关键词：
Battery electric vehicle;Energy flow;Vehicle test;Integrated simulation;Driving cycles
摘要：
To comprehensively investigate the energy distribution and performance of a battery electric vehicle (BEV), an integrated simulation model based on energy flow test data was developed and validated, and the energy flow characteristics of the BEV throughout the entire driving range in low-temperature conditions were studied. The results show that the battery heat loss and motor energy loss first increase and then decrease with an increment in cycle number, while the transmission loss first decreases and then remains constant. The energy recovery efficiency demonstrates an incremental trend with the number of cycles post-battery charging, while the energy utilization efficiency experiences a decline due to escalating energy losses within the power distribution unit (PDU). The energy flow characteristics of the BEV exhibit a pronounced connection with the speed properties inherent in the driving cycle. The battery charge energy is maximal under Urban Dynamometer Driving Schedule (UDDS), whereas the electricity consumption per 100 km is minimized under China light-duty vehicle test cyclepassenger (CLTC-P). Conversely, the energy utilization and recovery efficiency are the highest under Worldwide Light-duty Test Cycle (WLTC). These findings provide directional insights, theoretical support and data basis for rational performance evaluation and optimal energy distribution of BEVs.
摘要：
With the rapid growth of Internet data, recommendation systems have become the basic technology to alleviate information overload. The session-based recommendation (SBR) is a challenging task, and its purpose is to predict user behavior based on anonymous sessions. The existing SBR methods need to be improved in capturing the complex conversion relationship of items. In contrast, Graph Neural Network (GNN) can capture the complex conversion between items by modeling sessions as graph structure data. However, current methods just sort the clicked items within a session based on time, without utilizing the temporal information between sessions, leading to poor recommendation performance. To improve the accuracy of session recommendation (SR), we propose an SBR model based on GNN with Combined Temporal (CT-GNN) information. The proposed CT-GNN model is built based on the time of session occurrence, and it can learn the temporal association relationship between session items to enrich the connection between items. More importantly, based on the diversity problem faced by current SRs, which refers to the tendency of users to engage with popular items and resulting in limited exposure for other items, the CT-GNN model uses the Local Item Representation Learning (LIRL) module to learn users' local preferences. Through the LIRL module, the CT-GNN can capture users' interests, boost item exposure, and increase recommendation diversity. The experimental results show that the CT-GNN model is superior to the state-of-the-art SBR methods, with MRR scores 1.1 %∼3.4 % higher than the best-performing baseline; recall scores 0.9 %∼2.3 % higher than the best-performing baseline, and alleviates the diversity problem faced by SR, greatly improving the speed of model convergence, and the training time is 13.6 %∼20.7 % of the best-performing baseline.
作者机构：
[Li, Lin; Zhan, Jialei; Li, Rui; Li, L; Yang, Ruoli; Hu, Yaowen; Cai, Weiwei] Cent South Univ Forestry & Technol, Coll Comp & Informat Engn, Changsha 410004, Hunan, Peoples R China.;[Guan, Renxiang; Hu, Yaowen] Natl Univ Def Technol, Coll Comp, Changsha 410073, Hunan, Peoples R China.;[Zhan, Jialei; Wang, Yanfeng; Yang, Ruoli] Natl Univ Def Technol, Coll Syst Engn, Changsha 410073, Hunan, Peoples R China.;[Xu, Haiwen] Hunan Forest Grassland Fire Prevent Monitoring Dis, Changsha, Hunan, Peoples R China.;[Li, Liujun] Univ Idaho, Dept Soil & Water Syst, Moscow, ID 83844 USA.
通讯机构：
[Li, L ] C;Cent South Univ Forestry & Technol, Coll Comp & Informat Engn, Changsha 410004, Hunan, Peoples R China.
