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1. Impact of Tactile Sensor Quantities and Placements on Learning-based Dexterous Manipulation

Author

Guo, Haoran, Wang, Haoyang, Li, Zhengxiong, Bai, He, and Tao, Lingfeng

Subjects
Computer Science - Robotics
Abstract

Tactile information effectively enables faster training and better task performance for learning-based in-hand manipulation. Existing approaches are validated in simulated environments with a large number of tactile sensors. However, attaching such sensors to a real robot hand is not applicable due to high cost and physical limitations. To enable real-world adoption of tactile sensors, this study investigates the impact of tactile sensors, including their varying quantities and placements on robot hands, on the dexterous manipulation task performance and analyzes the importance of each. Through empirically decreasing the sensor quantities, we successfully find an optimized set of tactile sensors (21 sensors) configuration, which keeps over 93% task performance with only 20% sensor quantities compared to the original set (92 sensors) for the block manipulation task, leading to a potential reduction of over 80% in sensor manufacturing and design costs. To transform the empirical results into a generalizable understanding, we build a task performance prediction model with a weighted linear regression algorithm and use it to forecast the task performance with different sensor configurations. To show its generalizability, we verified this model in egg and pen manipulation tasks and achieved an average prediction error of 3.12%., Comment: This work has been submitted to the IEEE for possible publication

Published
2024

2. Exploring Prediction Targets in Masked Pre-Training for Speech Foundation Models

Author

Chen, Li-Wei, Higuchi, Takuya, Bai, He, Abdelaziz, Ahmed Hussen, Rudnicky, Alexander, Watanabe, Shinji, Likhomanenko, Tatiana, Theobald, Barry-John, and Aldeneh, Zakaria

Subjects
Electrical Engineering and Systems Science - Audio and Speech Processing, Computer Science - Sound
Abstract

Speech foundation models, such as HuBERT and its variants, are pre-trained on large amounts of unlabeled speech for various downstream tasks. These models use a masked prediction objective, where the model learns to predict information about masked input segments from the unmasked context. The choice of prediction targets in this framework can influence performance on downstream tasks. For example, targets that encode prosody are beneficial for speaker-related tasks, while targets that encode phonetics are more suited for content-related tasks. Additionally, prediction targets can vary in the level of detail they encode; targets that encode fine-grained acoustic details are beneficial for denoising tasks, while targets that encode higher-level abstractions are more suited for content-related tasks. Despite the importance of prediction targets, the design choices that affect them have not been thoroughly studied. This work explores the design choices and their impact on downstream task performance. Our results indicate that the commonly used design choices for HuBERT can be suboptimal. We propose novel approaches to create more informative prediction targets and demonstrate their effectiveness through improvements across various downstream tasks., Comment: Submitted to ICASSP 2025

Published
2024

3. Real-time Dexterous Telemanipulation with an End-Effect-Oriented Learning-based Approach

Author

Wang, Haoyang, Bai, He, Zhang, Xiaoli, Jung, Yunsik, Bowman, Michel, and Tao, Lingfeng

Subjects
Computer Science - Robotics
Abstract

Dexterous telemanipulation is crucial in advancing human-robot systems, especially in tasks requiring precise and safe manipulation. However, it faces significant challenges due to the physical differences between human and robotic hands, the dynamic interaction with objects, and the indirect control and perception of the remote environment. Current approaches predominantly focus on mapping the human hand onto robotic counterparts to replicate motions, which exhibits a critical oversight: it often neglects the physical interaction with objects and relegates the interaction burden to the human to adapt and make laborious adjustments in response to the indirect and counter-intuitive observation of the remote environment. This work develops an End-Effects-Oriented Learning-based Dexterous Telemanipulation (EFOLD) framework to address telemanipulation tasks. EFOLD models telemanipulation as a Markov Game, introducing multiple end-effect features to interpret the human operator's commands during interaction with objects. These features are used by a Deep Reinforcement Learning policy to control the robot and reproduce such end effects. EFOLD was evaluated with real human subjects and two end-effect extraction methods for controlling a virtual Shadow Robot Hand in telemanipulation tasks. EFOLD achieved real-time control capability with low command following latency (delay<0.11s) and highly accurate tracking (MSE<0.084 rad)., Comment: Accepted by IROS 2024

Published
2024

4. dMel: Speech Tokenization made Simple

Author

Bai, He, Likhomanenko, Tatiana, Zhang, Ruixiang, Gu, Zijin, Aldeneh, Zakaria, and Jaitly, Navdeep

