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Building information modeling (BIM) can store a large amount of civil engineering information and has become a high-value economic and social resource. To improve BIM data interoperability, Industry Foundation Class (IFC) was proposed. However, the IFC instance data usually exceeds megabytes, and the logical relationship of the data is complex and changeable. Therefore, how to further enhance the usability of IFC instance data will become very important. To this end, this paper proposes a data deconstruction model 'Topological Induction Model (TIM)', which deconstructs the IFC instance data into a network structure 'Topological Induction Network (TIN)'. Through the analysis and operation of TIN, more effective utilization of IFC instance data can be realized. Based on TIN, the skeleton structure, citation structure and corresponding acquisition algorithm of IFC instance data are discussed, and the hierarchical characteristic, internal aggregation characteristic and data similarity of data topology are found. Subsequently, the working performance of TIM (TIN) is evaluated and compared with existing data deconstruction strategies. The results show that the overall performance of TIM (TIN) is better than traditional methods. Finally, we show how TIM (TIN) can be used in a graph database to enhance the usability of IFC instance data. [ABSTRACT FROM AUTHOR]

Building Information Modeling (BIM) has attracted much attention as a vital information method in civil engineering. BIM data research has become increasingly important with the continuous understanding of BIM. The database designed especially for storing BIM data (IFC data) is called a BIM database. To realize centralized storage and sharing of complex building information, how to design and develop a BIM database will be a hot topic. However, the BIM database designed using an existing logical model (such as a relational model) is unsuitable for storing and managing a large amount of BIM data. To this end, we propose a database logical model for BIM database development called 'logical object structure'. Based on the database design methodology, the logical schema of the BIM database is discussed, and five relation forms are established to describe the feature of engineering information. According to the relation forms, the logical object structure is presented, and the corresponding system implementation process is discussed. Finally, four workloads are set to test the logical object structure. The results show that the logical object structure can well support interactive behaviors of BIM data and provide good performance for the BIM database. [ABSTRACT FROM AUTHOR]

In confronting the urgent challenges within the realm of international development, it has become imperative to explore novel pathways for economic growth, diminish the income disparity among diverse societal segments, and alleviate the discrepancies between urban and rural regions. However, previous research has yet to comprehensively investigate whether information infrastructure holds the potential to narrow the urban-rural development gap. Furthermore, the distinctive contributions of traditional infrastructure and information infrastructure to economic development have been insufficiently explored and compared. Drawing upon data from the China Household Panel Study (CFPS) spanning the period 2010–2018, this study extensively examines the role and advantages of information infrastructure in bridging the urban-rural development gap. By employing the fixed effect model and employing the ‘Broadband China’ strategy as a proxy variable for information infrastructure enhancement, the study reveals that the improvement of information infrastructure significantly amplifies the total income of Chinese households, with a pronounced impact in rural areas. The emergence of a ‘catch-up effect’ serves to diminish the income disparity between urban and rural areas. Moreover, when contrasted with contemporaneous investments in traditional infrastructure, which have reached a state of relative saturation in China, the positive effect of information infrastructure upgrading surpasses that of traditional infrastructure investment. Hence, upgrading information infrastructure effectively addresses the imbalances in urban and rural development and narrows the income gap. These findings carry considerable implications for government bodies in formulating development policies. [ABSTRACT FROM AUTHOR]

Two new open-chain cytochalasins, xylarchalasins A and B (1 and 2), together with six known analogues (3-8), were isolated from the endophytic fungus Xylaria sp. GDGJ-77B from the Chinese medicinal plant Sophora tonkinensis. Their structures were elucidated on the basis of comprehensive spectroscopic analysis. Compound 2 displayed moderate antibacterial activities against Bacillus subtilis and Escherichia coli with MIC values of 25 and 12.5 μg/mL, respectively. [ABSTRACT FROM AUTHOR]

The earthquake usually causes multi-dimensional vibration for the large span grid structure, how to effectively isolate and mitigate the vibration response of structure is an important problem in engineering. In this paper, a novel viscoelastic bio-inspired multi-dimensional vibration isolation (VBM-VI) device is proposed under the inspiration of bionic design of the bird legs, which possesses multi-dimensional vibration isolation performance by constituting of viscoelastic core pad and VE-LLS device together. The property experiment of the VBM-VI device is performed to explore the mechanical performance at vertical and horizonal directions, the hysteretic curves and characteristic parameters are discussed to reveal the influence of the excitation frequency and amplitude on the mechanical properties of the VBM-VI device, the experimental results show that the mechanical properties express significant frequency and amplitude dependence at vertical and horizontal directions. To further describe the mechanical proprieties of the VBM-VI device, the mathematical models are established at vertical and horizontal directions respectively, and the comparison analysis between experimental and theoretical results indicates that the established mathematical models can precisely describe mechanical performance of the VBM-VI device. [ABSTRACT FROM AUTHOR]

