bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Internet of Things Technology in Safe Centralized Storage of Big Data Information
Authors: Niu Aimin
Published: November 2023

To solve the problem of low data processing rate in traditional medical information storage methods, a safe centralized storage method of medical big data information is proposed. The data set storage model is designed through the Internet of Things, and VeritasBackupExee is used as data recovery and backup software, and data recovery and backup are realized by the Internet of Things. Encrypted storage of ciphertext index vector is carried out by using the ciphertext storage algorithm, and the medical data center of Internet of Things middleware is constructed. By sharing storage devices with multiple hosts, highly reliable backup can be realized. The average response time of the method in this paper is different for medical big data services. The average response time for modifying service is 11ms, creating service is 12ms, and migrating service is 13.7 ms. To verify the data service response time of this method, it is necessary to verify the response performance of different methods. The results show that this method has higher data download and upload rates and faster data service response.
Bluetooth Mesh Network-based Intelligent Light Replenishment System for Agricultural Greenhouses
Authors: Wang Jicun , Tang Liang , Mu Linhai , Rao Simin , Zhang Wanli
Published: November 2023

Given the actual situation of greenhouse production nowadays, this paper proposes a kind of intelligent light replenishment system for greenhouses based on a Bluetooth Mesh network. The system uses the ESP32-C3FH4 microcontroller from Espressif as Bluetooth Mesh nodes to form a Bluetooth Mesh monitoring network. This paper designs an intelligent IoT device control system based on Bluetooth Mesh network technology and cloud platform services. Through the flooded network composed of Bluetooth Mesh, the natural light intensity data monitored by each service node is sent to the cloud platform periodically through the gateway, the monitored data is accessed by the cloud platform for management, and the artificial light source module is triggered according to the deposited data to realize automatic control, realizing the modernized digital management function of agricultural greenhouses.
Design of Home Environment Monitoring System Based on a Cloud Platform for the Elderly Living Alone
Authors: Cai Xiangfan , Wang Dan
Published: November 2023

The phenomenon of elderly people living alone was becoming increasingly common in the new era, so the demand for monitoring the living environment of elderly people living alone was becoming increasingly strong. The design of home environment monitoring for elderly people living alone was designed based on a cloud platform. The system mainly consists of an STM32 main control module, a temperature and humidity detection module, an Internet of Things module, a security module, a relay control module, and a user App terminal. Then the fuzzy PID algorithm was designed to remotely control indoor temperature and humidity. After practical operation verification, the system can perform local and remote monitoring of the living environment of elderly people living alone and has the characteristics of reliability and stability.
Digitization of production line equipment of rail transit vehicles based on index and model
Authors: Zhang Hongyue , Chang Jie
Published: November 2023

In the process of digital transformation of rail transit vehicles, the digitalization of production line equipment is an important content. Starting from the whole life cycle business of production line equipment, this paper improves the existing production line equipment index system, proposes the production line equipment data acquisition model, describes the equipment portrait, proposes the comprehensive evaluation system based on the equipment index model, and further explores the digital twin architecture of production line equipment based on the integration of multiple models. Improve the digital level of rail transit vehicle manufacturing production line equipment.
Vibration Reduction of Robot End Effector Based on Co-simulation Method
Authors: Lu Daixing , Zhang Yang , Lu Junjie
Published: November 2023

Hydraulic cylinder replacement robot as a new type of engineering machinery has been increasingly used, but its end effector encounters vibrations in the process of clamping the object, so the accuracy of disassembling and assembling the cylinder will be reduced, thus reducing the replacement efficiency and affecting the user’s experience. To address this problem, virtual prototyping technology is used to study the cylinder disassembly process under real working conditions. We use the 3D modeling software Solidworks to construct a model of the cylinder replacement robot. After that, kinematic analysis of the model is carried out, then a dynamics model is built in multi-body dynamics simulation software ADAMS to simulate the process of the robot grasping the object, as a consequence, the trajectory of the end effector is calculated. A controlled dynamic model is established with Simulink and Adams by using the co-simulation technique, and optimization is carried out by using the model. Results show that the optimized control parameter can effectively reduce the end effector vibration and improve the stability and accuracy of the work.
Numerical analysis of flow and heat transfer characteristics of supercritical endothermic hydrocarbon fuel in taper tube
Authors: Zhao Jiajun , Gao Hui , Zhang Chen , Wen Dongsheng
Published: November 2023

To enhance the cooling performance of the scramjet regenerative cooling system, a novel taper tube is proposed. Under supercritical pressure, the flow characteristics and heat transfer characteristics of endothermic hydrocarbon fuel (EHF) in taper tube, narrow cylindrical tube, and wide cylindrical tube are numerical investigated and compared. The results of the investigation of flow and heat transfer processes in the above three tubes indicate that the taper tube effectively facilitates the pyrolysis of n-decane and the n-decane conversion is increased by 3.94%, compared with narrow cylindrical tube. Compared with wide cylindrical tube, the taper tube enhances cooling effect and the wall temperature near the outlet is reduced by 50.16 K. The taper tube contributes to the cooling structure optimization and promotion of regenerative cooling system performance.
Design and simulation of anti-sloshing baffles applied to detumbling payload propellant tanks
Authors: Tang J C , Liang Z H , Zheng K , Zheng P
Published: November 2023

