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The compartmentalization of chemo‐ and enzymatic reactions is an elegant strategy for one‐pot synthesis while avoiding reaction incompatibility issues. However, chemoenzymatic compartments developed to date are limited to complicated preparation. Herein, a simple, catalytically active polymer that stabilizes diverse types of emulsions for the encapsulation of active enzymes is presented. This design combines two distinct catalysts for cascade reaction while creating separate micro‐environments with a large interfacial area for high reactivity. Moreover, the system is developed for solvent‐free reactions, benefiting the "green" synthesis. [ABSTRACT FROM AUTHOR]

This article addresses the saturated stabilization control problem for nonholonomic vehicles with a novel c-nonholonomic trajectory approach on $\text{SE}(2)$ , with applications to automatic parking. First, by defining the c-nonholonomic configuration, a c-nonholonomic trajectory is obtained, which provides a novel approach to design stabilization controller to reach an arbitrary configuration. Second, a global discontinuous time-invariant feedback controller with input saturation is proposed, which does not involve time signal information, and its convergence is illustrated by a Lyapunov function approach. Thereafter, the motion trajectory of the proposed controller is analyzed, and the application scenario in automatic parking with the approximate desired trajectory is demonstrated. Finally, the performance of the proposed controller is validated by both numerical simulations and experiments. [ABSTRACT FROM AUTHOR]

This paper addresses the noncooperative attitude tracking control problem for rigid bodies whose dynamics evolves on the rotation matrix SO(3). First, based on the relative attitude measurement, a saturated angular velocity input is designed by a proposed saturated nonlinear function. Thereafter, the attitude tracking control torque for rigid body's dynamics with input saturation constraint and active disturbance rejection is developed by a modified dynamic surface control approach which can avoid large torque in practice. Furthermore, by using only relative attitude measurements, two types of velocity‐free attitude control laws are considered, respectively. In contrast to those control schemes that require that the desired angular velocity is available to the rigid body, the proposed scheme is able to solve the attitude control in noncooperative scenarios, where the desired angular velocity and acceleration are not accessible. Since the attitude described by rotation matrix SO(3) enables the controller to use local measurements in the body‐fixed frame rather than global measurements in an inertial frame, the proposed robust noncooperative control schemes with input saturation constraint are easier to implement in practice. Finally, numerical simulations and SimMechanics experiments are provided to illustrate the effectiveness of the proposed theoretical results. [ABSTRACT FROM AUTHOR]

A nuclear heating system integrated with a heat storage tank (HST-NHS) is a promising technical solution for countries with large-scale heating demand. HST-NHS can greatly curtail carbon dioxide emissions and contribute to sustainable development. Appropriate control strategies are not only crucial to realize the real-time matching between HST-NHS heat supply and heat demand, but also ensure the stable and safe operation of HST-NHS. Until now, control strategies for HST-NHS have received limited attention. A refined dynamic simulation model for HST-NHS is established based on APROS software. The verification of the built model in steady state and transient state is completed. Two basic control strategies for the primary heating network (PHN) of HST-NHS, constant supply water temperature and variable flow rate (CT-VF) and variable supply water temperature and constant flow rate (VT-CF) are presented in detail. Based on various typical working conditions of a central heating region in Liaoyuan City, the control effects of two control strategies are investigated. Additionally, a comprehensive performance comparison between the two strategies is explored. Simulation results indicated that under the two control strategies, the indoor temperature can be effectively controlled at a high comfort level. During the same typical day, the total energy consumption cost under the VT-CF control strategy is 0.5 × 105 yuan lower than that under the CT-VF control strategy. • Dynamic model of nuclear heating system with heat storage is developed. • The verification of the built model in steady and transient state is completed. • Control effects of two basic control strategies during typical days are evaluated. • A performance comparison of two basic control strategies is conducted. [ABSTRACT FROM AUTHOR]

This article discusses cooperative stabilization control of rigid formations via an event-based approach. We first design a centralized event-based formation control system, in which a central event controller determines the next triggering time and broadcasts the event signal to all the agents for control input update. We then build on this approach to propose a distributed event control strategy, in which each agent can use its local event trigger and local information to update the control input at its own event time. For both cases, the triggering condition, event function, and triggering behavior are discussed in detail, and the exponential convergence of the event-based formation system is guaranteed. [ABSTRACT FROM AUTHOR]

In this paper, we proposed several disturbance observer‐based matrix‐weighted consensus algorithms. A new disturbance observer is firstly designed for linear systems with unknown matched or mismatched disturbances representable as the multiplication of a known time‐varying matrix with a unknown constant vector. Under some assumptions on the boundedness and persistent excitation of the regression matrix, the disturbances can be estimated at an exponential rate. Then, a suitable compensation input is provided to compensate the unknown disturbances. Second, disturbance‐observer based consensus algorithms are proposed for matrix‐weighted networks of single‐ and double‐integrators with matched or mismatched disturbances. We show that both matched and mismatched disturbances can be estimated and actively compensated, and the consensus system uniformly globally asymptotically converges to a fixed point in the kernel of the matrix‐weighted Laplacian. Depending on the network connectivity, the system can asymptotically achieve a consensus or a cluster configuration. The disturbance‐observer based consensus design is further extended for a network of higher‐order integrators subjected to disturbances. Finally, simulation results are provided to support the mathematical analysis. [ABSTRACT FROM AUTHOR]