Type I diabetes is a metabolic syndrome that severely impacts the normal lives of patients through its multiple complications, such as diabetic cardiomyopathy (DCM). Phoenixin-14 is a peptide found to be widely expressed in eukaryons with multiple protective properties, including anti-oxidative stress and anti-inflammatory effects. The present study aims to explore the potential therapeutic impacts of Phoenixin-14 on DCM. Type I diabetes was induced by treatment with a single dose of STZ (40 mg/kg body weight) intraperitoneally for 5 consecutive days. Mice were divided into four groups: the Control, Phoenixin-14, T1DM, and Phoenixin-14 +T1DM groups. The levels of myocardial injury markers were measured. Cardiac hypertrophy was assessed using wheat germ agglutinin (WGA) staining. Phoenixin-14 was significantly downregulated in the cardiac tissue of diabetic mice. The myocardial injury and deteriorated cardiac function in diabetic mice induced by STZ were significantly ameliorated by Phoenixin-14, accompanied by the alleviation of cardiac hypertrophy. In addition, the severe oxidative stress and inflammation in diabetic mice were dramatically mitigated by Phoenixin-14. Lastly, the downregulated SIRT3 and upregulated p-FOXO3 in diabetic mice were pronouncedly reversed by Phoenixin-14. It is worth mentioning that compared to the Control, no significant changes to any of the investigated parameters in the present study were found in the Phoenixin-14-treated normal mice, suggesting that treatment with it has no side effects. Our data revealed that Phoenixin-14 protected against cardiac damages in STZ-induced diabetes mice models. [ABSTRACT FROM AUTHOR]

Based on the low cost and superior damping performance of viscoelastic dampers, the new structural system strengthened with viscoelastic energy dissipation braces (VEDB) is proposed to upgrade the reinforced concrete frame structures with insufficient seismic capability. For the dynamic performance researches and damage evolution predictions of this structure system during earthquakes, the dynamic performance of six RCFs (reinforced concrete frames) and six VEFs (another six special reinforced concrete frames with VEDB) are studied under sinusoidal wide frequency range loading excitation horizontally. On this basis, the qualitative and quantitative relations on the damage growing at the material-level and the member-level performance deteriorating about the frame structures are conducted. Furthermore, the empirical calculation model on the cross-level damage evolution of VEFs are established and verified. Finally, a set of useful and robust cross-level judgment criteria for damage performance rates is proposed. The research found that, the installation of VEDB can significantly improve the load bearing capacity, the lateral stiffness and the energy dissipation capacity of the structures. The damage pattern of the structures is improved by VEDB, and it ensures the design criteria of "strong joints and weak members." The empirical calculation model on the cross-level damage evolution and judgment criteria for damage performance rates proposed in this paper are useful and stable in practical engineering. [ABSTRACT FROM AUTHOR]

High endothelial venules (HEV) and tertiary lymphoid structures (TLS) are associated with clinical outcomes of patients with colorectal cancer (CRC). However, because HEV are components of TLS, there have been few studies of the role of the HEV proportion in TLS (HEV/TLS). This study investigated the role of the HEV/TLS and its relationship with the tumor immune microenvironment in CRC. A retrospective analysis of 203 cases of tissue pathologically diagnosed as CRC after general surgery was performed at the First Affiliated Hospital of Jinan University from January 2014 to July 2017. Paraffin sections were obtained from the paracancerous intestinal mucosal tissues. The area of HEV and TLS and immune cells were detected by immunohistochemistry. We further divided the positive HEV expression group into the high HEV/TLS group and the low HEV/TLS group by the average area of HEV/TLS. After grouping, the data were also analyzed using the chi-square test, Kaplan-Meier method, and univariate and multivariate Cox proportional risk regression analyses. A correlation analysis of the HEV/TLS and immune cells as well as angiogenesis was performed. Patients with a high HEV/TLS in CRC tissue were associated with longer OS, DFS and lower TNM stage. Meanwhile, CRC tissue with a high HEV/TLS showed a greater ability to recruit the CD3+ T cells, CD8+ T cells and M1 macrophages and correlated with less angiogenesis. Conclusively, high HEV/TLS links to the favorable prognosis of CRC patients and correlated with anti-tumor immune microenvironment, which can be a potential biomarker for prognosis of CRC patients. A high HEV/TLS is associated with a favorable prognosis for CRC and is correlated with the anti-tumor immune microenvironment. Therefore, it is a potential biomarker of the CRC prognosis. High HEV/TLS is associated with a favorable prognosis for CRC. High HEV/TLS correlated with the anti-tumor immune microenvironment of CRC and can serve as a novel prognostic biomarker. [ABSTRACT FROM AUTHOR]

