Three-dimensional electrochemical-magnetic-thermal coupling model for lithium-ion batteries and its application in battery health monitoring and fault diagnosis.

Storage batteries with elevated energy density, superior safety and economic costs continues to escalate. Batteries can pose safety hazards due to internal short circuits, open circuits and other malfunctions during usage, hence real-time surveillance and error diagnosis of the battery's operational state is imperative. In this paper, a three-dimensional model of electrochemical-magnetic field-thermal coupling is formulated with lithium-ion pouch cells as the research focus, and the spatial distribution pattern of the physical field such as magnetic field and temperature when the battery is operational is acquired. Furthermore, this manuscript also investigates the diagnostic methodology for defective batteries with internal short circuits and fissures, that is, the operational state of the battery is evaluated and diagnosed by the distribution of the magnetic field surrounding the battery. To substantiate the method's practical viability, the present study extends its examination to the 18650-battery pack. We obtained the magnetic field images of the normal operation of the battery pack and the failure state of some batteries and analyzed the relationship between the magnetic field distribution characteristics and the performance of the battery pack, providing a new method for the health monitoring and fault diagnosis of the battery pack. This non-contact method incurs no damage to the battery, concurrently exhibiting elevated sensitivity and extremely rapid response time. Meanwhile, it provides an effective means for non-destructive research on the batteries and can be applied to areas such as battery safety screening and non-destructive testing. This research not only helps to facilitate our understanding of the battery's operating mechanism, but also provides robust support for safe operation and optimal battery design.

A solid-state optical filter at 1530 nm based on Voigt anomalous dispersion effect in rare earth ion-doped crystal.

This paper proposes an ultra-narrow band solid state optical filter with Voigt anomalous dispersion at 1530 nm based on Er3+: LiYF4, sets a theoretical model for its realization of ultra-narrow band optical filtering, and performs simulations based on the model. The results show that the maxi-mum transmission of the filter is close to 80%, while the line-width is only in the order of 100 MHz, while its transmission peak can be tuned flexibly by adjusting the magnetic field. This filter has a natural advantage in space laser communications, which is another promising ultra-narrow band optical filter.

Design, synthesis, and antitumor evaluation of morpholine substituted bisnaphthalimides as DNA targeting agents.

A series of mono- and bisnaphthalimides derivatives containing 3-nitro and 4-morpholine moieties were designed, synthesized, and evaluated for their in vitro anticancer activities against four cancer cell lines. Some compounds exhibited relatively good antiproliferative activity on the cell lines tested, in comparison with mitonafide and amonafide. It is noteworthy that bisnaphthalimide A6 was identified as the most potent compound in anti-proliferation against MGC-803 cells, with an IC50 lowered to 0.09 µM, a far greater potency than that of mono-naphthalimide A7, mitonafide, and amonafide. A gel electrophoresis assay revealed that DNA and Topo I were the potential targets of compounds A6 and A7. The treatment of CNE-2 cells with compounds A6 and A7 resulted in an S phase cell cycle arrest, accompanied by the upregulation of the expression levels of the antioncogene p27 and the down-regulation of the expression levels of CDK2 and cyclin E. In addition, compounds A6 and A7-induced apoptosis was further confirmed by flow cytometry, ROS generation assay, and Hoechst 33,258 staining. In particular, in vivo antitumor assay results revealed that bisnaphthalimide A6 exhibited potent anticancer efficiency in an MGC-803 xenograft tumor model, in comparison with mitonafide, and had lower toxicity than mono-naphthalimide A7. In brief, the results suggested that bisnaphthalimide derivatives containing 3-nitro and 4-morpholine moieties might serve as DNA binding agents for the development of new antitumor agents.

Discovery of two biotin-PEG4­diarylidenyl piperidone prodrugs as potent antitumor agents with good efficacy, limited toxicity, and low resistance.