The method to suppress the liquid sloshing in the tank applied to the jet detumbling payload is investigated in this study. Among all kinds of anti-sloshing structures, the symmetrical annular baffle was chosen due to the features of impact on the payload’s tank. The damped mass-spring liquid sloshing model established is used to compare the damping ratio of the baffle with different baffle layers and different baffle heights. Using FLUENT software, based on VOF (volume of fluid) numerical simulation technology, the damping effect of baffles with different layers and heights is simulated. The results show that 3-layer 15mm or 4-layer 10mm baffles can effectively reduce the influence of liquid sloshing. The damping ratio of the storage tank with a 3-layer 15mm anti-sloshing baffle is at least 18.3 times that of a smooth tank, and the damping ratio of the tank with a 4-layer 10mm anti-sloshing baffle is at least 18.7 times that of a smooth tank.
Power Generation Performance of CdTe Thin Film Solar Modules in Lhasa
Authors: Dong Xiaodong , Zhen Bai , Liu Yue , Ding Haitao
Published: November 2023

With the increasing energy consumption of buildings, reducing the energy consumption of buildings has become a key link to achieving the goal of carbon neutrality. Building integrated photovoltaic (BIPV) is an important research direction. Based on the CdTe thin film solar modules power generation system on the south-facing wall of a building in Lhasa, the article collected the annual power generation data for 2022. The characteristics and variation patterns of the total monthly power generation and typical monthly daily power generation are analyzed. Furthermore, the correlation between power generation performance and the main influencing factors was analyzed. The differences in power generation characteristics between CdTe thin films solar modules and single crystal silicon solar modules were compared and analyzed. The results show that the annual power generation of the CdTe thin film solar modules power generation system exhibits a “U” shaped distribution, and the power generation in winter is greatly affected by weather conditions. The peak power of 1kWp CdTe thin film solar modules is lower than that of single crystal silicon solar modules. The generation duration is longer than single crystal silicon solar modules. The total power generation is greater than single crystal silicon solar modules.
Low Carbon Economic Dispatch of Rural Distribution Network under High Photovoltaic Penetration
Authors: Tian Fuhao , Chen Jiaxi , Sun Yikai , Zhou Sheyu , Yang Hongji , Wang Xiran
Published: November 2023

To promote the low-carbon development of the power grid, the penetration rate of distribution photovoltaics in power systems has greatly increased. Some distribution networks may switch roles between energy producers and energy consumers multiple times a day. Especially in rural areas with low loads and abundant land resources, a large number of distributed photovoltaics may increase the energy balancing burden of the transmission system. To address this, the optimal operation of local resources is the key to the local accommodation of photovoltaics. In rural distribution networks, the light industrial load and agricultural load in rural distribution networks have similar electricity consumption behavior, and are suitable for centralized load management. This article proposes a low-carbon economic dispatch model of rural distribution networks under high photovoltaic penetration.. In specific, the light industrial load and the agricultural load are modeled considering their production requirements. Carbon emission costs and photovoltaic consumption costs are incorporated into the dispatch model of the distribution network. The case study is conducted based on a rural distribution network. The results of the case study indicated that the proposed model could increase the photovoltaic absorption rate by 10.96% and reduce carbon emissions by 3.4% for the test system.
The goal and path of source network load storage coordination and interaction to help the construction of a new power system
Authors: Zhang Hanbing , Lan Xuanli , Ye Jichao , Huang Hui , Xu Yonghai , Ji Aoying , Hu Xinwei
Published: November 2023

Under the goal of “carbon peak and carbon neutral”, the characteristics of the power system mainly based on new energy will undergo significant changes. In order to solve the problem of insufficient power supply capacity caused by the precision of new energy generation, this paper puts forward the construction scheme of the new power system of source network, load, storage coordination, and interaction, and uses energy storage and flexible load adjustment to improve the transmission capacity of the connection line under emergency conditions. At the same time, energy storage centers and load aggregation providers are used to optimize the equivalent load under normal conditions and minimize the shortage of power supply capacity. Furthermore, the mathematical model of each index is established and the coordination level of source network load storage based on AHP-Delphi empowerment is proposed. Finally, the rationality of the actual planning scheme in the province is comprehensively evaluated, which provides a reference for the construction of the new power system.
Thrust Fluctuation Optimization of Permanent Magnet Linear Motor Based on Composite Slot Wedge
Authors: Zhang Zi hao , Wang Shu hua
Published: November 2023