To expand the inclusiveness of hybrid test platform research, enhance the flexibility of hybrid test platforms using various control strategies, and promote the development of hybrid test techniques, a low-cost user-configurable electric actuator hybrid test platform is established in this paper. This platform can be transferred to other medium or large electric actuator hybrid test platform, the research applications of this platform cannot be limited by their proposed setup. Firstly, the hardware system design including hybrid test facility integrated control system core architecture and all related signal routings are carried out. Then, the improved equivalent force control feedback method based on force-loading control is proposed, and the software system development including hybrid test process control system software and user-configurable STM32 microcontroller (UCSM) software are conducted. Next, the mechanical performance of viscoelastic damper is tested, and the mechanical model parameters of viscoelastic damper are regressed. The accuracy of electric actuator force control (inner control loop), of which the control tasks get executed on the UCSM is verified using the experimental substructure of viscoelastic damper. The hybrid test of viscoelastic damping system verifies the reliability and robustness of hybrid test platform (outer control loop). Finally, the developed hybrid test platform implements various hybrid tests of viscoelastic damping system under broad temperature range and different seismic intensities. The test results reveal the influence of temperature and seismic intensities on the seismic control effect of viscoelastic damper. [ABSTRACT FROM AUTHOR]

The bionics design method has been proverbially applied at vibration control field, and how to make bionic vibration control device possess excellent mechanical property and stable energy dissipation capacity is an important subject. In this paper, a bionic viscoelastic limb-like-structure (VE-LLS) device is proposed in conjunction with the viscoelastic (VE) damper and the limb-like-structure (LLS) device together, and the proposed device simultaneously possesses excellent mechanical propriety and energy dissipation capacity. Firstly, the mechanical property test of the VE-LLS device is conducted to investigate the effect of ambient temperature, excitation amplitude and frequency on its dynamic mechanical property and energy dissipation capacity. The energy dissipation contribution caused by the LLS joint friction for the VE-LLS device is discussed. Then, the energy dissipation model of the VE-LLS device is established by simultaneously considering the viscoelastic and friction factors, and the comparison result indicates that the established energy dissipation model can accurately describe the energy dissipation capacity of the VE-LLS device under different ambient temperature, exaction amplitude and frequency. Finally, to further promote the stability of energy dissipation capacity of the VE-LLS device at different temperature and frequency, an energy dissipation compensation strategy is proposed by increasing the energy dissipation of the LLS joint friction to compensate for the energy dissipation attenuation of the VE damper caused by high temperature and low frequency, and the results shows that the compensation strategy expresses excellent effect for the energy dissipation stability of the VE-LLS device. [ABSTRACT FROM AUTHOR]

This paper investigates a structure system that expresses stable and controllable quasi-zero stiffness in an integrated form, which is based on inclined bistable beams connected in series. This paper shows that interaction between the connected beams and their nonlinear axial stiffness always leads to a plateau trajectory in its force-displacement curve with very low tangential stiffness. The plateau part of the force-displacement occurs while each of the connected beam snaps through sequentially and ends when all of the beams are going though hardening behavior. A series of tests were conducted to validate this behavior. A numerical model capable of predicting the behavior is developed. Studies were performed based on the model for this kind of structure with different geometric configuration and details of coupling links. The results show that in addition to being able to achieve quasi-zero stiffness of an integrated structures, this kind of structure has increased initial stiffness and loading capacity compared with traditional bistable structures subjected to similar limitations of extreme strains. [ABSTRACT FROM AUTHOR]

Micro structures of viscoelastic materials (VEM) play an important role in their mechanical properties and energy dissipation capacities. This work shows a mathematical modeling of VEMs considering molecular chain-network configurations, and the temperature effects on mechanical properties of VEMs can also be characterized based on the equivalent relationship between temperature and frequency. The Dynamic Thermomechanical Analyzer (DMA) test is carried out to observe dynamic behaviors of the VEM and prove the accuracy of the proposed new mathematical model. The experimental data of viscoelastic damper (VED) are utilized to further verify the correctness of the proposed model with different ambient temperatures. [ABSTRACT FROM AUTHOR]

Context: Keguan-1 (KG-1) plays a vital role in enhancing the curative effects, improving quality of life, and reducing the development of acute lung injury (ALI). Objective: To unravel the protective effect and underlying mechanism of KG-1 against ALI. Materials and methods: C57BL/6J mice were intratracheally instilled with lipopolysaccharide to establish the ALI model. Then, mice in the KG-1 group received a dose of 5.04 g/kg for 12 h. The levels of proinflammatory cytokines, chemokines, and pathological characteristics were determined to explore the effects of KG-1. Next, untargeted metabolomics was used to identify the differential metabolites and involved pathways for KG-1 anti-ALI. Network pharmacology was carried out to predict the putative active components and drug targets of KG-1 anti-ALI. Results: KG-1 significantly improved the levels of TNF-α (from 2295.92 ± 529.87 pg/mL to 1167.64 ± 318.91 pg/mL), IL-6 (from 4688.80 ± 481.68 pg/mL to 3604.43 ± 382.00 pg/mL), CXCL1 (from 4361.76 ± 505.73 pg/mL to 2981.04 ± 526.18 pg/mL), CXCL2 (from 5034.09 ± 809.28 pg/mL to 2980.30 ± 747.63 pg/mL), and impaired lung histological damage. Untargeted metabolomics revealed that KG-1 significantly regulated 12 different metabolites, which mainly related to lipid, amino acid, and vitamin metabolism. Network pharmacology showed that KG-1 exhibited anti-ALI effects through 17 potentially active components acting on seven putative drug targets to regulate four metabolites. Discussion and conclusions: This work elucidated the therapeutic effect and underlying mechanism by which KG-1 protects against ALI from the view of the metabolome, thus providing a scientific basis for the usage of KG-1. [ABSTRACT FROM AUTHOR]