Two biotin-polyethylene glycol (PEG)4­diarylidenyl piperidone (DAP) prodrugs, compounds 3a and 3b, were designed as antineoplastic agents and synthesized by coupling biotin to bifluoro- and binitro-substituted DAP derivatives (DAP-F and DAP-NO2) through a PEG4 linker, respectively. The results of the MTT (3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di- phenytetrazoliumromide) assay and a SW480 xenograft model identified compounds 3a and 3b as candidate antitumor agents with good efficacy, limited toxicity, and low resistance, as compared to the original drugs (DAP-F and DAP-NO2), cisplatin, and doxorubicin (dox). The results of a preliminary pharmacokinetic study showed that compounds 3a and 3b slowly released their original drug DAP-F and DAP-NO2 within 12 h after intraperitoneal injection, respectively. Western blot analysis and computer docking simulations indicated that DAP-F, DAP-NO2, and compounds 3a and 3b were indeed inhibitors of signal transducer and activator of transcription 3 (STAT3) and the antitumor effects of compounds 3a and 3b were exerted by sequentially interacting with the SH2-binding domain followed by the DNA-binding domain after releasing the original drugs DAP-F and DAP-NO2, respectively. These results suggest that the targeted prodrug model led to good antitumor efficacy with reduced toxicity, while a dual STAT3-binding model may promote antitumor efficacy and resistance.

Auxiliary interferometer in an optoelectronic swept-frequency laser and its application to the measurement of the group refractive index.

An optoelectronic swept-frequency laser (SFL) is an optoelectronic feedback system that includes an auxiliary interferometer that can exert precise control over the optical frequency sweep. The arm-length difference (ALD) of the auxiliary interferometer directly affects the performance of the whole system. We established a theoretical model to choose the optimal ALD of an auxiliary interferometer in an optoelectronic SFL system using a frequency-modulated continuous-wave reflectometry experimental setup. The experimental results indicated that, based on our system, the optimal ALD was 7 m, which agreed with the theoretical analysis. As an example application, we implemented the proposed system for measurement of the group refractive index of a glass sample. A minimum measurement error of 0.12% was obtained with the ALD of 7 m.

Optical fiber sensor based on a cholesteric liquid crystal film for mixed VOC sensing.

This paper proposes a novel cholesteric liquid crystal (CLC) film-based dual-probe fiber sensor to monitor volatile organic compound (VOC) gas. The sensor consists of a 2×2 multimode fiber coupler, in which the two output fiber ends are covered by two types of CLC films (CLCF) with different pitches. It can be observed that the reflection peak wavelengths of CLCs shift to the red side as the VOC gas concentration increases. The sensitivities of the two CLCFs are 8.435 nm·L/mmol and 14.867 nm·L/mmol to acetone, 14.586 nm·L/mmol and 29.303 nm·L/mmol to ethanol, respectively. In addition, the dependence of the peak wavelength shift of CLCF on the total concentration of the acetone and ethanol mixed gas at different mixing ratios is measured. The linear relationships between the peak shift of CLCFs, the total mixed gas concentration and acetone/ethanol ratio are calculated using the least-squares method. Therefore, this proposed dual-probe fiber optic sensor can distinguish the concentrations of acetone and ethanol in a mixed gas of acetone and ethanol.

Fiber micro-tip temperature sensor based on cholesteric liquid crystal.

This Letter proposes and demonstrates a novel, miniature fiber-tip temperature sensor with a tapered hollow capillary tube (HCT) filled with glycerin and dye-doped cholesteric liquid crystal (CLC). The function of glycerin is to provide a surface anchoring force to control the uniform orientation of CLC molecules, so that the CLC in the tapered HCT can be considered as a mirrorless photonic bandgap (PBG) microcavity. An unambiguously identifiable PBG mode single peak appears in the emission spectra of the sensor. The CLC-based fiber-tip temperature sensor has a temperature sensitivity of -9.167nm/∘C, and the figure of merit can reach 67.4∘C-1. This sensor offers key features and advantages, including compactness, unambiguous identifiability, and biocompatibility, which can satisfy requirements of temperature measurement in various temperature sensing application fields and has great potential for biochemical detection at cell level. In addition, the CLC was integrated into the optical fiber terminal, and the PBG mode is excited, collected and transmitted by the multimode fiber coupler, which is reported for the first time, to the best of our knowledge.

An Optical Fiber Sensor Based on La2O2S:Eu Scintillator for Detecting Ultraviolet Radiation in Real-Time.

A novel ultraviolet (UV) optical fiber sensor (UVOFS) based on the scintillating material La2O2S:Eu has been designed, tested, and its performance compared with other scintillating materials and other conventional UV detectors. The UVOFS is based on PMMA (polymethyl methacrylate) optical fiber which includes a scintillating material. Scintillating materials provide a unique opportunity to measure UV light intensity even in the presence of strong electromagnetic interference. Five scintillating materials were compared in order to select the most appropriate one for the UVOFS. The characteristics of the sensor are reported, including a highly linear response to radiation intensity, reproducibility, temperature response, and response time (to pulsed light) based on emission from a UV source (UV fluorescence tube) centered on a wavelength of 308 nm. A direct comparison with the commercially available semiconductor-based UV sensor proves the UVOFS of this investigation shows superior performance in terms of accuracy, long-term reliability, response time and linearity.

