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A newly defined dioxygenase system from Mycobacterium vanbaalenii

Yiquan Wu, Ying Xu, Ningyi Zhou

《环境科学与工程前沿（英文）》 2020年 第14卷 第1期 doi: 10.1007/s11783-019-1193-5

摘要： • Mycobacterium vanbaalenii PYR-1 utilizes PAHs at different rates. • Both NidA3B3 and FNidA3B3 catalyze high-molecular-weight PAHs dihydroxylation. • NidA3B3 shows an enhanced activity with an endogenous electron transport chain. • FNidA3B3 has an enhanced activity by 50% approximately compared with NidA3B3. • FNidA3B3/NidA3B3 and NidAB in the same strain come from different ancestors. NidA3B3 is a terminal dioxygenase whose favorable substrates are high-molecular-weight polyaromatic hydrocarbons (PAHs) from Mycobacterium vanbaalenii PYR-1, a powerful PAHs degradation strain. NidA3B3 was reported to incorporate a dioxygen into the benzene ring of PAHs when equipped with an exogenous electron transport chain components PhdCD from Nocardioides sp. strain KP7 by biotransformation, but this enzyme system was not particularly efficient. In this study, strain PYR-1 was confirmed to utilize four different PAHs at different growth rates. When PhtAcAd, an endogenous electron transport chain of a phthalate dioxygenase system, was substituted for PhdCD to couple with NidA3B3, the specific activity to convert phenanthrene by strain BL21(DE3) [pNidA3B3-PhAcAd] was 0.15±0.03 U/mg, but the specific activity of strain BL21(DE3) [pNidA3B3-PhdCD] was only 0.025±0.006 U/mg. In addition, FNidA3, encoded by a newly defined ORF, has a prolonged 19-amino acid sequence at the N-terminal compared with NidA3. FNidA3B3 increased the activity by 50% approximately than NidA3B3 when using PhtAcAd. Components of the electron transport chain PhtAc and PhtAd were purified and characterized. The Km, kcat, kcat/Km values of the PhtAd were 123±26.9 M, 503±49.9 min−1, 4.1 M−1·min−1, respectively. And the Km, kcat, kcat/Km values of the ferredoxin PhtAc were 52.5±9.7 M, 3.8±0.19 min−1 and 0.07 M−1·min−1, respectively. Basing on the phylogenetic analysis, NidA3/FNidA3 were far from its isoenzyme NidA from the same strain. Combining their primary differences of transcriptional pattern in vivo, it indicated that the functionally similar Rieske dioxygenases NidA3B3/FNidA3B3 and NidAB might originate from different ancestors.

关键词： Biodegradation     polyaromatic hydrocarbons     biotransformation     ring-hydroxylating dioxygenase system    

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Effect of salinity on community structure and naphthalene dioxygenase gene diversity of a halophilic

Tingting Fang, Ruisong Pan, Jing Jiang, Fen He, Hui Wang

《环境科学与工程前沿（英文）》 2016年 第10卷 第6期 doi: 10.1007/s11783-016-0888-0

摘要： Various salinities affected the PAH-biodegrading community structure. Various salinities affected the growth of strains with different salt tolerance. The two genes belonged to a new divergent cluster of the known -like genes. The two main genes had correlations with the phenanthrene degradation. The aim of this study is to analyze the effect of salinity on polycyclic aromatic hydrocarbons (PAHs) biodegradation, community structure and naphthalene dioxygenase gene ( ) diversity of a halophilic bacterial consortium with the denaturing gradient gel electrophoresis (DGGE) approach. The consortium was developed from oil-contaminated saline soil after enrichment for six times, using phenanthrene as the substrate. The prominent species in the bacterial consortium at all salinities were identified as halophilic bacteria , , , , and uncultured bacteria. The predominant microbes gradually changed associating with the saline concentration fluctuations ranging from 0.1% to 25% (w/v). Two alpha subunits were dominant at salinities ranging from 0.1% to 20%, while not been clearly detected at 25% salinity. Consistently, the biodegradation occurred at salinities ranging from 0.1% to 20%, while no at 25% salinity, suggesting the two genes played an important role in the degradation. The phylogenetic analysis revealed that both of the two alpha subunits were related to the classic -like gene from AN10 and PaK1, while one with identity of about 82% and the other one with identity of 90% at amino acid sequence level. We concluded that salinity greatly affected halophilic bacterial community structure and also the functional genes which were more related to biodegradation.

