211 research outputs found
Shui de xiao hua zui hao xiao? = Whose joke is the funniest?
No full textThe joke-telling competition started. Whoever's joke was the funniest and could make every classmate laugh would get the most special gift! When Bai Leshan was telling his joke, everybody burst into laughter except for Lin Dewei. Why didn't Lin Dewei laugh?Lower-intermediate level. Includes 600 words corresponding to New HSK level
‐rGO Stacked Heterostructures Enabled Water State Modification for Highly Efficient Interfacial Solar Evaporation
No full textPublished online: March 14, 2023Improving interfacial solar evaporation performance is crucial for the practical application of this technology in solar-driven seawater desalination. Lowering evaporation enthalpy is one of the most promising and effective strategies to significantly improve solar evaporation rate. In this study, a new pathway to lower vaporization enthalpy by introducing heterogeneous interactions between hydrophilic hybrid materials and water molecules is developed. 2D MoN₁.₂ nanosheets are synthesized and integrated with rGO nanosheets to form stacked MoN₁.₂-rGO heterostructures with massive junction interfaces for interfacial solar evaporation. Molecular dynamics simulation confirms that atomic thick 2D MoN₁.₂ and rGO in the MoN₁.₂-rGO heterostructures simultaneously interact with water molecules, while the interactions are remarkably different. These heterogeneous interactions cause an imbalanced water state, which easily breaks the hydrogen bonds between water molecules, leading to dramatically lowered vaporization enthalpy and improved solar evaporation rate (2.6 kg m⁻²h⁻¹). This study provides a promising strategy for designing 2D-2D heterostructures to regulate evaporation enthalpy to improve solar evaporate rate for clean water production.Huimin Yu, Deyu Wang, Huanyu Jin, Pan Wu, Xuan Wu, Dewei Chu, Yi Lu, Xiaofei Yang, and Haolan X
Shi jiu shi ji zhong ye ru zhe dui Jidu zong jiao zhi li jie: yi Yao Ying ji Wei Yuan wei zhong xin = Mid-19th century Confucians' understanding of Christianity : Yao Ying and Wei Yuan.
No full text本文旨在闡釋十九世紀中葉的儒者如何理解基督宗教。筆者以兩位中層官員（姚瑩與魏源）作為主要例子，說明儒者思想和信仰構成的世界觀對世俗世界和超越世界都有一套完整的理解，亦引伸出儒者「經世」的信念。本文認為儒者對基督宗教的理解與他們的世界觀有密不可分的關係，但由於理解的目的在於「經世」，他們亦會在一些情況下基於現實考慮或新資訊的出現而暫時放棄自身的觀感，並進而修正他們的世界觀。藉著相類案例的比較，本文嘗試說明十九世紀中葉的儒者並非單純以自身的信仰批判基督宗教，亦非純粹以帝國官員的立場以純粹的管治和外交原則應對異國的宗教。對他們而言，理解基督宗教的過程就是世界觀、新資訊與現實考慮三者互動的結果。This thesis attempts to explain Confucian understanding of Christianity in the mid-nineteeth century through the views of two government officials, Yau Yin and Wai Yuin, who based their beliefs on both the immanent and transcendent aspects of "Jinshi" or the philosophy of statecraft. This work asserts that the Confucian understanding of Christianity was very much tied to the officials’ perception of secular society. Further, with the increase in knowledge and information, their view of Christianity began to change. Chinese officials’ criticism of Christianity was based on a complex set of factors which included the influx of new ideas, information, government edicts, diplomatic considerations as well as their status in the imperial government. In other words, understanding of Chrisitanity in China developed and evolved with new understanding of historical realities.Detailed summary in vernacular field only.孔德維.Parallel title from English abstract.Thesis (M.Phil.) Chinese University of Hong Kong, 2015.Includes bibliographical references (leaves 289-341).Abstracts in English and Chinese.Kong Dewei
The First Imperial Transition in China: A Microhistory of Jiangling (369 – 119 BCE)
No full textThis dissertation challenges the dominant historical narrative about the rise of early Chinese empires, the Qin (221 – 206 BCE) and the Han (202 – 220 BCE), which tends to fixate on the grand strategy and military power of the conquerors while neglecting the agency of the conquered populations. To counteract this one-sided narrative, I investigate the area of Jiangling 江陵 in the middle Yangzi River region, where the capital of Chu 楚—then the most powerful state in South China—was located. Qin’s invasion of the Chu capital area in 278 BCE and Han’s takeover of it in 202 BCE make Jiangling an ideal case study for tracing how a former regional center responded to the rising imperial order from the