关键词：
Forest fire smoke detection;Feature pyramid network;Loss function;Feature extraction;Deep learning
摘要：
Smoke is an early manifestation of forest fire. Accurate identification of smoke from forest fires is crucial for the prevention and control of forest fires, which helps protect the ecological environment and the safety of people. The texture features of smoke are complex and prone to detection omissions. The forest environment is complex, and smoke-like objects in the forest often interfere with smoke recognition. The concentration of smoke at the edge is thin, which easily leads to edge omission. In response to these problems, we propose a high-precision edge focused forest fire smoke detection network. To begin, in response to the problem of detection omission, we present a Swin multidimensional window extractor (SMWE) that enhances information exchange between windows in both horizontal and vertical dimensions to extract global texture features from images with smoke. Then, the guillotine feature pyramid network (GFPN) is suggested, along with a new guillotine convolution method for reducing redundant feature information from a feature fusion perspective, thereby improving the anti-interference ability of the model. Finally, taking into account the thinness and irregularity of the smoke near the borders, a contour adaptive loss function is suggested to minimize the boundary blur caused by down-sampling the feature map in the network. The experimental and application results show that SMWE-GFPNNet accomplishes 80.92 % of the mAP, 90.01 % of the mAP50, and 83.38 % of the mAP75 on the Forest Fire Smoke Complex Background Detection Dataset. Excellent in anti-interference ability and accuracy.
摘要：
The humidity stability and phase transition mechanism of the all-inorganic perovskite CsPbI2Br based on an optimized dual-source co-evaporation preparation process are investigated at the film interface level. It is found that the CsPbI2Br films annealed at 300(degrees)C for several minutes exhibit a best crystallinity and photoelectric properties. The as-grown CsPbI2Br film is confirmed to be a alpha phase with a dark brown cubic crystal structure and an average visible transparency of 35.9%. But it will be transformed into its delta phase with a transparent orthorhombic crystal structure and an average visible transparency of 80.3% after a certain amount of moisture exposure. Compared with the alpha phase film, the electronic structure of the delta phase has also changed significantly with a VBM shift of about 0.32 eV to high binding energy. The results of AR-XPS show that the water molecules in perovskite CsPbI2Br after a moisture exposure only adsorb on the surface rather than penetrate the interior of the lattice. When water molecules adsorb on the lattice surface, halide ions should migrate towards the lattice surface due to their high hydration enthalpy, resulting in halide vacancies within the lattice and causing the reduction of energy barrier for phase transition from alpha phase to delta phase. So the CsPbI2Br film will transform from its alpha phase to delta phase induced by water vapor, and this phase transition will be reversed to some extent after another annealing.
作者机构：
[Lili Pan; Weizhi Shao; Siyu Xiong; Qianhui Lei] College of Computer Science and Information Technology, Central South University of Forestry and Technology, Changsha 410114, China;[Shiqi Huang; Eric Beckman] Chaplin School of Hospitality and Tourism Management, Florida International University, North Miami 33181, USA;[Qinghua Hu] School of Artificial Intelligence, Tianjin University, Tianjin 300072, China
通讯机构：
[Weizhi Shao] C;College of Computer Science and Information Technology, Central South University of Forestry and Technology, Changsha 410114, China
摘要：
Recently, emotion recognition from facial expressions has achieved unprecedented accuracy with the development of deep learning. Despite this progress, most existing emotion recognition methods are supervised and thus require extensive annotation. This issue is particularly pronounced in continuous domain datasets where annotation costs are very high. Furthermore, discrete domain datasets containing specific poses are too uniform to reflect complex and actual emotions. Existing methods that employ classification loss pay little attention to image similarity, making it difficult to distinguish similar emotions. To improve the learning ability for image similarity and reduce the annotation cost of continuous domain datasets, this research proposes a Semi-Supervised Emotion Recognition (SSER) method, which incorporates Activation-matrix Triplet loss (AMT loss) and pseudo label with Complementary Information (CI label). Specifically, the AMT loss is constructed by encoding multiple activation channels of an image as a matrix, which are utilized to capture the image similarity. The CI label firstly adopts the coupling effect of the complementary information from images and the multi-stage model for SSL to obtain high-confidence pseudo-labels. Then, entropy minimization and consistency regularization are used to improve the accuracy of pseudo labels. The SSER is evaluated on continuous domain datasets (AFEW-VA and AFF-Wild) and discrete domain datasets (FER2013 and CK+). The experimental results demonstrate that the SSER combined with AMT loss and CI label makes improvement for emotion recognition on continuous domain datasets, meanwhile the SSER is also desirable and effective for emotion recognition on discrete domain datasets.
