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Multi-class dynamic network traffic flow propagation model with physical queues

Yanfeng LI, Jun LI

《工程管理前沿(英文)》 2017年 第4卷 第4期   页码 399-407 doi: 10.15302/J-FEM-2017041

摘要: This paper proposes an improved multi-class dynamic network traffic flow propagation model with a consideration of physical queues. Each link is divided into two areas: Free flow area and queue area. The vehicles of the same class are assumed to satisfy the first-in-first-out (FIFO) principle on the whole link, and the vehicles of the different classes also follow FIFO in the queue area but not in the free flow area. To characterize this phenomenon by numerical methods, the improved model is directly formulated in discrete time space. Numerical examples are developed to illustrate the unrealistic flows of the existing model and the performance of the improved model. This analysis can more realistically capture the traffic flow propagation, such as interactions between multi-class traffic flows, and the dynamic traffic interactions across multiple links.

关键词: first-in-first-out (FIFO)     multi-class traffic     physical queues     traffic flow modeling    

China Launched the First Wastewater Resource Recovery Factory in Yixing

《环境科学与工程前沿(英文)》 2022年 第16卷 第1期 doi: 10.1007/s11783-021-1496-1

Sustainable intensification of agriculture in sub-Saharan Africa: first things first!

Bernard VANLAUWE, Achim DOBERMANN

《农业科学与工程前沿(英文)》 2020年 第7卷 第4期   页码 376-382 doi: 10.15302/J-FASE-2020351

Ammonia adsorption on graphene and graphene oxide: a first-principles study

Yue PENG, Junhua LI

《环境科学与工程前沿(英文)》 2013年 第7卷 第3期   页码 403-411 doi: 10.1007/s11783-013-0491-6

摘要: Motivated by the recent realization of graphene sensor to detect gas molecules that are harmful to the environment, the ammonia adsorption on graphene or graphene oxide (GO) was investigated using first-principles calculation. The optimal adsorption and orientation of the NH molecules on the graphene surfaces were determined, and the adsorption energies ( ) as well as the Mulliken charge transfers of NH were calculated. The for the graphene are small and seem to be independent of the sites and orientations. The surface epoxy or hydroxyl groups can promote the adsorption of NH on the GO; the enhancement of the for the hydroxyl groups is greater than that for the epoxy groups on the surface. The charge transfers from the molecule to the surfaces also exhibit the same trend. The Br?nsted acid sites and Lewis acid sites could stably exist on the GO with surface hydroxyl groups and on the basal, respectively.

关键词: graphene oxide     first-principles calculations     NH3 adsorption    

The First Attempt for Accounts of Environmental Chemistry and Technology Research

Jinyong Liu, Yin Wang, Haoran Wei

《环境科学与工程前沿(英文)》 2020年 第14卷 第5期 doi: 10.1007/s11783-020-1270-9

Modified landfill gas generation rate model of first-order kinetics and two-stage reaction

Jiajun CHEN , Hao WANG , Na ZHANG ,

《环境科学与工程前沿(英文)》 2009年 第3卷 第3期   页码 313-319 doi: 10.1007/s11783-009-0025-4

摘要: This investigation was carried out to establish a new domestic landfill gas (LFG) generation rate model that takes into account the impact of leachate recirculation. The first-order kinetics and two-stage reaction (FKTSR) model of the LFG generation rate includes mechanisms of the nutrient balance for biochemical reaction in two main stages. In this study, the FKTSR model was modified by the introduction of the outflow function and the organic acid conversion coefficient in order to represent the in-situ condition of nutrient loss through leachate. Laboratory experiments were carried out to simulate the impact of leachate recirculation and verify the modified FKTSR model. The model calibration was then calculated by using the experimental data. The results suggested that the new model was in line with the experimental data. The main parameters of the modified FKTSR model, including the LFG production potential (), the reaction rate constant in the first stage (), and the reaction rate constant in the second stage () of 64.746 L, 0.202 d, and 0.338 d, respectively, were comparable to the old ones of 42.069 L, 0.231 d, and 0.231 d. The new model is better able to explain the mechanisms involved in LFG generation.

关键词: landfill gas (LFG)     generation rate model     first-order kinetics     two-stage reaction     outflow function    

Technology and management innovation of the first-of-a-kind (FOAK) demonstration project — HPR1000

Ji XING, Tianlei ZHEN, Hang YU, Yanling ZHENG

《工程管理前沿(英文)》 2021年 第8卷 第3期   页码 471-475 doi: 10.1007/s42524-021-0158-0

Predication of increased plasma homocysteine level on the prognosis of Chinese patients with first-onset