Multienzyme cascade biocatalysis is an efficient synthetic process, avoiding the isolation/purification of intermediates and shifting the reaction equilibrium to the product side.. However, multienzyme systems are often limited by their incompatibility and cross‐reactivity. Herein, we report a multi‐responsive emulsion to proceed multienzyme reactions sequentially for high reactivity. The emulsion is achieved using a CO2, pH, and thermo‐responsive block copolymer as a stabilizer, allowing the on‐demand control of emulsion morphology and phase composition. Applying this system to a three‐step cascade reaction enables the individual optimal condition for each enzyme, and a high overall conversion (ca. 97 % of the calculated limit) is thereby obtained. Moreover, the multi‐responsiveness of the emulsion allows the facile and separate yielding/recycling of products, polymers and active enzymes. Besides, the system could be scaled up with a good yield. [ABSTRACT FROM AUTHOR]

Multienzyme cascade biocatalysis is an efficient synthetic process, avoiding the isolation/purification of intermediates and shifting the reaction equilibrium to the product side.. However, multienzyme systems are often limited by their incompatibility and cross‐reactivity. Herein, we report a multi‐responsive emulsion to proceed multienzyme reactions sequentially for high reactivity. The emulsion is achieved using a CO2, pH, and thermo‐responsive block copolymer as a stabilizer, allowing the on‐demand control of emulsion morphology and phase composition. Applying this system to a three‐step cascade reaction enables the individual optimal condition for each enzyme, and a high overall conversion (ca. 97 % of the calculated limit) is thereby obtained. Moreover, the multi‐responsiveness of the emulsion allows the facile and separate yielding/recycling of products, polymers and active enzymes. Besides, the system could be scaled up with a good yield. [ABSTRACT FROM AUTHOR]

• Using functional near-infrared spectroscopy and short-time series and multi-layer neural network, the classification between ASD and TD children reached 90.6% in sensitivity and 97.5% in specificity. • The abnormalities occurred more frequently in left temporal lobe. • The multi-layer neural network identified ASD patients more efficiently and accurately, and also effectively avoided a misdiagnosis in TD children. To classify children with autism spectrum disorder (ASD) and typical development (TD) using short-term spontaneous hemodynamic fluctuations and to explore the abnormality of inferior frontal gyrus and temporal lobe in ASD. 25 ASD children and 22 TD children were measured with functional near-infrared spectroscopy located on the inferior frontal gyrus and temporal lobe. To extract features used to classify ASD and TD, a multi-layer neural network was applied, combining with a three-layer convolutional neural network, a layer of long and short-term memory network (LSTM) and a layer of LSTM with Attention mechanism. In order to shorten the time of data collection and get more information from limited samples, a sliding window with 3.5 s width was utilized after comparisons, and numerous short (3.5 s) fNIRS time series were then obtained and used as the input of the multi-layer neural network. A good classification between ASD and TD was obtained with considerably high accuracy by using a multi-layer neural network in different brain regions, especially in the left temporal lobe, where sensitivity of 90.6% and specificity of 97.5% achieved. The "CLAttention" multi-layer neural network has the potential to excavate more meaningful features to distinguish between ASD and TD. Moreover, the temporal lobe may be worth further study. The findings in this study may have implications for rapid diagnosis of children with ASD and provide a new perspective for future medical diagnosis. [ABSTRACT FROM AUTHOR]

Al-CNTs composite coatings were successfully prepared on AZ31 alloy using laser cladding (LC). The effect of TiC nanoparticles on microstructure and corrosion resistance of the LC Al-CNTs and Al-TiC-CNTs composite coatings were investigated. The LC composite coatings were composed of α-Mg solid solution phase and β-Al12Mg17, Mg2Al3, Mg32(Al,Zn)49 and TiC compound phases. A sound metallurgical bonding interface was produced between the LC composite coatings and AZ31 alloy. The surface microhardness and corrosion resistance of the LC composite coatings, which were gradually decreased with increasing the content of carbon nanotubes (CNTs) and TiC nanoparticles, were significantly enhanced compared to those of the AZ31 alloy. The LC Al-CNTs (99 wt% Al + 1 wt% CNTs) composite coating exhibits excellent surface microhardness and corrosion resistance. The mean surface microhardness, self-corrosion potential and self-corrosion current were 266.4 HV, −1.233 V and 2.55 × 10−5 A, which were 426.2%, 78.9% and 16.5% of the AZ31 alloy, respectively. [ABSTRACT FROM AUTHOR]

• The first HPLC-MS/MS method for simultaneous determination of donafenib, donafenib-N-oxide, sorafenib, and sorafenib-N-oxide in rat plasma is developed. • The limited sample volume (50 μL), simple sample preparation (protein precipitation), and short analysis time (2.8 min) are the advantages of the method. • The method is suitable for high-throughput analysis of biological samples. • The method successfully applied to comparing the pharmacokinetic behaviors of the donafenib and sorafenib in rat plasma. Donafenib and sorafenib are small molecule chemotherapy drugs for the management of hepatocellular carcinoma, with donafenib being a deuterated derivative of sorafenib. To date, a high liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method that quantify donafenib, sorafenib, and their main metabolites has not yet been developed. The objective of this study was to establish a HPLC-MS/MS method for the simultaneous detection of donafenib, donafenib-N-oxide, sorafenib, and sorafenib-N-oxide and for the pharmacokinetic studies in rat. The extraction of all analytes was achieved by simple protein precipitation utilizing acetonitrile. The Waters XBridge C 18 column (2.1 × 100 mm, 3.5 µm) was selected, and the analytes could be efficiently separated and quantitated during a 2.8 min gradient elution procedure. The method was linear within the predefined quantification ranges and provided acceptable precision (%CV < 9.4%), reproducible extraction recovery (99.4%–111.5%), and low matrix effect (88.1%–98.6%). The hemolysis effect did not interfere with the quantification of all analytes, and similar results were obtained by changing the anticoagulant K 2 -EDTA to heparin or sodium citrate. Plasma pharmacokinetics revealed that the values of t 1/2 , C max , and AUC 0-t of donafenib were 1.4-, 6.2-, and 3.1-fold higher than those of sorafenib, respectively. In conclusion, the proposed bioassay was successfully applied to pharmacokinetic studies in rat after administration of donafenib and sorafenib. Our work not only improves the bioanalytical method for determining the plasma concentrations of donafenib, sorafenib, and their N-oxide metabolites, but also provides a scientific reference for clinical pharmacokinetic studies. [ABSTRACT FROM AUTHOR]