Subjects
Computer Science - Computation and Language, Computer Science - Artificial Intelligence, Computer Science - Sound, Electrical Engineering and Systems Science - Audio and Speech Processing
Abstract

Large language models have revolutionized natural language processing by leveraging self-supervised pretraining on vast textual data. Inspired by this success, researchers have investigated complicated speech tokenization methods to discretize continuous speech signals so that language modeling techniques can be applied to speech data. However, existing approaches either model semantic (content) tokens, potentially losing acoustic information, or model acoustic tokens, risking the loss of semantic (content) information. Having multiple token types also complicates the architecture and requires additional pretraining. Here we show that discretizing mel-filterbank channels into discrete intensity bins produces a simple representation (dMel), that performs better than other existing speech tokenization methods. Using an LM-style transformer architecture for speech-text modeling, we comprehensively evaluate different speech tokenization methods on speech recognition (ASR) and speech synthesis (TTS). Our results demonstrate the effectiveness of dMel in achieving high performance on both tasks within a unified framework, paving the way for efficient and effective joint modeling of speech and text., Comment: under review

Published
2024

5. Denoising LM: Pushing the Limits of Error Correction Models for Speech Recognition

Author

Gu, Zijin, Likhomanenko, Tatiana, Bai, He, McDermott, Erik, Collobert, Ronan, and Jaitly, Navdeep

Subjects
Computer Science - Machine Learning, Computer Science - Computation and Language, Computer Science - Sound, Electrical Engineering and Systems Science - Audio and Speech Processing
Abstract

Language models (LMs) have long been used to improve results of automatic speech recognition (ASR) systems, but they are unaware of the errors that ASR systems make. Error correction models are designed to fix ASR errors, however, they showed little improvement over traditional LMs mainly due to the lack of supervised training data. In this paper, we present Denoising LM (DLM), which is a $\textit{scaled}$ error correction model trained with vast amounts of synthetic data, significantly exceeding prior attempts meanwhile achieving new state-of-the-art ASR performance. We use text-to-speech (TTS) systems to synthesize audio, which is fed into an ASR system to produce noisy hypotheses, which are then paired with the original texts to train the DLM. DLM has several $\textit{key ingredients}$: (i) up-scaled model and data; (ii) usage of multi-speaker TTS systems; (iii) combination of multiple noise augmentation strategies; and (iv) new decoding techniques. With a Transformer-CTC ASR, DLM achieves 1.5% word error rate (WER) on $\textit{test-clean}$ and 3.3% WER on $\textit{test-other}$ on Librispeech, which to our knowledge are the best reported numbers in the setting where no external audio data are used and even match self-supervised methods which use external audio data. Furthermore, a single DLM is applicable to different ASRs, and greatly surpassing the performance of conventional LM based beam-search rescoring. These results indicate that properly investigated error correction models have the potential to replace conventional LMs, holding the key to a new level of accuracy in ASR systems., Comment: under review

Published
2024

6. How Far Are We from Intelligent Visual Deductive Reasoning?

Author

Zhang, Yizhe, Bai, He, Zhang, Ruixiang, Gu, Jiatao, Zhai, Shuangfei, Susskind, Josh, and Jaitly, Navdeep

Subjects
Computer Science - Artificial Intelligence, Computer Science - Computation and Language, Computer Science - Computer Vision and Pattern Recognition
Abstract

Vision-Language Models (VLMs) have recently demonstrated incredible strides on diverse vision language tasks. We dig into vision-based deductive reasoning, a more sophisticated but less explored realm, and find previously unexposed blindspots in the current SOTA VLMs. Specifically, we leverage Raven's Progressive Matrices (RPMs), to assess VLMs' abilities to perform multi-hop relational and deductive reasoning relying solely on visual clues. We perform comprehensive evaluations of several popular VLMs employing standard strategies such as in-context learning, self-consistency, and Chain-of-thoughts (CoT) on three diverse datasets, including the Mensa IQ test, IntelligenceTest, and RAVEN. The results reveal that despite the impressive capabilities of LLMs in text-based reasoning, we are still far from achieving comparable proficiency in visual deductive reasoning. We found that certain standard strategies that are effective when applied to LLMs do not seamlessly translate to the challenges presented by visual reasoning tasks. A detailed analysis reveals that VLMs struggle to solve these tasks mainly because they are unable to perceive and comprehend multiple, confounding abstract patterns in RPM examples., Comment: COLM 2024. https://github.com/apple/ml-rpm-bench