Three new andrastin derivatives, 10-formyl andrastone A (1), 10-demethylated andrastone A (2) and andrastin G (3), together with four known andrastin analogues (4-7) were isolated from an endophytic fungus Penicillium vulpinum. Their structures were determined by 1 D, 2 D NMR, and the absolute configurations were further determined by experimental and calculated ECD spectra. Compound 5 exhibited significant antibacterial activity against Bacillus paratyphosus B with an MIC value of 6.25 µg·mL−1. Compounds 2 and 6 showed remarkable inhibitory activities against Bacillus megaterium with the MIC value of 6.25 µg·mL−1, respectively. [ABSTRACT FROM AUTHOR]

In present work, the three-dimensional constitutive equations considering hygrothermal conditions are derived firstly, and governing equations are established subsequently. Then the finite difference method and Newmark method are used to solve the hygrothermal dynamic equations in both space and time domains, respectively. Finally, the effects of moist coefficient, fiber type and fiber arrangement angle on the hygrothermal dynamic behaviors for the FML structures are analyzed. The amplitude of the normal stress for the FML structures increase with the increasing of the moist coefficient, which can be attributed to fact that the fiber materials (S2-glass fiber epoxy resin and glass-polymer) absorb more water and the volume expand greater when increasing the moist coefficient firstly, then the normal strain and normal stress of the FML structures increase subsequently. And for two different FML structures (one only considering S2-glass fiber epoxy resin for fiber layer and the other only considering glass-polymer) with the same workpiece sizes, the former FML structure has the better capability to resist deformation in the in-plane displacement as the S2-glass fiber epoxy resin is of greater density and mass than that of glass-polymer. The deflection profile of the 0°/45° fiber orientation is most affected when the temperature is high, both the fiber orientation and laminated interaction between the layers are two important factors determining the order of magnitude for normal stress. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the functional characteristics of mesenchymal stromal cells (MSCs) from a sheep model of traumatic temporomandibular joint (TMJ) fibrous and bony ankylosis. A sheep model of bilateral TMJ trauma-induced fibrous ankylosis on one side and bony ankylosis on the contralateral side was used. MSCs from fibrous ankylosed callus (FA-MSCs) or bony ankylosed callus (BA-MSCs) at weeks 1, 2, 4, and 8 after surgery were isolated and cultured. MSCs derived from the bone marrow of the mandibular condyle (BM-MSCs) were used as controls. The MSCs from the different sources were characterized morphologically, phenotypically, and functionally. Adherence and trilineage differentiation potential were presented in the ovine MSCs. These cell populations highly positively expressed MSC-associated specific markers, namely CD29, CD44, and CD166, but lacked CD31 and CD45 expressions. The BA-MSCs had higher clonogenic and proliferative potentials than the FA-MSCs. The BA-MSCs also showed higher osteogenic and chondrogenic potentials, but lower adipogenic capacity than the FA-MSCs. In addition, the BA-MSCs demonstrated higher chondrogenic, but lower osteogenic capacity than the BM-MSCs. Our study suggests that inhibition of the osteogenic and chondrogenic differentiations of MSCs might be a promising strategy for preventing bony ankylosis in the future. [ABSTRACT FROM AUTHOR]

Induction of host resistance is commonly considered to be the most effective disease control strategy, but no cultivar has yet been bred to effectively manage tobacco bacterial wilt. An alternative tactic is to induce host-acquired resistance against the pathogen, Ralstonia solanacearum. In this study, tobacco-acquired resistance was induced by an exopolysaccharide (EPS) fructan produced by Paenibacillus kribbensis PS04, and disease severity was reduced in pot trials. The photosynthetic pigment and leaf carbohydrate contents in tobacco leaves verified that tobacco scorch symptoms disappeared under the action of EPS. Further, when the malondialdehyde (MDA) content declined by two-thirds, lipid peroxidation was eliminated. Compared to the untreated control, the contents of non-enzymatic antioxidants, ascorbate (AsA) and glutathione (GSH), rose by 69% and 64%, respectively; while the activities of defense enzymes, superoxide dismutase (SOD) and peroxidase (POD), were enhanced by 22% and 82%, respectively, at the end of leaf sampling. This evidence was further supported by native PAGE on isoforms of SOD and POD. The results of this study demonstrate that tobacco-acquired resistance can be triggered by the EPS produced by P. kribbensis PS04. [ABSTRACT FROM AUTHOR]

