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Additive passivation can be an effective strategy to regulate and control the properties of organic–inorganic halide perovskite film. In this article, carbon quantum dots (CQDs), fabricated by non-focused laser irradiation of carbon nanomaterial diluted in anti-solvent ethyl acetate, denoted as EACQDs, were adopted for perovskite film defect passivation and modification of carbon-based CH3NH3PbI3 perovskite solar cells (PSCs). The size of EACQDs can be tuned by manipulating the laser fluence. The morphology of perovskite film was uncovered through scanning electron microscopy and atomic force microscopy. After embedding of EACQDs, the defect in perovskite crystal was reduced, resulting in the decreased carrier recombination and accelerated carrier transportation, which were demonstrated by electrochemical impedance spectroscopy, photoluminescence and time-resolved photoluminescence. As a consequence, with the optimization of 0.01 mg/mL EACQDs (1064 nm–300 mJ·pulse−1·cm−2–10 min), the power conversion efficiency (PCE) of carbon-based PSCs achieved a maximum value of 16.43%, which improved 23.81% when compared with the pristine PSCs of 13.27%. Furthermore, the EACQDs optimized PSCs also exhibited an excellent stability and still retained 86% of its initial PCE after 50-day storage at the room atmosphere with a humidity of 30–50%.

An online Extended Kalman Filter (EKF)-Dynamic Recurrent Neural Network (DRNN) autopilot implementation strategy for Very Large Crude Carrier (VLCC) heading hybrid control with uncertain dynamics is designed in this paper. The autopilot scheme is based on a DRNN control model, which learns VLCC dynamic characteristics, while the VLCC heading control is estimated by the EKF to minimize squared course error. The online EKF-DRNN autopilot provides optimal control on the basis of fuel-saving evaluation criteria using the heading deviation and rudder angle. Therefore, the autopilot output is guaranteed to converge to the desired VLCC trajectory asymptotically. The proposed strategy is evaluated by applying it to VLCC Yuan Kun Yang from COSCO Shipping, and works excellently under different loads, speed and weather conditions. The VLCC heading hybrid controller is also assessed by ‘Z’ manoeuvring and turning test, and the superiority of the online EKF-DRNN autopilot is demonstrated. The remote online monitoring of Yuan Kun Yang’s main navigation data shows that it improved fuel-saving properties despite worsening weather conditions causing increased yawing.

In this study, the graphene oxide (GO)-TiO2 nanocomposite film prepared by the sol–gel method was used to optimize the photoelectric performance of the perovskite solar cells (PSCs), which structure is based on the carbon electrode and no hole transport layer. Through a series of scientific experiments, it has been proved that the GO–TiO2 nanocomposite film has excellent electrical properties. The electron transport layer which containing 1 wt% of GO makes the PSCs have the most excellent performance. Compared with the controlling PSCs, the photoelectric conversion efficiency of PSCs, which containing 1 wt% GO, increased by 9.3%, from 12.44 to 13.60%. Short-circuit current density (Jsc) increased by 5.99%, from 21.55 to 22.84 mA/cm2, and open circuit voltage remained basically unchanged. It can be seen from the measurement results that the trend of incident photon-to-electron conversion efficiency spectrum is consistent with J–V characteristics, indicating that the PSCs device containing 1 wt% GO has the best electron extraction and transfer performance. However, when too much GO is used, the increased surface charge trap state will lead to the acceleration of carrier recombination and the decrease of electron transport path, and the photovoltaic parameters show a downward trend.

Neutrophils can responsively release reactive oxygen species (ROS) to actively combat infections by exogenous stimulus and cascade enzyme catalyzed bio-oxidation. A supramolecular nanogel is now used as an artificial neutrophil by enzymatic interfacial self-assembly of peptides (Fmoc-Tyr(H2 PO3 )-OH) with magnetic nanoparticles (MNPs) and electrostatic loading of chloroperoxidase (CPO). The MNPs within the nanogel can elevate H2 O2 levels in cancer cells under programmed alternating magnetic field (AMF) similar to the neutrophil activator, and the loaded CPO within protective peptides nanolayer converts the H2 O2 into singlet oxygen (1 O2 ) in a sustained manner for neutrophil-inspired tumor therapy. As a proof of concept study, both the H2 O2 and 1 O2 in cancer cells increase stepwise under a programmed alternating magnetic field. An active enzyme dynamic therapy by magnetically stimulated oxygen stress and sustained enzyme bio-oxidation is thus shown with studies on both cells and animals.