Abstract Most current results on coverage control using mobile sensors require that one partitioned cell is associated with precisely one sensor. In this paper, we consider a class of coverage control problems involving higher order Voronoi partitions, motivated by applications where more than one sensor is required to monitor and cover one cell. Such applications are frequent in scenarios requiring the sensors to localize targets. We introduce a framework depending on a coverage performance function incorporating higher order Voronoi cells and then design a gradient-based controller which allows the multi-sensor system to achieve a local equilibrium in a distributed manner. The convergence properties are studied and related to Lloyd algorithm. We study also the extension to coverage of a discrete set of points and its applications to clustering of discrete sets. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the formation scaling control problem for multi-agent systems by utilizing the stress matrix associated with a universally rigid framework. Compared with the existing results on formation scaling control, we consider a more challenging scenario where only one agent has the knowledge of the desired formation size. To cope with this constraint, we first propose a distributed estimator for the remaining agents to estimate the scaling parameter. Then by employing the outputs of the estimator, we design a new class of formation scaling control algorithms for universally rigid frameworks such that the overall formation converges to the prescribed shape with the desired scaling. Numerical simulations are carried out to validate the theoretical results. [ABSTRACT FROM AUTHOR]

Summary: In this paper, we discuss quantization effects in rigid formation control systems when target formations are described by interagent distances. Because of practical sensing and measurement constraints, we consider in this paper distance measurements in their quantized forms. We show that under gradient‐based formation control, in the case of uniform quantization, the distance errors converge locally to a bounded set whose size depends on the quantization error, while in the case of logarithmic quantization, all distance errors converge locally to zero. A special quantizer involving the signum function is then considered with which all agents can only measure coarse distances in terms of binary information. In this case, the formation converges locally to a target formation within a finite time. Lastly, we discuss the effect of asymmetric uniform quantization on rigid formation control. [ABSTRACT FROM AUTHOR]

Despite the rapid development of Pickering interfacial catalysis (PIC) at liquid–liquid interfaces with chemocatalysts, the use of unstable biocatalysts at emulsion interfaces remains a technical challenge. Herein, we present a Pickering interfacial biocatalysis (PIB) platform based on robust and recyclable enzyme–polymer conjugates that act as both catalytic sites and stabilizers at the interface of Pickering emulsions. The conjugates were prepared by growing poly(N‐isopropylacrylamide) on a fragile enzyme, benzaldehyde lyase, under physiological conditions. The mild in situ conjugation process preserved the enzyme structure, and the conjugates were used to emulsify a water–organic two‐phase system into a stable Pickering emulsion, leading to a significantly larger interfacial area and a 270‐fold improvement in catalytic performance as compared to the unemulsified two‐phase system. The PIB system could be reused multiple times. Conjugates of other enzymes were also fabricated and applied for cascade reactions. Gentle giants: Enzyme–polymer conjugates were created that acted simultaneously as catalytic sites and stabilizers at the interface of Pickering emulsions to enable effective Pickering interfacial biocatalysis (PIB; see picture, ATRP=atom‐transfer radical polymerization). The extraordinarily large contact area of the system contributed to the efficiency of the biotransformations in both single‐ and multiple‐step reactions. [ABSTRACT FROM AUTHOR]

Despite the rapid development of Pickering interfacial catalysis (PIC) at liquid–liquid interfaces with chemocatalysts, the use of unstable biocatalysts at emulsion interfaces remains a technical challenge. Herein, we present a Pickering interfacial biocatalysis (PIB) platform based on robust and recyclable enzyme–polymer conjugates that act as both catalytic sites and stabilizers at the interface of Pickering emulsions. The conjugates were prepared by growing poly(N‐isopropylacrylamide) on a fragile enzyme, benzaldehyde lyase, under physiological conditions. The mild in situ conjugation process preserved the enzyme structure, and the conjugates were used to emulsify a water–organic two‐phase system into a stable Pickering emulsion, leading to a significantly larger interfacial area and a 270‐fold improvement in catalytic performance as compared to the unemulsified two‐phase system. The PIB system could be reused multiple times. Conjugates of other enzymes were also fabricated and applied for cascade reactions. [ABSTRACT FROM AUTHOR]

