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CR-Fuxing high-speed EMU series

《工程管理前沿(英文)》   页码 742-748 doi: 10.1007/s42524-023-0281-1

摘要: CR-Fuxing high-speed EMU series

关键词: CR-Fuxing series     high-speed EMU     innovation     key system     digitalized collaborative design     engineering management    

Analyzing construction safety through time series methods

Houchen CAO, Yang Miang GOH

《工程管理前沿(英文)》 2019年 第6卷 第2期   页码 262-274 doi: 10.1007/s42524-019-0015-6

摘要: The construction industry produces a large amount of data on a daily basis. However, existing data sets have not been fully exploited in analyzing the safety factors of construction projects. Thus, this work describes how temporal analysis techniques can be applied to improve the safety management of construction data. Various time series (TS) methods were adopted for identifying the leading indicators or predictors of construction accidents. The data set used herein was obtained from a large construction company that is based in Singapore and contains safety inspection scores, accident cases, and project-related data collected from 2008 to 2015. Five projects with complete and sufficient data for temporal analysis were selected from the data set. The filtered data set contained 23 potential leading indicators (predictors or input variables) of accidents (output or dependent variable). TS analyses were used to identify suitable accident predictors for each of the five projects. Subsequently, the selected input variables were used to develop three different TS models for predicting accident occurrences, and the vector error correction model was found to be the best model. It had the lowest root mean squared error value for three of the five projects analyzed. This study provides insights into how construction companies can utilize TS data analysis to identify projects with high risk of accidents.

关键词: time series     temporal     construction safety     leading indicators     accident prevention     forecasting    

Selective targeted adsorption and inactivation of antibiotic-resistant bacteria by Cr-loaded mixed metal

《环境科学与工程前沿(英文)》 2022年 第16卷 第6期 doi: 10.1007/s11783-021-1502-7

摘要:

• LDHs and MMOs was synthesized by ultrasound-assisted one-step co-precipitation.

关键词: Heavy metal adsorption     Magnetic hydrotalcite     ARBs removal     Cr(VI)-MMOs combined antibacterial activity    

The biosorption of Cr(VI) ions by dried biomass obtained from a chromium-resistant bacterium

Paul Fabrice NGUEMA,Zejiao LUO,Jingjing LIAN

《化学科学与工程前沿(英文)》 2014年 第8卷 第4期   页码 454-464 doi: 10.1007/s11705-014-1456-4

摘要: The biosorption potential of many different kinds of biomaterials has been widely studied. However, there is little data on the biosorption mechanism of Cr(VI) by dried biomass. So the bio-removal of Cr(VI) ions from aqueous solutions was investigated using dried biomass from a chromium-resistant bacterium. The bacterium was isolated from dewatered sludge samples that were obtained from a sewage treatment plant. Equilibrium and kinetic experiments were performed at different metal concentrations, pH values, and biosorbents dosages. The biomass was characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The functional groups in the biomass which may play a role in the biosorption process were identified by Fourier transform infrared spectroscopy. The biosorption process was found to be highly pH dependent and the optimum pH for the adsorption of Cr(VI) was 2.0±0.3 at 30±2 °C. The experimental data fit well with Langmuir and Freundlich models as well as a pseudo-second order kinetic model. The mechanism for the biosorption was also studied by fitting the kinetic data with an intra-particle diffusion model and a Boyd plot. External mass transfer was found to be the rate-determining step for the adsorption process. Biosorption could be an alternative mechanism besides bio-oxidation and bio-reduction for the bioremediation of heavy metals.

关键词: Cr(VI)     biomass     Bacillus cereus Pf-1     biosorption capacity     biosorbents    

Decontamination of Cr(VI) facilitated formation of persistent free radicals on rice husk derived biochar

Kaikai Zhang, Peng Sun, Yanrong Zhang

《环境科学与工程前沿(英文)》 2019年 第13卷 第2期 doi: 10.1007/s11783-019-1106-7

摘要:

PFRs were produced on biochar during Cr(VI) decontamination.

PFRs formation on biochar was owing to the oxidization of phenolic-OH by Cr(VI).

Appearance of excessive oxidant led to the consumption of PFRs on biochar.

Biochar charred at high temperature possessed great performance to Cr(VI) removal.