Two new irregularity high-nuclearity clusters [Co26(TC4A)6(HL)4Cl4(HCOO)4(CH3O)2(OH)2(DMF)10(H2O)5] (+ solvent) (Co26) and [Ni28(TC4A)6(HL)6(PO4)2(μ3-O)2Cl2(CH3OH)14(H2O)2(DMF)8][(CH3NH2CH3)4] (+ solvent) (Ni28) have been solvothermally synthesized by p-tert-butylthiacalix[4]arene (H4TC4A), transition metals (CoCl2·6H2O/NiCl2·6H2O), and 1-hydroxy-2-(3-pyridinyl)ethylidene-1,1-diphosphonic acid (H5L). The clusters were structurally characterized by single crystal X-ray diffraction, PXRD, TGA, and FT-IR spectrum and Raman spectrum. Co26 features a rodlike Co26 core constructed by six Co4–TC4A secondary building units (SBUs) and four HL4– with two extra cobalt ions. Ni28 cluster represents a flowerlike Ni28 core built from six Ni4–TC4A SBUs, six HL4–, and four additional nickel ions. The multidentate risedronic acid displaying various new coordination mode bonds with SBUs to assemble two nanoclusters that enable high density possible coordinatively unsaturated metal sites (PCUMSs). Co26 and Ni28 clusters can...

In this work, inorganic tin-doped perovskite quantum dots (PQDs) are incorporated into carbon-based perovskite solar cells (PSCs) to improve their photovoltaic performance. On the one hand, by controlling the content of Sn2+ doping, the energy level of the tin-doped PQDs can be adjusted, to realize optimized band alignment and enhanced separation of photogenerated electron–hole pairs. On the other hand, the incorporation of tin-doped PQDs provided with a relatively high acceptor concentration due to the self-p-type doping effect is able to reduce the width of the depletion region near the back surface of the perovskite, thereby enhancing the hole extraction. Particularly, after the addition of CsSn0.2Pb0.8I3 quantum dots (QDs), improvement of the power conversion efficiency (PCE) from 12.80 to 14.22% can be obtained, in comparison with the pristine device. Moreover, the experimental results are analyzed through the simulation of the one-dimensional perovskite/tin-doped PQDs heterojunction.

Because of the special low-dimensional physical properties of quantum dots (QDs) and the excellent optoelectronic properties of perovskite, the combination of perovskite solar cells (PSCs) and QDs may largely be one of the breakthroughs in device performance. However, little attention has been paid to the effect of the size of QDs on device performance except for bandgap tuning. In this work, non-toxic SnS QDs of different sizes were prepared by varying the reaction temperature of the thermal injection method. Their optical bandgaps with sizes were investigated, and they were implanted into the active layers of the carbon-based PSCs without hole transport layer. The effects of implanting SnS QDs with different sizes on the perovskite film quality and PSCs performance were studied. The cells implanted with SnS QDs of the best size (average 6.9 nm) achieved a photoelectric conversion efficiency of 14.26%, reaching a 12.42% improvement. The improved performance was mainly attributed to the presence of SnS QDs, which provided more nucleation sites for the growth of perovskite grains, and contributed to better quality perovskite films (including higher crystallinity, increased grain numbers and fewer surface defects), thus improving the light utilization, accelerating carrier transfer and reducing carrier recombination in the active layers. The successful implantation of QDs with different sizes in this paper has facilitated the development of the combination of perovskite and QDs in mesoporous PSC.