The sorption potentials of two soil colloids and fine powder kaolinite for Pb(II) and Cu(II) were analyzed, and the effects of pH, ionic strength and organic matter on the sorption were invetigated. The two soil colloids and fine powder kaolinite were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis. Black soil had more mineral compositions and surface functional groups. The sorption was pH-dependent. In the presence of humic acid, the adsorption of Pb(II) and Cu(II) ions on soil was increased, while the increase in ionic strengths decreased the adsorption. Sorption kinetics and isotherms of Pb(II) and Cu(II) onto three soil colloids were well fitted with Pseudo-second-order model and Langmuir model/Freundlich model. Black soil had the highest sorption capacity of Pb(II) (44.287 mg g−1) and Cu(II) (11.109 mg g−1), followed by red soil (9.764 and 4.152 mg g−1) and kaolinite (7.612 and 3.064 mg g−1). The two metals competed with each other during sorption. [ABSTRACT FROM AUTHOR]

The complete mitogenome sequence of the lesser bandicoot rat (Bandicota bengalensis Gray and Hardwicke, 1833) was determined using long PCR. The genome was 16,327 bp in length and contained 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, 1 origin of L strand replication and 1 control region. The overall base composition of the heavy strand is A (34.2%), C (24.9%), T (28.5%) and G (12.4%). The base compositions present clearly the A–T skew, which is most obviously in the control region and protein-coding genes. Mitochondrial genome analyses based on MP, ML, NJ and Bayesian analyses yielded identical phylogenetic trees. This study verifies the evolutionary status of Bandicota bengalensis in Muridae at the molecular level. The mitochondrial genome would be a significant supplement for the Bandicota bengalensis genetic background. The two Bandicota species formed a monophyletic group with the high bootstrap value (100%) in all examinations. [ABSTRACT FROM AUTHOR]

This article presents a coordinated control scheme enabling the voltage source converter-based high-voltage direct current (VSC-HVDC) transmission system connected offshore wind farm to provide frequency response. Once the onshore system frequency deviates, the proposed control strategy will be activated so that both the wind farm and the VSC-HVDC can work together to provide frequency support. In this approach, each wind turbine should operate in de-loading mode to acquire reserve under normal condition. On detecting the frequency event, not only the reserve and kinetic energy of each wind turbine can be utilized for frequency regulation by adjusting rotor speed, but the DC capacitor installed in the VSC-HVDC is arranged to participate in frequency control by slightly changing the DC-link voltage as well. The superior performance of the proposed control method has been verified by simulation. [ABSTRACT FROM AUTHOR]

The growing integration of renewable energy sources, especially the residential photovoltaic (PV) systems, in the distribution networks (DNs) aggravates the ramp-events in transmission system. To address this issue, we propose a novel look ahead dispatch model for the ramp minimization in DNs using distributed energy storage systems (ESSs). The dispatch problem considering the scheduling of ESSs is modeled as a finite-horizon optimization problem and is carried out using model predictive control (MPC) method that takes both current and future information into account. In addition, the optimal power flow in DN is formulated as a second-order cone programing problem to guarantee the global optimality. Numerical results on IEEE 37-bus distribution network show that our proposed model not only brings about 74% reduction of maximum ramp but also yields the near-minimum system operating cost. [ABSTRACT FROM AUTHOR]

Different contents of expanded graphite (EG) composite phase change material (PCM) were prepared by the melt mixing method, taking paraffin as the PCM and EG as the supporting material. Phase compositions of EG, paraffin, and EG/paraffin composite were investigated using X-ray diffraction (XRD). Microstructures of EG and EG/paraffin composite PCMs with different EG contents were observed by a scanning electron microscope (SEM). Thermal properties, such as phase-transition temperature and latent heat of the materials, were determined by differential scanning calorimetry (DSC). Mass loss and thermal properties after 100 heating cycles were measured. The results show that physical absorption exists between paraffin and EG. EG is beneficial for the PCM composite to reduce leakage of paraffin, decrease the phase change temperature and latent heat, and strengthen the thermal stability. The solid-liquid phase change latent heat of materials is larger than that of the solid-solid one. The heating cycle has little effect on the phase-transition temperature and latent heat. [ABSTRACT FROM AUTHOR]

This paper proposes a coordinated DC-link voltage control and deloading control for two-stage PV system to offer frequency support in an islanded microgrid without energy storage system(ESS). The energy stored in the DC-link capacitor is utilized to emulate inertia response, which has an important implication on enhancing system inertia, since PV systems are equipped with power-electronic converter and have no natural inertia response. At the same time, a certain of power margin is reserved by increasing dc voltage of PV array, which provides PV system the ability to participate in primary frequency control. Simulations are conducted in DIgSILENT/ PowerFactory and results show that the proposed strategy is effective in improving the dynamic behavior of system frequency. [ABSTRACT FROM AUTHOR]

To ensure the proper operation of power system, some independent system operators have specified that wind power plants should be able to manipulate power output for frequency control. This article presents a combined control scheme which exploits the self-capability of permanent magnet synchronous generator-based wind turbine to provide primary frequency response. Under normal condition, the wind turbine operates in de-loading mode to obtain the power reserve. Once frequency deviation is detected, the proposed control strategy can not only make use of the power reserve for frequency regulation by adjusting the rotor speed, but utilize the kinetic energy in rotor to provide frequency response as well. Besides, the energy stored in DC capacitor is also employed for frequency support. The simulation results reveal that the wind turbines with the proposed method can improve frequency performance under both constant wind speed condition and variable wind speed condition. [ABSTRACT FROM AUTHOR]

