Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 213

年份

2024 1

2023 10

2022 6

2021 19

2020 15

2019 16

2018 13

2017 18

2016 8

2015 20

2014 12

2013 8

2012 8

2011 9

2010 4

2009 4

2008 9

2007 11

2006 1

2005 4

展开︾

关键词

不确定性 2

人工神经网络 2

仿真 2

增材制造 2

大菱鲆 2

并联机构 2

建模 2

汽车工业 2

生物材料 2

Aphanomyces euteiches 1

cyp17a1 1

Agent 1

CAN总线 1

L唱M算法 1

NPY 1

PEDOT:PSS 1

X射线成像 1

一维材料 1

两性异形 1

展开︾

检索范围：

排序：展示方式：

Effects of different doses of cadmium on secondary metabolites and gene expression in Artemisia annuaL.

null

《医学前沿（英文）》 2017年第11卷第1期页码 137-146 doi: 10.1007/s11684-016-0486-3

摘要：

This study aims to elucidate the underlying molecular mechanisms of artemisinin accumulation induced by cadmium (Cd). The effects of different Cd concentrations (0, 20, 60, and 120 μmol/L) on the biosynthesis of Artemisia annua L. were examined. Intermediate and end products were quantified by HPLC-ESI-MS/MS analysis. The expression of key biosynthesis enzymes was also determined by qRT-PCR. The results showed that the application of treatment with 60 and 120 μmol/L Cd for 3 days significantly improved the biosynthesis of artemisinic acid, arteannuin B, and artemisinin. The concentrations of artemisinic acid, arteannuin B, and artemisinin in the 120 μmol/L Cd-treated group were 2.26, 102.08, and 33.63 times higher than those in the control group, respectively. The concentrations of arteannuin B and artemisinin in 60 μmol/L Cd-treated leaves were 61.10 and 26.40 times higher than those in the control group, respectively. The relative expression levels of HMGR, FPS, ADS, CYP71AV1, DBR2, ALDH1, and DXR were up-regulated in the 120 μmol/L Cd-treated group because of increased contents of artemisinic metabolites after 3 days of treatment. Hence, appropriate doses of Cd can increase the concentrations of artemisinic metabolites at a certain time point by up-regulating the relative expression levels of key enzyme genes involved in artemisinin biosynthesis.

关键词： Cd secondary metabolites gene expressions Artemisia annua L.

HTML PDF 收藏

In memory of Perry L. McCarty, seminal founder of Environmental Biotechnology

《环境科学与工程前沿（英文）》 2023年第17卷第10期 doi: 10.1007/s11783-023-1730-0

HTML PDF 收藏

Comments on the special issue on forestry of

John L. INNES

《农业科学与工程前沿（英文）》 2017年第4卷第4期页码 502-503 doi: 10.15302/J-FASE-2017189

HTML PDF 收藏

Shear design of high strength concrete prestressed girders

Emad L. LABIB,Hemant B. DHONDE,Thomas T. C. HSU,Y. L. MO

《结构与土木工程前沿（英文）》 2014年第8卷第4期页码 373-387 doi: 10.1007/s11709-014-0087-7

摘要： Normal strength prestressed concrete I-girders are commonly used as the primary superstructure components in highway bridges. However, shear design guidelines for high strength PC girders are not available in the current structural codes. Recently, ten 7.62 m (25 feet) long girders made with high strength concrete were designed, cast, and tested at the University of Houston (UH) to study the ultimate shear strength and the shear concrete contribution ( ) as a function of concrete strength ( ). A simple semi-empirical set of equations was developed based on the test results to predict the ultimate shear strength of prestressed concrete I-girders. The UH-developed set of equations is a function of concrete strength ( ), web area ( ), shear span to effective depth ratio ( / ), and percentage of transverse steel ( ). The proposed UH-Method was found to accurately predict the ultimate shear strength of PC girders with concrete strength up to 117 MPa (17000 psi) ensuring satisfactory ductility. The UH-Method was found to be not as overly conservative as the ACI-318 (2011) code provisions, and also not to overestimate the ultimate shear strength of high strength PC girders as the AASHTO LRFD (2010) code provisions. Moreover, the proposed UH-Method was found fairly accurate and not exceedingly conservative in predicting the concrete contribution to shear for concrete strength up to 117 MPa (17000 psi).