关键词: Biochar     Persistent free radicals     Phenolic hydroxyl groups     Cr(VI) reduction    

General expression for linear and nonlinear time series models

Ren HUANG, Feiyun XU, Ruwen CHEN

《机械工程前沿(英文)》 2009年 第4卷 第1期   页码 15-24 doi: 10.1007/s11465-009-0015-z

摘要: The typical time series models such as ARMA, AR, and MA are founded on the normality and stationarity of a system and expressed by a linear difference equation; therefore, they are strictly limited to the linear system. However, some nonlinear factors are within the practical system; thus, it is difficult to fit the model for real systems with the above models. This paper proposes a general expression for linear and nonlinear auto-regressive time series models (GNAR). With the gradient optimization method and modified AIC information criteria integrated with the prediction error, the parameter estimation and order determination are achieved. The model simulation and experiments show that the GNAR model can accurately approximate to the dynamic characteristics of the most nonlinear models applied in academics and engineering. The modeling and prediction accuracy of the GNAR model is superior to the classical time series models. The proposed GNAR model is flexible and effective.

关键词: linear and nonlinear     autoregressive model     system identification     time series analysis    

Decreasing complexity of glucose time series derived from continuous glucose monitoring is correlated

《医学前沿(英文)》 2023年 第17卷 第1期   页码 68-74 doi: 10.1007/s11684-022-0955-9

摘要: Most information used to evaluate diabetic statuses is collected at a special time-point, such as taking fasting plasma glucose test and providing a limited view of individual’s health and disease risk. As a new parameter for continuously evaluating personal clinical statuses, the newly developed technique “continuous glucose monitoring” (CGM) can characterize glucose dynamics. By calculating the complexity of glucose time series index (CGI) with refined composite multi-scale entropy analysis of the CGM data, the study showed for the first time that the complexity of glucose time series in subjects decreased gradually from normal glucose tolerance to impaired glucose regulation and then to type 2 diabetes (P for trend < 0.01). Furthermore, CGI was significantly associated with various parameters such as insulin sensitivity/secretion (all P < 0.01), and multiple linear stepwise regression showed that the disposition index, which reflects β-cell function after adjusting for insulin sensitivity, was the only independent factor correlated with CGI (P < 0.01). Our findings indicate that the CGI derived from the CGM data may serve as a novel marker to evaluate glucose homeostasis.

关键词: complexity of glucose time series     continuous glucose monitoring     impaired glucose regulation     insulin secretion and sensitivity     refined composite multi-scale entropy    

复兴号中国标准动车组

齐延辉, 周黎

《工程(英文)》 2020年 第6卷 第3期   页码 227-233 doi: 10.1016/j.eng.2020.01.004

关键词: 工程成就    

Hyperbranched magnetic polymer: highly efficient removal of Cr(VI) and application in electroplating

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1568-1580 doi: 10.1007/s11705-023-2303-2

摘要: By using a two-step hydrothermal method and trithiocyanuric acid (TTCA), 2,4,6-trihydrazino-1,3,5-triazine (THT), and Fe3O4 as raw materials, a spherical magnetic adsorbent polymer (TTCA/THT@Fe3O4) was synthesized to achieve the efficient removal of Cr(VI) from wastewater. Under optimal adsorption conditions, the maximum adsorption capacity of TTCA/THT@Fe3O4 for Cr(VI) can reach 1340 mg∙g‒1. Notably, the removal efficiency can approach 98.9%, even at the lower concentration of 20 mg∙L‒1 Cr(VI). For actual wastewater containing Cr(VI), the Cr(VI) concentration was reduced from 25.8 to 0.4 mg∙L‒1, a remarkable 20% lower than the current industry discharge standard value. A mechanism for the high adsorption performance of Cr(VI) on TTCA/THT@Fe3O4 was investigated using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and density functional theory. It can be plausibly attributed to the formation of Cr/N and Cr/S coordination bonds. Additionally, surface electrostatic adsorption, reduction effects, and the spherical polymer structure increase the contact area with Cr(VI), maximizing adsorption. The synergistic effect of adsorption and reduction enhances the adsorption performance of TTCA/THT@Fe3O4 for Cr(VI) and total chromium in water. The resultant polymer has a simple preparation process, excellent adsorption performance, easy magnetic separation, and promising application for actual wastewater.

关键词: magnetic polymer     chromium removal     hydrogen bonding     recyclability     actual wastewater    

Enhancement of extracellular Cr(VI) reduction for anammox recovery using hydrazine: performance, pathways

《环境科学与工程前沿(英文)》 2023年 第17卷 第9期 doi: 10.1007/s11783-023-1715-z

摘要:

● N2H4 addition enhanced and recovered anammox performance under Cr(VI) stress.