Uncontrolled network separation (system island formation) is one of the most critical contingencies in power systems. The integrity of the whole power transmission network is a prerequisite for reliable system operation. Therefore, in order to safeguard the system operation and control, it is imperative to quickly identify the topological changes, especially the formation of system islands. In this paper, we developed a spectral clustering-based approach to efficiently detect the existing or the potential network islands. The core of this approach is a graph-algebraic model, which combines the real-power deliverability and topological information of a power transmission network. Based on an improved spectral clustering algorithm, the proposed approach can efficiently identify the critical situations of the network splitting under multiple line outages. This approach has been successfully tested by using the New England 39-bus and 118-bus systems under different scenarios. [ABSTRACT FROM AUTHOR]

Abstract The behavior of a coned disk spring can be significantly affected by friction or restraint, yet the existing theoretical solutions cannot fully capture these influences. The limitation is particularly problematic for analyzing the behavior of coned disk springs with bi-stability. This paper proposes an explicit solution that can predict the behavior of the coned disk spring under these boundary conditions. The solution considers detailed influences of friction and restraint at the edges of the coned disk spring on its moment equilibrium and location of the neutral fiber. The theoretical results are validated using existing literature, FE analysis, and a series of tests. The theoretical solution confirms that the friction force at the edge of the coned spring significantly affects the axial response of the spring but not its bending moment or distribution of tangential stress. The bending moment and overall behavior of the coned disk spring are, on the other hand, very sensitive to restraints in radial directions. The proposed explicit solution shows good accuracy for coned disk springs with restrained radial stretching and rotation. The solution is particularly useful for coned disk springs in multistable structures and metamaterials. [ABSTRACT FROM AUTHOR]

This paper proposes a novel control strategy for converter stations of multi-terminal DC (MTDC) grid system. It optimizes the offshore wind farms power generation dispatched to the separate onshore AC systems while minimizing their impacts on AC grids. Based on the MTDC power flow analysis, the minimal control dimensions of MTDC converters are firstly proposed. The impact of DC resistances on power dispatching among MTDC grid is then fully discussed by analyzing the structure of inverse Jacobian matrix of MTDC grid power flow equation and the power dispatch law for each onshore AC grid is deduced subsequently. Finally, an optimization strategy that seeks to re-dispatch the power to each onshore converter according to the system inertia of connected AC grid is proposed. Case study using a typical five-terminal MTDC system shows that the proposed strategy can effectively mitigate wind power fluctuations by approximately equalizing the induced disturbances to the system frequency of each AC grid. [ABSTRACT FROM AUTHOR]

This paper proposes a coordinated control strategy to provide system frequency support for separated main grids from offshore wind farms (WFs) that are integrated through multi-terminal DC (MTDC) system. The control strategy consists of two control loops including the MTDC frequency regulation loop (FRL) and the automatic WF power regulation loop (AWFPRL). In events of AC main grid disturbances, the former can re-dispatch MTDC grid power flow to support system frequency, while the latter can adjust wind power output accordingly through the variable frequency control of WF-connected converters. Inertia energy stored in wind turbines can be utilized to stabilize system frequency via MTDC grids. Moreover, wind power fluctuations can also be smoothed by the proposed control. An expression of frequency response coefficient is calculated, which is used to quantify the contribution of frequency support from offshore WF-connected MTDC system. Case studies have been conducted to demonstrate the effectiveness of the proposed control strategy using a four-terminal DC grid. [ABSTRACT FROM AUTHOR]

Hybrid simulation is an advanced structural dynamic experimental method that combines experimental physical models with analytical numerical models. It has increasingly been recognised as a powerful methodology to evaluate structural nonlinear components and systems under realistic operating conditions. One of the barriers for this advanced testing is the lack of flexible software for hybrid simulation using heterogeneous experimental equipment. In this study, an electrodynamic fatigue test machine is made and a MATLAB program is developed for hybrid simulation. Compared with the servo-hydraulic system, electrodynamic fatigue test machine has the advantages of small volume, easy operation and fast response. A hybrid simulation is conducted to verify the flexibility and capability of the whole system whose experimental substructure is one spring brace and numerical substructure is a two-storey steel frame structure. Experimental and numerical results show the feasibility and applicability of the whole system. [ABSTRACT FROM AUTHOR]

Effective building/house energy management has been considered as an efficient way to mitigate the fluctuation of renewable energy in power distribution system. This article studies the operation scheduling problem for microgrid with high penetration of solar power and thermostatically controlled loads. Based on the established photovolaic model and thermostatically controlled load model, an optimal operation strategy for microgird is proposed. The scheme is based on the rolling horizon optimization strategy, where the control window continues to proceed with the update of real-time information, aiming to minimize the total operation costs over the current control window. Differential evolution algorithm is used to solve the proposed model, and the simulation results validate the efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