YAN Jiangtao, SHAO Jiaomei, WANG Daowen, YUE Zhengliang, HUI Rutai

《医学前沿(英文)》 2008年 第2卷 第4期   页码 352-355 doi: 10.1007/s11684-008-0067-1

摘要: Epidemiological studies show that increased plasma total homocysteine (tHcy) level was an independent risk factor of cardiovascular diseases. This study was aimed to investigate the relationship between tHcy level and prognosis of first-onset stroke in Chinese people. One hundred ninety six patients with first-onset ischemic stroke and ninety-five patients with first-onset hemorrhagic stroke were enrolled in this study. The patients were divided into two groups in terms of tHcy level (< 18 ?mol/L and ≥ 18 ?mol/L). The plasma tHcy level was detected by a high performance liquid chromatography method with fluorescence detection. All the patients underwent a 5-year follow-up. Survival analysis shows that the probability of death or new vascular events in the ischemic stroke patients with high tHcy level (≥ 18 ?mol/L) was significantly higher than that in the counterparts with lower tHcy level (< 18 ?mol/L) (50.9% and 28.7%, respectively, = 0.004). The relative risk of death or new vascular events was 2.363 (95% CI, 1.209 to 4.617, = 0.012) in ischemic stroke patients with high tHcy levels(≥ 18 ?mol/L) compared to those with a lower tHcy level (< 18 ?mol/L). The increased tHcy level was significantly associated with the risk of death or new vascular events (, 2.492, 95% CI, 1.148 to 5.407, = 0.021) in patients with ischemic stroke in the exclusion of the influence of other risk factors such as gender, age, body mass index, plasma cholesterol level, the history of hypertension, diabetes or smoking. However, in the patients with hemorrhagic stroke, there was no significant difference in the probability of death or new vascular events between patients with a high tHcy level and those with a lower tHcy level (33.3% and 28.2%, respectively, = 0.546). Increased tHcy level was an independent risk factor for a worse outcome in patients with first-onset ischemic stroke, but not in hemorrhagic stroke patients.

Elevated C-reactive protein levels predict worsening prognosis in Chinese patients with first-onset stroke

Jiangtao YAN, Rutai HUI, Daowen WANG

《医学前沿(英文)》 2009年 第3卷 第1期   页码 30-35 doi: 10.1007/s11684-009-0005-x

摘要: The role of high sensitivity C-reactive protein (hsCRP) in predicting prognosis after stroke in the Asian population has not been investigated. We hypothesized that elevated levels of hsCRP were associated with worsening prognosis after stroke in Chinese patients. Two hundred and ninety consecutive patients with first-onset stroke and 290 age- and gender-matched control subjects without any cerebrovascular disease were enrolled for study. Plasma hsCRP level was detected and subsequent vascular events and death were recorded in both groups over a 5-year period. Compared to control group, patients presenting with stroke had higher plasma hsCRP level (3.3 ± 3.8 1.3 ± 2.2 mg/L, < 0.01). Furthermore, in the group of patients with stroke, the mean plasma hsCRP level was higher in patients who developed subsequent vascular diseases or died as compared with the patients without further complications (4.4 ± 4.3 2.7 ± 3.3 mg/L, < 0.01). Compared to the lowest tertile of hsCRP level, the relative risk for vascular events or death in stroke patients was 2.91 in the highest tertile of hsCRP (95% CI, 1.54–5.50, = 0.001). This increase in relative risk for vascular events or death in stroke patients continued after adjustment for age, sex and other cardiovascular risk factors such as hypertension and diabetes ( : 2.771, 95% CI: 1.367–5.617, = 0.005). These findings indicate that increased hsCRP level is associated with worsening prognosis after stroke in Chinese patients and suggests that inflammation is correlated with stroke outcome.

关键词: C-reactive protein     inflammation     stroke    

A case of thymic Langerhans cell histiocytosis with diabetes insipidus as the first presentation

null

《医学前沿(英文)》 2013年 第7卷 第1期   页码 143-146 doi: 10.1007/s11684-013-0238-6

摘要:

Langerhans cell histiocytosis (LCH) is an idiopathic group of reactive proliferative diseases linked to aberrant immunity, pathologically characterized by clonal proliferation of Langerhans cells. LCH rarely involves the thymus. We report a case of thymic LCH with diabetes insipidus as the first presentation, without evidence of myasthenia gravis and without evidenced involvement of the skin, liver, spleen, bones, lungs and superficial lymph nodes. This present case may have important clinical implications. In screening for LCH lesions, attention should be attached to rarely involved sites in addition to commonly involved organs. Follow-up and imageological examination are very important to a final diagnosis.

关键词: diabetes insipidus     thymus     Langerhans cell histiocytosis    

Comparison between linear and non-linear forms of pseudo-first-order and pseudo-second-order adsorption

Junxiong LIN , Lan WANG ,

《环境科学与工程前沿(英文)》 2009年 第3卷 第3期   页码 320-324 doi: 10.1007/s11783-009-0030-7

摘要: The best-fit equations of linear and non-linear forms of the two widely used kinetic models, namely pseudo-first-order and pseudo-second-order equations, were compared in this study. The experimental kinetics of methylene blue adsorption on activated carbon was used for this research. Both the correlation coefficient () and the normalized standard deviation Δ(%) were employed as error analysis methods to determine the best-fitting equations. The results show that the non-linear forms of pseudo-first-order and pseudo-second-order models were more suitable than the linear forms for fitting the experimental data. The experimental kinetics may have been distorted by linearization of the linear kinetic equations, and thus, the non-linear forms of kinetic equations should be primarily used to obtain the adsorption parameters. In addition, the Δ(%) method for error analysis may be better to determine the best-fitting model in this case.