Integrating heat storage devices with the pool-type low-temperature heating reactor (PLTHR) can improve the flexibility of PLTHR for load following. A novel low-temperature nuclear heating system (HST-NHS) is proposed, which combines the DHR-400 heating reactor system, a heat storage tank (HST), and a gas boiler (GB) to achieve real-time matching between heating supply and demand. A mixed integer nonlinear programming (MINLP) optimization model with the annual cost (AC) as the optimization objective is established. An operation strategy that considers the device priority is proposed. The capacity and operation of HST-NHS are simultaneously optimized using the CPLEX solver. The optimization results indicate that an HST with a rated capacity of 1324.14 MWh and a GB with a rated capacity of 201.69 MW can provide the operational flexibility needed for the HST-NHS throughout the heating period. When compared with comparison schemes 1 (DHR-400 and HST), 2 (DHR-400 and GB), and 3 (pure gas boiler heating system), HST-NHS achieves significant annual cost savings. Finally, a sensitivity analysis of device price and fuel price is conducted, revealing that the unit price of the DHR-400 heating reactor system and natural gas price are the main factors affecting the AC and dynamic payback period (DPP) of HST-NHS. This work offers theoretical guidance for the subsequent engineering application of the DHR-400 heating reactor system. • A novel nuclear heating system considering heat storage is proposed. • Operation strategy follows device priority is proposed. • The capacity and operation plan are optimized simultaneously by a MINLP model. • The nuclear heating system significantly reduces costs and CO 2 emissions. • Sensitivity analysis of device price and fuel price is carried out. [ABSTRACT FROM AUTHOR]

In this paper we discuss and discover several conservation and associated decay laws in distributed coordination control systems, in particular in formation shape control systems. Specifically, we reveal conservations of linear momentum and angular momentum for gradient-based multi-agent formation systems modelled by single integrators, and show several corresponding conservation/decay laws for double-integrator formation stabilization systems and double-integrator flocking systems, respectively. By exploiting translation and rotation symmetry properties and insights from Noether’s theorem, we further establish a multi-agent version of the relation between symmetry and conservation laws for gradient-based coordination systems derived from general potential functions, from which we generalize the conservation/decay laws to more general networked coordination control systems. The results hold in ambient spaces of any dimensions, and we focus on the 2-D and 3-D cases due to their natural interpretation as positions of agents. [ABSTRACT FROM AUTHOR]

Atomic force microscope (AFM) has been defined as the one of the most powerful instruments to explore micro/nanoworld in various fields. To lower imaging noise, AFMs are commonly equipped with open-loop nanopositioners (scanners). However, the hysteretic effect of the AFM positioners is a dominate factor that increases the position error during AFM-based manipulations. To reduce hysteresis, inverse compensation approach is an effective solution. Normally, one compensator is designed for the manipulation task with maximum working range, which may not be efficient enough for maintaining uniform accuracy for tasks with different working ranges. The objective of this study is to develop a working-range adapted compensator to tackle this challenge. First, a generalized method that can precisely model various types of hysteresis is required. To fulfill this, a flexible Prandtl–Ishlinskii (PI) type model, named extended unparallel PI model, is employed. Based on this model, an implicit hysteresis compensation approach is developed, and its stability condition and control gain optimization approach are proposed. Combining the modeling and compensation approaches, a working-range adapted hysteresis compensator is finally established. Experimental results demonstrate that the mean control errors of the compensator are uniformly below $5\%$ in different working ranges. [ABSTRACT FROM PUBLISHER]

In this paper, we study rigid formation control systems modelled by double integrators. Two kinds of double-integrator formation systems are considered, namely formation stabilisation systems and flocking control systems. Novel observations on the measurement requirement, the null space and eigenvalues of the system Jacobian matrix will be provided, which reveal important properties of system dynamics and the associated convergence results. We also establish some new links between single-integrator formation systems and double-integrator formation systems via a parameterised Hamiltonian system, which, in addition, provide novel stability criteria for different equilibria in double-integrator formation systems by using available results in single-integrator formation systems. [ABSTRACT FROM AUTHOR]

Most rigid formation controllers reported in the literature aim to only stabilize a rigid formation shape, while the formation orientation is not controlled. This paper studies the problem of controlling rigid formations with prescribed orientations in both 2-D and 3-D spaces. The proposed controllers involve the commonly-used gradient descent control for shape stabilization, and an additional term to control the directions of certain relative position vectors associated with certain chosen agents. In this control framework, we show the minimal number of agents which should have knowledge of a global coordinate system (2 agents for a 2-D rigid formation and 3 agents for a 3-D rigid formation), while all other agents do not require any global coordinate knowledge or any coordinate frame alignment to implement the proposed control. The exponential convergence to the desired rigid shape and formation orientation is also proved. [ABSTRACT FROM AUTHOR]

Most of the existing results on distributed distance-constrained rigid formation control establish asymptotic or exponential convergence. To further improve the convergence rate, we explain in this paper how to modify existing gradient controllers to obtain finite time stability. For point agents modeled by single integrators, the controllers proposed in this paper drive the whole formation to locally converge to a desired shape with finite settling time. We also show for undirected triangular formation shape control, if all the agents start with non-collinear positions, then the formation will converge to the desired shape in finite time. For agents modeled by double integrators, the proposed controllers allow all agents to both achieve the same velocity and reach a desired shape in finite time. All controllers are totally distributed. Simulations are also provided to validate the proposed control strategies. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper discusses generalized controllers for distance-based rigid formation shape stabilization and aims to provide a unified approach for the convergence analysis. We consider two types of formation control systems according to different characterizations of target formations: minimally rigid target formation and non-minimally rigid target formation. For the former case, we firstly prove the local exponential stability for rigid formation systems when using a general form of shape controllers with certain properties. From this viewpoint, different formation controllers proposed in previous literature can be included in a unified framework. We then extend the result to the case that the target formation is non-minimally rigid, and show that exponential stability of the formation system is still guaranteed with generalized controllers. [ABSTRACT FROM AUTHOR]