关键词: Extracellular Cr(VI) reduction     Electron transfer     Anammox     Hydrazine     Cr(VI) inhibition    

Time-series prediction based on global fuzzy measure in social networks

Li-ming YANG,Wei ZHANG,Yun-fang CHEN

《信息与电子工程前沿(英文)》 2015年 第16卷 第10期   页码 805-816 doi: 10.1631/FITEE.1500025

摘要: Social network analysis (SNA) is among the hottest topics of current research. Most measurements of SNA methods are certainty oriented, while in reality, the uncertainties in relationships are widely spread to be overridden. In this paper, fuzzy concept is introduced to model the uncertainty, and a similarity metric is used to build a fuzzy relation model among individuals in the social network. The traditional social network is transformed into a fuzzy network by replacing the traditional relations with fuzzy relation and calculating the global fuzzy measure such as network density and centralization. Finally, the trend of fuzzy network evolution is analyzed and predicted with a fuzzy Markov chain. Experimental results demonstrate that the fuzzy network has more superiority than the traditional network in describing the network evolution process.

关键词: Time-series network     Fuzzy network     Fuzzy Markov chain    

Efficient removal of Cr(VI) and Pb(II) from aqueous solution by magnetic nitrogen-doped carbon

Wanyue Liu, Xiaoqin Liu, Jinming Chang, Feng Jiang, Shishi Pang, Hejun Gao, Yunwen Liao, Sheng Yu

《化学科学与工程前沿(英文)》 2021年 第15卷 第5期   页码 1185-1196 doi: 10.1007/s11705-020-2032-8

摘要: The magnetic nitrogen-doped carbon (MNC) was prepared from polypyrrole by a simple high temperature calcination process in this paper. The structure and properties of MNC were analyzed by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, Brunner Emmet Teller, vibrating sample magnetometer, and X-ray photoelectron spectroscopy. The capacity of MNC to adsorb Cr(VI) and Pb(II) was evaluated. The effects of the initial pH, dosage, concentration and temperature on the adsorption capacity of MNC were measured. MNC had a large specific surface area and a special porous structure. Its nitrogen and carbon sources were rich, and the ratio of carbon to nitrogen was fixed. The maximum Cr(VI)-adsorption capacity and maximum Pb(II) adsorption capacity of MNC could reach 456.63 and 507.13 mg∙g at 318 K, respectively. The pseudo-second-order model was used to describe the adsorption kinetics of MNC, and the Freundlich model was employed to discuss its isotherms. The adsorption process was affected by the electrostatic force, the reducing reaction, pores and chelation. The results of this study suggest that MNC is a material with superior performance, and is very easily regenerated, reused, and separated in the adsorption process.

关键词: magnetic     nitrogen-doped carbon     adsorption     Cr(VI)     Pb(II)    

Response of indigenous Cd-tolerant electrochemically active bacteria in MECs toward exotic Cr(VI) based

Xia Hou, Liping Huang, Peng Zhou, Hua Xue, Ning Li

《环境科学与工程前沿(英文)》 2018年 第12卷 第4期 doi: 10.1007/s11783-018-1057-4

摘要:

Cell membrane of indigenous Cd-tolerant EAB harbored more cadmium than chromium.

Indigenous Cd-tolerant EAB cytoplasm located more chromium than cadmium.

Simultaneously quantitatively imaging Cd(II) and Cr(III) ions in EAB was achieved.

Current accelerated the harboring of cadmium in EAB at an initial 2 h.

Current directed the accumulation of more chromium in EAB over time.

关键词: Microbial electrolysis cell     Electrochemically active bacteria     Cd-tolerant bacteria     Cd(II) and Cr(VI)     Fluorescence probe    

A MATLAB code for the material-field series-expansion topology optimization method

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 607-622 doi: 10.1007/s11465-021-0637-3

摘要: This paper presents a MATLAB implementation of the material-field series-expansion (MFSE) topo-logy optimization method. The MFSE method uses a bounded material field with specified spatial correlation to represent the structural topology. With the series-expansion method for bounded fields, this material field is described with the characteristic base functions and the corresponding coefficients. Compared with the conventional density-based method, the MFSE method decouples the topological description and the finite element discretization, and greatly reduces the number of design variables after dimensionality reduction. Other features of this method include inherent control on structural topological complexity, crisp structural boundary description, mesh independence, and being free from the checkerboard pattern. With the focus on the implementation of the MFSE method, the present MATLAB code uses the maximum stiffness optimization problems solved with a gradient-based optimizer as examples. The MATLAB code consists of three parts, namely, the main program and two subroutines (one for aggregating the optimization constraints and the other about the method of moving asymptotes optimizer). The implementation of the code and its extensions to topology optimization problems with multiple load cases and passive elements are discussed in detail. The code is intended for researchers who are interested in this method and want to get started with it quickly. It can also be used as a basis for handling complex engineering optimization problems by combining the MFSE topology optimization method with non-gradient optimization algorithms without sensitivity information because only a few design variables are required to describe relatively complex structural topology and smooth structural boundaries using the MFSE method.

