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Catalysis of semihydrogenation of acetylene to ethylene: current trends, challenges, and outlook

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1031-1059 doi: 10.1007/s11705-021-2113-3

摘要: Ethylene is an important feedstock for various industrial processes, particularly in the polymer industry. Unfortunately, during naphtha cracking to produce ethylene, there are instances of acetylene presence in the product stream, which poisons the Ziegler–Natta polymerization catalysts. Thus, appropriate process modification, optimization, and in particular, catalyst design are essential to ensure the production of highly pure ethylene that is suitable as a feedstock in polymerization reactions. Accordingly, carefully selected process parameters and the application of various catalyst systems have been optimized for this purpose. This review provides a holistic view of the recent reports on the selective hydrogenation of acetylene. Previously published reviews were limited to Pd catalysts. However, effective new metal and non-metal catalysts have been explored for selective acetylene hydrogenation. Updates on this recent progress and more comprehensive computational studies that are now available for the reaction are described herein. In addition to the favored Pd catalysts, other catalyst systems including mono, bimetallic, trimetallic, and ionic catalysts are presented. The specific role(s) that each process parameter plays to achieve high acetylene conversion and ethylene selectivity is discussed. Attempts have been made to elucidate the possible catalyst deactivation mechanisms involved in the reaction. Extensive reports suggest that acetylene adsorption occurs through an active single-site mechanism rather than via dual active sites. An increase in the reaction temperature affords high acetylene conversion and ethylene selectivity to obtain reactant streams free of ethylene. Conflicting findings to this trend have reported the presence of ethylene in the feed stream. This review will serve as a useful resource of condensed information for researchers in the field of acetylene-selective hydrogenation.

关键词: selectivity     hydrogenation     acetylene     ethylene     palladium    

Mapping the trends and prospects of battery cathode materials based on patent landscape

《能源前沿(英文)》   页码 822-832 doi: 10.1007/s11708-023-0900-x

摘要: Advancing portable electronics and electric vehicles is heavily dependent on the cutting-edge lithium-ion (Li-ion) battery technology, which is closely linked to the properties of cathode materials. Identifying trends and prospects of cathode materials based on patent analysis is considered a kernel to optimize and refine battery related markets. In this paper, a patent analysis is performed on 6 popular cathode materials by comprehensively considering performance comparison, development trend, annual installed capacity, technology life cycle, and distribution among regions and patent assignees. In the technology life cycle, the cathode materials majorly used in electric vehicle have entered maturity stage, while the lithium cobalt oxide (LCO) cathode that is widely used in portable electronics is still in the growth stage. In global patent distributions, China holds more than 50% of total patents. In the top 10 patent assignees of 6 cathode materials, 2 institutes are from China with the rest being Japan (6) and Republic of Korea (2), indicating that the technology of cathode materials in China is relatively scattered while cathode research is highly concentrated in Japan and Republic of Korea. Moreover, the patent distribution has to consider practical issues as well as the impacts of core patents. For example, the high cost discourages the intention of applying international patents. This paper is expected to stimulate battery research, understand technical layout of various countries, and probably forecast innovative technology breakthroughs.

关键词: patent analysis     cathode     batteries     technology life cycle    

Trends of environmental accidents and impact factors in China

Pengli XUE, Weihua ZENG

《环境科学与工程前沿(英文)》 2011年 第5卷 第2期   页码 266-276 doi: 10.1007/s11783-010-0267-1

摘要: An overview of the spatial and temporal variations of the environmental accidents in China in recent years was presented in this paper using available data. The results showed that the frequency of pollution accidents was significantly decreased, from 3462 in 1990 to 462 in 2007. The water and air pollution accidents were found to be the dominant types, accounting for more than 80% of the total accidents. Considering the classification of environmental accidents at 4 scales, the general environmental accident, i.e., the least serious type, was the most frequent event, taking up 58.98% of the total pollution accidents. In addition, the distribution of environmental accidents was generally in accordance with the industrial layout in the country during the past decade. It is very important to note that the extraordinarily severe environmental accidents showed an increasing trend in underdeveloped regions, which was caused by the transfer and the development of heavy polluted industry in these areas. As to the losses of environmental accidents, the casualties presented an obvious reduction tendency, while the direct economic loss per accident tended to climb up. Furthermore, some key factors that affect the spatial and temporal tendencies of environmental accidents in China were discussed and some suggestions were put forward, hoping to shed light on environmental risk management and emergency plans making associated with environmental accidents in China.