Under the background of the rapid development of Internet technology, the emergence of Internet platform accelerates the industrial agglomeration. As a chain connecting the material circulation between industries, the rise of logistics industry is inevitable. As a key link of logistics industry, transportation, along with the rise of logistics industry, has led to an increase in traffic accidents year by year. Therefore, based on the national road traffic accident data from 2006 to 2019, this paper uses SPSS 26.0 to analyse the accident incidence, casualties and direct property loss indicators of different regions and occupation, and study the characteristics of perpetrators and casualties. The results show that the traffic accidents in the whole country show a downward trend, but they are unbalanced. Workers and farmers accounted for the largest proportion, but the death and injury rate showed a downward trend. Other showed an upward trend in the past five years, especially in the delivery industry. Future road traffic safety management should take corresponding measures to reduce the accident rate from the perspective of the development of related industries.

Perovskite solar cells (PSCs) have been developing rapidly since they were discovered, and their excellent photoelectric properties have attracted wide attention from researchers. The compact layer is an important part of PSCs, which can transport electrons and block holes. SnO2 is an excellent and commonly used electron transport layer (ETL) material, and doping modification is an effective way to improve performance. Here, Zn with a similar radius to Sn has been introduced to the doping of the SnO2 compact layer to achieve the purposes of conductivity enhancement of the compact layer and followed photoelectric performance improvement of the device. Zn-SnO2 compact layers with different doping concentrations were prepared and applied to mesoporous architecture PSCs. When the doping content was 5%, the power conversion efficiency (PCE) of the device based on the Zn-SnO2 compact layer has increased from 9.08% to 10.21%, with an increase of 12.44%. The doping of SnO2 promotes its application in low-cost PSCs.

With the aim to improve the accuracy of laser triangulation measurements, this paper proposes to analyze the error caused by different colors of a measurand surface and proposes a compensation method. By investigating the fundamentals of laser triangulation, the color error is obtained via the Phong model, while the relationship between the measurement error and color is obtained through experiments. Based on the above results, a color error compensation method is proposed, which produces a color-error library according to the error of the different colors. Thus, the correlation between the error and color of the measurand surface is also calculated. The experimental data demonstrates that this method can reduce the error to 10% and maintain the color measurement error to within 90 μm. Moreover, this technique is of great significance to measure a measurand surface with different colors.

Developing a spatiotemporal-controlled platform with feasible synthesis and multifunctionality is highly desirable in the field of nanomedicine. Here, we present a near-infrared (NIR)-light-triggered approach to control the supramolecular assembly system for drug release and achieve synergistic chemo-photothermal therapy for cancer. A cucurbit[7]uril (CB[7]) stabilized gold nanostar (GNS) platform is designed to encapsulate the anticancer drug camptothecin (CPT) via host-guest chemistry. Importantly, CB[7] behaves not only as a surfactant to improve the stability of GNS in the aqueous solution but also as the cage for intermolecular assembly of CPT molecules. Moreover, without the competitive complexation, the drug release could be stimulated under NIR light irradiation. Synergistic treatment of cancer can be achieved by combining chemotherapy with the photothermal effect of GNS. This work develops a NIR-light-triggered cucurbituril-based drug-release approach that opens the door for remote control of drug release in the supramolecular assembly system.

Fiber-shaped supercapacitors with remarkable flexibility and considerable energy-storage capacity have become the promising candidates in the field of wearable and portable electronic devices. In fact, both of the mechanical properties and electrochemical performance are in need of significant improvement to satisfy the practical applications of fiber-shaped supercapacitors. In this paper, a high-performance cellulose nanofibers reinforced graphene/polypyrrole microfiber is fabricated by a convenient wet-spinning strategy. The cellulose nanofibers act as both “enhancer” and “spacer”, which not only provide substantial hydrogen bonds to strengthen the interlaminar force but also prevent the restacking of the graphene sheets. This microfiber exhibits excellent tensile strength (364.3 MPa), which is superior to most of the reported fibers for supercapacitors. Meanwhile, the assembled fiber-shaped supercapacitors possess high specific capacitances of 334 mF cm−2 in liquid electrolyte and 218 mF cm−2 in solid electrolyte at the current density of 0.1 mA cm−2, which are also at the top level of fiber-shaped supercapacitors. The presented strategy combines the industrially viable wet-spinning technology and the well-designed structure for the fabrication of high-performance ternary fiber-shaped supercapacitors, providing a good reference for the development of wearable and portable energy storage devices.