关键词: MATLAB implementation     topology optimization     material-field series-expansion method     bounded material field     dimensionality reduction    

Effects of phosphorus concentration on Cr(VI) sorption onto phosphorus-rich sludge biochar

DING Wenchuan,PENG Wenlong,ZENG Xiaolan,TIAN Xiumei

《环境科学与工程前沿(英文)》 2014年 第8卷 第3期   页码 379-385 doi: 10.1007/s11783-013-0606-0

摘要: To investigate effects of phosphorus content on Cr(VI) sorption onto phosphorus-rich biochar, sewage sludge of different phosphorus concentrations from 4 to 60 mg·g by dry weight were prepared and carbonized to make biochar for batch sorption experiments. Test results revealed that different phosphorous concentration of raw sludge had respective impacts on surface area, pore surface area, average pore diameter and pH value of derived biochar. The adsorption kinetics of phosphorus-rich biochar could be described by the pseudo-second-order model. The sorption isotherm data followed Langmiur model better than Freundlich model. Biochar produced from sludge with phosphorus concentration of 20 mg·g gave the largest chromium sorption capacity, which could be attributed to its largest surface area and pores surface area comparing with those of biochars from sludge with other phosphorus concentrations. The chromium loaded biochar was analyzed using Fourier Transform Infrared Spectroscopy and X-ray Diffraction measurement. The results indicated that chemical functional groups hydroxyl and methyl on surface of biochar were involved in Cr(VI) binding and its reducing to Cr(III). Then, a portion of Cr(III) in form of various phosphate precipitates was bound onto biochar surface and the rest was released into the solution. The experimental results suggested that phosphorus played an important role in pore and surface area development of sludge biochar during pyrolytic process. It also could react with Cr(III) on the biochar surface that impacted on capacity of Cr(VI) removal from solution by sludge biochar. Therefore, phosphorus concentration in sludge should be considered when sludge pyrolytic residue would be reused for heavy metals sorbing.

关键词: phosphorus     biochar     sewage sludge     hexavalent chromium     adsorption    

标题 作者 时间 类型 操作

CR-Fuxing high-speed EMU series

期刊论文

Analyzing construction safety through time series methods

Houchen CAO, Yang Miang GOH

期刊论文

Selective targeted adsorption and inactivation of antibiotic-resistant bacteria by Cr-loaded mixed metal

期刊论文

The biosorption of Cr(VI) ions by dried biomass obtained from a chromium-resistant bacterium

Paul Fabrice NGUEMA,Zejiao LUO,Jingjing LIAN

期刊论文

Decontamination of Cr(VI) facilitated formation of persistent free radicals on rice husk derived biochar

Kaikai Zhang, Peng Sun, Yanrong Zhang

期刊论文

General expression for linear and nonlinear time series models

Ren HUANG, Feiyun XU, Ruwen CHEN

期刊论文

Decreasing complexity of glucose time series derived from continuous glucose monitoring is correlated

期刊论文

复兴号中国标准动车组

齐延辉, 周黎

期刊论文

Hyperbranched magnetic polymer: highly efficient removal of Cr(VI) and application in electroplating

期刊论文

Enhancement of extracellular Cr(VI) reduction for anammox recovery using hydrazine: performance, pathways

期刊论文

Time-series prediction based on global fuzzy measure in social networks

Li-ming YANG,Wei ZHANG,Yun-fang CHEN

期刊论文

Efficient removal of Cr(VI) and Pb(II) from aqueous solution by magnetic nitrogen-doped carbon

Wanyue Liu, Xiaoqin Liu, Jinming Chang, Feng Jiang, Shishi Pang, Hejun Gao, Yunwen Liao, Sheng Yu

期刊论文

Response of indigenous Cd-tolerant electrochemically active bacteria in MECs toward exotic Cr(VI) based

Xia Hou, Liping Huang, Peng Zhou, Hua Xue, Ning Li

期刊论文

A MATLAB code for the material-field series-expansion topology optimization method

期刊论文

Effects of phosphorus concentration on Cr(VI) sorption onto phosphorus-rich sludge biochar

DING Wenchuan,PENG Wenlong,ZENG Xiaolan,TIAN Xiumei

期刊论文