In order to reduce the thrust fluctuation of the linear motor, combined with its structural characteristics, the method of embedding a magnetic slot wedge is adopted. Based on the design of a common slot wedge structure, the genetic algorithm is used to optimize the slot wedge size, select the best size of the slot wedge structure, and then carry out finite element analysis. The results show that the thrust fluctuation of the single-sided linear motor is reduced by 66.42%, and that of the double-sided linear motor is reduced by 61.23%, which effectively reduces the thrust fluctuation. It has certain practical application value.
Design and modeling of an all-solid-state high power bidirectional DC switch
Authors: Cui Renhao , Hao Cheng
Published: November 2023

In order to improve the reliability of the aircraft ring network power distribution system for the future development needs of advanced multi-power and all-power aircraft, a design scheme of an all-solid-state high-power bidirectional DC switch is proposed to upgrade the aircraft power distribution system originally composed of traditional mechanical switches and some low-power solid-state power controllers to an all-solid-state aircraft power distribution system. The solid-state high-power bi-directional DC switch uses SiC MOSFETs as switching elements is modeled and simulated by Saber simulation software and uses reverse time overcurrent protection and short circuit protection design to realize high voltage control distribution, circuit protection, and fault isolation functions. The simulation verifies that the designed all-solid-state high-power bidirectional DC switch has short-circuit protection and overcurrent protection intelligent protection functions. Applying the design to the aircraft distribution loop network greatly enhances the reliability of the aircraft distribution system drives the development of aircraft multi-electricity-all-electricity technology, and also promotes the application of digital solid-state series modular switches in civil transportation and high-voltage power supply fields.
AC Series Arc Fault Diagnosis Method Based on AO-VMD Multidimensional Feature Extraction
Authors: Di Xinyi , Liu Song , Li Dan , Ma Wenxiao , Xue Maofang
Published: November 2023

In view of the difficulty in determining the number of mode components K and penalty factor α in VMD, which leads to poor signal decomposition effect and low diagnosis and recognition rate due to insufficient feature extraction in AC arc fault, an arc fault diagnosis method based on the Aquila algorithm was proposed to optimize the multivariate feature extraction of variational mode decomposition. First of all, the arc fault test platform was set up to consider the resistive, inductive, capacitive, and other household loads were considered to obtain the normal and fault current data. Second, the optimal K and α parameters were obtained by AO-VMD optimization and then decomposed into intrinsic mode functions (IMFs) by substituting them into VMD. Then, the time domain characteristics of the IMF2 component, the Energy Entropy of IMFs, and the Fuzzy Entropy of the kurtosis maximum IMFk component were extracted respectively, and the multidimensional fault characteristic matrix was constructed. Finally, the random forest (RF) model was used to accurately identify arc faults. The experiment shows that the average fault recognition rate of each type of load is above 99%, which has an excellent diagnostic effect.
Micro-fault identification for lithium-ion batteries in electric vehicles based on similarity measurement of the charging sequence
Authors: Chen Yingjie , Hou Yankai , Yan Zhu
Published: November 2023

Battery fault diagnosis is critical to safeguard the safety of electric vehicles. Since lithium-ion battery cells are usually inconsistent and difficult to distinguish from faults, existing micro-fault identification methods are difficult to detect faults as early as possible based on real-world vehicle data. In contrast to the operation process, the voltage and temperature changes are more regular since the current relatively remains constant and the charging strategy is fixed, which is conducive to accurate micro-fault identification. According to the charging strategy of electric vehicles, charging data extraction and selection methods are introduced. Considering the practicality and the difficulty of threshold value determination, the micro-fault identification approach based on DBSCAN is proposed. Normalized IAVs and LIP distances are utilized as features, which come from charging sequences. The results of the thermal runaway vehicle show that the method can effectively find fault cells in voltage signals 18 days before thermal runaway occurs.
Simulation Analysis Based on COMSOL Helicopter Time-domain Aeromagnetic Method
Authors: Su Rui , Zhang Yiming , Zhang Dong , Gao Junxia
Published: November 2023

This paper takes the time-domain aeromagnetic system as the research object and uses the finite element software COMSOL Multiphysics 6.0 to establish the three-dimensional system model. By comparing the COMSOL Multiphysics forward simulation solution with the one-dimensional numerical solution, it verifies that the COMSOL software meets the simulation accuracy requirements of the three-dimensional time-domain aeromagnetic method, and focuses on the analysis of the transient response at different flight altitudes is also analyzed. Based on the analysis of this paper, a set of aeromagnetic parameters with high detection capability is determined for engineering practice, and a test of the system is completed.
The effect of the ceramic foam cell structure on the combustion performance of porous media burner: experimental study
Authors: Zheng Xiaolong , Hu Jinglei , Chen Yuanyuan , Xu Xuecheng
Published: November 2023