Published
2024

8. Divide-or-Conquer? Which Part Should You Distill Your LLM?

Author

Wu, Zhuofeng, Bai, He, Zhang, Aonan, Gu, Jiatao, Vydiswaran, VG Vinod, Jaitly, Navdeep, and Zhang, Yizhe

Subjects
Computer Science - Computation and Language, Computer Science - Machine Learning
Abstract

Recent methods have demonstrated that Large Language Models (LLMs) can solve reasoning tasks better when they are encouraged to solve subtasks of the main task first. In this paper we devise a similar strategy that breaks down reasoning tasks into a problem decomposition phase and a problem solving phase and show that the strategy is able to outperform a single stage solution. Further, we hypothesize that the decomposition should be easier to distill into a smaller model compared to the problem solving because the latter requires large amounts of domain knowledge while the former only requires learning general problem solving strategies. We propose methods to distill these two capabilities and evaluate their impact on reasoning outcomes and inference cost. We find that we can distill the problem decomposition phase and at the same time achieve good generalization across tasks, datasets, and models. However, it is harder to distill the problem solving capability without losing performance and the resulting distilled model struggles with generalization. These results indicate that by using smaller, distilled problem decomposition models in combination with problem solving LLMs we can achieve reasoning with cost-efficient inference and local adaptation., Comment: Findings of the Association for Computational Linguistics: EMNLP 2024

Published
2024

9. Rephrasing the Web: A Recipe for Compute and Data-Efficient Language Modeling

Author

Maini, Pratyush, Seto, Skyler, Bai, He, Grangier, David, Zhang, Yizhe, and Jaitly, Navdeep

Subjects
Computer Science - Computation and Language
Abstract

Large language models are trained on massive scrapes of the web, which are often unstructured, noisy, and poorly phrased. Current scaling laws show that learning from such data requires an abundance of both compute and data, which grows with the size of the model being trained. This is infeasible both because of the large compute costs and duration associated with pre-training, and the impending scarcity of high-quality data on the web. In this work, we propose Web Rephrase Augmented Pre-training ($\textbf{WRAP}$) that uses an off-the-shelf instruction-tuned model prompted to paraphrase documents on the web in specific styles such as "like Wikipedia" or in "question-answer format" to jointly pre-train LLMs on real and synthetic rephrases. First, we show that using WRAP on the C4 dataset, which is naturally noisy, speeds up pre-training by $\sim3x$. At the same pre-training compute budget, it improves perplexity by more than 10% on average across different subsets of the Pile, and improves zero-shot question answer accuracy across 13 tasks by more than 2%. Second, we investigate the impact of the re-phrasing style on the performance of the model, offering insights into how the composition of the training data can impact the performance of LLMs in OOD settings. Our gains are attributed to the fact that re-phrased synthetic data has higher utility than just real data because it (i) incorporates style diversity that closely reflects downstream evaluation style, and (ii) has higher 'quality' than web-scraped data.

Published
2024

30. Interface Effect on the Out‐of‐Plane Spin‐Orbit Torque in the Ferromagnetic CoPt Single Layers.

Author

Li, Jialiang, Guo, Qixun, Lin, Ting, Zhang, Qinghua, Bai, He, Cheng, Sheng, Zhan, Xiaozhi, Gu, Lin, and Zhu, Tao

Subjects
NEUTRON reflectometry, NEUTRON measurement, FERROMAGNETIC materials, LOGIC devices, SUBSTRATES (Materials science)
Abstract

Field‐free switching of a perpendicularly magnetized heavy metal/ferromagnetic metal bilayer or single alloy layer through spin‐orbit torque (SOT) provides a potential way for next‐generation spintronic devices with fast speed and high efficiency. Here, a sizable symmetry dependence of field‐free magnetization switching via an out‐of‐plane torque in CoxPt100−x single layers is reported. It is found that the sign of in‐plane SOT in CoxPt100−x when x ≤ 25 is positive. However, it changes to negative when x > 25, while the out‐of‐plane SOT changes its sign when x > 30. The polarized neutron reflectometry measurement further suggests an interface layer with rich Pt content near the substrate, which could have a strong interface effect on the out‐of‐plane SOT. The sign of the out‐of‐plane SOT, and then the polarity of the field‐free magnetization switching, is determined by the competition between the out‐of‐plane torques arising from the bulk and interface parts in the CoxPt100−x single layers. It is expected that such interface effect of the out‐of‐plane torque is desirable to the applications in spin logic devices using symmetry dependence of field‐free magnetization switching in the ferromagnetic CoPt single layers. [ABSTRACT FROM AUTHOR]

Published
2024
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31. Association between perceived stress, loneliness and sleep disorders among breast cancer patients: the moderating roles of resilience.

