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polyhydroxyalkanoates and glycogen transformations: Key aspects to biologic nitrogen and phosphorus removal in lowdissolved oxygen systems

Hongjing LI, Yinguang CHEN

《环境科学与工程前沿(英文)》 2011年 第5卷 第2期   页码 283-290 doi: 10.1007/s11783-010-0243-9

摘要: In this paper, a study was conducted on the effect of polyhydroxyalkanoates (PHA) and glycogen transformations on biologic nitrogen and phosphorus removal in low dissolved oxygen (DO) systems. Two laboratory-scale sequencing batch reactors (SBR1 and SBR2) were operating with anaerobic/aerobic (low DO, 0.15–0.45 mg·L ) configurations, which cultured a propionic to acetic acid ratio (molar carbon ratio) of 1.0 and 2.0, respectively. Fewer poly-3-hydroxybutyrate (PHB), total PHA, and glycogen transformations were observed with the increase of propionic/acetic acid, along with more poly-3-hydroxyvalerate (PHV) and poly-3-hydroxy-2-methyvalerate (PH2MV) shifts. The total nitrogen (TN) removal efficiency was 68% and 82% in SBR1 and SBR2, respectively. In the two SBRs, the soluble ortho-phosphate (SOP) removal efficiency was 94% and 99%, and the average sludge polyphosphate (poly-P) content (g·g-MLVSS ) was 8.3% and 10.2%, respectively. Thus, the propionic to acetic acid ratio of the influent greatly influenced the PHA form and quantity, glycogen transformation, and poly-P contained in activated sludge and further determined TN and SOP removal efficiency. Moreover, significant correlations between the SOP removal rate and the (PHV+ PH2MV)/PHA ratio were observed ( >0.99). Accordingly, PHA and glycogen transformations should be taken into account as key components for optimizing anaerobic/aerobic (low DO) biologic nitrogen and phosphorus removal systems.

关键词: low dissolved oxygen (DO)     biological nitrogen and phosphorus removal     polyhydroxyalkanoates (PHA)     glycogen    

Effect of the addition of organic carbon sources on nitrous oxide emission in anaerobic-aerobic (lowdissolved oxygen) sequencing batch reactors

Hongjing LI, Xiurong CHEN, Yinguang CHEN

《环境科学与工程前沿(英文)》 2010年 第4卷 第4期   页码 490-499 doi: 10.1007/s11783-010-0248-4

摘要: The effect of additional organic carbon sources on the production of nitrous oxide (N O) in anaerobic-aerobic (low dissolved oxygen) real wastewater treatment system was investigated. In this paper, three laboratory-scale sequencing batch reactors (SBRs) (SBR-1, SBR-2 and SBR-3) were operating under an anaerobic-aerobic (low dissolved oxygen, 0.15–0.45 mg·L ) configuration. The SBRs were ‘long-term cultured’ respectively with a single municipal wastewater sample, sodium acetate, and a waste-activated sludge alkaline fermentation liquid as the additional carbon sources of real wastewater. Off-gas analysis showed that N O was emitted into the atmosphere during the aerobic (low dissolved oxygen) period in the three SBRs, and the order of N O emission rate was SBR-2>SBR-1>SBR-3. It was observed that the higher poly-β-hydroxyvalerate fraction of polyhydroxyalkanoates, the lower glycogen transformation and less nitrite accumulation was in SBR-3, while the opposite behavior was observed in SBR-2. Further research indicated that the interaction of the factors above potentially affected the N O emission in the anaerobic-aerobic (low dissolved oxygen) system.