To investigate the effect of the ceramic foam cell structure on the combustion characteristics, a porous media burner(PMB) composed of foamed ceramic plates with Kelvin and WP cell models as structural features was designed and developed. The combustion chamber temperature, lean combustion limit, radiation efficiency and flue gas emission characteristics of the burner were analysed in the combustion of methane. The results show that with the same pore density, skeleton diameter and operating parameters, the combustion chamber temperature and radiation efficiency of the WP model are higher than those of the Kelvin model, while the CO and NOx emissions of WP model have an opposite tendency. When the ceramic foams are composed by WP cell model, under the same pore density and operating parameters, the burner has better combustion performance when the skeleton is thin. The combustion chamber temperature and radiation efficiency are higher, CO and NOx emissions are lower, and the lean combustion limit equivalent ratio is lower.
Study on hydro-thermal coupling heat transfer performance of flue gas-water heat exchanger
Authors: Jia Zile , Liu Dan , Sun Hao , Zhao Meng , Lan Xingbo
Published: November 2023

The finned tube heat exchanger is the core component of the flue gas waste heat utilization system. In order to optimize and control the heat transfer efficiency of the heat exchanger in real time under smart heating conditions, we use the entransy dissipation thermal resistance as a kernel index to assess its heat exchange performance, and Trnsys simulation software is employed to figure out the influence of heat exchanger operating parameters (flue gas inlet velocity) and fin structure parameters (fin height, fin pitch) on heat exchanger heat transfer characteristics. The results show that in a reasonable range, increasing the flue gas inlet velocity can decrease the irreversible loss of heat transfer, obviously improving the heat transfer effect. The pitch and height of the fin also have a large impact on the performance of heat transfer. To significantly promote the performance of the heat exchanger, it is useful to reduce the pitch of the fin and increase the fin height within a reasonable range.
A Power-to-Gas Model Considering the Waste Heat Compensation for Power System Application
Authors: Hu Bohan , Huang Zhi , Lin Danning , Lei Xingyu
Published: November 2023

Power-to-Gas (P2G) technology is a crucial enabler for the new energy-based power system. In this study, a daily economic dispatch model is proposed for the power system operation with P2G units. It incorporates collecting and utilizing waste heat generated by the methanation plant and connected with the Proton exchange membrane (PEM) electrolysis. The simulation results demonstrate that the proposed model achieves a 1.1% decrease in power system operation costs compared to the conventional P2G model. This paper provides valuable insights into the power systems optimization with P2G units for more efficient and cost-effective renewable energy integration into the power grid.
Operation Optimization of Biomass Integrated Energy System Based on Adjustable Heat-to-Electric Ratio
Authors: Song Changcheng , Lu Zhaojun , Zhang Wen , Guo Ao
Published: November 2023

Considering the application of biomass energy, the Biomass Integrated Energy System (BIES) was first constructed. An integrated energy system operation optimization model was proposed with the objective functions of minimizing economic costs and maximizing clean energy utilization. Secondly, according to the characteristics of biomass Cogeneration, the scheme of adjusting the ratio of heat and power is proposed. Finally, a simulation analysis was conducted on a certain region in China. The results indicate that utilizing biomass energy in an integrated energy system can greatly reduce operating costs and improve energy utilization efficiency. After the heat-to-power ratio is adjusted, economic costs can be reduced again by 7.66%, and clean energy utilization can be increased by 6.15%.
Research on the microstructure and properties of Al-Mg-Si alloy with different amounts of B element
Authors: Li Dongqing , Gu Jian , Zheng Shuhui , Liu Shengchun , Si Jiajun
Published: November 2023

The microstructure and properties of Al-Mg-Si alloy with different contents of B element were studied through microstructure, mechanical properties, and conductivity. The results showed that after adding the B element, the precipitates tended to precipitate along grain boundaries. As the amount of the B element increased, the grain coursing was severe, and the tensile strength was slightly improved. However, the impact on hardness was not significant, and the yield strength ratio showed a downward trend. When the addition amount of B element was 0.02wt.%, the Al-Mg-Si alloy had the best conductivity. Therefore, by comprehensive consideration of the conductivity and mechanical properties, the optimal addition amount of B was 0.02 wt.%.
A failure mechanism of IGBT module in MMC and improvement
Authors: Li Cui , Jin Rui , He Feng , Liu Yueyang , Liu Jiang , Wu Tianyi , Tian Baohua , Nie Ruifen , Sun Wanru , Hao Xiamin
Published: November 2023

In modular multi-level converter valves, as the blocked mode happens, the failure in IGBT modules often causes a chain explosion reaction, which masks the initial failure mechanism. The root cause of the failure was that the voltage, consisting of the diode forward voltage and the induced voltage on the parasitic inductance, exceeded the reverse blocking capability of the anti-parallel IGBT. The methods against the failure were studied from three aspects: decreasing the diode’s peak forward voltage, increasing the reverse blocking capability of IGBT, and minimizing the parasitic inductance of the package. It was found that the doping concentration’s effect on the diode’s peak forward voltage is not monotonic. It can be explained from the carrier density distribution during forward recovery transient that lower doping concentration reduces the carrier injection, and higher doping concentration reduces the excess carrier concentration in the doping region. Then, the influence of two buffer designs on the reverse blocking capability of IGBT was compared. It was found that a higher reverse blocking voltage would be achieved when a multi-proton implantation buffer replaced the diffused buffer. And the new design has almost no degradation in forward blocking capability.
An Improved Circuit of Super Source Follower Based on gm-boosting Technology
Authors: Yan Junjie , Liu Qiming
Published: November 2023