The temperature adaptation of zooplankton is fundamental to determining their distribution and assessing the likelihood of changes in both the distribution of individual species and the community structure that may occur due to climate change. The reciprocal quadratic, a yield-density model, was used to predict the optimal temperature for 21 copepod species from empirical data. The data for the modelling were collected during four surveys in the East China Sea (23°30′~ 33°N, 118°30′~ 128°E) from 1997 to 2000. The present study indicates that the proposed model is suitable for predicting the relationship between temperature and the abundance of copepods. The response curves of the copepod species to temperature were varied. Among the 21 copepod species, eight with an optimal temperature above 25°C were considered tropical species, while the remaining 13 species, with an estimated optimal temperature between 20 and 25°C, were considered subtropical species. Additionally, the dominant copepod species e.g.Euchaeta concinna,Undinula vulgarisandSubeucalanus subcrassus, with intermediate or narrow peak patterns, were generally sensitive or moderately sensitive to temperature changes. Estimating the optimal temperature and thermal sensitivity of copepod species would be helpful in understanding the species-specific response to climate change. [ABSTRACT FROM AUTHOR]

A novel configuration for offshore wind farms based on variable-speed permanent magnet synchronous generator integration via high-voltage DC transmission is proposed. Each permanent magnet synchronous generator is equipped with a full-bridge diode rectifier and a DC/DC boost chopper, which constitutes a cascaded submodule. Quite a number of submodules are series-parallel connected to form a DC collector system for the offshore wind farm. Any unit that needs maintenance or that undergoes fault in a series-connected branch can be isolated from the system by the natural commutated process without influencing other normal units in the same branch. The proposed submodule has several prominent features, such as low cost, low power loss, and simple control strategy. A maximum power point tracking algorithm of each wind turbine is realized by controlling the current through the inductor of each DC/DC boost circuit in one submodule. The proposed topology and control strategy are verified by simulations in Power Systems Computer Aided Design/Electromagnetic Transients including Direct Current (PSCAD/EMTDC; Manitoba HVDC Research Centre, Manitoba, Canada). [ABSTRACT FROM AUTHOR]

China experienced a rapid economic growth in the past few decades, whereas it has been facing a critical environmental situation. It is palpable that creating a sustainable energy structure in China is urgently required. As reported in China's 12th Five-year (2011–2015) Plan (which is a five-year development plan that outlines the development focus and strategic plan for different sectors in the next five-year period, published by the State Council of the PRC every five years), integrating more renewable energy, especially from solar and wind sources, becomes an essential part of their smart grid development. This article comprehensively reviews the existing achievements of renewable technology development and current status including relevant policies from central government and some on-going demonstration projects. Promoting new energy vehicles (e.g., electric vehicles) as an effective way of reducing carbon emissions is addressed in this article as well. Finally, the difficulties at the current stage are analyzed and future trends for a subsequent phase of development are also outlined. [ABSTRACT FROM AUTHOR]

The problem of comparing the means of two lognormal distributions based on samples with multiple detection limits is considered. Tests and confidence intervals for the ratio of the two means, based on pivotal quantities involving the maximum likelihood estimators, are proposed. The merits of the proposed approaches are evaluated by Monte Carlo simulation. Simulation study indicates that the procedures are satisfactory in terms of coverage probabilities of confidence intervals, and powers of tests. The proposed approach can also be applied to find confidence intervals for the difference between the means of the two lognormal distributions. Illustrative examples with a real data set and with a simulated data set are given. [ABSTRACT FROM AUTHOR]

In the smart grid environment, a power system restoration plan with flexibility is needed to improve reliability and efficiency in an automated way. Traditional system restoration methods based on fixed time intervals may not meet the requirement. This article proposes a new permutation-based model for power system restoration within an optimized flexible duration considering available generator capability and load prioritization. By utilizing this new model, power system restoration is formulated as a permutation-based combinatorial optimization problem to maximize the restored load per unit time. Finally an action-by-action flexible time schedule is obtained for generator startup. A novel quantum-inspired evolutionary algorithm, called the quantum-inspired differential evolutionary algorithm, has been applied to solve this problem due its to high population diversity and fast convergence. The effectiveness of the proposed restoration approach has been validated using IEEE 39- and 57-bus systems. [ABSTRACT FROM PUBLISHER]

China's 12th Five-Year Plan (2011–2015) identifies smart grid development as a national priority in the energy sector. It is expected that through development of a strong smart grid across the nation, overall power grid security and efficiency can be largely improved and significant growth of relevant industrial sectors can be achieved. Consequently, different research and development programs are taking place, many of which have pilot activities involved to validate and demonstrate the technical and social–economic effectiveness of new technologies. This article gives an overview of the governmental policy and strategy that drives smart grid development, followed by detailed descriptions of research activities with respect to the implementation of China's smart grid vision. Based on the analysis and evaluation of difficulties and problems in the current system, the remaining gaps are identified for future activities to enable a smooth transition toward a strong and smart power grid in China. [ABSTRACT FROM PUBLISHER]