关键词: environmental accidents     spatial and temporal trends     environmental risk    

Emerging trends in self-healable nanomaterials for triboelectric nanogenerators: A comprehensive review

《能源前沿(英文)》   页码 727-750 doi: 10.1007/s11708-023-0896-2

摘要: A thorough analysis of triboelectric nanogenerators (TENGs) that make use of self-healable nanomaterials is presented in this review. These TENGs have shown promise as independent energy sources that do not require an external power source to function. TENGs are developing into a viable choice for powering numerous applications as low-power electronics technology advances. Despite having less power than conventional energy sources, TENGs do not directly compete with these. TENGs, on the other hand, provide unique opportunities for future self-powered systems and might encourage advancements in energy and sensor technologies. Examining the many approaches used to improve nanogenerators by employing materials with shape memory and self-healable characteristics is the main goal of this review. The findings of this comprehensive review provide valuable information on the advancements and possibilities of TENGs, which opens the way for further research and advancement in this field. The discussion of life cycle evaluations of TENGs provides details on how well they perform in terms of the environment and identifies potential improvement areas. Additionally, the cost-effectiveness, social acceptability, and regulatory implications of self-healing TENGs are examined, as well as their economic and societal ramifications.

关键词: triboelectric nanogenerator (TENG)     self-healable nanomaterials     self-powered devices     energy    

CONCENTRATIONS AND FLUXES OF DISSOLVED NUTRIENTS IN THE YANGTZE RIVER: LONG-TERM TRENDS AND ECOLOGICAL

《农业科学与工程前沿(英文)》 2021年 第8卷 第4期   页码 559-567 doi: 10.15302/J-FASE -2020344

摘要:

Intensifying human activity in the Yangtze River basin has substantially increased nutrient concentrations in the Yangtze River Estuary, leading to degradation of the coastal environment. Analysis of nutrient determinations published over the past 50 years reveals a gradual decreasing trend in the concentrations and fluxes of dissolved silicate (DSi). However, both dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphate (DIP) concentrations have increased significantly since the 1970s. The frequency of and area covered by red tide outbreaks have increased greatly during this period, mainly due to changes in nutrient supply ratios [i.e., N/P (DIN/DIP), N/Si (DIN/DSi), P/Si (DIP/DSi)]. A strong correlation was found between the riverine DIN fluxes and the estimated DIN inputs from the major N sources, particularly fertilizers and atmospheric deposition. The data provide a comprehensive assessment of nutrients in the Yangtze River basin and their ecological impacts and indicate a potentially significant influence of atmospheric deposition on DIN loadings and fluxes.

 

关键词: atmospheric deposition / ecological impacts / nitrogen sources / nutrients / Yangtze delta    

Research Trends in Information Technology Applications in Construction Safety Engineering and Management

Mirosɬaw J. Skibniewski

《工程管理前沿(英文)》 2014年 第1卷 第3期   页码 246-259 doi: 10.15302/J-FEM-2014034

摘要: Through analysis of articles published from 2000 to March 2014 in Automaton in Construction (AUTCON), an international research journal published by Elsevier, this paper summarizes the topics of research and the institutions worldwide where research was conducted in construction safety engineering and management. Seventy-one articles published during this time focused on Information Technology (IT) applications in this field were selected for analysis. The underlying research topics and their related IT implementations are discussed, and research trends in allied specialties are identified.

关键词: automation     international research journal     research trends     industrial safety engineering and management     construction technology     building engineering     information technology    

Emergency strategies and trends in the management of liver trauma

null

《医学前沿(英文)》 2012年 第6卷 第3期   页码 225-233 doi: 10.1007/s11684-012-0186-6

摘要:

The liver is the most frequently injured organ during abdominal trauma. The management of hepatic trauma has undergone a paradigm shift over the past several decades, with mandatory operation giving way to nonoperative treatment. Better understanding of the mechanisms and grade of liver injury aids in the initial assessment and establishment of a management strategy. Hemodynamically unstable patients should undergo focused abdominal sonography for trauma, whereas stable patients may undergo computed tomography, the standard examination protocol. The grade of liver injury alone does not accurately predict the need for operation, and nonoperative management is rapidly becoming popular for high-grade injuries. Hemodynamic instability with positive focused abdominal sonography for trauma and peritonitis is an indicator of the need for emergent operative intervention. The damage control concept is appropriate for the treatment of major liver injuries and is associated with significant survival advantages compared with traditional prolonged surgical techniques. Although surgical intervention for hepatic trauma is not as common now as it was in the past, current trauma surgeons should be familiar with the emergency surgical skills necessary to manage complex hepatic injuries, such as packing, Pringle maneuver, selective vessel ligation, resectional debridement, and parenchymal sutures. The present review presents emergency strategies and trends in the management of liver trauma.

关键词: liver trauma     nonoperative management     operative management    

LAND-USE INTENSIFICATION TRENDS IN THE RIO DE LA PLATA REGION OF SOUTH AMERICA: TOWARD SPECIALIZATION

《农业科学与工程前沿(英文)》 2021年 第8卷 第1期

摘要:

• Current intensification trends in the Rio de la Plata need urgent re-direction.

•Integrated crop-livestock systems reconcile food production with ecosystem services.

•Case studies validate recoupling as a sustainable way to ecological intensification.

 

The Rio de la Plata region comprises central Argentina, Uruguay, and southern Brazil. Modern agriculture developed around 1900 with recent decades being characterized by the advance of cropping areas over native grasslands. Highly specialized agriculture has decoupled crop and livestock production but has succeeded in intensifying yields. However, significant losses of ecosystem services have been reported. Thus, questions have been raised on the sustainability of this pathway. A glance at world regions that have experienced similar trends suggests that an urgent course correction is needed. A major concern has been the lack of diversity in regions with highly specialized agriculture, promoting renewed interest in integrated crop-livestock systems (ICLS), not only because ICLS are more diverse than specialized systems, but also because they are rare examples of reconciliation between agroecosystem intensification and environmental quality. Consequently, this paper discusses alternatives to redesign multifunctional landscapes based on ICLS. Recent data provide evidence that recoupling crop and animal production increases the resilience of nutrient cycling functions and economic indicators to external stressors, enabling these systems to face climate-market uncertainty and reconcile food production with the provision of diverse ecosystem services. Finally, these concepts are exemplified in case studies where this perspective has been successfully applied.

From Green to Sustainability—Trends in the Assessment Methods of Green Buildings

Steve Hsueh-Ming Wang,Paula Williams,Jing Shi,Huojun Yang

《工程管理前沿(英文)》 2015年 第2卷 第2期   页码 114-121 doi: 10.15302/J-FEM-2015018

摘要: This research investigates recent developments in assessment methods of green buildings and compares the differences in rating systems among the United Kingdom, USA, and Germany. There are indications that the rating systems are moving from green buildings to sustainable buildings. In order to understand the recent research in academic areas, we survey the recent Ph.D. dissertations and literature related to green building assessment. Discussion is provided on the major research areas of green buildings, which cover accountability of life cycle cost, methodology for balancing the three pillars, and government vision and public policy.

关键词: green     sustainability     buildings     assessment     methods     rating systems    

Age-related trends in genetic parameters for wood properties in

Chao SUN, Meng LAI, Shougong ZHANG, Xiaomei SUN

《农业科学与工程前沿(英文)》 2017年 第4卷 第4期   页码 482-492 doi: 10.15302/J-FASE-2017184

摘要: Wood properties are important traits that determine quality of structural wood. With the aim of performing efficient early selection for wood properties, we investigated genetic variation in 20 clones aged from 4 to 15 years for four quality traits: wood density, wall thickness to lumen area, microfibrillar angle (MFA) and modulus of elasticity (MOE). We observed that age-related trends in overall means varied for different traits: MFA decreased with the age, while the others generally increased with the age. Phenotypic variance always showed significant differences from the age of 8 years onward, with CVG ranging from 4% to 25%. Also, clonal repeatability increased steadily until 9 years old and then kept medium or higher intensity (0.4–0.8). After the age of 6, genetic correlations were generally higher than phenotypic correlations. Estimates of early selection efficiency suggested that the optimal selection age for wood density was at age 5–6 years, while it was 9–10 years for the other traits. In combination with previous results, we proposed a comprehensive early selection strategy for larch clonal breeding that involved selection based on nursery rooting ability, phenology, growth traits, and wood properties.

