To solve problems of heavy calculation burden and low solution accuracy for redundant robot in inverse kinematics problem,a solution method based on improved fruit fly optimization algorithm（IFOA） ...was proposed. On the basis of FOA,the evolutionary equation is optimized by adding an improved strategy of learning worst individuals. The ability of the IFOA to break away from the local optimum and to find the global optimum is greatly enhanced. Experimental results of several typical functions show that IFOA has better global search ability,faster speed,higher accuracy and reliability,compared with FOA. In the application of inverse kinematics problem of the redundant robot,the accuracy,speed and stability were improved effectively,and is thus applicable to solve the inverse kinematics problem of redundant robot.
Supramolecular polymers are constructed based on the novel bisalkynylplatinum(II) terpyridine molecular tweezer/pyrene recognition motif. Successive addition of anthracene as the diene and ...cyano‐functionalized dienophile triggers the reversible supramolecular polymerization process, thus advancing the concept of utilizing Diels–Alder chemistry to access stimuli‐responsive materials in compartmentalized systems.
Trigger happy: Supramolecular polymers are constructed based on the novel bisalkynylplatinum(II) terpyridine molecular tweezer/pyrene recognition motif. Successive addition of anthracene as the diene and a cyano‐functionalized dienophile triggers the reversible supramolecular polymerization process, thus advancing the concept of utilizing Diels–Alder chemistry to access stimuli‐responsive materials in compartmentalized systems.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The forecast of electricity consumption plays an essential role in marketing management. In this study, a random forest (RF) model coupled with ensemble empirical mode decomposition (EEMD) named ...EEMD-RF is presented for forecasting the daily electricity consumption of general enterprises. The candidate data is first decomposed into several intrinsic mode functions (IMFs) by the EEMD. Through fast Fourier transformation, the features in each IMF are extracted in the time-frequency domain, then simulated and predicted by the RF model. Finally, the results of each IMF are integrated into the overall trend of the daily electricity consumption for those enterprises. The proposed method was applied to two enterprises located in the Jiangsu High-Tech Zone, and the period of collected data was from January 1, 2015 to May 3, 2016. To show the applicability and superiority of the EEMD-RF approach, two basic models (a back-propagation neural network (BPNN) and least squares support vector regression (LSSVM) and five model experiments (EEMD-BPNN, EEMD-LSSVM, RF, BPNN and LSSVM) were selected for comparison. Among these approaches, the proposed model exhibited the best forecast performance in terms of mean absolute error, mean absolute percentage error, and root-mean-square error.
•A random forest model coupled with ensemble empirical mode decomposition (EEMD-RF) is proposed.•The EEMD is applied for extracting complex features of different modes.•The RF is applied for modeling the changes of different modes.•The EEMD-RF has high accuracy in enterprise electricity consumption forecasting.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Two‐dimensional (2D) imine‐based covalent organic frameworks (COFs) hold potential for photocatalytic CO2 reduction. However, high energy barrier of imine linkage impede the in‐plane photoelectron ...transfer process, resulting in inadequate efficiency of CO2 photoreduction. Herein, we present a dimensionality induced local electronic modulation strategy through the construction of one‐dimensional (1D) pyrene‐based covalent organic frameworks (PyTTA‐COF). The dual‐chain‐like edge architectures of 1D PyTTA‐COF enable the stabilization of aromatic backbones, thus reducing energy loss during exciton dissociation and thermal relaxation, which provides energetic photoelectron to traverse the energy barrier of imine linkages. As a result, the 1D PyTTA‐COF exhibits significantly enhanced CO2 photoreduction activity under visible‐light irradiation when coordinated with metal cobalt ion, yielding a remarkable CO evolution of 1003 μmol g−1 over an 8‐hour period, which surpasses that of the corresponding 2D counterpart by a factor of 59. These findings present a valuable approach to address in‐plane charge transfer limitations in imine‐based COFs.
One‐dimensional pyrene‐based covalent organic frameworks (1D PyTTA‐COF) have been applied for CO2 photoreduction for the first time. The stabilization of the aromatic backbone by interchain interaction in 1D PyTTA‐COF improved exciton dissociation and attenuated the thermal relaxation processes of excited photoelectrons, aiding the movement of photoelectrons across the imine linkage to catalytic sites for CO2 conversion.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
In this work, a class of transition metal-modified MCM-41 mesoporous silica supported ionic liquids nanocatalysts were constructed and efficiently used as catalysts for the effective carboxylation of ...terminal alkynes through CO2 utilization. The main factors affecting the catalytic performance of carboxylation and its possible reaction mechanism were sufficiently discussed. The results showed that when the dosage was 0.2 g, the temperature was 40°C and the CO2 pressure was 0.3 MPa, the supported catalyst MCM-41@IL-Sm showed the optimal catalytic efficiency. The novel catalyst proved to be highly efficient for the sustainable synthesis of alkynyl carboxylic acids attributing good to excellent yields of 82%–95% within 7–12 h. Moreover, MCM-41@IL-Sm could be recycled and reused six times without noticeable decrease in catalytic activity from two-phase system under external heterogeneous field. The application of supported ionic liquids in the field of carbon dioxide carboxylation has injected a new power source for the efficient and effective production of value-added chemicals from waste CO2.