作者机构：
[Gen-Hua Liu; Jin-Xiang Yan] College of Computer and Information Engineering, Central South University of Forestry and Technology, Changsha 410004, People's Republic of China
摘要：
The spin polarization of current plays an important role in the performance of spintronic devices. Therefore, a highly spin-polarized current source has always been explored through various methods. We study the effects of magnetic order on the electronic structures of antiferromagnetic (AFM) MnBi2Te4 films. A significant spin splitting is found in the surface states of a AFM MnBi2Te4 film with three septuple layers (SLs). The AFM film can show typical metallic behavior for spin-down electrons, and exhibit a semiconductor or insulator behavior with a band gap at the Fermi level for spin-up electrons, just like semimetal ferromagnets with theoretical spin polarization up to 100%. We also study that the electron transport in the 3-SLs AFM film with a square potential barrier, we find a highly spin-polarized current can be switched on and off by modulating the barrier height in the film.
摘要：
BACKGROUND: Camellia oleifera, an essential woody oil tree in China, propagates through grafting. However, in production, it has been found that the interaction between rootstocks and scions may affect fruit characteristics. Therefore, it is necessary to predict fruit characteristics after grafting to identify suitable rootstock types. METHODS: This study used Deep Neural Network (DNN) methods to analyze the impact of 106 6-year-old grafting combinations on the characteristics of C.oleifera, including fruit and seed characteristics, and fatty acids. The prediction of characteristics changes after grafting was explored to provide technical support for the cultivation and screening of specialized rootstocks. After determining the unsaturated fat acids, palmitoleic acid C16:1, cis-11 eicosenoic acid C20:1, oleic acid C18:1, linoleic acid C18:2, linolenic acid C18:3, kernel oil content, fruit height, fruit diameter, fresh fruit weight, pericarp thickness, fresh seed weight, and the number of fresh seeds, the DNN method was used to calculate and analyze the model. The model was screened using the comprehensive evaluation index of Mean Absolute Error (MAPE), determinate correlation R(2) and and time consumption. RESULTS: When using 36 neurons in 3 hidden layers, the deep neural network model had a MAPE of less than or equal to 16.39% on the verification set and less than or equal to 13.40% on the test set. Compared with traditional machine learning methods such as support vector machines and random forests, the DNN method demonstrated more accurate predictions for fruit phenotypic characteristics, with MAPE improvement rates of 7.27 and 3.28 for the 12 characteristics on the test set and maximum R(2) improvement values of 0.19 and 0.33. In conclusion, the DNN method developed in this study can effectively predict the oil content and fruit phenotypic characteristics of C. oleifera, providing a valuable tool for predicting the impact of grafting combinations on the fruit of C. oleifera.
通讯机构：
[Zhong, SH ] C;Cent South Univ Forestry & Technol, Sch Comp & Informat Engn, Changsha 410004, Peoples R China.
关键词：
Age of Information;resource scheduling;Industrial Internet of Things;deep reinforcement learning
摘要：
Effective resource scheduling methods in certain scenarios of Industrial Internet of Things are pivotal. In time-sensitive scenarios, Age of Information is a critical indicator for measuring the freshness of data. This paper considers a densely deployed time-sensitive Industrial Internet of Things scenario. The industrial wireless device transmits data packets to the base station with limited channel resources under the constraints of Age of Information. It is assumed that each device has the capacity to store the packets it generates. The device will discard the data to alleviate the data queue backlog when the Age of Information of the data packet exceeds the threshold. We developed a new system utility equation to represent the scheduling problem and the problem is expressed as a trade-off between minimizing the average Age of Information and maximizing network throughput. Inspired by the success of reinforcement learning in decision-processing problems, we attempt to obtain an optimal scheduling strategy via deep reinforcement learning. In addition, a reward function is constructed to enable the agent to achieve improved convergence results. Compared with the baseline, our proposed algorithm can achieve better system utility and lower Age of Information violation rate.