Author

Ban, Yue and Bai, He

Subjects
*PSYCHOLOGICAL resilience, *CROSS-sectional method, *RESEARCH funding, *BREAST tumors, *QUESTIONNAIRES, *MULTIPLE regression analysis, *LONELINESS, *DESCRIPTIVE statistics, *PSYCHOLOGICAL stress, *SLEEP quality, *SLEEP disorders
Abstract

Sleep disorders are prevalent and often neglected among breast cancer patients. This study aimed to identify the association among perceived stress, loneliness, resilience and sleep disorders and to further explore whether resilience could be a moderator in the association between them and sleep disorders. A cross-sectional study was conducted by 492 female breast cancer patients. Patients were asked in response to the questionnaires including the Pittsburgh Sleep Quality Index, Perceived Stress Scale-10, the Three-Item Loneliness Scale and Resilience Scale-14. The association among perceived stress, loneliness, resilience and perceived stress/loneliness × resilience interaction with sleep disorders were examined by hierarchical multiple regression analysis. The interaction was visualized by using simple slope analysis. 36.58% of the female breast cancer patients reported sleep disorders in our study. Perceived stress and loneliness were related to sleep disorders. Resilience could moderate the relationship between them and sleep disorders. When resilience was higher, perceived stress and loneliness had a weaker impact on sleep disorders. Medical staff should systematically evaluate the internal environmental factors related to patients' sleep quality and help patients relieve their emotional distress caused by the disease through positive psychological guidance. [ABSTRACT FROM AUTHOR]

Published
2024
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32. Regenerating and Developing a National Botanical Garden (NBG) in Khartoum, Sudan: Effect on Urban Landscape and Environmental Sustainability.

Author

Fadelelseed, Safa, Xu, Dawei, Li, Lianying, Tran, Ducthien, Chen, Xi, Alwah, Abdulfattah, Bai, He, and Farah, Zoheir

Abstract

This research focuses on the National Botanic Garden in Khartoum, Sudan, proposing tools and methods to assess botanical garden quality from multiple perspectives. It explores the related concepts between national botanical gardens and landscapes, regeneration landscapes and their components such as botanical gardens, their effects on urban regeneration in cities, urban environments, and environmental sustainability. This study aims to: regenerate and develop a National Botanical Garden in the Almogran area of Khartoum, Sudan, and highlight the importance of establishing a national botanical garden for each climatic region in Sudan. The study used questionnaires to identify the necessary needs for regeneration, and the opinions of employees of the Ministry of Agriculture and Forestry were surveyed about the purposes of: (1) evaluating the garden's total area and interior design; (2) building regeneration; (3) establishing constructions, such as a library, seed gene bank, tissue culture laboratory, etc.; (4) emphasizing the need for modern technology to enhance quality. The study summarizes five regeneration technology methods: environmental plant restoration, water body restoration, building and facility restoration, reconstruction technology, and resource utilization; (5) botanical gardens were proposed for each climatic region in Sudan, and we studied the effects of establishing a botanical garden for each climate region in Sudan on environmental resilience, the effect of the botanical gardens' regeneration on gardens within the cities, and effect of a national botanical garden on the urban landscape and environmental sustainability. These findings suggest that the comprehensive regeneration of the National Botanical Garden, integrating it with the urban regeneration of cities, especially urban greening regeneration, is important for enhancing urban landscapes, enhancing environmental resilience, environmental sustainability, climate change, and achieving land development goals, thus helping to address actual requirements and develop sustainable cities. [ABSTRACT FROM AUTHOR]

Published
2024
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37. Syntropic spin alignment at the interface between ferromagnetic and superconducting nitrides

Author

Jin, Qiao, primary, Zhang, Qinghua, additional, Bai, He, additional, Yang, Meng, additional, Ga, Yonglong, additional, Chen, Shengru, additional, Hong, Haitao, additional, Cui, Ting, additional, Rong, Dongke, additional, Lin, Ting, additional, Wang, Jia-Ou, additional, Ge, Chen, additional, Wang, Can, additional, Cao, Yanwei, additional, Gu, Lin, additional, Song, Guozhu, additional, Wang, Shanmin, additional, Jiang, Kun, additional, Cheng, Zhi-Gang, additional, Zhu, Tao, additional, Yang, Hongxin, additional, Jin, Kui-juan, additional, and Guo, Er-Jia, additional

Published
2024
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38. Asynchronous Distributed Reinforcement Learning for LQR Control via Zeroth-Order Block Coordinate Descent

Author

Jing, Gangshan, Bai, He, George, Jemin, Chakrabortty, Aranya, and Sharma, Piyush K.