A controlled release method of antifouling agent was demonstrated via the model coating which was fabricated by sodium paeonolsilate (PAS) intercalated into Zn 2 Al Layered Double hydroxides (LDH) and then dispersed in the mixture of acrylic resin and colophony with weight ratio of 2:1. The powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) confirm the intercalation of PAS into the galleries of Zn 2 Al-LDH. Some larger particles of Zn 2 Al-PAS-LDH composite in the coating were observed owing to its aggregation, which was revealed by Laser scanning confocal microscope (LSCM). The release tests of the Zn 2 Al-PAS-LDH coating in 3.5% NaCl solution showed that no burst release phenomenon occurred at the beginning stage and a slower release rate of PAS (0.54 ppm/d) was obtained compared with the pristine PAS coating (1.06 ppm/d), exhibiting its preferable controlled release behavior. The adhesion experiment using Ulva zoospores indicated that Zn 2 Al-PAS-LDH composite obviously increases the utilization rate of PAS owing to its controlling release property. Therefore, the present work provided a useful strategy to decrease the waste of antifouling agent and prolong the lifetime of antifouling coatings. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) were functionalized with Lanthanum (La) modifier and appropriate acid-treatment methods. CNT-containing film was deposited on silicon substrates via a self-assembly process. The formation and microstructure of La treated CNTs and CNT-containing film were characterized by high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray photoelectron spectrometry (XPS) and water contact angle (WCA). Its tribological properties were evaluated with a UMT-2MT reciprocating friction tester. The results show that CNTs were adsorbed on silicon substrates by means of chemically bonding between La and oxygen-containing functional groups. The friction coefficient of the silicon substrates is reduced from 0.87 to 0.12 after the deposition of CNT-containing film on its surface. CNT-containing film shows excellent antiwear, friction reducing ability and load-carrying capacity due to excellent mechanical and self-lubrication properties of CNTs. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) film was prepared on silicon () substrate with a 3-aminopropyltriethoxysilane (APTES) film as the interlayer in a multistep self-assembly process. The formation and microstructure of the CNTs film were characterized by using scanning electron microscopy (SEM), water contact angles (WCAs) and X-ray photoelectron spectrometry (XPS). Tribological properties were evaluated with a UMT-2MT reciprocating friction tester. Results show that the CNTs were successfully assembled on substrates by chemical bonding between functional groups. CNTs film exhibited excellent friction reduction, high load-bearing capacity and antiwear ability. The friction coefficient was reduced drastically from 0.7 to 0.16, with markedly prolonged antiwear lifetime compared to bare substrates or APTES film. These superior tribological properties are attributable to the remarkable mechanical properties of CNTs and strong bond properties with the APTES film. CNTs film is thus expected to find wider application as high-performance lubricating film in micro/nanoelectromechanical systems (M/NEMS) in future. Carbon nanotubes (CNTs) were successfully assembled on Si substrates via self-assembly technique. Carbon nanotubes film exhibited excellent friction reduction and wear resistance abilities under certain applied load and sliding speed. The relatively long antiwear life of CNTs film may be attributed to the covalent bonding of CNTs to APTES film and the "rolling log" effect of the desorbed CNTs. Compared to SAM developed in M/NEMS, CNTs film are overall more favorable candidate for tribological applications in M/NEMS. [ABSTRACT FROM AUTHOR]

This paper proposes an elevation angle rigidity theory in both 2D and 3D spaces, and applies it to solve multi-agent formation control with only inter-agent bearing/direction measurements in agents' local coordinate frames. Motivated by the sensor technology in measuring elevation angle and angular diameter, we develop elevation angle rigidity by attaching each agent in a multi-agent framework with a rod in 2D and a ball in 3D, respectively. By defining the elevation angle rigidity matrix, conditions for infinitesimal elevation angle rigidity are derived. Compared to previously developed angle rigidity-based and bearing rigidity-based formation control laws, the proposed elevation angle rigidity-based control law can maintain the gradient-based control property. Compared to distance-based formation control laws, less sensor measurements are required. The formation maneuvering with desired translation and rotation is also realized by using only local bearing measurements. Simulation examples illustrate the advantages and effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

This paper develops a sign rigidity theory to characterize and examine multi-agent rigid formations consistent with a formation specification including distance- and signed area-constraints, and to control an arbitrarily positioned set of agents to take up the specifications. The sign rigidity theory can be viewed as an extended version of the standard distance rigidity theory with the addition of signed area constraints. This property enables elimination of possible formation specification ambiguities arising when a formation specification includes distance constraints only. As an application of the sign rigidity theory, this paper explores formation specification control in 2-D space. Under the proposed gradient-based formation control law, almost global convergence (from arbitrary initial positions) can be achieved when a target formation consists of triangulated sub-formations defined by distance- and signed area-constraints; the formation control law is applied for either single-integrator models or unicycle models. [ABSTRACT FROM AUTHOR]

Abstract: In the present paper, multiplex polymerase chain reaction (PCR) was coupled to a suspension array to construct an assay for simultaneous identification of six kinds of pathogens. The suspension array allows the simultaneous detection of different target sequences in a multiplex and high-throughput format. The assay uses a liquid suspension hybridization format with specific oligonucleotide probes covalently bound to the surface of fluorescent color-coded microspheres. Biotinylated target amplicons, hybridized to their complementary probe sequences, are quantified by adding the conjugate, streptavidin R-phycoerythrin. Six probes derived from the sequence analysis of a specific gene were developed and validated. There was little cross-reaction among the various probes. In the multi-channel method, the detection sensitivity was 1.6 × 10−6 mM. Results of nucleic acid detection assays show detection sensitivity for 20–4 × 103 CFU/ml, which is one to five orders of magnitude higher than those of PCR-agarose method in different bacteria. Aside from single channel capability, the assay allows the simultaneous detection of target genes in a single reaction, with detection limits of 1–10 CFU/ml. The accuracy, speed, flexibility, and sensitivity of the proposed assay are beneficial for the diagnosis of pathogenic diseases. [Copyright &y& Elsevier]