期刊：
Construction and Building Materials,2024年411:134825 ISSN：0950-0618
通讯作者：
Sun, DL
作者机构：
[Zou, Weihua; Wang, Zhangheng] Cent South Univ Forestry & Technol, Coll Furniture & Art Design, Changsha 410004, Hunan, Peoples R China.;[Sun, Delin; Song, Ling; Sun, Zhenyu; Zhao, Shan; Liu, Wenshuang; Yu, Minggong; Zou, Weihua; Liu, Fang; Wang, Zhangheng] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Sun, Delin; Sun, DL] 498 Shaoshan South Rd, Changsha, Hunan, Peoples R China.
通讯机构：
[Sun, DL ] 4;498 Shaoshan South Rd, Changsha, Hunan, Peoples R China.
关键词：
Superhydrophobic wood;Wet chemical method;Wettability;Bond strength;Interface modification
摘要：
Superhydrophobic modification transforms the wood surface into a non-wetting state, which hinders the effective spreading and penetration of the adhesive at the gluing interface. In this study, a wet chemical method was used to optimize the wettability of the glued interface of superhydrophobic wood (S-wood) through NaOH@KH-550 synergistic treatment. The method can improve the structrue and chemical condition to increase the adsorption capacity of the wood surface for the adhesive, and the bond strength of S-wood increased to 3.21 MPa, which was beneficial to the efficient use of S-wood in construction and furniture fields.
摘要：
The "Annual Report 2021" from the United Nations Environment Programme (UNEP) highlights that the transportation sector is the fastest-growing greenhouse gas emissions sector, accounting for approximately 25% of energy-related emissions. What is even more concerning is that, at a time when carbon emissions need to be urgently reduced across various industries globally, carbon emissions from the transportation sector continue to rise. This is because the improvement in the efficiency of vehicle power combustion struggles to offset the increasing emissions resulting from the massive volume of travel. With the enhancement of transportation networks in various countries, it is projected that the growth rate of carbon emissions in the transportation sector will surpass that of the industrial and power sectors, presenting a significant challenge to achieving the emission reduction goals outlined in the Paris Agreement. Carbon emissions in the global transportation sector encompass various modes of transportation, including road, rail, aviation, and maritime, with road transportation being the largest contributor to carbon emissions. This study utilized the Stacking technique to build the X-MARL model for predicting
$$\hbox {CO}_{2}$$
emissions from vehicles and formulated recommendations for carbon reduction in the transportation industry. The model was tested using a dataset of vehicle
$$\hbox {CO}_{2}$$
emissions officially recorded by the Canadian government, comprising 7385 data points and covering 12 different vehicle parameter attributes. During the experimentation process, three statistical evaluation metrics were employed, namely mean squared error (MSE), root-mean-squared error (RMSE), and the coefficient of determination (R2). The dataset was randomly split into a training set (80% of the total data) and a testing set (20% of the total data). The experimental results demonstrated that the X-MARL model exhibited the highest prediction accuracy. This study provides an original strategy for accurately predicting carbon emissions from road transportation, which can offer support and guidance to decision-makers in formulating and implementing effective environmental policies.
期刊：
Economic Analysis and Policy,2024年 ISSN：0313-5926
通讯作者：
Yi Fan
作者机构：
[Yi Fan] College of Economics, Central South University of Forestry and Technology, Changsha, CHINA;Allameh Tabataba'i University, Tehran, Iran;Trade Promotion Organization of Iran, IRAN;[Omid Ranjbar] Allameh Tabataba'i University, Tehran, Iran<&wdkj&>Trade Promotion Organization of Iran, IRAN
通讯机构：
[Yi Fan] C;College of Economics, Central South University of Forestry and Technology, Changsha, CHINA
摘要：
Energy security is affected by extreme natural, human, domestic political, geopolitical, and fossil energy price shocks/events and green energy policies. The degree of persistence in energy security determines the magnitudes of social, economic, and environmental outcomes of the shocks/policies. In this paper, we examined the degree of persistence in energy security of G7 countries using a new proxy namely the energy security risk index, and a novel second-generation panel quantile unit root test over the period 1980-2018. In addition, we applied the sequential panel selection method (SPSM), to identify the stationary members within each quantile. Our results indicated the stochastic properties of the energy security risk indexes vary across the quantile and the countries. Among the G7 countries, the energy security risk index of the US displays unit root process within all quantiles. While the energy security risk indexes of other countries display stationary processes, especially within high quantiles. Our results have important policy implications regarding the effectiveness of green policies in improving the energy security of the G7 countries and the disturbance effects of anti-energy security shocks. According to our findings, the US has to constantly pursue the risks that threaten the country's energy system while other G7 countries likely do not have such severe concerns about shocks affecting energy security, and these shocks have a short-term effect on their energy security.