Abstract

Recently introduced distributed zeroth-order optimization (ZOO) algorithms have shown their utility in distributed reinforcement learning (RL). Unfortunately, in the gradient estimation process, almost all of them require random samples with the same dimension as the global variable and/or require evaluation of the global cost function, which may induce high estimation variance for large-scale networks. In this paper, we propose a novel distributed zeroth-order algorithm by leveraging the network structure inherent in the optimization objective, which allows each agent to estimate its local gradient by local cost evaluation independently, without use of any consensus protocol. The proposed algorithm exhibits an asynchronous update scheme, and works for stochastic nonconvex optimization with a possibly nonconvex feasible domain based on the block coordinate descent method. The algorithm is later employed as a distributed model-free RL algorithm for distributed linear quadratic regulator design. We provide an empirical validation of the proposed algorithm to benchmark its performance on convergence rate and variance against a centralized ZOO algorithm.

Published
2024
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39. Distributed Multiagent Reinforcement Learning Based on Graph-Induced Local Value Functions

Author

Jing, Gangshan, Bai, He, George, Jemin, Chakrabortty, Aranya, and Sharma, Piyush K.

Abstract

Achieving distributed reinforcement learning (RL) for large-scale cooperative multiagent systems (MASs) is challenging because: 1) each agent has access to only limited information and 2) issues on scalability and sample efficiency emerge due to the curse of dimensionality. In this article, we propose a general distributed framework for sample efficient cooperative multiagent reinforcement learning (MARL) by utilizing the structures of graphs involved in this problem. We introduce three coupling graphs describing three types of interagent couplings in MARL, namely, the state graph, observation graph, and reward graph. By further considering a communication graph, we propose two distributed RL approaches based on local value functions derived from the coupling graphs. The first approach is able to reduce sample complexity significantly under specific conditions on the aforementioned four graphs. The second approach provides an approximate solution and can be efficient even for problems with dense coupling graphs. Here there is a tradeoff between minimizing the approximation error and reducing the computational complexity. Simulations show that our RL algorithms have a significantly improved scalability to large-scale MASs compared with centralized and consensus-based distributed RL algorithms.

Published
2024
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40. Screening and pilot-scale evaluation of a highly efficient pesticide-degrading Pseudomonassp. strain BL5

Author

Chen, Rui, Zuo, Xinyu, Bai, He, Qin, Ruolin, Chen, Zhiguo, Liu, Yiyun, Cao, Wenqing, Song, Jingpeng, and Jia, Xiaoqiang

Abstract

The widespread use of pesticides has caused serious harm to ecosystems, necessitating effective and environmentally friendly treatment methods. Bioremediation stands out as a promising approach for pollutant treatment, wherein the metabolic activities of microorganisms can transform toxic pesticides into compounds with lower or no toxicity. In this study, we obtained eight pesticide-degrading strains from pesticide-contaminated sites through continuous enrichment and screening. Four highly efficient pesticide-degrading strains (degradation ratios exceeding 80%) were identified. Among them, Pseudomonassp. BL5 exhibited the strongest growth (exceeding 109CFU·ml−1) and outstanding degradation of benzene derivatives and chlorinated hydrocarbons at both laboratory and pilot scales, with degradation ratios exceeding 98% and 99.6%, respectively. This research provides new tools and insights for the bioremediation of pesticide-related pollutants.

Published
2024
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41. Amplitude Modulation Scheme for an Acoustically Actuated Magnetoelectric Antenna Using Field-Dependent Magneto-Mechanical Effect

Author

Qiao, Jiacheng, Wu, Jingen, Du, Yongjun, Xu, Yiwei, Bai, He, Wang, Zhiguang, Cui, Wanzhao, Hu, Zhongqiang, and Liu, Ming

Abstract

Mechanical antennas that are driven by external mechanical oscillation and acoustic self-resonance have been demonstrated for portable very low-frequency (VLF) electromagnetic (EM) wave transmitting. However, the mechanical relaxation, caused by the energy transition between mechanical and EM energies during signal modulation, limits the modulation rate of mechanical antennas. Here, we use direct antenna amplitude modulation (DAAM) to enhance the modulation rate of the proposed magnetoelectric (ME) antenna. First, we construct a nonlinear converse ME (CME) equivalent circuit model to optimize the dc magnetic field and operating frequency. The relaxation of Young’s modulus of the magnetic layer is gradually eliminated with the increase of modulation rate until Young’s modulus and radiation intensity of the ME antenna are no longer changed. Ideally, the modulation rate of DAAM is half of the carrier rate, but the actual value is lower than the ideal value due to the overshoot and ringing from the modulation coil. Under the carrier frequency of 27.6 kHz and the modulation frequency of 6 kHz, the bit rate of DAAM reaches up to 12 kbps, which is six times higher than that of the conventional electrical modulation. Our work demonstrates the potential of portable ME antenna for practical high-rate VLF EM communication.