In this study, hole-conductor-free perovskite solar cells (PSCs) were incorporated with a core/shell-structured upconversion emission material, β-NaYF4:Yb3+,Er3+@SiO2 (NYEY@S) nanoparticles, which led to an excellent performance due to the expanded range of spectral response in ambient air. The advantage of core/shell-structured NYEY@S nanoparticles in PSCs is that they overcome the electron trapping caused by bare β-NaYF4:Yb3+,Er3+ (NYEY) nanocrystals. By incorporating NYEY@S nanoparticles into PSCs as an upconverting mesoporous layer, the PSCs achieve greater conversion efficiency and attain a value of 9.92%, which is 21% higher than that of normal PSCs (only TiO2 nanoparticles as the mesoporous layer). This result indicates that incorporating NYEY@S into PSCs provides a new approach to enhance the photovoltaic performance of PSCs.

We designed and explored self-assembled gold nanoparticles (SAGNPs) by introducing dithiol modified polyethylene glycol (PEG) for internanoparticle cross-linking. SAGNPs could enhance uptake into cancer cells and be disintegrated by glutathione (GSH) to achieve tumor microenvironment-activated biodegradation. This assembled structure improved the photothermal effect compared to single gold nanospheres.

A new tetradecanuclear cobalt cluster [Co14(TC4A)3Cl3(Tz)12(H2O)6](OH)(DMF)14(CH3OH)6(H2O)4 (Abbr. Co14, H4TC4A = p-tert-Butylthiacalix[4]arene, HTz = 1H-tetrazole) was obtained by the solvothermal reaction of CoCl2·6H2O, H4TC4A and Htz in DMF. The cluster featured the quadrilateral planar CoII4 units housing tri-capped trigonal Co12 clusters with two enclosed Co nanocages linked by Tz ligands. The uniform CoO/Co9S8@CN composite derived from direct annealing of Co14 clusters was obtained and characterized by XRD, EDS, XPS, and Raman spectra. The composite on nickel foam (CoO/Co9S8@CN/NF) was used as an electrode to fabricate supercapacitors with specific capacitances of 83.7% at 2 A g−1 and 70.0% at 5 A g−1 at 0.5 A g−1 (303.3 F g−1). The composite from Co14 precursor also shows high charge–discharge reversibility with a capacity retention of 96.3% and average columbic efficiency of 98.2% after 1000 cycles at 2.0 A g−1.

Metal particles with excellent conductivity can be used as additives to ameliorate the performance of perovskite solar cells (PSCs). However, it is formidable to generate stable liquid metal particles especially quantum dots because of the room-temperature fluidity. Herein, in this work, eutectic gallium-indium liquid metal quantum dots (GIQDs) were prepared via pulsed laser irradiation in anti-solvent and incorporated in perovskite film to accelerate electron transport due to the superior conductivity. As a result, the charge transport resistance was decreased, leading to the fast quenching effect and short carrier lifetime at the surface of perovskite film, which were verified by steady-state and time-resolved photoluminescence. Besides, the reduced charge recombination contributed to the enhancement of current density. Moreover, after the optimization of 0.1 mg/mL GIQDs incorporated in perovskite film, the power conversion efficiency of PSCs obtained a champion value of 15.55%, which improved 17.18% when compared with pristine samples of 13.27%. This article will pave the way for binary liquid metal synthesizing and optoelectronic applications.

Road network bottleneck would shift around according to the demand or supply, and therefore behaves differently from static bottlenecks such as on–off ramp and lane drop. The identification of dyna...

In this paper, a TiO2 nanowire film synthesized via a hydrothermal method was prepared as a photoanode for dye-sensitized solar cells (DSSCs). The synthesized TiO2 nanowires were characterized by t ...