关键词： Phenanthrene     Halophilic bacteria     Gene diversity     Naphthalene dioxygenase genes    

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Frequencies of circular plate with concentric ring and elastic edge support

null

《机械工程前沿（英文）》 2014年 第9卷 第2期   页码 168-176 doi: 10.1007/s11465-014-0299-5

摘要：

Exact solutions for the flexural vibrations of circular plates having elastic edge conditions along with rigid concentric ring support have been presented in this paper. Values of frequency parameter for the considered circular plate are computed for different sets of values of elastic rotational and translation restraints and the radius of internal rigid ring support. The results for the first three modes of plate vibrations are computed and are presented in tabular form. The effects of rotational and linear restraints and the radius of the rigid ring support on the vibration behavior of circular plates are studied over a wide range of non-dimensional parametric values. The values of the exact frequency parameter presented in this paper for varying values of restraint parameters and the radius of the rigid ring support can better serve in design and as benchmark solutions to validate the numerical methods obtained by using other methods of solution.

关键词： circular plate     frequency     elastic edge     rigid ring     mode switching    

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Fundamental buckling of circular plates with elastically restrained edges and resting on concentric rigid ring

Lokavarapu Bhaskara Rao, Chellapilla Kameswara Rao

《机械工程前沿（英文）》 2013年 第8卷 第3期   页码 291-297 doi: 10.1007/s11465-013-0255-9

摘要：

This work presents the existence of buckling mode switching with respect to the radius of concentric rigid ring support. The buckling mode may not be axisymmetric as previously assumed. In general, the plate may buckle in an axisymmetric mode but when the radius of the ring support becomes small, the plate may buckle in an asymmetric mode. The optimum radius of the concentric rigid ring support for maximum buckling load is also determined. Introducing internal rigid ring support, when placed at an optimal position increases the elastic buckling load capacity by 149.39 percent. The numerical results obtained are in good agreement with the previously published data.

关键词： buckling     circular plate     elastically restrained edge     rigid ring support     mode switching    

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A novel algorithm for frequency dependent modeling of ferrite ring and its optimum design to study VFTO

Mehrdad MAJIDI, Hamid JAVADI, Moein MANBACHI

《能源前沿（英文）》 2014年 第8卷 第1期   页码 90-100 doi: 10.1007/s11708-013-0286-2

摘要： One of the fundamental issues in gas insulated substations (GIS) which has destructive effects on GIS equipment is the very fast transient over-voltages (VFTOs). This paper models a 400/230 kV substation in order to study the effects of VFTO extensively implemented on EMTP-RV. In addition, the application of ferrite rings for suppressing VFTOs is assessed thoroughly. The main advantage of this paper is its new proposed algorithm according to the ferrite ring frequency dependent modeling that is validated with experimental results. This paper examines the effects of three compositions of the ferrite ring on VFTO suppression. Moreover, it estimates the dimension of the ferrite ring based on the SF6 gas insulation withstand and the maximum effect of ferrite rings on VFTO suppression constraint with the COMSOL multiphysics software. Furthermore, it gains VFTO attenuated percentages due to the installation of the ferrite ring in different GIS nodes. Finally, it analyzes the offered VFTO amendment technique in various GIS switching scenarios.

关键词： comsol multiphysics     EMTP-RV     ferrite ring     gas insulated substations (GIS)     transient over-voltage     insulation coordination    

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单向离合器外环应力计算的有限元方法研究

罗一新,吴波

《中国工程科学》 2004年 第6卷 第9期   页码 56-59

摘要：

单向离合器是一种常见的机械传动部件，其外环应力计算尚无理想的方法。文章以五滚柱式单向离合器为研究对象，根据外环的特点，采用有限元分析方法，分析了影响其计算精度的各种因素，计算出其外环的应力，并且将计算结果与曲梁计算法进行了比较。研究表明，有限元分析方法对于外环类零件的应力计算确是一种理想的方法。

关键词： 离合器     外环     应力     有限元    

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Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distributionsystem

L. RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

《能源前沿（英文）》 2012年 第6卷 第1期   页码 47-56 doi: 10.1007/s11708-011-0159-5

摘要： The advancement in power distribution system poses a great challenge to power engineering researchers on how to best monitor and estimate the state of the distribution network. This paper is executed in two stage processes. The first stage is to identify the optimal location for installation of monitoring instrument with minimal investment cost. The second stage is to estimate the bus voltage magnitude, where real time measurement is conducted and measured through identified meter location which is more essential for decision making in distribution supervisory control and data acquisition system (DSCADA). The hybrid intelligent technique is applied to execute the above two algorithms. The algorithms are tested with institute of electrical and electronics engineers (IEEE) and Tamil Nadu electricity board (TNEB) benchmark systems. The simulated results proves that the swarm tuned artificial neural network (ANN) estimator is best suited for accurate estimation of voltage with different noise levels.

关键词： artificial intelligence     power distribution control     state estimation    

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非连续接触下滚圈的接触压力及疲劳寿命预测

时彧,肖友刚,雷先明

《中国工程科学》 2006年 第8卷 第7期   页码 54-57

摘要：

建立了非连续接触下筒体-滚圈接触压力的计算模型，得出了滚圈弯矩及弯曲应力计算公式。应用名义应力法和局部应力应变法，建立了滚圈疲劳寿命预测模型。通过实例分析，得出了如下结论：通过调窑，将滚圈的最大支承载荷控制在2500kN以内，能显著提高滚圈的疲劳寿命；在传统设计中，将滚圈支承角定为30°不合理；存在一个最佳滚圈支承角，此时滚圈疲劳寿命最大。

关键词： 滚圈     接触压力     支承角     疲劳寿命    

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Preparation and properties of hollow fibre nanofiltration membrane with continuous coffee-ring structure

Xiuzhen Wei, Xufeng Xu, Yi Chen, Qian Zhang, Lu Liu, Ruiyuan Yang, Jinyuan Chen, Bosheng Lv

《化学科学与工程前沿（英文）》 2021年 第15卷 第2期   页码 351-362 doi: 10.1007/s11705-020-1943-8

摘要： Polyamide (PA) hollow fibre composite nanofiltration (NF) membranes with a coffee-ring structure and beneficial properties were prepared by adding graphene oxide (GO) into the interfacial polymerization process. The presentation of the coffee-ring structure was attributed to the heterogeneous, finely dispersed multiphase reaction system and the “coffee-stain” effect of the GO solution. When the piperazine concentration was 0.4 wt-%, the trimesoyl chloride concentration was 0.3 wt-%, and the GO concentration was 0.025 wt-%, the prepared NF membranes showed the best separation properties. The permeate flux was 76 L·m ·h , and the rejection rate for MgSO was 98.6% at 0.4 MPa. Scanning electron microscopy, atomic force microscopy, and attenuated total reflectance-Fourier transform infrared spectroscopy were used to characterize the chemical structure and morphology of the PA/GO NF membrane. The results showed that GO was successfully entrapped into the PA functional layer. Under neutral operating conditions, the PA/GO membrane showed typical negatively charged NF membrane separation characteristics, and the rejection rate decreased in the order of Na SO >MgSO >MgCl >NaCl. The PA/GO NF membrane showed better antifouling performance than the PA membrane.

关键词： GO     PA     interfacial polymerization     hollow fibre NF membrane    

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大直径盾构负环管片拆除及隧道换装技术

翟志国,黄学军,杨志永

《中国工程科学》 2010年 第12卷 第12期   页码 83-88

摘要：

通过对北京铁路地下直径线2标工程的研究，确定在刀盘改造期间进行负环管片拆除的一系列工作，重点如部分反力架的拆除方法、负环管片的详细拆除方法以及拆除反力架后临时支撑的架设方法，同时就泥水盾构隧道的换装技术进行了叙述，最终在7 d之内成功拆除了7环负环管片，节约了工期，保证了后继施工的材料运输速度。

关键词： 大直径盾构     负环管片     拆除     隧道换装    

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环缝天线罩的近似分析方法 Article

罗康, 孟进, 韩江枫, 朱丹妮

《工程（英文）》 2023年 第30卷 第11期   页码 75-82 doi: 10.1016/j.eng.2023.07.015

摘要：

本文提出了一种基于近似分析方法的环缝天线罩带内和带外微波无线功率传输特性分析方法。本文的主要贡献是对环形天线罩的近似分析，推导了E平面和H平面扫描时天线罩表面入射场的统一表达式，并将环形天线罩近似分为30段直条。求解相应的60 × 60线性方程得到了沿环形带的电流分布。沿着互补槽环的磁电流是通过对偶获得的。得益于电流分布的全解析格式，使用Munk方案有效地计算了微波无线功率传输特性。以环缝双层对称混合天线罩为例，验证了该方法的准确性和有效性。HFSS和所提出的方法的CPU计算时间分别约为690 s和2.82 s。

