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Isolation, identification and primary application of bacteria from putrid alkaline silica sol

Lijie REN,Ye HAN,Shuwen YANG,Xiqian TAN,Jin WANG,Xin ZHAO,Jie FAN,Ting DONG,Zhijiang ZHOU

《化学科学与工程前沿(英文)》 2014年 第8卷 第3期   页码 330-339 doi: 10.1007/s11705-014-1419-9

摘要: The putrefaction of alkaline silica sol was investigated in this paper. The total colony numbers in three alkaline silica sol samples were 1.47×10 , 1.25×10 , and 9.45×10 cfu·mL , respectively. The salt- and alkali-tolerant strains were isolated and selected using nutrient agar medium at 2.5% salinity and pH 9.5. Basic morphological, physiological and biochemical tests were conducted to confirm the preliminary characterizations of the strains. Based on API 50 CH test and 16S rDNA gene sequence analysis, the isolated strains were finally identified as sp., sp., and . The survivability of the strains under different conditions such as salinities, acidities and temperatures was also studied. Some suitable methods for degerming, such as product pipe steam sterilization and regular canister cleaning, were proposed. To explore the possibility of isolates in industrial application, their alkaline protease and amylase production abilities were preliminarily studied. Five strains produced alkaline protease, whereas two strains produced alkaline amylase. Thus, understanding of the putrefaction on alkaline silica sol would be beneficial for improving industrial production.

关键词: putrid alkaline silica sol     alkaliphile     isolation and identification     sterilization     alkaline protease and alkaline amylase    

Innovative seismic retrofitting strategy of added stories isolation system

Min-Ho CHEY, J. Geoffrey CHASE, John B. MANDER, Athol J. CARR

《结构与土木工程前沿(英文)》 2013年 第7卷 第1期   页码 13-23 doi: 10.1007/s11709-013-0195-9

摘要: The seismic performance of “added stories isolation” (ASI) systems are investigated for 12-story moment resisting frames. The newly added and isolated upper stories on the top of the existing structure are rolled to act as a large tuned mass damper (TMD) to overcome the limitation of the size of tuned mass, resulting to “12+2” and “12+4” stories building configurations. The isolation layer, as a core design strategy, is optimally designed based on optimal TMD design principle, entailing the insertion of passive flexible laminated rubber bearings to segregate two or four upper stories from a conventionally constructed lower superstructure system. Statistical performance metrics are presented for 30 earthquake records from the 3 suites of the SAC project. Time history analyses are used to compute various response performances and reduction factors across a wide range of seismic hazard intensities. Results show that ASI systems can effectively manage seismic response for multi-degree-of freedom (MDOF) systems across a broader range of ground motions without requiring burdensome extra mass. Specific results include the identification of differences in the number of added story by which the suggested isolation systems remove energy.

关键词: added stories     seismic isolation     tuned mass damper     parametric optimization     statistical method    

H control in the frequency domain for a semi-active floor isolation system

Yundong SHI, Tracy C BECKER, Masahiro KURATA, Masayoshi NAKASHIMA

《结构与土木工程前沿(英文)》 2013年 第7卷 第3期   页码 264-275 doi: 10.1007/s11709-013-0214-x

摘要: A floor isolation system installed in a single floor or room in a fixed base structure is designed to protect equipment. With this configuration, the input motions to the floor isolation from the ground motions are filtered by the structure, leaving the majority of the frequency content of the input motion lower than the predominant frequency of the structure. The floor isolation system should minimize the acceleration to protect equipment; however, displacement must also be limited to save floor space, especially with long period motion. Semi-active control with an control was adopted for the floor isolation system and a new input shaping filter was developed to account for the input motion characteristics and enhance the effectiveness of the control. A series of shake table tests for a semi-active floor isolation system using rolling pendulum isolators and a magnetic-rheological damper were performed to validate the control. Passive control using an oil damper was also tested for comparison. The test results show that the control effectively reduced acceleration for short period motions with frequencies close to the predominant frequency of the structure, as well as effectively reduced displacement for long period motions with frequencies close to the natural frequency of the floor isolation system. The control algorithm proved to be more advantageous than passive control because of its capacity to adjust control strategies according to the different motion frequency characteristics.