In this paper, nanofibrous membranes based on chitosan (CS), poly (vinyl alcohol) (PVA) and graphene oxide (GO) composites, loaded with antibiotic drugs, such as Ciprofloxacin (Cip) and Ciprofloxacin ...hydrochloride (CipHcl) were prepared via the electrospinning technique. The uniform and defect-free CS/PVA nanofibers were obtained and GO nanosheets, shaping spindle and spherical, were partially embedded into nanofibers. Besides, the antibiotic drugs were effectively loaded into the nanofibers and part of which were absorbed into GO nanosheets. Intriguingly, the release of the drug absorbed in GO nanosheets regulated the drug release profile trend, avoiding the “burst” release of drug at the release initial stage, and the addition of GO slightly improved the drug release ratio. Nanofibrous membranes showed the significantly enhanced antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis after the addition of antibiotic drug. Moreover, the drug-loaded nanofibrous membranes exhibited excellent cytocompatibility with Melanoma cells, indicative to the great potential potential for applications in wound dressing.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
E-commerce has a strong development momentum in recent years, and the oligopoly structure trend of e-commerce platforms has become more and more obvious. At the same time, the “Pick One of Two” ...behavior of e-commerce platforms has been constantly performed in various fields. Although “Pick One of Two” behavior has existed for many years in China, it has not been effectively regulated so far. The “Pick One of Two” behavior of e-commerce platforms not only destroys the fair competition order between platforms, but also damages the legitimate rights and interests of operators and consumers. In view of this, this paper analyzes the dual nature of e-commerce platform “Pick One of Two” behavior and the inadequacy of the theory of abuse of comparative advantage.
Dielectric ceramics are highly desired for electronic systems owing to their fast discharge speed and excellent fatigue resistance. However, the low energy density resulting from the low breakdown ...electric field leads to inferior volumetric efficiency, which is the main challenge for practical applications of dielectric ceramics. Here, we propose a strategy to increase the breakdown electric field and thus enhance the energy storage density of polycrystalline ceramics by controlling grain orientation. We fabricated high-quality -textured Na
Bi
TiO
-Sr
Bi
TiO
(NBT-SBT) ceramics, in which the strain induced by the electric field is substantially lowered, leading to a reduced failure probability and improved Weibull breakdown strength, on the order of 103 MV m
, an ~65% enhancement compared to their randomly oriented counterparts. The recoverable energy density of -textured NBT-SBT multilayer ceramics is up to 21.5 J cm
, outperforming state-of-the-art dielectric ceramics. The present research offers a route for designing dielectric ceramics with enhanced breakdown strength, which is expected to benefit a wide range of applications of dielectric ceramics for which high breakdown strength is required, such as high-voltage capacitors and electrocaloric solid-state cooling devices.
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
► An intermittently aerated MBMBR was investigated to achieve SND via nitrite. ► The intermittent-aeration strategy was an effective approach to achieve nitrition. ► The activities of NOBs were ...inhibited under the intermittently aerated mode. ► The intermittently aerated mode had no effect on the activities of AOBs.
An intermittently aerated moving bed membrane bioreactor (MBMBR) was developed and crucial parameters affecting nitrogen removal from wastewater by simultaneous nitrification and denitrification via nitrite were investigated, without strict control of solids retention time. Changes in the microbiological community and distribution in the reactor were monitored simultaneously. The intermittent-aeration strategy proved effective in achieving nitrition and the chemical oxygen demand (COD) to total nitrogen (TN) ratio was an important factor affecting TN removal. In the MBMBR, the nitrite accumulation rate reached 79.4% and TN removal efficiency averaged at 87.8% with aeration 2
min/mix 4
min and an influent COD/TN ratio of 5. Batch tests indicated that under the intermittently aerated mode, nitrite-oxidizing bacteria (NOB) were not completely washed out from the reactor but NOB activity was inhibited. The intermittently aerated mode had no effect on the activities of ammonia-oxidizing bacteria. Fluorescence in situ hybridizations (FISH) results also suggested that NOBs remained within the system.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This paper presents a 12/8-pole, three-phase, modular-stator hybrid excitation switched reluctance machine (MSHSRM) assisted with permanent magnets (PMs) as well as its design consideration and ...performance evaluation. The basic operating principle is illustrated through a specific form of this machine, and the magnetic equivalent circuit model is built and analyzed. Then, the main parameters of the machine are optimized by the finite-element method. The static magnetic characteristics and dynamic performance of this novel machine are simulated and compared with other two SRMs, one is segmented 12/8 SRM without PM, and the other is the conventional 12/8 SRM with unsegmented structure. Finally, two motor prototypes, including one MSHSRM and one conventional SRM of the same size are manufactured. The static magnetic characteristic and dynamic operation of two motor drives are measured to confirm the predictions. The simulation and experimental results indicate that this MSHSRM has higher power and stronger load capacities than the conventional SRM in whole speed range with higher torque/power density and higher torque per ampere.
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