关键词： 近似解析     环形     天线罩     基尔霍夫型电路    

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Insight into fluorescence properties of 14 selected toxic single-ring aromatic compounds in water: Experimental

Muhammad Farooq Saleem Khan, Jing Wu, Cheng Cheng, Mona Akbar, Chuanyang Liu, Bo Liu, Jian Shen, Yu Xin

《环境科学与工程前沿（英文）》 2020年 第14卷 第3期 doi: 10.1007/s11783-020-1219-z

摘要： The fluorescence peak location of 14 compounds interpreted at protein-like region. The p-electron system inside aromatic ring contributes to the fluorophore region. Functional group variation effects the emission spectra. Decrease in quantum yield and increase in DE is due to atomic weight F>Cl>Br>I. Theoretically results are in line with experimental ones. Various single-ring aromatic compounds in water sources are of great concern due to its hazardous impact on the environment and human health. The fluorescence excitation-emission matrix (EEMs) spectrophotometry is a useful method to identify organic pollutants in water. This study provides a detailed insight into the fluorescence properties of the 14 selected toxic single-ring aromatic compounds by experimental and theoretical analysis. The theoretical analysis were done with Time-Dependent Density Functional Theory (TD-DFT) and B3LYP/6-31G (d,p) basis set, whereas, Polarizable Continuum Model (PCM) was used to consider water as solvent. The selected compounds displayed their own specific excitation-emission (Ex/Em) wavelengths region, at Ex<280 nm and Em<340 nm, respectively. Whereas the theoretical Ex/Em was observed as, Ex at 240 nm–260 nm and Em at 255 nm–300 nm. Aniline as a strong aromatic base has longer Em (340 nm) than alkyl, carbonyl, and halogens substituted benzenes. The lone pair of electrons at amide substituent serves as a p-electron contributor into the aromatic ring, hence increasing the stability and transition energy, which results in longer emission and low quantum yield for the aniline. The fluorescence of halogenated benzenes illustrates an increase in the HOMO-LUMO energy gap and a decrease in quantum yield associated with atomic size (F>Cl>Br>I). In this study the theoretical results are in line with experimental ones. The understanding of fluorescence and photophysical properties are of great importance in the identification of these compounds in the water.

关键词： Fluorescence     Photophysical properties     Effect of the substituent     Toxic aromatic compounds    

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Temperature field simulation of laser homogenizing equipment

Juanjuan WANG, Yunshan WANG, Fudong ZHU

《机械工程前沿（英文）》 2009年 第4卷 第1期   页码 49-52 doi: 10.1007/s11465-009-0005-1

摘要： The laser homogenizing equipment was devised using the ring scanning principle. Its working principle is explained. A laser scanning ring facula is obtained when the laser beam goes through the equipment’s optical system rotating with high-frequency. The scanning ring facula’s mathematic model is established based on the temperature field’s superposing principle. The ring facula’s light intensity distribution and temperature distribution characteristics are achieved by simulating its temperature field. By studying the effect of parameters on the temperature field, the best parameter can be found. Results show that favorable temperature distribution characteristics can be attained by choosing appropriate parameters, and even the thermal effect can be realized by utilizing the circumference power compensating for the heat exchange lost in the horizontal direction. The uniform hardness layer and better process quality can be attained using the ring facula optimized for metal laser heat treatment.