关键词: semi-active     floor isolation     H control     MR damper     shaping filter     shaking table test    

Isolation and application of predatory

Ran Yu, Shiwen Zhang, Zhoukai Chen, Chuanyang Li

《环境科学与工程前沿(英文)》 2017年 第11卷 第1期 doi: 10.1007/s11783-017-0900-3

摘要: Indigenous predatory BALO strains were successfully isolated from activated sludge. Sludge SRF and CST were significantly reduced by BALOs induced biolysis process. The increase of BALO input dosage promoted the sludge biolysis efficiency. Sludge biolysis disintegrated flocs and lysed cells for internal water release. The optimal sludge biolysis time was 24 h and no pH adjustment was needed. -and-like organisms (BALOs) are a group of ubiquitous and obligate predatory bacteria and commonly used as biocontrol agents. In this study, an efficient, environmental-friendly, and convenient BALOs encouraged municipal waste sludge biolysis pretreatment technique was developed and investigated for dewaterability enhancement of excess waste sludge. The indigenous predatory BALOs were successfully isolated from the sludge for biolysis treatment. Without any chemical addition or pH adjustment, the sludge specific resistance (SRF) and capillary suction time (CST) were significantly reduced by as high as 53.4% and 23.8%, respectively within 24 h’s treatment, which would further be lowered with the increase of BALOs input dosage. However, the continuous extension of reaction time would worsen the sludge dewaterability. The decreases of SRF and CST accompanied with the increases of sludge disintegration degree and soluble chemical oxygen demand, nitrogen, and phosphorus concentrations all emphasized the contributions of BALOs’ predation activities to sludge disturbance, cell lysis, and consequently the release of sludge intracellular water to finally effectively improve the sludge dewaterability and disposal efficiency.

关键词: Bdellovibrio-and-like organisms (BALOs)     Biolysis     Activated sludge     Dewaterability     Predation    

Novel polymorphic EST-based microsatellite marker isolation and characterization from

Manosh Kumar BISWAS,Peng CHEN,Mohamed Hamdy AMAR,Xiuxin DENG

《农业科学与工程前沿(英文)》 2015年 第2卷 第1期   页码 60-65 doi: 10.15302/J-FASE-2015048

摘要: Novel simple sequence repeat (SSR) markers were developed to evaluate their utility for genetic diversity and breeding studies of and related species. A total of 108 primer pairs were characterized by PCR amplification experiments. Among these, 61 were polymorphic and transferable to other citrus species. The number of alleles per locus ranged from 2 to 6, with an average of 2.37 alleles per locus. The expected heterozygosity and observed heterozygosity ranged from 0 to 0.83 and 0 to 1.00, respectively. These novel polymorphic SSR markers will be useful for citrus cultivar identification and evaluation as well as breeding studies.

关键词: microsatellite     polymorphism     Poncirus trifoliata    

seismic response control on top of Three-Gorges ship lift towers using magnetorheological intelligent isolation

Weilian QU, Jianwei TU

《结构与土木工程前沿(英文)》 2009年 第3卷 第1期   页码 32-41 doi: 10.1007/s11709-009-0003-8

摘要: A vertical ship lift under earthquake excitation may suffer from a whipping effect due to the sudden change of building lateral stiffness at the top of the ship lift towers. This paper proposes a roof magnetorheological (MR) intelligent isolation system to prevent the seismic whipping effect on machinery structures. Theoretically, the dynamic models of MR damper and the mechanical model of ship lift was established, the inverse neural network controlling algorithm was proposed and the fundamental semi-active control equation for the Three-Gorges ship lift where the MR intelligent isolation system was installed was deduced. Experimentally, the experimental model of the ship lift was given, the vibrating table experiment of the MR intelligent isolation system controlling the whipping effect was carried out and the results of the inverse neural network control strategy and passive isolation strategy were compared. In practical aspect, the large-scale MR damper (500 kN) and a sliding support with limited stiffness were designed and fabricated. It was proven that the MR intelligent isolation system with proper control strategy can greatly reduce the seismic whipping effect on the top workshop of the ship lift and be simple and effective enough to be applied to real engineering structures.