An improved circuit of super source follower (SSF) based on gm-boosting technology is proposed in this paper. The traditional SSF circuit is used to reduce the output impedance of the source follower, to provide stronger load capacity as the output stage of the whole circuit, or to push the non-dominant poles in the multi-stage amplifier circuit to a higher frequency position. In the paper, based on the above SSF circuit, an operational amplifier is connected in parallel between the gate and drain of the Nmos as the feedback loop, which takes the drain as the positive input and the gate as the output to form the gm-boosting structure. The advantage of this structure is to further reduce the output resistance through the voltage-voltage feedback characteristics of the gm-boosting structure. Because two loops are formed after adding the structure, as long as the open-loop gain of the operational amplifier is high enough, the loop formed by the operational amplifier will occupy a dominant position, thus shielding the influence of the source follower on the overall output resistance. The output resistance can change with the operational amplifier gain. The simulation results show that the output impedance of the circuit is only about 92 Ω, which is much lower than 1 kΩ of SSF structure.
A Bootstrap Drive and Level Shifting Method for Buck-boost Converter with NMOS as the Main Switch Transistor
Authors: Wang Yapeng , Guo Zhongjie , Qiu Ziyi , Li Mengli , Ren Yuan
Published: November 2023

In the design of DC-DC power supply, compared with a P-type metal oxide semiconductor field effect transistor (PMOS) with the same width-to-length ratio, N-type metal oxide semiconductor field effect transistor (NMOS) as the main switching transistor greatly reduces the on-off loss and improves the conversion efficiency of the system. This article introduces a gate voltage bootstrap and level shifter circuit for a Buck-Boost DC-DC converter with NMOS main switching transistor. The drive voltage between the gate and the source pole of the main switch transistor can be stabilized, which is independent of the switch junction voltage (V
SW) and solves the problem that the drive voltage of the gate is too high or too low due to the influence of the bootstrap voltage in the traditional structure. Based on the 0.18 μm BCD process, the circuit design and physical implementation of the proposed method are verified. The test results show that the bootstrap drive circuit functions normally and the bootstrap drive voltage is about 5 V when the input voltage is 2.9~4.5 V and the output voltage is −2~-5 V. In addition, the proposed gate-level shifting circuit can reduce the drive delay of the main switch transistor to less than 12 ns.
Reaction Controllable preparation and electrocatalytic performance of two-dimensional sulfides
Authors: XinWang  , Yang Qi Chao , Wang Hai tao , Zheng Yu , Zhong Geng hang , Zhao Jiang wei
Published: November 2023

Two-dimensional sulfide has been widely recognized as a promising new type of catalyst to replace precious metals due to its adjustable electronic structure, low cost, and high stability. In this paper, monolayer molybdenum disulfide (MoS2) and layer-controlled tungsten disulfide (WS2) were successfully prepared by chemical vapor deposition (CVD). The two prepared materials’ morphology, structure, and thickness were investigated. The catalytic performance of two-dimensional sulfides was studied under an acidic environment. The results exhibit good catalytic performance toward hydrogen evolution with 63.6 mV/dec low Tafel slope of MoS2 and 72.8 mV/dec of WS2.
A low-power and high-gain frontend for GHz application using trans-impedance amplifier for fast particle detection
Authors: Kholili M.J. , Miyahara M. , Shoji M. , Kurniawan E. , Prakosa J.A. , Tanaka M.M.
Published: November 2023

In this paper, we present a front-end for gigahertz
applications, FGATI, which utilizes a transimpedance amplifier
design to amplify the current signal from a diamond particle
detector. The transimpedance amplifier design adopts a
flipped-voltage-follower-based current-mirror (FVF-CM) topology as
the input stage, offering advantages such as low power consumption,
large transimpedance gain, gigahertz bandwidth, and reasonable noise
levels. The FVF-CM topology was realized to improve noise reduction
with a fully differential output configuration. The design was
implemented as an ASIC chip using 65 nm CMOS silicon technology. The
bandwidth measurement of the FGATI prototype demonstrated a 3-dB
bandwidth of 1.2 GHz. Furthermore, the amplifier's power
consumption is low, drawing only 7.2 mW/channel from a 1.2 V power
supply, including the buffer stage. The measurement of the FGATI
output signal indicated an excellent transimpedance gain of
79.2 dBΩ and a noise level of
6.7 mVrms. These findings highlight the feasibility
and effectiveness of the proposed front-end design in high-frequency
applications.
Where the past meets the present: connecting nitrogen from watersheds to streams through groundwater flowpaths
Authors: Moore Eric M , Barclay Janet R , Haynes Adam B , Jackson Kevin E , Bisson Alaina M , Briggs Martin A , Helton Ashley M
Published: November 2023