关键词: anaerobic-aerobic (low dissolved oxygen)     nitrous oxide (N2O) emitting rate     municipal wastewater     waste activated sludge     alkaline fermentation liquid    

Control of sludge settleability and nitrogen removal under low dissolved oxygen condition

Zhaoxu PENG, Yongzhen PENG, Zhenbo YU, Xuliang LIU, Xiaoling LI, Randeng WANG

《环境科学与工程前沿(英文)》 2012年 第6卷 第6期   页码 884-891 doi: 10.1007/s11783-012-0408-9

摘要: Low dissolved oxygen (DO) is an energy-saving condition in activated sludge process. To investigate the possible application of limited filamentous bulking (LFB) in sequencing batch reactor (SBR), two lab-scale SBRs were used to treat synthetic domestic wastewater and real municipal wastewater, respectively. The results showed that prolonging low DO aeration duration and setting pre-anoxic (anaerobic) phase were effective strategies to induce and inhibit filamentous sludge bulking, respectively. According to the sludge settleability, LFB could be maintained steadily by adjusting operation patterns. Filamentous bacteria content and sludge volume index (SVI) were likely correlated. SVI fluctuated dramatically within a few cycles when around 200 mL·g , where altering operation pattern could change sludge settleability in spite of the unstable status of activated sludge system. Energy consumption by aeration reduced under low DO LFB condition, whereas the nitrification performance deteriorated. However, short-cut nitrification and simultaneous nitrification denitrification (SND) were prone to take place under such conditions. When the cycle time kept constant, the anoxic (anaerobic) to aerobic time ratio was determining factor to the SND efficiency. Similarity keeping aerobic time as constant, the variation trends of SND efficiency and specific SND rate were uniform. SBR is a promising reactor to apply the LFB process in practice.

关键词: limited filamentous bulking     sequencing batch reactor     sludge settleability     sludge volume index     simultaneous nitrification denitrification    

Impact of dissolved oxygen on the production of nitrous oxide in biological aerated filters

Qiang He, Yinying Zhu, Guo Li, Leilei Fan, Hainan Ai, Xiaoliu Huangfu, Hong Li

《环境科学与工程前沿(英文)》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0964-0

摘要: Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and microelectrode technology were employed to evaluate the Nitrous oxide (N O) production in biological aerated filters (BAFs) under varied dissolved oxygen (DO) concentrations during treating wastewater under laboratory scale. The average yield of gasous N O showed more than 4-fold increase when the DO levels were reduced from 6.0 to 2.0 mg·L , indicating that low DO may drive N O generation. PCR-DGGE results revealed that were dominant and may be responsible for N O emission from the BAFs system. While at a low DO concentration (2.0 mg·L ), might play a role. When DO concentration was the limiting factor (reduced from 6.0 to 2.0 mg·L ) for nitrification, it reduced NO -N oxidation as well as the total nitrification. The data from this study contribute to explain how N O production changes in response to DO concentration, and may be helpful for reduction of N O through regulation of DO levels.

关键词: Nitrous oxide     Biological aerated filter     Microelectrode     Dissolved oxygen     Biofilm    

Phosphorus transformation under the influence of aluminum, organic carbon, and dissolved oxygen at the

Ouchen Cai, Yuanxiao Xiong, Haijun Yang, Jinyong Liu, Hui Wang

《环境科学与工程前沿(英文)》 2020年 第14卷 第3期 doi: 10.1007/s11783-020-1227-z

摘要: The three simulation factors caused various changes in both water and sediment. Responses to simulations differed with the reported natural lakes and wetlands. Al has dominant effects on sediment P release control among the three factors. Adding sediment Al can be effective and safe under the simulated conditions. Polyphosphates were not generated, while added phytate was rather stable. The effects of sediment aluminum (Al), organic carbon (OC), and dissolved oxygen (DO) on phosphorus (P) transformation, at the water-sediment interface of a eutrophic constructed lake, were investigated via a series of simulative experiments. The above three factors had various influences on dissolved P concentration, water pH, water and surface sediment appearance, and P fractions. Additions of Al had the greatest effect on suppressing P release, and the water pH remained alkaline in the water-sediment system under various OC and DO conditions. No dissolution of the added Al was detected. 31P-NMR characterization suggested that OC addition did not promote biological P uptake to polyphosphates under oxic conditions. The simulation result on the added phytate indicated the absence of phytate in the original lake sediment. As compared to the reported natural lakes and wetland, the water-sediment system of the constructed lake responded differently to some simulative conditions. Since Al, OC, and DO can be controlled with engineering methods, the results of this study provide insights for the practical site restorations.

