31 research outputs found
Chinese Fine-Grained Financial Sentiment Analysis with Large Language Models
Entity-level fine-grained sentiment analysis in the financial domain is a
crucial subtask of sentiment analysis and currently faces numerous challenges.
The primary challenge stems from the lack of high-quality and large-scale
annotated corpora specifically designed for financial text sentiment analysis,
which in turn limits the availability of data necessary for developing
effective text processing techniques. Recent advancements in large language
models (LLMs) have yielded remarkable performance in natural language
processing tasks, primarily centered around language pattern matching. In this
paper, we propose a novel and extensive Chinese fine-grained financial
sentiment analysis dataset, FinChina SA, for enterprise early warning. We
thoroughly evaluate and experiment with well-known existing open-source LLMs
using our dataset. We firmly believe that our dataset will serve as a valuable
resource to advance the exploration of real-world financial sentiment analysis
tasks, which should be the focus of future research. The FinChina SA dataset is
publicly available at https://github.com/YerayL/FinChina-SAComment: FinLLM Symposium at IJCAI 202
Effect of Molecular Structure of C<sub>10</sub> Hydrocarbons on Production of Light Olefins in Catalytic Cracking
The effect of the molecular structure of feedstock on the cracking reaction of C10 hydrocarbons to ethylene and propylene over H-ZSM-5 zeolite was investigated. To better compare the effect of decane on the production of light olefins, the thermal cracking and catalytic cracking performance of decane were first investigated. As a comparison, the thermal cracking and catalytic cracking of decane were studied by cracking over quartz sand and H-ZSM-5. Compared with the thermal cracking reaction over quartz sand, the catalytic cracking reaction of decane over H-ZSM-5 has a significantly higher conversion and light olefins selectivity, especially when the reaction temperature was lower than 600 °C. On this basis, the catalytic cracking reactions of decane and decene over H-ZSM-5 were further compared. It was found that decene with a double bond structure had high reactivity over H-ZSM-5 and was almost completely converted, and the product was mainly olefin. Compared with decane as feedstock, it has a lower methane yield and higher selectivity of light olefins. Therefore, decene was more suitable for the production of light olefins than decane. To this end, we designed a new light olefin production process. Through olefin cracking, the yield of light olefins in the product can be effectively improved, and the proportion of different light olefins such as ethylene, propylene and butene can be flexibly adjusted
Mangrove Response to the Continuous Disturbance by Multiple Typhoons on the Qi'ao Island, Zhuhai, Using Sentinel-2 Remote Sensing Images
Mangroves are typical ecosystems located in the intertidal zone of tropical and subtropical coasts that protect the area against wave action, promote accretion in river estuaries, and act as an important global carbon sink. However, several natural mangroves have recently degraded due to climate change and human activities, increasing the risk to coastal areas' ecological environments. The mangroves on Qi'ao Island in Zhuhai, China, have been destroyed by human activities and the invasion of the exotic species Spartina alterniflora. In 1999, the Zhuhai municipal government imported pioneer species, such as Sonneratia apetala, to Qi'ao Island to restore the degraded mangroves, which have now evolved into a sufficiently continuous community with a stable area since 2015 with S. apetala as the dominant species. However, because the intensity and frequency of typhoon landfalls are increasing under global warming, dominant species in the mangroves of Qi'ao Island, S. apetala, is more vulnerable to typhoon disturbance due to its height and low trunk density, leading to greater uncertainty regarding their ecological functions on Qi'ao Island. Existing studies have mainly focused on the damage and recovery patterns of mangroves by a single typhoon, having seldom analyzed the response process of mangroves to consecutive disturbances by multiple typhoons; thus, these studies cannot be used to predict the succession process of mangroves with increasing typhoon frequency. In this study, the damage and recovery patterns of mangroves on Qi'ao Island were studied under the disturbance of three consecutive typhoons (2016 NIDA, 2017 Hugo, and 2018 Mangkhut), and their influencing factors were discussed based on the Normalized Difference Vegetation Index (NDVI) using Sentinel-2 remote sensing images. The results showed that (1) the NDVI of mangroves on Qi'ao Island decreased after the typhoon, and the damage levels could be classified as mild or mild to moderate. Moreover, the severity of the damage was relatively small. (2) An annual legacy effect existed across