作者机构：
College of Science, Hunan Province Key Laboratory of Materials Surface & Interface Science and Technology, Central South University of Forestry and Technology, Changsha , Hunan, China;College of Science, Jiujiang University, Jiujiang , Jiangxi, China;[Mengdong He; Yuxiang Peng; Wei Li; Jianbo Li; Peihao Su; Exian Liu; Kaijun Wang] College of Science, Hunan Province Key Laboratory of Materials Surface & Interface Science and Technology, Central South University of Forestry and Technology, Changsha , Hunan, China;[Jianqiang Liu] College of Science, Jiujiang University, Jiujiang , Jiangxi, China
摘要：
The immunity of topological states against backscattering and structural defects provides them with a unique advantage in the exploration and design of high-precision low-loss optical devices. However, the operating bandwidth of the topological states in certain photonic structures is difficult to actively tune and flexibly reconfigure. In this study, we propose a valley topological photonic crystal (TPC) comprising two inverse honeycomb photonic crystals, consisting of hexagonal silicon and Ge2Sb2Te5 (GST) rods. When GST transitions from the amorphous phase to the crystalline phase, the edge band of the TPC appears as a significant redshift and is inversed from a"∪"to an"∩"shape with topological phase transition, which enables active tuning of the operating bandwidth and propagation direction of topological edge states. Both the topological edge and corner states in a triangular structure constructed using TPCs can be simultaneously adjusted and reconfigured via GST phase transition, along with a change in the group number of corner states. Using the adjustability of topological edge states and electromagnetic coupling between two different topological bearded interfaces, we develop a multichannel optical router with a high tuning degree of freedom, where channels can be actively reconfigured and their on/off states can be freely switched. Our study provides a strategy for the active regulation of topological states and may be beneficial for the development of reconfigurable topological optical devices. The immunity of topological states against backscattering and structural defects provides them with a unique advantage in the exploration and design of high-precision low-loss optical devices. However, the operating bandwidth of the topological states in certain photonic structures is difficult to actively tune and flexibly reconfigure. In this study, we propose a valley topological photonic crystal (TPC) comprising two inverse honeycomb photonic crystals, consisting of hexagonal silicon and Ge2Sb2Te5 (GST) rods. When GST transitions from the amorphous phase to the crystalline phase, the edge band of the TPC appears as a significant redshift and is inversed from a"∪"to an"∩"shape with topological phase transition, which enables active tuning of the operating bandwidth and propagation direction of topological edge states. Both the topological edge and corner states in a triangular structure constructed using TPCs can be simultaneously adjusted and reconfigured via GST phase transition, along with a change in the group number of corner states. Using the adjustability of topological edge states and electromagnetic coupling between two different topological bearded interfaces, we develop a multichannel optical router with a high tuning degree of freedom, where channels can be actively reconfigured and their on/off states can be freely switched. Our study provides a strategy for the active regulation of topological states and may be beneficial for the development of reconfigurable topological optical devices.
作者机构：
[Liu, Dongbo; Zhang, Zhixu] State Key Lab Subhlth Intervent Technol, Changsha 410128, Hunan, Peoples R China.;[Liu, Dongbo; Zhang, Zhixu] Hunan Agr Univ, Coll Hort, Changsha 410128, Hunan, Peoples R China.;[Qin, Dan] Hunan Agr Univ, Coll Food Sci & Technol, Changsha 410128, Hunan, Peoples R China.;[Guo, Xin] Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Hunan, Peoples R China.;[Lin, Haiyan] Natl Res Ctr Engn Technol Utilizat Ingredients Bot, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Guo, X ] C;Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Hunan, Peoples R China.