关键词： laser homogenizing technology     laser scanning ring facula     temperature field    

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A “Sequential Design of Simulations” approach for exploiting and calibrating discrete element simulations of cohesive powders

《化学科学与工程前沿（英文）》 2022年 第16卷 第6期   页码 874-885 doi: 10.1007/s11705-021-2131-1

摘要： The flow behaviours of cohesive particles in the ring shear test were simulated and examined using discrete element method guided by a design of experiments methodology. A full factorial design was used as a screening design to reveal the effects of material properties of partcles. An augmented design extending the screening design to a response surface design was constructed to establish the relations between macroscopic shear stresses and particle properties. It is found that the powder flow in the shear cell can be classified into four regimes. Shear stress is found to be sensitive to particle friction coefficient, surface energy and Young’s modulus. A considerable fluctuation of shear stress is observed in high friction and low cohesion regime. In high cohesion regime, Young’s modulus appears to have a more significant effect on the shear stress at the point of incipient flow than the shear stress during the pre-shear process. The predictions from response surface designs were validated and compared with shear stresses measured from the Schulze ring shear test. It is found that simulations and experiments showed excellent agreement under a variety of consolidation conditions, which verifies the advantages and feasibility of using the proposed “Sequential Design of Simulations” approach.

关键词： discrete element method     cohesive materials     parameter calibration     ring shear cell     design of experiments    

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浅谈五种宫内节育器不良反应分析

李华洁

《中国工程科学》 2015年 第17卷 第6期   页码 28-30

摘要：

通过观察放置宫内节育器（IUD），爱母环（MCU）、母体乐（MCU375）、宫形环（GCU300）、TCU220C和吉妮环术后不良反应情况，为育龄妇女知情选择IUD提供参考依据。将671例自愿采取放置宫内节育器避孕而无禁忌症的妇女随机分成五组，分别放置A组MCU，B组MCU375，C组GCU300，D组TCU220C，E组吉妮环五种IDU，随访两年，对其术后月经量增多，经期延长，阴道不规则流血，疼痛，脱环，带器妊娠，白带增多情况进行比较。MCU的不良反应较为严重，MCU375和GCU300的不良反应次之，TCU220C和吉妮环不良反应最轻。GCU300的脱环率最高，TCU220C、MCU和MCU375、吉妮环的脱环率都比较低；带器妊娠MCU和GCU300最高，MCU375、TCU220C和吉妮环均低。临床应根据受器者的具体情况选择适当的IUD，提高育龄妇女对避孕措施的满意程度。

关键词： 节育环；不良反应；吉妮环    

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标题 作者 时间 类型 操作

A newly defined dioxygenase system from Mycobacterium vanbaalenii

Yiquan Wu, Ying Xu, Ningyi Zhou

期刊论文

Effect of salinity on community structure and naphthalene dioxygenase gene diversity of a halophilic

Tingting Fang, Ruisong Pan, Jing Jiang, Fen He, Hui Wang

期刊论文

Frequencies of circular plate with concentric ring and elastic edge support

null

期刊论文

Fundamental buckling of circular plates with elastically restrained edges and resting on concentric rigid ring

Lokavarapu Bhaskara Rao, Chellapilla Kameswara Rao

期刊论文

A novel algorithm for frequency dependent modeling of ferrite ring and its optimum design to study VFTO

Mehrdad MAJIDI, Hamid JAVADI, Moein MANBACHI

期刊论文

单向离合器外环应力计算的有限元方法研究

罗一新,吴波

期刊论文

Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distributionsystem

L. RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

期刊论文

非连续接触下滚圈的接触压力及疲劳寿命预测

时彧,肖友刚,雷先明

期刊论文

Preparation and properties of hollow fibre nanofiltration membrane with continuous coffee-ring structure

Xiuzhen Wei, Xufeng Xu, Yi Chen, Qian Zhang, Lu Liu, Ruiyuan Yang, Jinyuan Chen, Bosheng Lv

期刊论文

大直径盾构负环管片拆除及隧道换装技术

翟志国,黄学军,杨志永

期刊论文

环缝天线罩的近似分析方法

罗康, 孟进, 韩江枫, 朱丹妮

期刊论文

Insight into fluorescence properties of 14 selected toxic single-ring aromatic compounds in water: Experimental

Muhammad Farooq Saleem Khan, Jing Wu, Cheng Cheng, Mona Akbar, Chuanyang Liu, Bo Liu, Jian Shen, Yu Xin

期刊论文

Temperature field simulation of laser homogenizing equipment

Juanjuan WANG, Yunshan WANG, Fudong ZHU

期刊论文

A “Sequential Design of Simulations” approach for exploiting and calibrating discrete element simulations of cohesive powders

期刊论文

浅谈五种宫内节育器不良反应分析

李华洁

期刊论文