关键词: Phosphorus     Sediment     Simulation     Dissolved oxygen     Organic carbon     Aluminum    

Removal of dissolved oxygen from water using a Pd-resin based catalytic reactor

Wenxin SHI, Chongwei CUI, Liye ZHAO, Shuili YU, Xia YUN

《化学科学与工程前沿(英文)》 2009年 第3卷 第1期   页码 107-111 doi: 10.1007/s11705-009-0154-0

摘要: The removal of dissolved oxygen (DO) from water was studied experimentally in a Pd-resin base catalyst reactor using purified hydrogen gas as a reducing agent. The effects of various operating conditions, such as hydrogen and water flow rates, height of the catalytic resin bed, temperature, pH value and run time, on the removal of DO, had been studied extensively. The results shows that DO could be removed by the reactor from ppm to ppb levels at ambient temperature. Increases of temperature, H gas rate and the height of the catalytic resin were helpful to improve the DO removal rate. The change of pH value from 4 to 12 resulted in no effect on DO removal. Reaction time was the key factor to control the DO removal efficiency. Only when the reaction time was longer than 2.3 minutes under the experimental conditions, could a very low DO level be achieved.

关键词: dissolved oxygen     palladium     catalytic reactor     hydrogen     resin    

An experimental study on ignition of single coal particles at low oxygen concentrations

Wantao YANG, Yang ZHANG, Lilin HU, Junfu LYU, Hai ZHANG

《能源前沿(英文)》 2021年 第15卷 第1期   页码 38-45 doi: 10.1007/s11708-020-0692-1

摘要: An experimental study on the ignition of single coal particles at low oxygen concentrations ( <21%) was conducted using a tube furnace. The surface temperature ( ) and the center temperature ( ) of the coal particles were obtained from the images taken by an infrared camera and thermocouples respectively. The ignition processes were recorded by a high-speed camera at different values and furnace temperatures . Compared with literature experimental data obtained at a high value, the ignition delay time decreases more rapidly as increases at the low region. The responses of and to the variation of are different: decreases while remains nearly constant with increasing at a low value. In addition, is less sensitive to while the ignition temperature is more sensitive to at a low value than in air. Observations of the position of flame front evolution illustrate that the ignition of a coal particle may change from a homogeneous mode to a heterogeneous or combined ignition mode as decreases. At a low value, buoyancy plays a more significant role in sweeping away the released volatiles during the ignition process.

关键词: coal particles     low oxygen concentration     ignition     ignition temperature     ignition modes    

Effects of oxidizing environment on digestate humification and identification of substances governing the dissolved

《环境科学与工程前沿(英文)》 2022年 第16卷 第8期 doi: 10.1007/s11783-022-1520-0

摘要:

• Liquid digestate humification was investigated under different oxidizing environment.

关键词: Liquid digestate     MnO2     Oxygen     DOM transformation     Humic-like acids    

Simultaneous nitrification and denitrification in activated sludge system under low oxygen concentration

ZHANG Peng, ZHOU Qi

《环境科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 49-52 doi: 10.1007/s11783-007-0009-1

摘要: Simultaneous nitrification and denitrification (SND), which is more economical compared with the traditional method for nitrogen removal, is studied in this paper. In order to find the suitable conditions of this process, a mixed flow activated sludge system under low oxygen concentration is investigated, and some key control parameters are examined for nitrogen removal from synthetic wastewater. The results show that SND is accessible when oxygen concentration is 0.3 0.8 mg/L. The nitrogen removal rate can be obtained up to 66.7% with solids retention time (SRT) of 45 d, C/N value of 10, and F/M ratio of 0.1 g COD/(g MLSS·d). Theoretical analysis indicates that SND is a physical phenomenon and governed by oxygen diffusion in flocs.