multiple typhoons. The recovery process of mangroves generally followed a circulating succession mode after typhoon disturbances in the order of more severe damage→slow recovery→milder damage→rapid recovery→ more severe damage pattern. (3) The damage levels of mangroves on Qi'ao Island increased with typhoon intensity. However, they decreased if S. apetala recovered slowly before the typhoon. Thus, the recovery pattern was mainly influenced by the damage levels of S. apetala after the typhoon landing and was not largely dependent on the hydrothermal conditions at regional scales. The results suggest that mangroves on Qi'ao Island, mainly consisting of S. apetala, have evolved to adapt to the consecutive typhoon disturbances, which has promoted their succession from plantations to near natural forests and the formation of a stable typhoon-resistant ecosystem
Numerical exploration of the flow regime transition of a novel catalytic cracking reactor and operation mode analysis
The maximizing isoparaffins (MIP) reactor has multiple reaction zones by expanding the diameter of the middle section of the conventional equal-diameter FCC riser to produce high-quality gasoline. This study aimed to probe the flow regime transition and corresponding regulation of such diameter-transformed reactors using multiscale CFD simulations with twelve-lump kinetics. It was found that a choking plateau that appears in a low-velocity, equal-diameter riser was captured at a much higher solid concentration in the new reactor when considering reactions, while the plateau disappears and becomes a slowly ascending slope under cold-model conditions. Using the particle circulating mode instead of the fixed mode gives rise to large fluctuations in solids flow and reaction rate in the first zone, but the formation of fast fluidization in the expanded second zone can help stabilize the flow behaviors and product yield. This finding sheds light on the design and operation of diameter-transformed fluidized beds. 漏 2022 Elsevier B.V
Chem. Eng. Sci.
The MIP (maximizing iso-paraffins) reactor, which was developed by SINOPEC to meet the challenge for clean fuels, consists of a series of reaction zones with different diameters, thus allowing coexistence of multiple flow regimes. This study is to probe the flow behavior in the MIP reactor through computational fluid dynamics (CFD) simulation, in which a new drag-coefficient relation based on the energy minimization multi-scale (EMMS) model was applied. A testing simulation of a lab-scale MIP reactor validates our approach first; further investigation of an industrial MIP reactor indicates that, the so-called "choking" phenomenon, which is characterized by an S-shaped profile of voidage and saturation carrying of particles, also exists in the MIP reactor. This choking phenomenon deserves our reemphasis, since most of the existent simulations take for granted that, a riser flow can be determined by specification of only gas and solids velocities, ignoring the effect of solids inventory. In practice, understanding of the "choking" may facilitate troubleshooting of MIP units, as the related flow and transition behaviors are critical to the reaction performance. In general, this simulation unfolds a fresh perspective of the EMMS-based multi-scale CFD approach. (c) 2007 Elsevier Ltd. All rights reserved.The MIP (maximizing iso-paraffins) reactor, which was developed by SINOPEC to meet the challenge for clean fuels, consists of a series of reaction zones with different diameters, thus allowing coexistence of multiple flow regimes. This study is to probe the flow behavior in the MIP reactor through computational fluid dynamics (CFD) simulation, in which a new drag-coefficient relation based on the energy minimization multi-scale (EMMS) model was applied. A testing simulation of a lab-scale MIP reactor validates our approach first; further investigation of an industrial MIP reactor indicates that, the so-called "choking" phenomenon, which is characterized by an S-shaped profile of voidage and saturation carrying of particles, also exists in the MIP reactor. This choking phenomenon deserves our reemphasis, since most of the existent simulations take for granted that, a riser flow can be determined by specification of only gas and solids velocities, ignoring the effect of solids inventory. In practice, understanding of the "choking" may facilitate troubleshooting of MIP units, as the related flow and transition behaviors are critical to the reaction performance. In general, this simulation unfolds a fresh perspective of the EMMS-based multi-scale CFD approach. (c) 2007 Elsevier Ltd. All rights reserved
CaO/CaCO₃ thermochemical energy storage performance of MgO/ZnO co-doped CaO honeycomb in cycles