mid-fourth through the second century BCE. Drawing on a wealth of new archaeological and manuscript evidence, this dissertation is among the first within early China studies to offer a locality-centered microhistory. Chapter 1 analyzes the anatomy of this narrative, which I call the Great Unification—or dayitong 大一統—narrative. Chapter 2 examines settlement and architectural remains from Jinancheng 紀南城 and Yingcheng 郢城 to expose the reality of the Qin conquest. The available evidence suggests that the Qin invaders did not destroy indiscriminately but exercised violence strategically and relied on local know-how to fortify their colonial headquarters. Chapter 3 explores the changing mortuary landscape in Jiangling and the funeral workmen communities in particular. It argues that social change in postconquest Jiangling was the result of a series of negotiations between the native communities and the colonial governments, negotiations that were as constrained by local conditions as they were by imperial directives. Chapter 4 devises a funeral organizers-centered perspective to trace cultural shifts in Jiangling. Through a statistical analysis of the burial objects arranged by funeral organizers and their changing mortuary representations in tombs, the chapter reveals that cultural perceptions related to food and drink, personal property, and government service were deeply affected by the intrusion of Qin and Han modes of social organization. Chapter 5 scales up to a more macro level to analyze the institutional development of three rank systems, i.e., Qin, Neo-Chu, and Han. It discovers an important phenomenon called “rank inflation” and argues that the different ways of controlling rank inflation had a profound effect on Jiangling denizens. Chapter 6 utilizes a group of mortuary documents called gaodice 告地策 (“notifications to underworld authorities”) to focus on the lived experience of three widows of top rank-holders in Jianging, whose tombs were interred with such documents. The chapter reveals the tensions within newly emergent and liminal rank-related identities in the wake of the Han imperial incursion in Jiangling. In a brief conclusion, the dissertation offers some reflections on how to write the first imperial transition free from the Great Unification mantra
Solar driven ammonia synthesis with Co-TiOx and Ag nanowires enhanced Cu2ZnSnS4 photocathodes
No full textRestoring ammonia from waste nitrate stands as a promising strategy for reducing reliance on the energyintensive Haber-Bosch process and tackling environmental pollutants. Advancing the catalytic aspects of photoelectrochemical (PEC) ammonia synthesis via waste nitrate reduction is of great importance to enhance its viability for sustainable chemical production. However, this process still suffers from low ammonia faradaic efficiency (FE) with high operational potential due to its involvement in multi-electron reactions. Herein, we integrated a cobalt-doped TiOx (Co-TiOx) cocatalyst and Ag nanowires (NWs) electron extraction layer onto TiOx/CdS/Cu2ZnSnS4 (CZTS) photocathode, achieving nearly 100 % ammonia FE and an onset potential of ~0.49 V vs. RHE. Evidenced by the in-situ synchrotron-radiated FTIR (SR-FTIR) and theoretical calculations, the increased ratio of surface oxygen vacancy sites (Vo) induced by Co-TiOx is crucial for the key reaction intermediates adsorption (i.e. *NO3 and *NO2) for subsequent ammonia production. Moreover, the transparent Ag NWs facilitates the electron extraction from TiOx/CdS/CZTS to the surface catalytic sites. Powered by CZTS solar cells, a standalone solar-to-ammonia system has been demonstrated with outstanding activity and catalytic performance.Shujie Zhou, Kaiwen Sun, Cui Ying Toe, Jialiang Huang, Ao Wang, Jodie Yuwono, Priyank Kumar, Tao Wan, Doudou Zhang, Zhipeng Ma, Jitraporn Vongsvivut, Dewei Chu, Xiaojing Hao, Rose Ama
Making Interfacial Solar Evaporation of Seawater Faster than Fresh Water