关键词： shear design high strength concrete prestressed girders full-scale tests

HTML PDF 收藏

Purification of artemisinin from quercetin by anti-solvent crystallization

Chandrakant R. MALWADE, Haiyan QU, Ben-Guang RONG, Lars P. CHRISTENSEN

《化学科学与工程前沿（英文）》 2013年第7卷第1期页码 72-78 doi: 10.1007/s11705-013-1305-x

摘要： In the present work, anti-solvent crystallization of artemisinin from four different organic solvents (methanol, ethanol, acetonitrile, and acetone) was studied. Water was used as anti-solvent. The effect of an impurity (quercetin) on the performance of anti-solvent crystallization of artemisinin was investigated. The fundamental process data such as solubility of artemisinin in pure organic solvents and their binary mixtures with varying composition water were measured at room temperature. The solubility of quercetin was measured only in pure organic solvents at room temperature. Anti-solvent crystallization experiments were designed based on the fundamental process data determined. Firstly, the anti-solvent crystallization of artemisinin without impurity was performed from all four organic solvents and then the experiments were repeated with addition of an impurity (quercetin) while keeping all other process parameters constant. Two different concentrations of impurity, i.e., 10% and 50% of its solubility, in the respective organic solvents at room temperature were used. The effect of impurity on performance of anti-solvent crystallization was evaluated by comparing the yield and purity of the artemisinin obtained with those in the absence of impurity. Results of the present work demonstrated that the presence of quercetin in the solution does not affect the final yield of artemisinin from the solution of each of four organic solvents used. However, the purity of artemisinin crystals were reduced when quercetin concentration was 50% of its solubility in all solvents studied.

关键词： anti-solvent crystallization artemisinin quercetin solubility Artemisia annua

HTML PDF 收藏

Deeply missing my career idol and role model ― Professor Perry L. McCarty

《环境科学与工程前沿（英文）》 2023年第17卷第9期 doi: 10.1007/s11783-023-1717-x

HTML PDF 收藏

Urban watershed management under rapid urbanization

Pengfei DU, Haifeng JIA, Shaw L. YU

《环境科学与工程前沿（英文）》 2012年第6卷第5期页码 595-595 doi: 10.1007/s11783-012-0452-5

HTML PDF 收藏

地下工程的发展提升现代生活质量

Raymond L. Sterling

《工程（英文）》 2017年第3卷第6期页码 780-781 doi: 10.1016/j.eng.2017.12.006

HTML PDF 收藏

A Standard for the Commissioning Process

William L. Gillis,Elizabeth A. Cudney

《工程管理前沿（英文）》 2015年第2卷第1期页码 39-51 doi: 10.15302/J-FEM-2015006

摘要： The demand for commissioning services for new-building construction projects is experiencing rapid growth. Commissioning (Cx) is touted as being a quality-focused process for ensuring the owner’s project requirements (OPR) are met by design, final construction, and the operations of a building. To an owner this is just what is needed to receive a perfect building at occupancy. However, as many owners have realized, the Cx process does not guarantee the completed building will be what was expected. It should be pointed out that this is typically not caused by the Cx process, but the Cx process should or could have identified, in the early phases of the project, many of the issues that made it through to the completed building. There are a number of reasons why the Cx services received may not be optimal. Often it is poor communication and the transfer of knowledge between project teams. Cx should and can facilitate both communication and the transfer of knowledge from phase to phase. An adaptation of the quality function deployment (QFD) four-phase model can accomplish this by filling the gaps among the major Cx activities and provide a standard approach to the process. The four-phase model effectively links each of the Cx activities to each other and back to the OPR, providing a method for improved communication and knowledge transfer. This paper investigates some potential reasons for inconsistent Cx services, presents an argument for the need of a Cx standard, and proposes a potential standard.

关键词： construction engineering management quality commissioning

HTML PDF 收藏

The Decarbonization of Construction—How Can Alkali-Activated Materials Contribute?

John L. Provis,Susan A. Bernal,Zuhua Zhang,

《工程（英文）》 doi: 10.1016/j.eng.2023.09.014

HTML PDF 收藏

Quality Function Deployment Implementation in Construction: A Systematic Literature Review

Cudney,William L. Gillis

《工程管理前沿（英文）》 2016年第3卷第3期页码 224-230 doi: 10.15302/J-FEM-2016036

摘要： The construction of new buildings represents a significant investment. The goal of new building construction is to maximize value and minimize cost while staying on time and within budget. Translating customer requirements into engineering terms for new construction design is vital for a construction project to be successful. Quality function deployment has been successfully used in product development to capture the voice of the customer and translate it into engineering characteristics. Quality function deployment then carries these parameters into production and service to ensure the voice of the customer is being met with the final product. The house of quality, a tool within quality function deployment, can provide a means for comparison of owner’s project requirements and the proposed design, along with identifying how the design decisions impact meeting customer requirements and green building requirements. Quality function deployment can effectively link the project phases through design and construction and into operations and maintenance to ensure the owner’s project requirements are met with the final building. This research identifies and categorizes studies of quality function deployment applications in construction. The research method used is a systematic literature review from databases related to quality function deployment in the construction industry published in the periodicals through 2016. The principal findings of implementations, practices, and integrated approaches are then summarized. This article intends to propel further research of quality function deployment in the construction sector.