Extraction of radioactive uranium from the natural seawater is regarded as one of the most promising ways to address the shortage of uranium resources. As a kind of potential uranium adsorbent, more attention has been paid to metal–organic framework materials (MOFs) due to large specific surface area and high ion selectivity. Currently, however, MOF adsorbents are hardly applied to the real seawater in view of the relatively low uranium adsorption capacity and recyclable issues. Herein, we present the monolithic MOF adsorbent with photothermally enhancing uranium adsorption capacity. Carbon sponge (CS) substrate with macroporous open cell structure was used as excellent photothermal conversion material. Zr-MOF (UiO-66-NH2) crystals were in situ grown on the fibrils network of polydopamine (PDA) pre-coated CS to obtain UiO-66-NH2@CS-PDA adsorbent. It is found that UiO-66-NH2 coating with perfect coverage and good adhesion has a high mass loading (>85 wt%). As a result, UiO-66-NH2@CS-PDA adsorbents exhibited the advantage of high-selectivity, high-affinity and cycling stability. Compared with the dark condition, the uranium adsorption amount was increased by 32.37% after 4 weeks in the natural seawater under simulated solar irradiation, which was mainly ascribed to the endothermic behavior of uranium adsorption process. Moreover, the elasticity attribute of CS was essential for sustenance of volume variation buffering during seawater flow. As a recyclable and favorable elastic large-scale monolithic MOF adsorbent, UiO-66-NH2@CS-PDA holds great promise for extracting uranium from the natural seawater.

In this work, NaEuF4 nanoparticles (NPs) with high dispersity and uniformity were synthesized using a hydrothermal method and introduced into the TiO2 mesoporous layer of perovskite solar cells (PSCs) for testing as high efficiency, downconversion materials. NaEuF4 can convert high-energy photons into low-energy photons for absorption by CH3NH3PbI3 and generation of more electron–hole pairs; we tested the hypothesis that this would extend the sunlight absorption range and improve the photovoltaic performance of PSCs. When NaEuF4 NPs were incorporated into TiO2 mesoporous layers, PSCs achieved power conversion efficiencies of 14.51%, which were better than those of the control PSCs. The use of NaEuF4 NPs for improving PSC photovoltaic performance, as shown herein, could encourage the greater use of solar energy.

In this study, Ag@SiO2 nanoparticles were synthesized by a modified St&ouml, ber method for preparing the TiO2 mesoporous layer of carbon counter electrode-based perovskite solar cells (PSCs) without a hole transporting layer. Compared with normal PSCs (without Ag@SiO2 incorporated in the TiO2 mesoporous layer), PSCs with an optimal content of Ag@SiO2 (0.3 wt. % Ag@SiO2-TiO2) show a 19.46% increase in their power conversion efficiency, from 12.23% to 14.61%, which is mainly attributed to the 13.89% enhancement of the short-circuit current density, from 20.23 mA/cm2 to 23.04 mA/cm2. These enhancements mainly contributed to the localized surface Plasmon resonance effect and the strong scattering effect of Ag@SiO2 nanoparticles. However, increasing the Ag@SiO2 concentration in the mesoporous layer past the optimum level cannot further increase the short-circuit current density and incident photon-to-electron conversion efficiency of the devices, which is primarily ascribed to the electron transport pathways being impeded by the insulating silica shells inside the TiO2 network.

Targeted therapy is highly challenging and urgently needed for patients diagnosed with triple negative breast cancer (TNBC). Here, a synergistic treatment platform with plasmonic–magnetic hybrid nanoparticle (lipids, doxorubicin (DOX), gold nanorods, iron oxide nanocluster (LDGI))–loaded mesenchymal stem cells (MSCs) for photoacoustic imaging, targeted photothermal therapy, and chemotherapy for TNBC is developed. LDGI can be efficiently taken up into the stem cells with good biocompatibility to maintain the cellular functions. In addition, CXCR4 on the MSCs is upregulated by iron oxide nanoparticles in the LDGI. Importantly, the drug release and photothermal therapy can be simultaneously achieved upon light irradiation. The released drug can enter the cell nucleus and promote cell apoptosis. Interestingly, light irradiation can control the secretion of cellular microvehicles carrying LDGI for targeted treatment. A remarkable in vitro anticancer effect is observed in MDA‐MB‐231 with near‐infrared laser irradiation. In vivo studies show that the MSCs‐LDGI has the enhanced migration and penetration abilities in the tumor area via both intratumoral and intravenous injection approaches compared with LDGI. Subsequently, MSCs‐LDGI shows the best antitumor efficacy via chemo‐photothermal therapy compared to other treatment groups in the TNBC model of nude mice. Thus, MSCs‐LDGI multifunctional system represents greatly synergistic potential for cancer treatment.