Published
2024
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42. Design and Fabrication of Island‐Like CoNi2S4@NiCo‐LDH/Biomass Carbon Heterostructure as Advanced Electrodes for High‐Performance Hybrid Supercapacitors.

Author

Wang, Haoze, Gao, Xin, Xie, Yanqiu, Guo, Erjun, Bai, He, Jiang, Fan, Li, Qian, and Yue, Hongyan

Subjects
CHEMICAL kinetics, ENERGY density, POWER density, ADSORPTION capacity, CHARGE transfer, SUPERCAPACITORS, SUPERCAPACITOR electrodes
Abstract

The utilization of heterostructured electrodes offers an effective approach to boost the energy density of supercapacitors without sacrificing their power density. However, the adoption of such materials is frequently impeded by sluggish reaction kinetics. Herein, an island‐like CoNi2S4@NiCo‐layered double hydroxide/biomass carbon (CoNi2S4@NiCo‐LDH/BC) heterostructure is synthesized by embedding CoNi2S4 in the interlayer of NiCo‐LDH nanosheets on BC through a partial in situ sulfidation process. Theoretical and experimental analyses indicate that this unique structural configuration lowers transport barriers and enhances ion adsorption capacity, leading to a significant improvement in ion/electron reaction kinetics. In addition, the embedded structural design effectively alleviates the significant volume expansion during charge–discharge process, while the robust BC framework prevents electrode degradation, thereby enhancing stability. These advantages enable the developed electrode material to achieve a high specific capacity (1655.75 C g−1 at 1 A g−1) and an extended cycle life (86.82% capacity retention after 10 000 cycles). Significantly, the assembled hybrid supercapacitor CoNi2S4@NiCo‐LDH/BC// activated carbon demonstrates a remarkable energy density of 95.57 Wh kg−1 at 866.61 W kg−1 and exceptional cycling stability, maintaining 95.16% capacity after 10 000 cycles. This research offers an effective strategy to promote ion/charge transfer and adsorption capacity of heterostructure and provides a new approach to the development of advanced supercapacitor electrodes. [ABSTRACT FROM AUTHOR]

Published
2024
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43. Recent advances and optimization strategies for the microbial degradation of PCBs: From monocultures to microbial consortia.

Author

Chen, Rui, Qin, Ruolin, Bai, He, and Jia, Xiaoqiang

Subjects
POLYCHLORINATED biphenyls, MICROBIAL communities, SPECIES diversity, BIOREMEDIATION, ORGANIC compounds, METAGENOMICS
Abstract

Polychlorinated biphenyls (PCBs) are a class of synthetic organic compounds that are widely distributed in the environment and have significant adverse effects on humans as well as the ecosystem. Many microorganisms that can degrade PCBs have been reported, including monocultures of bacteria and fungi, as well as natural and artificial microbial consortia. Generally, anaerobic dechlorination can degrade highly chlorinated PCBs to reduce their toxicity, while aerobic oxidation degrades lowly chlorinated PCBs (four or fewer chlorine atoms) and realizes their complete mineralization into CO2 by disrupting the benzene ring structure. Due to the need for the metabolism of a wide range of PCB congeners in the environment, microbial consortia have become a research hotspot, and their species diversity facilitates metabolic cooperation, enabling them to undertake more complex tasks. In this review, we will discuss the metabolic mechanisms of PCB degradation by monocultures as well as microbial consortia, and focus on the recent progress in the development and optimization of PCB-degrading microbial consortia, the community composition analysis methods, the prevailing optimization strategies such as biostimulation, bioaugmentation, metagenomics, and the combination of other methods for a better remediation effect, which will provide theoretical and practical bases for the rational design, construction and further optimization of efficient microbial consortia for the high-efficiency degradation of PCBs. [ABSTRACT FROM AUTHOR]

Published
2024
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45. Coupling Coordination Relationship and Spatiotemporal Heterogeneity between Urbanization and Ecosystem Services in the Songhua River Basin.