关键词: Three-Gorges ship lift tower     whipping effect     magnetorheological (MR) intelligent isolation system     neural network     sliding steel supporting    

Aseismic smart building isolation systems under multi-level earthquake excitations: Part II, energy-dissipation

Min-Ho CHEY,J. Geoffrey CHASE,John B. MANDER,Athol J. CARR

《结构与土木工程前沿(英文)》 2015年 第9卷 第3期   页码 297-306 doi: 10.1007/s11709-015-0308-8

摘要: Based on the performance results of the previously suggested smart building isolation systems (1st companion paper), this following study verifies the control effects of the systems from the view point of energy dissipation and damage level metrics. Several different model cases of the strategically isolated multi-story building structures utilizing passive dampers and semi-active resettable devices are analyzed and the energy-based target indices are compared. Performance comparisons are conducted on statistically calculated story/structural hysteretic energy and story/structural damage demands over realistic suites of earthquake ground motion records, representing seismic excitations of specific return period probability. Again, the semi-active solutions show significant promise for applications of resettable device, offering advantages over passive systems in the consistent damage reductions. The specific results of this study include the identification of differences in the mechanisms by which smart building isolation systems remove energy, based on the differences in the devices used. Less variability is also seen for the semi-active isolation systems, indicating an increased robustness.

关键词: smart building isolation     story and structural     energy-dissipation     damage assessment    

Aseismic smart building isolation systems under multi-level earthquake excitations: Part I, conceptual

Min-Ho CHEY,J. Geoffrey CHASE,John B. MANDER,Athol J. CARR

《结构与土木工程前沿(英文)》 2015年 第9卷 第3期   页码 286-296 doi: 10.1007/s11709-015-0307-9

摘要: As a novel structural control strategy, tuned mass damper (TMD) inspired passive and semi-active smart building isolation systems are suggested to reduce structural response and thus mitigate structural damage due to earthquake excitations. The isolated structure’s upper stories can be utilized as a large scaled TMD, and the isolation layer, as a core design point, between the separated upper and lower stories entails the insertion of rubber bearings and (i) viscous dampers (passive) or (ii) resettable devices (semi-active). The seismic performance of the suggested isolation systems are investigated for 12-story reinforced concrete moment resisting frames modeled as “10+ 2” stories and “8+ 4” stories. Passive viscous damper or semi-active resettable devices are parametrically evaluated through the optimal design principle of a large mass ratio TMD. Statistical performance metrics are presented for 30 earthquake records from the three suites of the SAC project. Based on nonlinear structural models, including P-delta effects and modified Takeda hysteresis, the inelastic time history analyses are conducted to compute the seismic performances across a wide range of seismic hazard intensities. Results show that semi-active smart building isolation systems can effectively manage seismic response for multi-degree-of freedom (MDOF) systems across a broader range of ground motions in comparison to uncontrolled case and passive solution.

关键词: tuned mass damper     smart building isolation     resettable device     non-linear     statistical assessment    

Variational mode decomposition based modal parameter identification in civil engineering

Mingjie ZHANG, Fuyou XU

《结构与土木工程前沿(英文)》 2019年 第13卷 第5期   页码 1082-1094 doi: 10.1007/s11709-019-0537-3

摘要: An out-put only modal parameter identification method based on variational mode decomposition (VMD) is developed for civil structure identifications. The recently developed VMD technique is utilized to decompose the free decay response (FDR) of a structure into to modal responses. A novel procedure is developed to calculate the instantaneous modal frequencies and instantaneous modal damping ratios. The proposed identification method can straightforwardly extract the mode shape vectors using the modal responses extracted from the FDRs at all available sensors on the structure. A series of numerical and experimental case studies are conducted to demonstrate the efficiency and highlight the superiority of the proposed method in modal parameter identification using both free vibration and ambient vibration data. The results of the present method are compared with those of the empirical mode decomposition-based method, and the superiorities of the present method are verified. The proposed method is proved to be efficient and accurate in modal parameter identification for both linear and nonlinear civil structures, including structures with closely spaced modes, sudden modal parameter variation, and amplitude-dependent modal parameters, etc.

关键词: modal parameter identification     variational mode decomposition     civil structure     nonlinear system     closely spaced modes    

Non-convex sparse optimization-based impact force identification with limited vibration measurements