Micro-gun based on laser pulse propulsion.

This paper proposes a novel "micro-gun" structure for laser pulse propulsion. The "micro-bullets" (glass microspheres) are irradiated by a laser pulse with a 10 ns duration in a dynamic process. Experimental parameters such as the microsphere diameter and the laser pulse energy are varied to investigate their influence on laser pulse propulsion. The energy field and spatial intensity distribution in the capillary tube were simulated using a three-dimensional finite-difference time-domain method. The experimental results demonstrate that the propulsion efficiency is dependent on the laser pulse energy and the microsphere size. The propulsion modes and sources of the propelling force were confirmed through direct observation and theoretical calculation. Waves also generated by light-pressure and thermal expansions assisted the propulsion.

Whispering gallery modes in a liquid-filled hollow glass microsphere.

We develop a hydrofluoric (HF) etching process to open a microhole on the hollow glass microsphere (HGM). The typical whispering gallery mode (WGM) resonance was observed by coupling the HGM with a tapered fiber. Dioctyl phthalate was filled into the HGM, and the resonance wavelength decreased at elevated temperatures. We analyzed the WGM resonance properties inside the liquid-filled HGM with a higher or lower refractive index in comparison to the HGM wall. Four different liquids were also injected into the HGM to investigate the influence of the thermo-optic coefficient on the temperature sensitivity. Size-dependent experiments further showed that HGMs with varying sizes have varying temperature sensitivity. The maximum temperature sensitivity observed was 334.3 pm/°C.

Humidity-insensitive temperature sensor based on a quartz capillary anti-resonant reflection optical waveguide.

A compact, humidity-insensitive, fiber optic temperature sensor based on a quartz capillary, antiresonant reflecting optical waveguide was proposed and experimentally demonstrated. The transmission spectral responses of the proposed sensor were experimentally investigated regarding temperature variation and environmental humidity. Resonant dips exhibited temperature sensitivity as large as 201 pm/°C from -30 to 45 °C in a humid environment. By coating a sufficiently thick gold film onto the sensor surface, the humidity cross-sensitivity issue was effectively resolved. This proposed sensor was anticipated to find potential applications in humid environments, and moreover, immunity to humidity-sensitivity ensures its applicability in marine environments.

Tapered optical fiber waveguide coupling to whispering gallery modes of liquid crystal microdroplet for thermal sensing application.

We demonstrate efficient coupling to the optical whispering gallery modes (WGMs) of nematic liquid crystal (NLC) microdroplets immersed in an immiscible aqueous environment. An individual NLC microdroplet, confined at the tip of a microcapillary, was coupled via a tapered optical fiber waveguide positioned correctly within its vicinity. Critical coupling of the taper-microdroplet system was facilitated by adjusting the gap between the taper and the microdroplet to change the overlap of the evanescent electromagnetic fields; efficient and controlled power transfer from the taper waveguide to the NLC microdroplet is indeed possible via the proposed technique. We also found that NLC microdroplets can function as highly sensitive thermal sensors: A maximum temperature sensitivity of 267.6 pm/°C and resolution of 7.5 × 10-2 °C were achieved in a 78-µm-diameter NLC microdroplet.

Incoherent pump assisted atomic filter based on laser-induced optical anisotropy.

We describe the effects of incoherent pump on an atomic filter based on laser-induced optical anisotropy in a three-level ladder system interacting with a strong pump polarized circularly and a weak probe polarized linearly. According to the analysis of the numerical simulation results with some comparison, at the same time of eliminating noise, the filter can enhance the probe's transmission or even the probe gain can be achieved without population inversion. Moreover, the incoherent pumping rate and the cell temperature performance are evaluated and measures are taken to improve the filter's transmission and tunability by selecting proper parameters.

Selective optical pumping process in Doppler-broadened atoms.

By solving the optical Bloch equations with the rate-equation approximation, we calculate the time dependence of the magnetic sublevel populations of Doppler-broadened atoms. With an increase of the left-circularly polarized pump intensity, the population fraction of a certain sublevel of the excited state almost reaches 0.3, resulting in anisotropy in the excited state, which is important to the optical filter based on circular birefringence and dichroism. Furthermore, numerical results show that the real saturation pump intensity for the moving atoms is much larger than that for the resting atoms.