No full textData source: Supporting information, https://doi.org/10.1002/adma.202414045Interfacial solar evaporation-based seawater desalination is regarded as one of the most promising strategies to alleviate freshwater scarcity. However, the solar evaporation rate of real seawater is significantly constricted by the ubiquitous salts present in seawater. In addition to the common issue of salt accumulation on the evaporation surface during solar evaporation, strong hydration between salt ions and water molecules leads to a lower evaporation rate for real seawater compared to pure water. Here a facile and general strategy is developed to reverse this occurrence, that is, making real seawater evaporation faster than pure water. By simply introducing specific mineral materials into the floating photothermal evaporator, ion exchange at air–water interfaces directly results in a decrease in seawater evaporation enthalpy, and consequently achieves much higher seawater evaporation rates compared to pure water. This process is spontaneously realized during seawater solar evaporation. Considering the current enormous clean water production from evaporation-based desalination plants, such an evaporation performance improvement can remarkably increase annual clean water production, benefiting millions of people worldwide.Huimin Yu, Huanyu Jin, Meijia Qiu, Yunzheng Liang, Peng Sun, Chuanqi Cheng, Pan Wu, Yida Wang, Xuan Wu, Dewei Chu, Min Zheng, Tong Qiu, Yi Lu, Bin Zhang, Wenjie Mai, Xiaofei Yang, Gary Owens, and Haolan X
Atomically Dispersed Cu Catalysts on Sulfide-Derived Defective Ag Nanowires for Electrochemical CO2 Reduction
No full textPublished: February 2, 2023Single-atom catalysts (SACs) have shown potential for achieving an efficient electrochemical CO2 reduction reaction (CO2RR) despite challenges in their synthesis. Here, Ag2S/Ag nanowires provide initial anchoring sites for Cu SACs (Cu/Ag2S/Ag), then Cu/Ag(S) was synthesized by an electrochemical treatment resulting in complete sulfur removal, i.e., Cu SACs on a defective Ag surface. The CO2RR Faradaic efficiency (FECO2RR) of Cu/Ag(S) reaches 93.0% at a CO2RR partial current density (jCO2RR) of 2.9 mA/cm2 under −1.0 V vs RHE, which outperforms sulfur-removed Ag2S/Ag without Cu SACs (Ag(S), 78.5% FECO2RR with 1.8 mA/cm2jCO2RR). At −1.4 V vs RHE, both FECO2RR and jCO2RR over Cu/Ag(S) reached 78.6% and 6.1 mA/cm2, which tripled those over Ag(S), respectively. As revealed by in situ and ex situ characterizations together with theoretical calculations, the interacted Cu SACs and their neighboring defective Ag surface increase microstrain and downshift the d-band center of Cu/Ag(S), thus lowering the energy barrier by ∼0.5 eV for *CO formation, which accounts for the improved CO2RR activity and selectivity toward related products such as CO and C2+ products.Zhipeng Ma, Tao Wan, Ding Zhang, Jodie A. Yuwono, Constantine Tsounis, Junjie Jiang, Yu-Hsiang Chou, Xunyu Lu, Priyank V. Kumar, Yun Hau Ng, Dewei Chu, Cui Ying Toe, Zhaojun Han, and Rose Ama
Estimation of train dwell time at short stops based on track occupation event data
No full textTrain dwell time is one of the most unpredictable components of railway operations mainly due to the varying volumes of alighting and boarding passengers. For reliable estimations of train running times and route conflicts on main lines it is however necessary to obtain accurate estimations of dwell times at the intermediate stops on the main line, the so-called short stops. This is a big challenge for a more reliable, efficient and robust train operation. Previous research has shown that dwell time is highly dependent on the number of boarding and alighting passengers. However, the latter numbers are usually not available in real time. This paper discusses the possibility of a dwell time estimation model at short stops without passenger demand information, by means of a statistical analysis of track occupation data from the Netherlands. The analysis showed that the dwell times are best estimated for peak and off-peak hour separately. The peak hour dwell times are estimated using a linear regression model of train length, dwell times at previous stops and dwell times of the previous trains. The off-peak hour dwell times are estimated using a non-parametric regression model. There are two major advantages of the proposed estimation model. The model does not need passenger flow data which is usually impossible to know in real time in practice. Also, detailed parameters of rolling stock configuration and platform layout are not required, which eases implementation.Transport & PlanningCivil Engineering and Geoscience
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