关键词：
Adsorption;Carbon dots;Pb(II);Starch
摘要：
The adsorption removal of lead (Pb) ions has become a crucial area of research due to the potential health hazards associated with Pb contamination. Developing cost-effective adsorbents for the removal of Pb(II) ions is significantly important. Hence, a novel fluorescent starch-based hydrogel (FSH) using starch (ST), cellulose nanofibrils (CN), and carbon dots (CD) was fabricated for simultaneous adsorption and detection of Pb(II). A comprehensive characterization of FSH, including its morphological features, chemical composition, and fluorescence characteristics, was conducted. Notably, FSH exhibited a maximum theoretical adsorption capacity of 265.9mg/g, which was 13.0 times higher than that of pure ST. Moreover, FSH was employed as a fluorescent sensor for Pb(II) determination, achieving a limit of detection (LOD) of 0.06μg/L. An analysis was further performed to investigate the adsorption and detection mechanisms of Pb(II) utilizing FSH. This study provides valuable insights into the production of a novel cost-effective ST-based adsorbent for the removal of Pb(II) ions.
通讯机构：
[Deng, T ] C;[Li, JS ] H;Hunan Univ, Coll Chem & Chem Engn, State Key Lab Chemo Biosensing & Chemometr, Changsha 410082, Peoples R China.;Cent South Univ Forestry & Technol, Sch Sci, Inst Appl Chem, Changsha 410004, Hunan, Peoples R China.
摘要：
A novel AIEgen molecular probe (N-3QL) with typical AIE effects, good biocompatibility, lysosome targeting, pH activation, excellent photostability, and high brightness was synthesized using two simple synthetic steps. Spectroscopic and cytotoxicity experiments indicate that N-3QL can not only be used for the dynamic monitoring of cancer cell lysosomes, but also for photodynamic therapy (PDT) ablation of cancer cells. A pH-activated AIE molecular probe (N-3QL) was synthesized for the purpose of lysosome fluorescence tracking and PDT ablation of cancer cells.
作者机构：
[Ning Zhang] College of Science, Central South University of Forestry and Technology, Changsha 410004, P. R. China;[Dandan Gao; Ziyu Zhuang] Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, P. R. China;Key Lab of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Chinese Academy of Sciences, Xining 810008, P. R. China;College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P.R. China;[Dongdong Li] Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, P. R. China<&wdkj&>Key Lab of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Chinese Academy of Sciences, Xining 810008, P. R. China
通讯机构：
[Dongdong Li] Q;Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, P. R. China<&wdkj&>Key Lab of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Chinese Academy of Sciences, Xining 810008, P. R. China
摘要：
Lithium aluminum layered double hydroxide chlorides (LADH-Cl) have been widely used for lithium extraction from brine. Elevation of the performances of LADH-Cl sorbents urgently requires knowledge of the composition-structure-property relationship of LADH-Cl in lithium extraction applications, but these are still unclear. Herein, combining the phase equilibrium experiments, advanced solid characterization methods, and theoretical calculations, we constructed a cyclic work diagram of LADH-Cl for lithium capture from aqueous solution, where the reversible (de)hydration and (de)intercalation induced phase evolution of LADH-Cl dominates the apparent lithium "adsorption-desorption" behavior. It is found that the real active ingredient in LADH-Cl type lithium sorbents is a dihydrated LADH-Cl with an Al:Li molar ratio varying from 2 to 3. This reversible process indicates an ultimate reversible lithium (de)intercalation capacity of ∼10 mg of Li per g of LADH-Cl. Excessive lithium deintercalation results in the phase structure collapse of dihydrated LADH-Cl to form gibbsite. When interacting with a concentrated LiCl aqueous solution, gibbsite is easily converted into lithium saturated intercalated LADH-Cl phases. By further hydration with a diluted LiCl aqueous solution, this phase again converts to the active dihydrated LADH-Cl. In the whole cyclic progress, lithium ions thermodynamically favor staying in the Al-OH octahedral cavities, but the (de)intercalation of lithium has kinetic factors deriving from the variation of the Al-OH hydroxyl orientation. The present results provide fundamental knowledge for the rational design and application of LADH-Cl type lithium sorbents.