《机械工程前沿(英文)》 2023年 第18卷 第3期 doi: 10.1007/s11465-023-0762-2

摘要: Impact force identification is important for structure health monitoring especially in applications involving composite structures. Different from the traditional direct measurement method, the impact force identification technique is more cost effective and feasible because it only requires a few sensors to capture the system response and infer the information about the applied forces. This technique enables the acquisition of impact locations and time histories of forces, aiding in the rapid assessment of potentially damaged areas and the extent of the damage. As a typical inverse problem, impact force reconstruction and localization is a challenging task, which has led to the development of numerous methods aimed at obtaining stable solutions. The classical 2 regularization method often struggles to generate sparse solutions. When solving the under-determined problem, 2 regularization often identifies false forces in non-loaded regions, interfering with the accurate identification of the true impact locations. The popular 1 sparse regularization, while promoting sparsity, underestimates the amplitude of impact forces, resulting in biased estimations. To alleviate such limitations, a novel non-convex sparse regularization method that uses the non-convex 12 penalty, which is the difference of the 1 and 2 norms, as a regularizer, is proposed in this paper. The principle of alternating direction method of multipliers (ADMM) is introduced to tackle the non-convex model by facilitating the decomposition of the complex original problem into easily solvable subproblems. The proposed method named 12-ADMM is applied to solve the impact force identification problem with unknown force locations, which can realize simultaneous impact localization and time history reconstruction with an under-determined, sparse sensor configuration. Simulations and experiments are performed on a composite plate to verify the identification accuracy and robustness with respect to the noise of the 12-ADMM method. Results indicate that compared with other existing regularization methods, the 12-ADMM method can simultaneously reconstruct and localize impact forces more accurately, facilitating sparser solutions, and yielding more accurate results.

关键词: impact force identification     inverse problem     sparse regularization     under-determined condition     alternating direction method of multipliers    

The research on structural damage identification using rough set and integrated neural network

Juelong LI, Hairui LI, Jianchun XING, Qiliang YANG

《机械工程前沿(英文)》 2013年 第8卷 第3期   页码 305-310 doi: 10.1007/s11465-013-0259-5

摘要:

A huge amount of information and identification accuracy in large civil engineering structural damage identification has not been addressed yet. To efficiently solve this problem, a new damage identification method based on rough set and integrated neural network is first proposed. In brief, rough set was used to reduce attributes so as to decrease spatial dimensions of data and extract effective features. And then the reduced attributes will be put into the sub-neural network. The sub-neural network can give the preliminary diagnosis from different aspects of damage. The decision fusion network will give the final damage identification results. The identification examples show that this method can simplify the redundant information to reduce the neural network model, making full use of the range of information to effectively improve the accuracy of structural damage identification.

关键词: rough set     integrated neural network     damage identification     decision making fusion    

核电站安全的地震威胁及对策分析

周福霖,谭平,刘德稳

《中国工程科学》 2013年 第15卷 第4期   页码 36-40

摘要:

核能是一种清洁高效的无碳能源,在人类文明进程及世界现代化发展中具有重要意义,但也存在核泄漏和核废料等问题。对世界核能利用情况及各国核电站建设与规划情况进行了回顾与展望,总结了历史上历次核电站事故发生的根本原因,着重探讨了地震对核电站的威胁。以2011年日本大地震造成的福岛核电站事故为例,分析了核电站事故对社会、经济及生态环境造成的影响,同时还提出了一些建议:对已建核电站进行抗震加固和延寿评估,做好未来核电站建设规划,改善管理机制,做好地震预警及核电站安全监测,优化应急处置机制,深化核能概率安全分析,普及群众安全教育,定期开展灾难演习,强化国际合作等举措,为人类在探索正确使用核能的进程中少受核能副作用的伤害而发挥重要作用。

关键词: 核电站     地震危险性     海啸     选址安全     隔震     消能     三维隔震    

新型SMA隔震支座动载性能试验研究

邓宗才,孙宏俊,刘春国,牛坤,邓洪亮

《中国工程科学》 2005年 第7卷 第12期   页码 61-68

摘要:

以提高SMA利用率为目的,设计了几种不同形式的SMA橡胶支座并进行了耗能试验。研究了水平位移幅值、水平加载频率以及竖向荷载等因素对SMA橡胶支座水平刚度、耗能量以及阻尼等基本力学性能的影响,结果表明,新型的SMA橡胶支座均可有效提高橡胶支座的耗能性能和回复能力,并为SMA橡胶支座优化设计提供了依据。

关键词: 形状记忆合金     隔震支座     初始刚度     滞回耗能     等效阻尼比    

Mechanical design, modeling, and identification for a novel antagonistic variable stiffness dexterous

《机械工程前沿(英文)》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0691-5

摘要: This study traces the development of dexterous hand research and proposes a novel antagonistic variable stiffness dexterous finger mechanism to improve the safety of dexterous hand in unpredictable environments, such as unstructured or man-made operational errors through comprehensive consideration of cost, accuracy, manufacturing, and application. Based on the concept of mechanical passive compliance, which is widely implemented in robots for interactions, a finger is dedicated to improving mechanical robustness. The finger mechanism not only achieves passive compliance against physical impacts, but also implements the variable stiffness actuator principle in a compact finger without adding supererogatory actuators. It achieves finger stiffness adjustability according to the biologically inspired stiffness variation principle of discarding some mobilities to adjust stiffness. The mechanical design of the finger and its stiffness adjusting methods are elaborated. The stiffness characteristics of the finger joint and the actuation unit are analyzed. Experimental results of the finger joint stiffness identification and finger impact tests under different finger stiffness presets are provided to verify the validity of the model. Fingers have been experimentally proven to be robust against physical impacts. Moreover, the experimental part verifies that fingers have good power, grasping, and manipulation performance.