Groundwater discharge to streams is a nonpoint source of nitrogen (N) that confounds N mitigation efforts and represents a significant portion of the annual N loading to watersheds. However, we lack an understanding of where and how much groundwater N enters streams and watersheds. Nitrogen concentrations at the end of groundwater flowpaths are the culmination of biogeochemical and physical processes from the contributing land area where groundwater recharges, within the aquifer system, and in the near-stream riparian area where groundwater discharges to streams. Our research objectives were to quantify the spatial distribution of N concentrations at groundwater discharges throughout a mixed land-use watershed and to evaluate how relationships among contributing and riparian land cover, modeled aquifer characteristics, and groundwater discharge biogeochemistry explain the spatial variation in groundwater discharge N concentrations. We accomplished this by integrating high-resolution thermal infrared surveys to locate groundwater discharge, biogeochemical sampling of groundwater, and a particle tracking model that links groundwater discharge locations to their contributing area land cover. Groundwater N loading from groundwater discharges within the watershed varied substantially between and within streambank groundwater discharge features. Groundwater nitrate concentrations were spatially heterogeneous ranging from below 0.03–11.45 mg-N/L, varying up to 20-fold within meters. When combined with the particle tracking model results and land cover metrics, we found that groundwater discharge nitrate concentrations were best predicted by a linear mixed-effect model that explained over 60% of the variation in nitrate concentrations, including aquifer chemistry (dissolved oxygen, Cl−, SO4
2−), riparian area forested land cover, and modeled physical aquifer characteristics (discharge, Euclidean distance). Our work highlights the significant spatial variability in groundwater discharge nitrate concentrations within mixed land-use watersheds and the need to understand groundwater N processing across the many spatiotemporal scales within groundwater cycling.
A storyline analysis of Hurricane Irma’s precipitation under various levels of climate warming
Authors: Huprikar Annika S , Stansfield Alyssa M , Reed Kevin A
Published: November 2023

Understanding how extreme weather, such as tropical cyclones, will change with future climate warming is an interesting computational challenge. Here, the hindcast approach is used to create different storylines of a particular tropical cyclone, Hurricane Irma (2017). Using the community atmosphere model, we explore how Irma’s precipitation would change under various levels of climate warming. Analysis is focused on a 48 h period where the simulated hurricane tracks reasonably represent Irma’s observed track. Under future scenarios of 2 K, 3 K, and 4 K global average surface temperature increase above pre-industrial levels, the mean 3-hourly rainfall rates in the simulated storms increase by 3–7% K−1 compared to present. This change increases in magnitude for the 95th and 99th percentile 3-hourly rates, which intensify by 10–13% K−1 and 17–21% K−1, respectively. Over Florida, the simulated mean rainfall accumulations increase by 16–26% K−1, with local maxima increasing by 18–43% K−1. All percent changes increase monotonically with warming level.
Projections of central Arctic summer sea surface temperatures in CMIP6
Authors: Han Ju-Seok , Park Hyo-Seok , Chung Eui-Seok
Published: November 2023

One of the most dramatic climate responses to future global warming is the near-disappearance of the perennial sea ice cover in the central Arctic Ocean, a phenomenon known as the ice-free summer Arctic. The immediate consequence of an ice-free Arctic would be the surface warming of the central Arctic Ocean, where sea surface temperatures (SSTs) used to be at freezing levels. Through an analysis of climate models participating in the climate model intercomparison project phase-6, this study demonstrates a wide range of responses in the central Arctic SSTs in August–September as a result of the projected ice-free summer Arctic. These responses vary from 0.7 to 8 °C in the shared socioeconomic pathway 2 (SSP2-4.5), referred to as the ‘middle of the road’ scenario, in which socioeconomic and technological trends do not significantly deviate from historical patterns. The extent of the central Arctic sea surface warming in August–September is found to have a loose correlation with the September sea ice extent (SIE), but a stronger connection to the SIE during spring to early summer (May–July), when incoming shortwave radiation is most intense. In certain climate models, the perennial sea ice cover disappears completely in September, causing central Arctic SSTs to rise by 5 °C–8 °C by the end of the 21st century. This leads to a bimodal distribution of annual SSTs. Further analysis reveals a close relationship between mid-summer SSTs in the central Arctic Ocean and preceding winter sea ice thickness (SIT). This underscores the significance of winter SIT in predicting future Arctic surface warming and marine heatwaves.
Material and component developments for the DEMO divertor using fibre reinforcement and additive manufacturing
Authors: Neu R , Coenen J W , Curzadd B , Gietl H , Greuner H , Höschen T , Hunger K , Lürbke R , Müller Av , Riesch J , Schlick G , Siefken U , Visca E , You JH
Published: November 2023