关键词： construction engineering management quality function deployment systematic review

HTML PDF 收藏

Effects of iron oxide nanoparticles on phenotype and metabolite changes in hemp clones ( L.)

《环境科学与工程前沿（英文）》 2022年第16卷第10期 doi: 10.1007/s11783-022-1569-9

摘要：

● Fe₃O₄ NPs increased the biomass and chlorophyll content of hemp clones.

关键词： Fe₃O₄ nanoparticle Hemp Growth enhancement THC Metabolite

HTML PDF 收藏

Antifungal and antibacterial functions of medicinal leech recombinant destabilase-lysozyme and its heated-up derivative

PAVLOVA, L. L. ZAVALOVA, I. P. BASKOVA

《化学科学与工程前沿（英文）》 2012年第6卷第2期页码 203-209 doi: 10.1007/s11705-012-1277-2

摘要： Antifungal activity of recombinant medicinal leech destabilase-lysozyme (rec.Dest-Lys) was investigated by using fungi: , and , including yeasts and . Its antibacterial activity was investigated on gram-negative bacteria . These activities were assessed by radial agar diffusion assay, and scanning and transmission electron microscopy. Therefore, destabilase-lysozyme not only is endo-isopeptidase and lysozyme, but also has antifungal and antibacterial activities. Muramidase activity of rec.Dest-Lys disappeared after heat-treating at 90°C for 50 min without the loss of its antimicrobial activity. Furthermore we showed for the first time that the heated-up derivative of rec.Dest-Lys exhibited more potent activities against the above enumerated fungi and gram-negative bacteria than original protein.

关键词： recombinant destabilase-lysozyme (rec.Dest-Lys) antimicrobial activity antifungal activity medicinal leech heated-up derivative of rec.Dest-Lys (T-rec.Dest-Lys)

HTML PDF 收藏

Simultaneous harvesting and cell disruption of microalgae using ozone bubbles: optimization and characterization study for biodiesel production

Lim, Peck L. Kiew, Steven Lim, Siti S. Rosli, Chung Y. Wong, Pau L. Show, Keat T. Lee

《化学科学与工程前沿（英文）》 2021年第15卷第5期页码 1257-1268 doi: 10.1007/s11705-020-2015-9

摘要： In the present study, ozone was introduced as an alternative approach to harvest and disrupt microalgae cells ( ) simultaneously for biodiesel production. At the optimum ozonation conditions (6.14 g·h ozone concentration, 30 min ozonation time, 1 L·min of ozone flowrate at medium pH of 10 and temperature of 30 °C), the sedimentation efficiency of microalgae cells increased significantly from 12.56% to 68.62%. It was observed that the microalgae cells aggregated to form flocs after pre-treated with ozone due to the increment of surface charge from –20 to –6.59 mV. Besides, ozone had successfully disrupted the microalgae cells and resulted in efficient lipid extraction, which was 1.9 times higher than the control sample. The extracted microalgae lipid was mainly consisted of methyl palmitate (C16:0), methyl oleate (C18:1) and methyl linolenate (C18:3), making it suitable for biodiesel production. Finally, utilization of recycled culture media after ozonation pre-treatment showed robust growth of microalgae, in which the biomass yield was maintained in the range of 0.796 to 0.879 g·h for 5 cycles of cultivation.

关键词： microalgae biodiesel ozonation pre-treatment lipid

HTML PDF 收藏

Reduced texaphyrin: A ratiometric optical sensor for heavy metals in aqueous solution

Root, Gregory Thiabaud, Jonathan L. Sessler

《化学科学与工程前沿（英文）》 2020年第14卷第1期页码 19-27 doi: 10.1007/s11705-019-1888-y

摘要： We report here a water-soluble metal cation sensor system based on the as-prepared or reduced form of an expanded porphyrin, texaphyrin. Upon metal complexation, a change in the redox state of the ligand occurs that is accompanied by a color change from red to green. Although long employed for synthesis in organic media, we have now found that this complexation-driven redox behavior may be used to achieve the naked eye detectable colorimetric sensing of several number of less-common metal ions in aqueous media. Exposure to In(III), Hg(II), Cd(II), Mn(II), Bi(III), Co(II), and Pb(II) cations leads to a colorimetric response within 10 min. This process is selective for Hg(II) under conditions of competitive analysis. Furthermore, among the subset of response-producing cations, In(III) proved unique in giving rise to a ratiometric change in the ligand-based fluorescence features, including an overall increase in intensity. The cation selectivity observed in aqueous media stands in contrast to what is seen in organic solvents, where a wide range of texaphyrin metal complexes may be prepared. The formation of metal cation complexes under the present aqueous conditions was confirmed by reversed phase high-performance liquid chromatography, ultra-violet-visible absorption and fluorescence spectroscopies, and high-resolution mass spectrometry.

关键词： texaphyrin fluorescent sensor ion-sensing indium mercury