关键词: synthetic wastewater     accessible     Simultaneous nitrification     MLSS·d     diffusion    

一种基于多因素分析和多模型集成的海洋溶解氧浓度时间序列预测混合神经网络模型 Article

刘辉, 杨睿, 段铸, 吴海平

《工程(英文)》 2021年 第7卷 第12期   页码 1751-1765 doi: 10.1016/j.eng.2020.10.023

摘要:

溶解氧是水产养殖的重要指标,准确预测溶解氧浓度可有效提高水产品质量。本文提出了一种新的溶解氧混合预测模型,该模型包括多因素分析、自适应分解和优化集成三个阶段。首先,考虑到影响溶解氧浓度的因素复杂繁多,采用灰色关联度法筛选出与溶解氧关系最密切的环境因素,多因素的考虑使得模型融合更加有效。其次,运用经验小波变换方法自适应地将溶解氧、水温、盐度和氧饱和度等序列分解为子序列。然后,利用5个基准模型对经验小波变换分解出的子序列进行预测,这五个子预测模型的集成权重通过粒子群优化和引力搜索算法计算得出。最后,通过加权分配得到溶解氧多因素集成模型。来自太平洋岛屿海洋观测系统希洛WQB04站收集的时间序列数据验证了该模型的性能。实验的评价指标包括Nash-Sutcliffe效率系数、Kling-Gupta效率系数、平均绝对百分比误差、误差标准差和决定系数。实例分析表明:①所提出的模型能够获得优异的溶解氧预测结果;②该模型优于文中其他对比模型;③预测模型可用于分析溶解氧变化趋势,便于管理者能够做出更好的决策。

关键词: 溶解氧浓度预测     时间序列多步预测     多因素分析     经验小波变化分解     多模型优化集成    

Unusual global outbreak of monkeypox: what should we do?

《医学前沿(英文)》 2022年 第16卷 第4期   页码 507-517 doi: 10.1007/s11684-022-0952-z

摘要: Recently, monkeypox has become a global concern amid the ongoing COVID-19 pandemic. Monkeypox is an acute rash zoonosis caused by the monkeypox virus, which was previously concentrated in Africa. The re-emergence of this pathogen seems unusual on account of outbreaks in multiple nonendemic countries and the incline to spread from person to person. We need to revisit this virus to prevent the epidemic from getting worse. In this review, we comprehensively summarize studies on monkeypox, including its epidemiology, biological characteristics, pathogenesis, and clinical characteristics, as well as therapeutics and vaccines, highlighting its unusual outbreak attributed to the transformation of transmission. We also analyze the present situation and put forward countermeasures from both clinical and scientific research to address it.

关键词: monkeypox     poxviruses     vaccine     infectious diseases    

Do right PLS and do PLS right: A critical review of the application of PLS-SEM in construction management

Ningshuang ZENG, Yan LIU, Pan GONG, Marcel HERTOGH, Markus KÖNIG

《工程管理前沿(英文)》 2021年 第8卷 第3期   页码 356-369 doi: 10.1007/s42524-021-0153-5

摘要: Partial least squares structural equation modeling (PLS-SEM) is a modern multivariate analysis technique with a demonstrated ability to estimate theoretically established cause-effect relationship models. This technique has been increasingly adopted in construction management research over the last two decades. Accordingly, a critical review of studies adopting PLS-SEM appears to be a timely and valuable endeavor. This paper offers a critical review of 139 articles that applied PLS-SEM from 2002 to 2019. Results show that the misuse of PLS-SEM can be avoided. Critical issues related to the application of PLS-SEM, research design, model development, and model evaluation are discussed in detail. This paper is the first to highlight the use and misuse of PLS-SEM in the construction management area and provides recommendations to facilitate the future application of PLS-SEM in this field.

关键词: PLS     SEM     construction management     literature review     misuse    

of different valent iron on anaerobic sludge digestion: Focusing on oxidation reduction potential, dissolved

《环境科学与工程前沿(英文)》 2022年 第16卷 第6期 doi: 10.1007/s11783-021-1514-3

摘要:

• ORP value from −278.71 to −379.80 mV showed indiscernible effects on methane yield.