关键词: multifingered hand     mechanism design     robot safety     variable stiffness actuator    

Damage identification in connections of moment frames using time domain responses and an optimization

《结构与土木工程前沿(英文)》 2021年 第15卷 第4期   页码 851-866 doi: 10.1007/s11709-021-0739-3

摘要: Damage is defined as changes to the material and/or geometric properties of a structural system, comprising changes to the boundary conditions and system connectivity, adversely affecting the system’s performance. Inspecting the elements of structures, particularly critical components, is vital to evaluate the structural lifespan and safety. In this study, an optimization-based method for joint damage identification of moment frames using the time-domain responses is introduced. The beam-to-column connection in a metallic moment frame structure is modeled by a zero-length rotational spring at both ends of the beam element. For each connection, an end-fixity factor is specified, which changes between 0 and 1. Then, the problem of joint damage identification is converted to a standard optimization problem. An objective function is defined using the nodal point accelerations extracted from the damaged structure and an analytical model of the structure in which the nodal accelerations are obtained using the Newmark procedure. The optimization problem is solved by an improved differential evolution algorithm (IDEA) for identifying the location and severity of the damage. To assess the capability of the proposed method, two numerical examples via different damage scenarios are considered. Then, a comparison between the proposed method and the existing damage identification method is provided. The outcomes reveal the high efficiency of the proposed method for finding the severity and location of joint damage considering noise effects.

关键词: damage identification     beam-to-column connection     time-domain response     optimization    

标题 作者 时间 类型 操作

Isolation, identification and primary application of bacteria from putrid alkaline silica sol

Lijie REN,Ye HAN,Shuwen YANG,Xiqian TAN,Jin WANG,Xin ZHAO,Jie FAN,Ting DONG,Zhijiang ZHOU

期刊论文

Innovative seismic retrofitting strategy of added stories isolation system

Min-Ho CHEY, J. Geoffrey CHASE, John B. MANDER, Athol J. CARR

期刊论文

H control in the frequency domain for a semi-active floor isolation system

Yundong SHI, Tracy C BECKER, Masahiro KURATA, Masayoshi NAKASHIMA

期刊论文

Isolation and application of predatory

Ran Yu, Shiwen Zhang, Zhoukai Chen, Chuanyang Li

期刊论文

Novel polymorphic EST-based microsatellite marker isolation and characterization from

Manosh Kumar BISWAS,Peng CHEN,Mohamed Hamdy AMAR,Xiuxin DENG

期刊论文

seismic response control on top of Three-Gorges ship lift towers using magnetorheological intelligent isolation

Weilian QU, Jianwei TU

期刊论文

Aseismic smart building isolation systems under multi-level earthquake excitations: Part II, energy-dissipation

Min-Ho CHEY,J. Geoffrey CHASE,John B. MANDER,Athol J. CARR

期刊论文

Aseismic smart building isolation systems under multi-level earthquake excitations: Part I, conceptual

Min-Ho CHEY,J. Geoffrey CHASE,John B. MANDER,Athol J. CARR

期刊论文

Variational mode decomposition based modal parameter identification in civil engineering

Mingjie ZHANG, Fuyou XU

期刊论文

Non-convex sparse optimization-based impact force identification with limited vibration measurements

期刊论文

The research on structural damage identification using rough set and integrated neural network

Juelong LI, Hairui LI, Jianchun XING, Qiliang YANG

期刊论文

核电站安全的地震威胁及对策分析

周福霖,谭平,刘德稳

期刊论文

新型SMA隔震支座动载性能试验研究

邓宗才,孙宏俊,刘春国,牛坤,邓洪亮

期刊论文

Mechanical design, modeling, and identification for a novel antagonistic variable stiffness dexterous

期刊论文

Damage identification in connections of moment frames using time domain responses and an optimization

期刊论文