A structuredcatalyst has been fabricated by immobilizing cobaltphthalocyanine tetrasulfonate (CoPcS) on a MgNiAl mixed metal oxide(MgNiAl-MMO) film derived from calcination of layered double hydroxide(LDH). The resulting CoPcS/MgNiAl-MMO catalyst exhibits excellentactivity, stability, and recyclability for the reaction of mercaptansweetening. SEM images show that the structured catalyst is composedof thin MMO nanoflakes perpendicular to the Al substrate. The synergisticeffect between the oxidation center (CoPcS) and the abundant moderatebasic sites on the surface of the MgNiAl-MMO substrate plays an importantrole in the sweetening process, accounting for the largely enhancedcatalytic behavior (conversion: 92.8%; selectivity: 100%). In addition,the structured catalyst exhibits superior catalysis regeneration performance,owing to its specific architecture and strong mechanical stability.This work demonstrates a facile approach for modulating the synergisticeffect between the active center and the basicity for the structuredcatalyst, for the purpose of achieving largely enhanced catalyticbehavior in the petroleum refining industry. [ABSTRACT FROM AUTHOR]

Abstract: A hierarchical Mg/Ni/Al layered double hydroxide (LDH) framework has been fabricated via the in situ crystallization process on aluminum foam (denoted as Mg/Ni/Al LDH/Al-foam). XRD and SEM confirm that the as-prepared Mg/Ni/Al LDH displays flowerlike microspheres (2–5μm) composed of numerous LDH nanoplatelets (1–2μm in width and ~50nm in thickness). The BET analysis shows that the specific surface area of the Mg/Ni/Al LDH is 96.8m²/g owing to its hierarchical structure, which is much higher than that of the traditional bi-metal Mg/Al LDH. Two steps of the synthesis strategy were carried out in order to eliminate the competitive difference between cations composed of LDH. The present work provided a new strategy for a scale-up synthesis of well-crystallized tri-metal LDH materials on metal substrate by the in situ crystallization technique. [Copyright &y& Elsevier]

Abstract: The fingerprints of Aconitum L. plants, Radix Aconiti (RA), Radix Aconiti Singularis (RAS), Radix Aconiti Kusnezoffii (RAK), Radix Aconiti Lateralis Preparata (RALP) and Radix Aconiti Brachypodi (RAB), were established by ultra-high performance liquid chromatography (UPLC) and the metabolism of Aconitum L. plants on Escherichia coli (E. coli) were studied by microcalorimetry. The spectrum-effect relationships between UPLC fingerprints and bacterial metabolism were investigated using canonical correlation analysis (CCA). Because of their inherent differences of chemical compositions, the main actives of bacterial metabolism were different among five Aconitum L. plants. The potency bioactivity sequence of the tested five Aconitum L. products on E. coli was obtained that were RAB>RALP>RAK>RAS>RA. This work establishes a universal model of the combination of UPLC and microcalorimetry to study the spectrum-effect relationships of Aconitum L. plants, which offers some references for detecting principle components of traditional Chinese medicine on bioactivity. [Copyright &y& Elsevier]

Cell injection procedure is very essential in the field of molecular biology, and the injection force affects the success rates very much. However, conventional methods of manipulating individual biological cell failed to make use of the injection force information. This article is intended to design a static micro-force sensor with a simple structure which employs the piezoelectric material PVDF (polyvinylidene fluoride) film as its sensing element to detect the micro-force during cells injection and to develop a close-loop control method to regulate the whole fore-tracking system. A Fuzzy-PID and an ordinary PD feedback control method are employed separately in this article to regulate the micro-force tracking system which is used to carry out automatic living-cell injection tests. Experimental results with different control methods are achieved. And the Fuzzy-PID and PVDF sensor based force control method is validated. [ABSTRACT FROM AUTHOR]

When grown in a nonanoic acid-limited chemostat at adilution rateof 0.25 h–1, Pseudomonas putidaKT2440 produced poly(3-hydroxynonanoate-co-3-hydroxyheptanoate)containing 68 mol % 3-hydroxynonanoate (C9) and 32 mol % 3-hydroxyheptanoate(C7). Under the same conditions, but in the presence of acrylic acid,a fatty acid β-oxidation inhibitor, the C9 monomer content increasedto 88 mol %. Cofeeding glucose (3.9 g L–1) and nonanoicacid (2.9 ± 0.1 g L–1) in continuous culturewith 0.2 g L–1of acrylic acid in the feed, furtherincreased the C9 content to 95 mol %. A yield of PHA from nonanoicacid of 0.93 mol mol–1was attained. PHA with a3-hydroxyoctanoate (C8) content of 98 mol % was produced with thesame cofeeding methodology from octanoic acid. As the dominant monomercontent increased, the melting point of the poly(3-hydroxynonanoate)copolymers increased from 46 to 63 °C and that of the poly(3-hydroxyoctanoate)copolymers from 54 to 62 °C. All copolymer compositions resultedin elongation to break values of about 1300%, but tensile strengthat break and Young’s modulus both increased with increasingamounts of the dominant monomer. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates the projective synchronization (PS) of different fractional order chaotic systems while the derivative orders of the states in drive and response systems are unequal. Based on some essential properties on fractional calculus and the stability theorems of fractional-order systems, we propose a general method to achieve the PS in such cases. The fractional operators are introduced into the controller to transform the problem into synchronization problem between chaotic systems with identical orders, and the nonlinear feedback controller is proposed based on the concept of active control technique. The method is both theoretically rigorous and practically feasible. We present two examples that illustrate the effectiveness and applications of the method, which include the PS between two 3-D commensurate fractional-order chaotic systems and the PS between two 4-D fractional-order hyperchaotic systems with incommensurate and commensurate orders, respectively. Abundant numerical simulations are given which agree well with the analytical results. Our investigations show that PS can also be achieved between different chaotic systems with non-identical orders. We have further reviewed and compared some relevant methods on this topic reported in several recent papers. A discussion on the physical implementation of the proposed method is also presented in this paper. [Copyright &y& Elsevier]