Within the research along the European Fusion Roadmap, water-cooled divertor PFCs are foreseen in the design of a first fusion demonstration power plant (DEMO) in order to provide reliable heat removal capability. In the frame of this concerted attempt, the Max Planck Institute for Plasma Physics is concentrating on the development and testing of composite materials based on tungsten (W, preferred armour material) and copper (Cu, preferred heat sink material). W fibres (Wf) as monofilaments and yarns as reinforcement play a central role in these investigations due to their extraordinary properties concerning ductility already at room temperature and high tensile strength. Recent investigations on the impact of radiation damage suggest that the fibres retain their ductility upon irradiation. W reinforced with W fibres (Wf/W) allows to overcome the intrinsic brittleness of W. Quantitative mechanical fracture tests of Wf /W confirm the basic mechanisms of fibre reinforcement and the increased resistance to mechanical fatigue. The good wettability of W with liquid Cu and the absence of any metallurgical solubility make up an ideal material pairing for composite production. W fibre-reinforced Cu (Wf/Cu) cooling tubes provide a rather high thermal conductivity (> 250 W mK−1) and at least twice the strength of CuCrZr in hoop direction in the temperature range up to at least 500 °C. Very recent neutron irradiation experiments confirm the sustainment of ductility of the Wf/Cu composite. Numerical simulations suggest that thermal stresses in W-Cu PFCs could be strongly reduced by tailoring the local W and Cu volume fraction. This ‘freely’ distributed material composition can be achieved by means of additively manufactured W skeletons consecutively infiltrated by Cu. Investigations with W preforms produced by Laser Beam Powder Bed Fusion and infiltrated by Cu demonstrate the feasibility of this approach while testing of specifically prepared specimen is ongoing.
Influence of the position relationship between the cathode and magnetic separatrix on the discharge process of a Hall thruster
Authors: CAO 曹 Xifeng 希峰 , MA 麻 Hongning 洪宁 , XIA 夏 Guojun 国俊 , LIU 刘 Hui 辉 , ZHAO 赵 Fangzhou 方舟 , WANG 王 Yuhang 宇航 , CHEN 陈 Juhui 巨辉
Published: November 2023

Previous studies have shown that there is an obvious coupling relationship between the installation location of the external cathode and the magnetic separatrix in the plume region of a Hall thruster. In this paper, the particle-in-cell simulation method is used to compare the thruster discharge process under the conditions of different position relationships between the cathode and the magnetic separatrix. By comparing the distribution of electron conduction, potential, plasma density and other microscopic parameters, we try to explain the formation mechanism of the discharge difference. The simulation results show that the cathode inside and outside the magnetic separatrix has a significant effect on the distribution of potential and plasma density. When the cathode is located on the outer side of the magnetic separatrix, the potential above the plume region is relatively low, and there is a strong potential gradient above the plume region. This potential gradient is more conducive to the radial diffusion of ions above the plume, which is the main reason for the strong divergence of the plume. The distribution of ion density is also consistent with the distribution of potential. When the cathode is located on the outer side of the magnetic separatrix, the radial diffusion of ions in the plume region is enhanced. Meanwhile, by comparing the results of electron conduction, it is found that the trajectories of electrons emitted from the cathode are significantly different between the inner and outer sides of the magnetic separatrix. This is mainly because the electrons are affected by the magnetic mirror effect of the magnetic tip, which makes it difficult for the electrons to move across the magnetic separatrix. This is the main reason for the difference in potential distribution. In this paper, the simulation results of macroscopic parameters under several conditions are also compared, and they are consistent with the experimental results. The cathode is located on the inner side of the magnetic separatrix, which can effectively reduce the plume divergence angle and improve the thrust. In this paper, the cathode moves from R = 50 mm to R = 35 mm along the radial direction, the thrust increases by 3.6 mN and the plume divergence angle decreases by 23.77%. Combined with the comparison of the ionization region and the peak ion density, it is found that the main reason for the change in thrust is the change in the radial diffusion of ions in the plume region.
Weavable thermoelectrics: advances, controversies, and future developments
Authors: Shi Xiao-Lei , Sun Shuai , Wu Ting , Tu Jian , Zhou Zhiming , Liu Qingfeng , Chen Zhi-Gang
Published: November 2023

Owing to the capability of the conversion between thermal energy and electrical energy and their advantages of light weight, compactness, noise-free operation, and precision reliability, wearable thermoelectrics show great potential for diverse applications. Among them, weavable thermoelectrics, a subclass with inherent flexibility, wearability, and operability, find utility in harnessing waste heat from irregular heat sources. Given the rapid advancements in this field, a timely review is essential to consolidate the progress and challenge. Here, we provide an overview of the state of weavable thermoelectric materials and devices in wearable smart textiles, encompassing mechanisms, materials, fabrications, device structures, and applications from recent advancements, challenges, and prospects. This review can serve as a valuable reference for researchers in the field of flexible wearable thermoelectric materials and devices and their applications.
Sexual attraction with pollination during feeding behaviour: implications for transitions between specialized strategies
Authors: Phillips Ryan D , Bohman Björn , Peakall Rod , Reiter Noushka
Published: November 2023

Background and Aims

Understanding the origin of pollination by sexual deception has proven challenging, as sexually deceptive flowers are often highly modified, making it hard to resolve how any intermediate forms between sexual deception and an ancestral strategy might have functioned. Here, we report the discovery in Caladenia (Orchidaceae) of sexual attraction with pollination during feeding behaviour, which may offer important clues for understanding shifts in pollination strategy.

