亮氨酸和异亮氨酸降解途径、TNF信号通路、T细胞受体信号通路、RIG-I样受体信号通路、吞噬体、剪接体、胆汁分泌、甲状腺激素合成和凋亡;对3个蛋白编码基因的3’UTR中的IRPRE1元件进行鉴定发现,其在多个组织中广泛表达。

Survivin及Caspase-3在鼻腔鼻窦内翻性乳头状瘤及鼻腔鳞状细胞癌中的表达及其意义

目的探讨细胞凋亡抑制蛋白Survivin及半胱氨酸天冬氨酸蛋白酶3(Caspase-3)在鼻腔鼻窦内翻性乳头状瘤(sinonasal inverted papillomas,SNIP)及鼻腔鳞状细胞癌(nasal squamous cell carcinoma,NSCC)中的表达及其意义。方法采用免疫组化Envision二步法检测37例SNIP、19例NSCC及20例下鼻甲黏膜组织标本中的Survivin及Caspase-3的表达。结果 SNIP组和NSCC组中Survivin的表达率分别为67.6%(25/37)、89.5%(17/19),均显著高于下鼻甲黏膜组的表达率0(0/20,P<0.01)。NSCC组中Caspase-3的表达率为26.3%(5/19),显著低于下鼻甲黏膜组的表达率100.0%(20/20,P<0.01),SNIP组中Caspase-3的表达率为43.2%(16/37),低于下鼻甲黏膜组,但两者之间的差异无显著性(P>0.05)。Survivin和Caspase-3在SNIP和NSCC中的表达呈负相关(P<0.01)。结论 Survivin可能在SNIP和NSCC发生和发展过程中起着重要的促进作用,且与Caspase-3呈负相关,Survivin可能成为SNIP和NSCC基因治疗的新靶点。

SINAMICS G120变频器的2线、3线控制

Siemens A&D推出新一代集成式变频器SINAMICS G120。全新的模块化变频器,集成了故障安全保护功能和通用的现场总线通讯,并具有再生能量回馈功能,是一款更加灵活可靠的变频器。通过对G120变频器调试,阐述了如何应用利用STATER软件配置系统参数,设置变频器的2线,3线控制方式,并详细阐述2线,3线控制方式的控制时序。

一种用于DC 3000V供电制式的动车组牵引辅助逆变器的研制

介绍了一种用于直流3 000 V供电制式下的动车组牵引辅助逆变器的主电路、技术参数及总体结构,重点分析了该逆变器的器件选型、结构特点和辅助滤波器设计。通过实际装车考核运行情况表明,该型牵引逆变器运行稳定,满足DC 3 000 V电网供电动车组的运用要求。

3×3相永磁辅助同步磁阻电机两相开路故障容错控制策略

单逆变器驱动的3×3相永磁辅助同步磁阻电机系统具有低成本、高可靠性的优点。该文针对此系统的两相开路故障,提出一种各模块转矩重新分配的容错控制策略。当同一模块发生两相开路故障时,将该故障模块完全切除,通过增加非故障模块的电流来实现容错运行。对于不同模块同相位两相开路,通过分析故障后各模块的等效电路,获得两相静止坐标系下电流之间的关系,然后构造拉格朗日函数,以铜耗最小为目标,求解电流幅值的最优解,最终实现转矩的重新分配。当发生不同相位两相开路时,以故障模块输出最大平均转矩以及总的转矩脉动最小为目标,对各模块转矩进行重新分配。该方法通过增加正常模块转矩脉动来部分抵消故障模块产生的脉动,达到抑制输出转矩脉动的目的。实验结果验证了所提容错控制策略能有效降低故障后电机的转矩脉动,提高了控制系统的可靠性。

Intrinsic thermal stability of inverted perovskite solar cells based on electrochemical deposited PEDOT

Thermal stability of perovskite materials is an issue impairing the long-term operation of inverted perovskite solar cells(PSCs). Herein, the thermal attenuation mechanism of the MAPb I3films that deposited on two different hole transport layers(HTL), poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS) and poly(3,4-ethylenedioxythiophene)(PEDOT), is comprehensively studied by applying a heat treatment at 85℃. The thermal stress causes the mutual ions migration of I, Pb and Ag through the device, which leads to the thermal decomposition of perovskite to form Pb I2. Interestingly, we find that I ions tend to migrate more towards electron transport layer(ETL) during heating, which is different with the observation of I ions migration towards HTL when bias pressure is applied. Moreover, the use of electrochemical deposited PEDOT as HTL significantly decreases the defect density of MAPb I3films as compared to PEDOT:PSS supported one. The electrochemical deposition PEDOT has good carrier mobility and low acidity, which avoids the drawbacks of aqueous PEDOT:PSS. Accordingly, the inverted PSCs based on PEDOT show superior durability than that with PEDOT:PSS. Our results reveal detailed degradation routes of a new kind of inverted PSCs which can contribute to the understanding of the failure of thermal-aged inverted PSCs.

Hyperbranched phthalocyanine enabling black-phase formamidinium perovskite solar cells processing and operating in humidity open air

The extreme instability of pureα-phase FAPbI_(3) under high humidity conditions restricts the highthroughput fabrication in unmodified air environments,resulting in poor performance ofα-phase FAPbI_(3) perovskite devices obtained by scalable fabrication methods.Here we synthesized hyperbranched copper phthalocyanine(HCuPc)as a supramolecular additive with twisted phthalocyanine units to realize the molecular-level encapsulation at the grain boundaries through supramolecular interaction,which greatly broadened the processing window of FAPbI_(3) under high humidity.At the same time,unlike traditional encapsulation layer that carrier can only be collected by tunneling effect,the twisted phthalocyanine ring of HCu Pc in perovskite films is more conducive to hole extraction.Finally,a record efficiency was achieved in pure FAPbI_(3) based inverted structured solar cell by blade-coating to the best of our knowledge,even under unmodified humid air conditions(relative humidity of 65%–85%).The best operational stability of 3D pure FAPbI_(3) devices can also be achieved at the same time and unencapsulated HCuPc-FAPbI_(3) device can even operate with negligible degradation for 100 h in the open air(RH 30%–40%).