A structured catalyst has been fabricated by immobilizing cobalt phthalocyanine tetrasulfonate (CoPcS) on a mixed metal oxide (denoted as MMO) film, which exhibits excellent activity, stability and recyclability for mercaptan sweetening. Scanning electron microscopy (SEM) images show that the structured catalyst is composed of MMO nanoflakes whose ab-plane is perpendicular to the Al substrate, with desired mechanical strength and high adhesion to the substrate. In addition, in situ IR spectra and carbon dioxide temperature programmed desorption (CO2-TPD) reveal that the moderate basic site is overwhelming in the CoPcS/MMO structured catalyst, while the strong basic site predominates in the corresponding CoPcS/MMO powder catalyst. It was found that the structured catalyst exhibits high conversion (85.7%) for the oxidation of mercaptan to disulphide, markedly higher than that of the corresponding powder catalyst (38.7%), as a result of the high exposure of active species as well as the synergistic effect between the oxidation center (CoPcS) and the moderate basic site. In addition, the structured catalyst shows superior catalysis-regeneration performance, which facilitates its repeatable and cyclic usage over a long period. Therefore, this work provides a facile and effective method for the fabrication of structured catalyst with high catalytic activity and stability, as well as recyclability, which can be used as an eco-friendly catalyst for the sweetening process in the petroleum refining industry. [ABSTRACT FROM AUTHOR]

Abstract: A novel optical chemosensor was fabricated based on 1-amino-8-naphthol-3,6-disulfonic acid sodium (H-acid) intercalated layered double hydroxide (LDH) film via the electrophoretic deposition (EPD) method. The film of H-acid/LDH with the thickness of 1μm possesses a well c-orientation of the LDH microcrystals confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The fluorescence detection for Hg(II) in aqueous solution was performed by using the H-acid/LDH film sensor at pH 7.0, with a linear response range in 1.0×10−7 to 1.0×10−5 molL−1 and a detection limit of 6.3×10−8 molL−1. Furthermore, it exhibits excellent selectivity for Hg(II) over a large number of competitive cations including alkali, alkaline earth, heavy metal and transitional metals. The specific fluorescence response of the optical sensor is attributed to the coordination between Hg(II) and sulfonic group in the H-acid immobilized in the LDH matrix, which was verified by NMR spectroscopy and UV–vis spectra. In addition, density functional theory (DFT) calculation further confirms that the coordination occurs between one Hg2+ and two O atoms in the sulfonic group, which is responsible for the significant fluorescence quenching of the H-acid/LDH film. The results indicate that the H-acid/LDH composite film can be potentially used as a chemosensor for the detection of Hg2+ in the environmental and biomedical field. [Copyright &y& Elsevier]

Abstract: The inorganic–organic composites have been prepared by intercalation of ammonium 1-anilinonaphthalene-8-sulfonate (ANS) into ZnAl and MgAl layered double hydroxide (LDH) with the molar ratio (M2+/M3+) of 2:1 and 3:1, respectively. The powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) confirm the intercalation of ANS into the galleries of LDH. Fluorescence polarization method was applied to investigate the preferential orientation of the interlayer ANS molecule, and the results show that ANS anions are accommodated between the sheets of Zn2Al-LDH, Zn3Al-LDH, Mg2Al-LDH and Mg3Al-LDH with an orientation angle Ψ (defined as the angle between the transition moment of ANS molecule with respect to the normal to the LDH layer) of 58°, 57°, 55° and 52°, respectively. TG–DTA results reveal that the thermal stability of ANS was markedly enhanced upon intercalation. Fluorescence spectra demonstrate that the Zn3Al-ANS-LDH sample exhibits the optimal luminous intensity among the four ANS-LDH composites. It was also found that the luminescence behavior of ANS can be modulated via changing the two parameters: the type and ratio of cation species in LDH matrix due to host–guest interactions. Therefore, the ANS-LDH composites can be used as good candidates for solid photoluminescence materials. [Copyright &y& Elsevier]

Abstract: Medium-chain-length polyhydroxyalkanoates (MCL-PHAs) were produced in carbon-limited, single-stage, fed-batch fermentations of Pseudomonas putida KT2440 by co-feeding nonanoic acid (NA) and glucose (G) to enhance the yield of PHA from NA. An exponential (μ =0.25h−1) followed by a linear feeding strategy at a NA:G ratio of 1:1 (w/w) achieved 71gl−1 biomass containing 56% PHA. Although the same overall PHA productivity (1.44gl−1 h−1) was obtained when NA alone was fed at the same specific growth rate, the overall yield of PHA from NA increased by 25% (0.66gPHAgNA−1 versus 0.53gg−1) with glucose co-feeding. Further increasing glucose in the feed (NA:G=1:1.5) resulted in a slightly higher yield (0.69gPHAgNA−1) but lower PHA content (48%) and productivity (1.16gl−1 h−1). There was very little change in the PHA composition. [Copyright &y& Elsevier]