关键词: Enhanced anaerobic sludge digestion     Different iron valence     Oxidation reduction potential     Dissolved organic nitrogen     Microbial community    

Photoaging mechanism of microplastics: a perspective on the effect of dissolved organic matter in natural

《环境科学与工程前沿(英文)》 2023年 第17卷 第11期 doi: 10.1007/s11783-023-1743-8

摘要:

● Microplastics (MPs) undergo photoaging in natural water under light irradiation.

关键词: Microplastics     Photoaging     Dissolved organic matter     ROS generation    

How do project-oriented organizations enhance innovation? An institutional theory perspective

《工程管理前沿(英文)》   页码 427-438 doi: 10.1007/s42524-023-0258-0

摘要: A project-oriented organization is a hybrid form of organization where a functional hierarchy is augmented with structures to manage projects strategically across the organization. Six project-oriented organizations from diverse industries that emphasize innovation in their strategies were selected for this study. We use the three pillars of institutional theory — regulative, normative and cultural-cognitive — and institutional entrepreneurship to analyze interview data from executive and project, program and portfolio management personnel in the project-oriented organizations to investigate how innovation is facilitated through external influences and internal responses. Our findings indicate that processes and new structures provide effective ways for innovation and, while individuals are important, processes are more effective than individuals at enabling innovation. We put forward some lessons for practice that emerge directly from the findings, including suggestions on improving allocation of resources, a need to focus on processes, reconceptualization of “failure”, and dedicated investment in market knowledge, customer knowledge, performance metrics and flexible governance structures.

关键词: project-oriented organizations     innovation     institutional entrepreneurship     institutional theory    

标题 作者 时间 类型 操作

polyhydroxyalkanoates and glycogen transformations: Key aspects to biologic nitrogen and phosphorus removal in lowdissolved oxygen systems

Hongjing LI, Yinguang CHEN

期刊论文

Effect of the addition of organic carbon sources on nitrous oxide emission in anaerobic-aerobic (lowdissolved oxygen) sequencing batch reactors

Hongjing LI, Xiurong CHEN, Yinguang CHEN

期刊论文

Control of sludge settleability and nitrogen removal under low dissolved oxygen condition

Zhaoxu PENG, Yongzhen PENG, Zhenbo YU, Xuliang LIU, Xiaoling LI, Randeng WANG

期刊论文

Impact of dissolved oxygen on the production of nitrous oxide in biological aerated filters

Qiang He, Yinying Zhu, Guo Li, Leilei Fan, Hainan Ai, Xiaoliu Huangfu, Hong Li

期刊论文

Phosphorus transformation under the influence of aluminum, organic carbon, and dissolved oxygen at the

Ouchen Cai, Yuanxiao Xiong, Haijun Yang, Jinyong Liu, Hui Wang

期刊论文

Removal of dissolved oxygen from water using a Pd-resin based catalytic reactor

Wenxin SHI, Chongwei CUI, Liye ZHAO, Shuili YU, Xia YUN

期刊论文

An experimental study on ignition of single coal particles at low oxygen concentrations

Wantao YANG, Yang ZHANG, Lilin HU, Junfu LYU, Hai ZHANG

期刊论文

Effects of oxidizing environment on digestate humification and identification of substances governing the dissolved

期刊论文

Simultaneous nitrification and denitrification in activated sludge system under low oxygen concentration

ZHANG Peng, ZHOU Qi

期刊论文

一种基于多因素分析和多模型集成的海洋溶解氧浓度时间序列预测混合神经网络模型

刘辉, 杨睿, 段铸, 吴海平

期刊论文

Unusual global outbreak of monkeypox: what should we do?

期刊论文

Do right PLS and do PLS right: A critical review of the application of PLS-SEM in construction management

Ningshuang ZENG, Yan LIU, Pan GONG, Marcel HERTOGH, Markus KÖNIG

期刊论文

of different valent iron on anaerobic sludge digestion: Focusing on oxidation reduction potential, dissolved

期刊论文

Photoaging mechanism of microplastics: a perspective on the effect of dissolved organic matter in natural

期刊论文

How do project-oriented organizations enhance innovation? An institutional theory perspective

期刊论文