Author

Bai, He, Chen, Yuanyuan, Wang, Shaohan, Chu, Rui, Fang, Jiyuan, Zhang, Huina, Xing, Shuhan, Wang, Lei, and Xu, Dawei

Subjects
ECOSYSTEM services, ENVIRONMENTAL security, WATERSHEDS, HISTORIC districts, URBANIZATION, HETEROGENEITY
Abstract

Rapid urbanization in the Songhua River Basin (SRB), a crucial ecological barrier in China and Northeast Asia, has led to the degradation of ecosystem service functions and a decline in their value, thereby posing a significant threat to regional ecological security. Clarifying the complex coupling coordination relationship between urbanization and ecosystem services (ESs) and identifying the spatiotemporal heterogeneity of their interactions will facilitate the high-quality and coordinated development of urbanization and ESs in the SRB. This study employed a systems approach, treating urbanization and ESs as overarching systems and delineating different aspects of urbanization and ecosystem service functions as subsystems within these systems. The spatiotemporal characteristics of urbanization and the ecosystem service value (ESV) in the SRB from 1985 to 2021 were revealed. The coupling coordination relationship and the spatiotemporal heterogeneity of the interactions between urbanization and ESs in the SRB at both the system and subsystem levels were analyzed using the coupling coordination degree (CCD) model and the spatiotemporal geographically weighted regression (GTWR) model. The findings indicated that during the study period: (1) The urbanization index of SRB rose from 0.09 to 0.34, while the ESV experienced a decrease from 2091.42 × 107 CNY to 2002.44 × 107 CNY. (2) The coupling coordination degree (CCD) between urbanization and ESs in the SRB at both the system and subsystem levels increased significantly, generally transitioning from the moderately unbalanced to the basically balanced stage. Areas with high CCD values were mainly distributed in ecological function areas and low-level urbanized areas, while areas with low CCD values were mainly distributed in grassland ecological degradation areas, ecologically fragile areas, resource-dependent old industrial cities, and highly urbanized areas. (3) The subsystems of urbanization had an overall negative impact on Ess, with varying trends, but the spatial distribution pattern of the interactions remained relatively stable. Conversely, the subsystems of ESs all exhibited a trend of initially strengthening and then weakening their negative impacts on urbanization, and the spatial distribution pattern was highly correlated with the spatial distribution pattern of ESV in the SRB. [ABSTRACT FROM AUTHOR]

Published
2024
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46. Assessing Carbon Sink Capacity in Coal Mining Areas: A Case Study from Taiyuan City, China.

Author

Chen, Fan, Liu, Yang, Guo, Jinkai, Bai, He, Wu, Zhitao, and Li, Ruijin

Subjects
GREENHOUSE gases, GLOBAL warming, CARBON cycle, COAL mining, ENVIRONMENTAL quality
Abstract

Climate warming and air pollution are atmospheric environmental problems that have aroused broad concern worldwide. Greenhouse gas emissions are the main cause of global warming. In addition to reducing carbon emissions, increasing carbon sink capacity and improving environmental quality are essential for building green and low-carbon enterprises under carbon peak and carbon neutrality goals. Currently, the research on the methods and application of carbon sink capacity assessment in coal mining enterprises is limited. Given this, this study estimated the carbon absorption, carbon storage, and net ecosystem productivity of a typical coal mining area in Taiyuan City, China, and compared the characteristics and applicability of the three methods. The results showed the following: (1) The total carbon absorption (carbon sink) of the mining area in 2021 was 117.39 t, the primary source of which is forest land. (2) The total carbon storage in the mining area in 2021 was 29,561.96 t. From different land use types, the carbon storage in the mining area mainly came from forest land (27,867.73 t); from the perspective of carbon pool, soil carbon storage (21,970.96 t) had the most significant contribution to the carbon storage of mining areas. (3) The net ecosystem productivity of the mining area in 2021 was 781.97 g/(m2·a), indicating that the ecosystem of the mining area was a carbon sink. (4) The three estimation methods differed in the current case. The estimation method for carbon absorption is the simplest, and the results are the most intuitive. The estimation method for net ecosystem productivity is the most complex. The carbon sink estimation via carbon storage needs to collect two years of data. Enterprises should assess the carbon sink capacity of mining areas based on existing conditions and data. This study proposes methods for estimating carbon sink capacity in mining areas, which have positive practical significance for the low-carbon green development of coal mine enterprises. [ABSTRACT FROM AUTHOR]

Published
2024
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47. CLOSURE TIME OF NENJIANG OCEAN: Constrains from Zircon Geochronology and Geochemistry of the Early Permian Dawusu Monzogranite.