Unsaturated medium-chain-length polyhydroxyalkanoates (MCL-PHA) were produced at a productivity of 0.63–1.09 g PHA l−1 h−1 with final PHA content ranging from 42.6 to 55.8% in single-stage, carbon-limited, fed-batch fermentations of Pseudomonas putida KT2440. A mixture of nonanoic acid (NA) and 10-undecenoic acid (UDA=) was fed exponentially to control growth rate. Varying the specific growth rate (0.14 h−1 vs. 0.23 h−1) at similar substrate feed ratios (NA:UDA= = 5:1) had little effect on the final PHA content and relative composition. However, decreasing the NA:UDA= ratio decreased the final amount of PHA produced from 56% with NA:UDA= = 5.07:1 to only 42% at NA:UDA= = 2.47:1. The molar fraction of all 3-hydroxyalkanoate monomers in the PHA product was relatively constant throughout each fermentation, indicating that the final product was homogeneous rather than a mixture of different copolymers. A linear relationship between unsaturation of the PHA produced and unsaturation of the carbon feed was found, which demonstrates the feasibility of producing unsaturated MCL-PHAs with controlled polymeric composition in a fed-batch process. [ABSTRACT FROM AUTHOR]

Decaying exponential feeding strategies for the production of medium-chain-length poly(3-hydroxyalkanoates) by Pseudomonas putida KT2440 have been developed as a method of delaying oxygen limitation that is typically responsible for the termination of high cell density aerobic fermentations. Two feeding strategies were evaluated to control the biomass generation rate and consequently control the oxygen uptake rate of the cells. A linear decaying strategy allowed the production of 90 g L–1 dry biomass containing 65% PHA in 31 h with a cumulative productivity of 1.9 g L–1 h–1, while a quadratic decaying exponential feeding rate followed by a constant feeding rate produced 109 g L–1 of dry biomass containing 63% PHA. The latter methodology improved the cumulative PHA productivity to 2.3 g L–1 h–1, which is the highest MCL-PHA productivity ever reported. Analysis of the relationship between the final biomass concentration and the associated maximum cell generation rate (which is directly related to the maximum oxygen transfer rate) indicated that higher biomass levels could be attained by decreasing the substrate feeding rate at high biomass concentrations. [ABSTRACT FROM AUTHOR]

The ability to intrinsically label plant constituents with stable isotopes has the potential to advance the study of vitamin K-absorption and metabolism in humans. Broccoli, a primary food source of phylloquinone (VK-1), was grown hydroponically using 31 atom % deuterium oxide in order to label VK-1 within the food matrix. Deuterium-labeled broccoli (115 g; 168 μg VK-1) was fed to one male subject in a single serving. Multiple serum samples were drawn throughout the subsequent 24-hr period. Reversed-phase HPLC was used to extract and purify VK-1 in both broccoli and serum. Ion abundances of the deuterium-labeled and unlabeled (endogenous) VK-1 were determined using GC/MS in negative chemical ionization mode. No sample derivatization was required. Endogenous VK-1 produced isotopomers from m/z 450 to m/z 453. The labeled VK-1 isotopomers in the broccoli were from m/z 452 to m/z 467, with the most abundant isotopomer being m/z 458 (14.1% of total labeled VK-1). The GC/MS chromatograms from serum revealed both endogenous VK-1 and VK-1 derived from the deuterium-labeled broccoli. The profile of labeled VK-1 isotopomers in serum was identical to the VK-1 isotopomer profile in labeled broccoli, indicating that no deuterium was lost due to exchange either in the body or in sample preparation. At 4 hr following broccoli intake, there was an 81.1% enrichment of phylloquinone in serum; labeled VK-1 was no longer detectable in serum at 24 hr. Use of isotope labeled vegetables enables one to discriminate exogenous intake of VK-1 from endogenous pools and ultimately to determine bioavailability of VK-1 from foods. [Copyright &y& Elsevier]

In this paper we consider distributed adaptive stabilization for uncertain multivariable linear systems with a time-varying diagonal matrix gain. We show that uncertain multivariable linear systems are stabilizable by diagonal matrix high gains if the system matrix is an H-matrix with positive diagonal entries. Based on matrix measure and stability theory for diagonally dominant systems, we consider two classes of uncertain linear systems, and derive a threshold condition to ensure their exponential stability by a monotonically increasing diagonal gain matrix. When each individual gain function in the matrix gain is updated by state-dependent functions using only local state information, the boundedness and convergence of both system states and adaptive matrix gains are guaranteed. We apply the adaptive distributed stabilization approach to adaptive synchronization control for large-scale complex networks consisting of nonlinear node dynamics and time-varying coupling weights. A unified framework for adaptive synchronization is proposed that includes several general design approaches for adaptive coupling weights to guarantee network synchronization. [ABSTRACT FROM AUTHOR]

This paper describes control methods to improve electric vehicle performance in terms of handling, stability and cornering by adjusting the weight distribution and implementing control systems (e.g., wheel slip control, and yaw rate control). The vehicle is first simulated using the bicycle model to capture the dynamics. Then, a study on the effect of weight distribution on the driving behavior is conducted. The study is performed for three different weight configurations. Moreover, a yaw rate controller and a wheel slip controller are designed and implemented to improve the vehicle's performance for cornering and longitudinal motion under the different loading conditions. The simulation through the bicycle model is compared to the experiments conducted on a rear-wheel driven radio-controlled (RC) electric vehicle. The paper shows how the wheel slip controller contributes to the stabilization of the vehicle, how the yaw rate controller reduces understeering, and how the location of the center of gravity (CoG) affects steering behavior. Lastly, an analysis of the combination of control systems for each weight transfer is conducted to determine the configuration with the highest performance regarding acceleration time, braking distance, and steering behavior. [ABSTRACT FROM AUTHOR]