关键词: early selection     genetic variation     wood properties     SilviScan     Larix kaempferi    

分析仪器发展趋势展望

金钦汉

《中国工程科学》 2001年 第3卷 第1期   页码 85-88

摘要:

科学仪器的创新是知识创新和技术创新的重要内容。发展科学仪器应当视为国家战略。分析仪器是科学仪器的重要组成部分。分析仪器工业是高技术信息产业。分析仪器的发展是现代科学、经济和社会发展的重要基础和推动力之一。分析仪器的主要应用领域正向生物医学领域转移。分析仪器本身将不断微型化、智能化。但人类向时间和空间的两个极限挑战所需的高级精密仪器也不容忽视。生命过程、生产、科研和社会活动大量需要的将是在线、非侵入、非损坏、原位、实时、多维分析仪器。我国分析仪器与国外的差距在扩大的趋势值得髙度重视。改变这种局面的要素之一是领导者、企业家和科技工作者都必须改变对科学仪器的旧观念。

关键词: 分析仪器     科学仪器     仪器创新     科技创新     发展趋势    

Research Trends in Fischer--Tropsch Catalysis for Coal to Liquids Technology

Emiel J. M. Hensen,Peng Wang,Wayne Xu

《工程管理前沿(英文)》 2016年 第3卷 第4期   页码 321-330 doi: 10.15302/J-FEM-2016051

摘要: Fischer–Tropsch Synthesis (FTS) constitutes catalytic technology that converts synthesis gas to synthetic liquid fuels and chemicals. While synthesis gas can be obtained from any carbonaceous feedstock, current industrial FTS operations are almost exclusively based on natural gas. Due to the energy structure of China where cheap coal is abundant, coal to liquids (CTL) technology involving coal gasification, FTS and syncrude upgrading is increasingly being considered as a viable option to convert coal to clean transportation fuels. In this brief paper, we review some pertinent issues about Fe- and Co-based FTS catalysts. Fe is better suited to convert synthesis gas derived from coal gasification into fuels. The authors limit themselves to noting some important trends in the research on Fe-based catalysts. They focus on the preparation of phase-pure carbides and innovative cheap synthesis methods for obtaining active and stable catalysts. These approaches should be augmented by (1) computational investigations that are increasingly able to predict not only mechanism, reaction rates and selectivity but also optimum catalyst composition, as well as (2) characterization of the catalytic materials under conditions close to the operation in real reactors.

关键词: Fischer–Tropsch     FTS     CTL     Fe catalyst     iron carbide     computational modeling    

高层超高层建筑的产生与发展及今后趋向预计

戴复东

《中国工程科学》 1999年 第1卷 第2期   页码 6-18

摘要:

世界上的人造物得以实现是需要与可能的结合,高层与超高层建筑的产生也不能违背这一规律。人类从古以来就有要高,登高和居高的精神和物质愿望和需要,但它变成高层超高层建筑的现实却是:在19世纪末至20世纪初产业革命后,生产力大发展,大城市快速发展;钢铁工业的发展,钢材被大量应用于建筑;电梯的发明。当时只有美国同时具备这三项条件。高层建筑产生以后就以迅猛的方式往高及超高层建筑发展。目前它的最高高度向460m冲刺。它的发展大约可以分成四个阶段,即初始摸索、纵深探索、现代主义、成熟时期。前不久,由于亚洲及西太平洋经济的发展,这一地区高层、超高层建筑有了较大发展,但它们毕竟是经济的产物。今后它要走生态化道路,在工程材料及力学上仍有广阔的前景,但高究竟会有什么负面问题?高度是否有上限?上限在哪里?是值得研究与探讨的。

关键词: 高层及超高层建筑     发展     趋向预计    

A Further Discussion on Trends in the Development of Advanced Manufacturing Technology

YANG Shu-zi, WU Bo, LI Bin

《机械工程前沿(英文)》 2006年 第1卷 第1期   页码 1-5 doi: 10.1007/s11465-005-0002-y

摘要:

This paper is a supplement to Trends in the Development of Advanced Manufacturing Technology (Yang and Wu in Chin. J. Mech. Eng., 39: 73, 2003) but delves deeper into it. It first points out the strategic status of manufacturing industry in state development. Then, a detailed analysis is given on the features and trends in the development of advanced manufacturing technology in a total of 12 points from three aspects: precision, extreme, and culture from the aspect of the product itself; green, rapidness, saving, and efficiency during the manufacturing process; and digit, auto, integration, networking, and intelligence in view of the manufacturing method. In addition, it emphasizes that all the above aspects should be based on two base points: manufacture and machinery. Finally, it puts forth the guiding ideologies for the development of advanced manufacturing technology and the aspects China should give priority to in development, while stressing on the principles of independence, innovation and human orientation.

关键词: Development     development     integration     networking     orientation    

CONCENTRATIONS AND FLUXES OF DISSOLVED NUTRIENTS IN THE YANGTZE RIVER: LONG-TERM TRENDS AND ECOLOGICAL

Yandan FU, Jiahui KANG, Ziyue LI, Xuejun LIU, Wen XU

《农业科学与工程前沿(英文)》 2021年 第8卷 第4期   页码 559-567 doi: 10.15302/J-FASE-2020344

摘要: Intensifying human activity in the Yangtze River Basin (YRB) has substantially increased nutrient concentrations in the Yangtze River Estuary, leading to degradation of the coastal environment. Analysis of nutrient determinations published over the past 50 years reveals a gradual decreasing trend in the concentrations and fluxes of dissolved silicate (DSi). However, both dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphate (DIP) concentrations have increased significantly since the 1970s. The frequency and area covered by red tide outbreaks have increased greatly during this period, mainly due to changes in nutrient supply ratios [i.e., N/P (DIN/DIP), N/Si (DIN/DSi), P/Si (DIP/DSi)]. A strong correlation was found between the riverine DIN fluxes and the estimated DIN inputs from the major N sources, particularly fertilizers and atmospheric deposition. The data provide a comprehensive assessment of nutrients in the YRB and their ecological impacts and indicate a potentially significant influence of atmospheric deposition on DIN loadings and fluxes.

关键词: atmospheric deposition     ecological impacts     nitrogen sources     nutrients     Yangtze River Delta    

标题 作者 时间 类型 操作

Catalysis of semihydrogenation of acetylene to ethylene: current trends, challenges, and outlook

期刊论文

Mapping the trends and prospects of battery cathode materials based on patent landscape

期刊论文

Trends of environmental accidents and impact factors in China

Pengli XUE, Weihua ZENG

期刊论文

Emerging trends in self-healable nanomaterials for triboelectric nanogenerators: A comprehensive review

期刊论文

CONCENTRATIONS AND FLUXES OF DISSOLVED NUTRIENTS IN THE YANGTZE RIVER: LONG-TERM TRENDS AND ECOLOGICAL

期刊论文

Research Trends in Information Technology Applications in Construction Safety Engineering and Management

Mirosɬaw J. Skibniewski

期刊论文

Emergency strategies and trends in the management of liver trauma

null

期刊论文

LAND-USE INTENSIFICATION TRENDS IN THE RIO DE LA PLATA REGION OF SOUTH AMERICA: TOWARD SPECIALIZATION

期刊论文

From Green to Sustainability—Trends in the Assessment Methods of Green Buildings

Steve Hsueh-Ming Wang,Paula Williams,Jing Shi,Huojun Yang

期刊论文

Age-related trends in genetic parameters for wood properties in

Chao SUN, Meng LAI, Shougong ZHANG, Xiaomei SUN

期刊论文

分析仪器发展趋势展望

金钦汉

期刊论文

Research Trends in Fischer--Tropsch Catalysis for Coal to Liquids Technology

Emiel J. M. Hensen,Peng Wang,Wayne Xu

期刊论文

高层超高层建筑的产生与发展及今后趋向预计

戴复东

期刊论文

A Further Discussion on Trends in the Development of Advanced Manufacturing Technology

YANG Shu-zi, WU Bo, LI Bin

期刊论文

CONCENTRATIONS AND FLUXES OF DISSOLVED NUTRIENTS IN THE YANGTZE RIVER: LONG-TERM TRENDS AND ECOLOGICAL

Yandan FU, Jiahui KANG, Ziyue LI, Xuejun LIU, Wen XU

期刊论文