Author

MA Wei, MA Jing-xuan, HONG Yang-bai-he, and WEN Yun-qi

Abstract

Nenjiang Ocean is an important branch of the eastern section of Paleo-Asian Ocean, and its closure time is of great significance to define the tectonic evolution of the eastern section of Central Asian orogenic belt. The paper studies the petrology, chronology and geochemistry of the Permian rock mass in Dawusu area, northern Daxinganling Mountains, and discusses its tectonic background, which provides new evidence for the constrains on the closure time of Nenjiang Ocean and tectonic evolution in northern Daxinganling Mountains. The zircon U-Pb geochronology results show that the weighted mean age of monzogranite is 292±4 Ma, corresponding to Early Permian. The monzogranite belongs to weak peraluminous I-type granite, with the REE distributions in right-inclined pattern, enriched LILEs (Rb, Ba and K) and depleted HFSEs (Nb, P and Ti), showing the characteristics of post-orogenic granites, which may be formed in extensional environment. Geochemically, the rock shows moderately negative Eu anomaly (δEu=0.46-0.47), with the Th/U ratio of 5.61-5.94, Nb/Ta ratio of 7.98-8.14, Ti/Zr ratio of 6.11-6.36, and low Mg# value (22-23), indicating that it was formed in the partial melting of lower crust, with a high degree of crystallization differentiation occurred during the ascent. Based on the published regional chronological data, the Carboniferous-Permian magmatism can be divided into three stages : 360 -350 Ma, 345 -292 Ma and 289 -260 Ma. By comparing the spatiotemporal distribution, lithological assemblage and geochemical characteristics of magmatic rocks of each stage, it is concluded that the magmatic rocks of the three stages show a continuous change of subduction-postcollision-postorogenic extension, which records the closure process of Nenjiang Ocean. It is believed that Dawusu monzogranite is the product of the second-stage magmatism, formed in the extensional environment after the collision between Erguna-Xing'an block and Songnen block, which defines that Nenjiang Ocean should be closed at the end of Early Carboniferous. [ABSTRACT FROM AUTHOR]

Published
2024
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48. Dynamic Changes in Gut Microbiota-Derived Metabolite Trimethylamine-N-Oxide and Risk of Type 2 Diabetes Mellitus: Potential for Dietary Changes in Diabetes Prevention.

Author

Huang, Yuliang, Wu, Yani, Zhang, Yao, Bai, He, Peng, Ruiheng, Ruan, Wenli, Zhang, Qianlong, Cai, Enmao, Ma, Mingfeng, Zhao, Yueyang, Lu, Ying, and Zheng, Liqiang

Abstract

Background: A gut-microbial metabolite, trimethylamine N-oxide (TMAO), has been associated with type 2 diabetes mellitus (T2DM). Few previous prospective studies have addressed associations between the changes in TMAO and T2DM incidence. Methods: Data were derived from a longitudinal cohort conducted from 2019 to 2021 in rural areas of Fuxin County, Liaoning Province, China, and 1515 diabetes-free participants aged above 35 years were included. The concentrations of serum TMAO and its precursors were measured at two time points, namely in 2019 and 2021. TMAO and TMAO changes (ΔTMAO) were separately tested in a logistic regression model. For further examination, the odds ratios (ORs) for T2DM were calculated according to a combination of TMAO levels and ΔTMAO levels. Results: During a median follow-up of 1.85 years, 81 incident cases of T2DM (5.35%) were identified. Baseline TMAO levels exhibited a nonlinear relationship, first decreasing and then increasing, and only at the highest quartile was it associated with the risk of T2DM. The OR for T2DM in the highest quartile of serum TMAO was 3.35 (95%CI: 1.55–7.26, p = 0.002), compared with the lowest quartile. As for its precursors, only choline level was associated with T2DM risk and the OR for T2DM in the Q3 and Q4 of serum choline was 3.37 (95%CI: 1.41–8.05, p = 0.006) and 4.72 (95%CI: 1.47–15.13, p = 0.009), respectively. When considering both baseline TMAO levels and ΔTMAO over time, participants with sustained high TMAO levels demonstrated a significantly increased risk of T2DM, with a multivariable-adjusted OR of 8.68 (95%CI: 1.97, 38.34). Conclusion: Both initial serum TMAO levels and long-term serum TMAO changes were collectively and significantly associated with the occurrence of subsequent T2DM events. Interventions aimed at normalizing TMAO levels, such as adopting a healthy dietary pattern, may be particularly beneficial in T2DM prevention. [ABSTRACT FROM AUTHOR]

Published
2024
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