The West Junggar lies in the southwest part of the Central Asian Orogenic Belt (CAOB) and consists of Palaeozoic ophiolitic mélanges, island arcs, and accretionary complexes. The Barleik ophiolitic mélange comprises several serpentinite-matrix strips along a NE-striking fault at Barleik Mountain in the southern West Junggar. Several small late Cambrian (509–503 Ma) diorite-trondhjemite plutons cross-cut the ophiolitic mélange. These igneous bodies are deformed and display island arc calc-alkaline affinities. Both the mélange and island arc plutons are uncomfortably covered by Devonian shallow-marine and terrestrial volcano-sedimentary rocks and Carboniferous volcano-sedimentary rocks. Detrital zircons (n = 104) from the Devonian sandstone yield a single age population of 452–517 million years, with a peak age of 474 million years. The Devonian–Carboniferous strata are invaded by an early Carboniferous (327 Ma) granodiorite, late Carboniferous (315–311 Ma) granodiorites, and an early Permian (277 Ma) K-feldspar granite. The early Carboniferous pluton is coeval with subduction-related volcano-sedimentary strata in the central West Junggar, whereas the late Carboniferous–early Permian intrusives are contemporary with widespread post-collisional magmatism in the West Junggar and adjacent regions. They are typically undeformed or only slightly deformed. Our data reveal that island arc calc-alkaline magmatism occurred at least from middle Cambrian to Late Ordovician time as constrained by igneous and detrital zircon ages. After accretion to another tectonic unit to the south, the ophiolitic mélange and island arc were exposed, eroded, and uncomfortably overlain by the Devonian shallow-marine and terrestrial volcano-sedimentary strata. The early Carboniferous arc-related magmatism might reflect subduction of the Junggar Ocean in the central Junggar. Before the late Carboniferous, the oceanic basins apparently closed in this area. These different tectonic units were stitched together by widespread post-collisional plutons in the West Junggar during the late Carboniferous–Permian. Our data from the southern West Junggar and those from the central and northern West Junggar and surroundings consistently indicate that the southwest part of the CAOB was finally amalgamated before the Permian. [ABSTRACT FROM AUTHOR]

Methods to predict the temperature field of a steel-concrete composite structure under fire conditions have been developed using different mathematical techniques. But, one of the drawbacks of these approaches is ignoring the effect of thermal contact resistance at the steel-concrete interface. The main object of the research in this article is the thermal contact resistance at steel-concrete interface of concrete-filled steel tubular (CFST) columns with circular cross-section. In order to obtain the temperature field of the columns under fire conditions, two circular steel tubes filled with normal weight concrete were used to measure the temperatures at some selected points. To obtain the solution of the governing equation for one-dimensional transient heat conduction problems by applying Laplace transformation and inverse Laplace transformation, the selected points temperatures are described as polynomial series or piecewise polynomial series of time. According to Fourier's law and Newton's law of cooling, the thermal contact resistance is obtained. The temperatures calculated for some representative problems show good agreement with the experimental results. The proposed approach can be applied to predict the thermal contact resistance. [ABSTRACT FROM PUBLISHER]

A rapid and precise continuous flow method was described for the determination of catecholamines based on the catecholamines great inhibitory effects on the chemiluminescence reaction of luminol–potassium chlorate in basic solutions. The optimum chemical conditions for the chemiluminescence reaction were investigated. Under the optimized conditions, four catecholamines: adrenaline, noradrenaline, isoprenaline, and dopamine were determined. The detection limits are 0.2 ng mL−1 for adrenaline, 0.4 ng mL−1 for noradrenaline, 0.7 ng mL−1 for isoprenaline, and 0.4 ng mL−1 for dopamine. The method was successfully applied to the determination of the four catecholamines in pharmaceutical injections. A brief discussion on the possible chemiluminescence reaction mechanism is presented. [ABSTRACT FROM AUTHOR]

The weak basic bicarbonate-activated hydrogen peroxide is applied to the catalytic asymmetric epoxidation of the enones, and the catalyst polyleucine cannot be deteriorated and can successfully be reused in this asymmetric reaction. The ee value of the optically active epoxidation product is up to 95%. [ABSTRACT FROM AUTHOR]

According to the cDNA sequence of anti-neuroexcitation peptide of scorpion Buthus martensii Karsch, the putative mature anti-neuroexcitation peptide (ANEP) encoding DNA fragment was obtained by a PCR method, then was cloned into expression plasmid pET28a, fused with His tag at its 3′ end. When expressed in E. coli BL21 (DE3), the expression of recombinant ANEP was 15% of total cellular proteins, while most recombinant ANEP products existed in the form of insoluble inclusion bodies. Co-expression of molecular chaperones or protein disulfide isomerase could not improve its solubility. The recombinant ANEP in the cell lysate was purified to homogeneity by metal chelating affinity chromatography and Superdex 30 chromatography. In bioassay with convulsive mice model induced by thiosemicarbazide, recombinant ANEP could apparently delay the convulsion seizure of model animals by 18% and showed anti-neuroexcitatory activity. [ABSTRACT FROM AUTHOR]