Methods

For Caladenia robinsonii, we observed the behaviour of its male wasp pollinator, Phymatothynnus aff. nitidus (Thynnidae), determined the site of release of the sexual attractant, and experimentally evaluated if the position of the attractant influences rates of attempted copulation and feeding behaviour. We applied GC-MS to test for surface sugar on the labellum. To establish if this pollination strategy is widespread in Caladenia, we conducted similar observations and experiments for four other Caladenia species.

Key Results

In C. robinsonii, long-range sexual attraction of the pollinator is via semiochemicals emitted from the glandular sepal tips. Of the wasps landing on the flower, 57 % attempted copulation with the sepal tips, while 27 % attempted to feed from the base of the labellum, the behaviour associated with pollen transfer. A similar proportion of wasps exhibited feeding behaviour when the site of odour release was manipulated. A comparable pollination strategy occurs in another phylogenetically distinct clade of Caladenia.

Conclusions

We document a previously overlooked type of sexual deception for orchids involving long-distance sexual attraction, but with pollination occurring during feeding behaviour at the labellum. We show this type of sexual deception operates in other Caladenia species and predict that it is widespread across the genus. Our findings may offer clues about how an intermediate transitional strategy from a food-rewarding or food-deceptive ancestor operated during the evolution of sexual deception.
Fraud on the tribunal in investor–State arbitration
Authors: Sharma Gunjan
Published: November 2023

Fraud on investor–State arbitration tribunals is somewhat uncommon but hardly rare. This article summarises 17 publicly known investor–State arbitration awards addressing fraud on the tribunal, to contribute to this underdeveloped field of law. The article notes that investor–State tribunals have confronted this wrongdoing in various ways, ranging from avoiding findings of fraud to imposing arbitral sanctions. It notes, however, the apparent dearth of referral to criminal processes arising out of proven fraud. It concludes with a summary of the potential remedies available to the tribunal when confronted with fraud.
ReGeNNe: genetic pathway-based deep neural network using canonical correlation regularizer for disease prediction
Authors: Sharma Divya , Xu Wei
Published: November 2023

Motivation

Common human diseases result from the interplay of genes and their biologically associated pathways. Genetic pathway analyses provide more biological insight as compared to conventional gene-based analysis. In this article, we propose a framework combining genetic data into pathway structure and using an ensemble of convolutional neural networks (CNNs) along with a Canonical Correlation Regularizer layer for comprehensive prediction of disease risk. The novelty of our approach lies in our two-step framework: (i) utilizing the CNN’s effectiveness to extract the complex gene associations within individual genetic pathways and (ii) fusing features from ensemble of CNNs through Canonical Correlation Regularization layer to incorporate the interactions between pathways which share common genes. During prediction, we also address the important issues of interpretability of neural network models, and identifying the pathways and genes playing an important role in prediction.

Results

Implementation of our methodology into three real cancer genetic datasets for different prediction tasks validates our model’s generalizability and robustness. Comparing with conventional models, our methodology provides consistently better performance with AUC improvement of 11% on predicting early/late-stage kidney cancer, 10% on predicting kidney versus liver cancer type and 7% on predicting survival status in ovarian cancer as compared to the next best conventional machine learning model. The robust performance of our deep learning algorithm indicates that disease prediction using neural networks in multiple functionally related genes across different pathways improves genetic data-based prediction and understanding molecular mechanisms of diseases.

Availability and implementation

https://github.com/divya031090/ReGeNNe.
Temporary Agency Workers in the Personal Social Services—Doing Core Tasks in the Periphery
Authors: Shanks Emelie
Published: November 2023

Despite concerns about negative consequences for clients and permanent staff, temporary agency workers (TAWs) are frequently employed to manage staff shortages in personal social services (PSS) in Sweden and elsewhere. Drawing on qualitative interviews with thirty-four TAWs, managers and permanent social workers, this article aims to enhance our understanding of how TAWs are utilised in the PSS and the impact this has on (i) the preconditions for TAWs and (ii) the work environment for permanent employees. The findings suggest that TAWs are mainly contracted for core tasks, and often for heavy-duty work. In order to meet demands for expedient case administration, the supportive aspects of social work are sometimes deprioritised. Permanent staff report that positive effects of the use of TAWs include relief of workload and an influx of new knowledge, whereas negative effects include stagnated work development, deteriorating group dynamics and additional work. Moreover, it is shown that TAWs often reside in the periphery of the organisation and that they typically are contracted on an ad-hoc basis and during times of crisis. It is suggested that the organisational conditions that TAWs are contracted to help remedy paradoxically are unlikely to create the best preconditions for a successful use.