The calcium-based honeycomb used in thermochemical energy storage (TCES) is promising for industrial applications, but its energy storage performance needs to be further improved. In this work, a novel MgO/ZnO co-doped calcium-based honeycomb for thermochemical energy storage was fabricated by extrusion molding method. The CaO/CaCO3 TCES performance of the MgO/ZnO co-doped CaO honeycomb was tested. ZnO and MgO show a synergistic impact on the CaO/CaCO3 TCES performance of the calcium-based honeycomb. The CaO honeycomb doped with MgO and ZnO exhibits the highest energy storage capacity with the mass ratio of CaO:MgO:ZnO of 100:10:3. After 25 cycles, the effective conversion and energy storage density of MgO/ZnO co-doped CaO honeycomb are 1.33 times those of the unmodified CaO honeycomb, respectively. MgO as the support improves the sintering resistance of the CaO honeycomb. ZnO strengthens the support effect of MgO for CaO and further improves the cyclic stability of the MgO doped CaO honeycomb in the multiple CaO/CaCO3 cycles. In addition, ZnO enhances the basicity and increases oxygen vacancies of the CaO honeycomb, which promotes energy storage. Moreover, MgO/ZnO co-doped CaO honeycomb exhibits much higher mechanical properties. The crushing strength of MgO/ZnO co-doped CaO honeycomb is 0.8 MPa after 20 cycles, which is 25.0 % higher than that of unmodified CaO honeycomb. The density functional theory calculation indicates that the movement of the CaO cluster is limited effectively by the Cac-Os bonds strengthened by ZnO and the Oc-Mgs bonds. Therefore, MgO/ZnO co-doped CaO honeycomb is a potential material for thermochemical energy storage.This work was financially supported by the National Natural Science Foundation of China (52276204) and Shandong Provincial Natural Science Foundation, China (ZR2020ME188)
High-Temperature Cracking of Pentene to Ethylene and Propylene over H-ZSM-5 Zeolites: Effect of Reaction Conditions and Mechanistic Insights
The effects of reaction conditions on the yield of ethylene and propylene from pentene cracking were investigated in a fixed-bed reactor at 500–750 °C and for a weight hourly space velocity (WHSV) of 15–83 h−1. The total yield of ethylene and propylene reached a maximum (67.8 wt%) at 700 °C and 57 h−1. In order to explore the reaction mechanism at high temperatures, a thermal/catalytic cracking proportion model was established. It was found that the proportion of pentene feed chemically adsorbed with the acid sites and cracked through catalytic cracking was above 88.4%, even at 750 °C. Ethylene and propylene in the products were mainly derived from catalytic cracking rather than thermal cracking at 650–750 °C. In addition, the suitable reaction network for pentene catalytic cracking was deduced and estimated. The results showed that the monomolecular cracking proportion increased from 1% at 500 °C to 95% at 750 °C. The high selectivity of ethylene and propylene at high temperatures was mainly due to the intensification of the monomolecular cracking reaction. After 20 times of regeneration, the acidity and pore structure of the zeolite had hardly changed, and the conversion of pentene remained above 80% at 650 °C
Constructing a Low-Impedance Interface on a High-Voltage LiNi0.8Co0.1Mn0.1O2 Cathode with 2,4,6-Triphenyl Boroxine as a Film-Forming Electrolyte Additive for Li-Ion Batteries
Soybean image dataset for classification
This paper presents a dataset with 5513 images of individual soybean seeds, which encompass five categories: (Ⅰ) Intact, (Ⅱ) Immature, (Ⅲ) Skin-damaged, (Ⅳ) Spotted, and (Ⅴ) Broken. Furthermore, there are over 1000 images of soybean seeds in each category. Those images of individual soybeans were classified into five categories based on the Standard of Soybean Classification (GB1352-2009) [1]. The soybean images with the seeds in physical touch were captured by an industrial camera. Subsequently, individual soybean images (227×227 pixels) were divided from the soybean images (3072×2048 pixels) using an image-processing algorithm with a segmentation accuracy of over 98%. The dataset can serve to study the classification or quality assessment of soybean seeds
Control analysis and experimental investigation of a multi-coil moving coil linear motor based on an improved bacterial foraging algorithm
This study tries to improve the response performance of a moving coil linear motor (MCLM). A newly designed MCLM with a bobbin of triple coils is proposed. A mathematic model and a solution of searching time optimum using an improved Bacterial Foraging Algorithm (BFA) are developed, and a dual-mode controller with Bang-Bang & PI based on the proposed method is put forward. Control analysis and simulation results show the response time of the proposed MCLM driven by the dual-mode controller is reduced from 8.5 to 2.5 ms compared to the traditional single coil MCLM, and the ringing and overshoot are below 5%. The experimental frequency and response time of the proposed MCLM are 300 Hz at 3 dB and 4 ms, respectively. Analysis and experimental results show that the effectiveness of the proposed control technology is verified and the proposed MCLM displays good performance of high frequency and rapid response