关键词: adsorption     pseudo-first order     pseudo-second order     kinetic model     linear method     non-linear method    

The world’s first offshore wind power non-desalination of seawater electrolysis for hydrogen production

《能源前沿(英文)》 2023年 第17卷 第3期   页码 317-319 doi: 10.1007/s11708-023-0888-2

摘要: The world’s first offshore wind power non-desalination of seawater electrolysis for hydrogen production successfully tested in Fujian, China

关键词: China     wind power non    

创刊词

徐匡迪

《工程(英文)》 2015年 第1卷 第1期   页码 6-6 doi: 10.15302/J-ENG-2015003

全球首个CRISPR基因编辑疗法有望造福患者

Jennifer Welsh

《工程(英文)》 2023年 第30卷 第11期   页码 3-6 doi: 10.1016/j.eng.2023.09.005

Mechanism of methanol decomposition on the Pd/WC(0001) surface unveiled by first-principles calculations

Jinhua Zhang, Yuanbin She

《化学科学与工程前沿(英文)》 2020年 第14卷 第6期   页码 1052-1064 doi: 10.1007/s11705-019-1908-y

摘要: In this study, the decomposition of methanol into the CO and H species on the Pd/tungsten carbide (WC)(0001) surface is systematically investigated using periodic density functional theory (DFT) calculations. The possible reaction pathways and intermediates are determined. The results reveal that saturated molecules, i.e., methanol and formaldehyde, adsorb weakly on the Pd/WC(0001) surface. Both CO and H prefer three-fold sites, with adsorption energies of ‒1.51 and ‒2.67 eV, respectively. On the other hand, CH O stably binds at three-fold and bridge sites, with an adsorption energy of ‒2.58 eV. However, most of the other intermediates tend to adsorb to the surface with the carbon and oxygen atoms in their sp and hydroxyl-like configurations, respectively. Hence, the C atom of CH OH preferentially attaches to the top sites, CHOH and CH O adsorb at the bridge sites, while COH and CHO occupy the three-fold sites. The DFT calculations indicate that the rupture of the initial C–H bond promotes the decomposition of CH OH and CH OH, whereas in the case of CHOH, O–H bond scission is favored over the C–H bond rupture. Thus, the most probable methanol decomposition pathway on the Pd/WC(0001) surface is CH OH → CH OH → -CHOH → CHO → CO. The present study demonstrates that the synergistic effect of WC (as carrier) and Pd (as catalyst) alters the CH OH decomposition pathway and reduces the noble metal utilization.

关键词: density functional theory     methanol     direct methanol fuel cells     WC(0001)-supported Pd monolayer     decomposition mechanism    

标题 作者 时间 类型 操作

Multi-class dynamic network traffic flow propagation model with physical queues

Yanfeng LI, Jun LI

期刊论文

China Launched the First Wastewater Resource Recovery Factory in Yixing

期刊论文

Sustainable intensification of agriculture in sub-Saharan Africa: first things first!

Bernard VANLAUWE, Achim DOBERMANN

期刊论文

Ammonia adsorption on graphene and graphene oxide: a first-principles study

Yue PENG, Junhua LI

期刊论文

The First Attempt for Accounts of Environmental Chemistry and Technology Research

Jinyong Liu, Yin Wang, Haoran Wei

期刊论文

Modified landfill gas generation rate model of first-order kinetics and two-stage reaction

Jiajun CHEN , Hao WANG , Na ZHANG ,

期刊论文

Technology and management innovation of the first-of-a-kind (FOAK) demonstration project — HPR1000

Ji XING, Tianlei ZHEN, Hang YU, Yanling ZHENG

期刊论文

Predication of increased plasma homocysteine level on the prognosis of Chinese patients with first-onset

YAN Jiangtao, SHAO Jiaomei, WANG Daowen, YUE Zhengliang, HUI Rutai

期刊论文

Elevated C-reactive protein levels predict worsening prognosis in Chinese patients with first-onset stroke

Jiangtao YAN, Rutai HUI, Daowen WANG

期刊论文

A case of thymic Langerhans cell histiocytosis with diabetes insipidus as the first presentation

null

期刊论文

Comparison between linear and non-linear forms of pseudo-first-order and pseudo-second-order adsorption

Junxiong LIN , Lan WANG ,

期刊论文

The world’s first offshore wind power non-desalination of seawater electrolysis for hydrogen production

期刊论文

创刊词

徐匡迪

期刊论文

全球首个CRISPR基因编辑疗法有望造福患者

Jennifer Welsh

期刊论文

Mechanism of methanol decomposition on the Pd/WC(0001) surface unveiled by first-principles calculations

Jinhua Zhang, Yuanbin She

期刊论文