In this study, Ag nanoparticles with diverse particle size and concentration, fabricated via the polyol method, were embedded in a TiO2 compact film to improve the power conversion efficiency of perovskite solar cells. Obtained results showed that Ag nanoparticles embedded in the TiO2 compact film do not affect the crystal structure of TiO2, while the size of the Ag nanoparticles can strongly influence the light absorption capacity of perovskite materials. However, the absorption intensity and power conversion efficiency of perovskite cells decreased with the increase in size of Ag nanoparticles. The amount of Ag nanoparticles was also an important factor for the performance of perovskite solar cells, and Ag nanoparticles in the compact layer were optimized to measure 10 nm in diameter, being embedded at a molar ratio of 1.5% (Ag:Ti = 1.5 mol%). Compared with hole-conductor-free perovskite solar cells that use carbon as counter electrodes, without Ag nanoparticles incorporated in the compact film, the enhanced efficiency of cells developed in this study can be mainly ascribed to the accelerated charge transfer, decreased charge recombination, and enhanced light absorption of the perovskite material in the visible region.

In this study, Ag/nano-TiO2 composites were prepared and introduced into a compact film of perovskite solar cells. A new method was used to create a compact precursor solution consisting of a mixture of ethanol, titanium diisopropoxide bis, and silver nitrate. The Ag/nano-TiO2 composite compact film was formed by spin-coating a compact precursor solution on a fluorine-doped tin-oxide substrate after annealing at 500 °C for 30 min. The Ag/nano-TiO2 composites were observed with a transmission electron microscope. The perovskite solar cells with different contents of the Ag/nano-TiO2 composite compact film were entirely fabricated in ambient air and based on carbon counter electrodes with diverse power conversion efficiency. The addition of Ag to the nano-TiO2 strengthened the optical absorption of the perovskite solar cells in the visible light region and enhanced the efficiency of electron injection in the perovskite solar cell; this result was mainly ascribed to the strong scattering effect and the surface plasmon resonance effect of the metallic Ag nanoparticles in the Ag/nano-TiO2 composite compact film. Because of the enhancement of electron injection, a small content of Ag/nano-TiO2 composite compact film improved the performance of the perovskite solar cell. Moreover, a perovskite solar cell with 1.5% Ag/nano-TiO2 composite compact film possessed the highest power conversion efficiency (η = 8.96%) and short-circuit photocurrent density (J sc) (=20.42 mA cm−2), resulting in a 30% enhancement in power conversion efficiency and a 23% enhancement in J sc when compared to the pristine TiO2 perovskite solar cell.

In cells, mechanical forces play a key role in impacting cell behaviors, including adhesion, differentiation, migration, and death. Herein, a 20 nm mitochondria-targeted zinc-doped iron oxide nanocube is designed as a nanospinner to exert mechanical forces under a rotating magnetic field (RMF) at 15 Hz and 40 mT to fight against cancer. The nanospinners can efficiently target the mitochondria of cancer cells. By means of the RMF, the nanocubes assemble in alignment with the external field and produce a localized mechanical force to impair the cancer cells. Both in vitro and in vivo studies show that the nanospinners can damage the cancer cells and reduce the brain tumor growth rate after the application of the RMF. This nanoplatform provides an effective magnetomechanical approach to treat deep-seated tumors in a spatiotemporal fashion.

As an important part of perovskite solar cells (PSCs), the compact electron transport layer largely determines the performance of devices. Titanium dioxide (TiO2) and tin dioxide (SnO2) are very common materials for the electron transport layer (ETL) in PSCs. However, less has been reported regarding the development of high efficiency mesoporous PSCs based on a SnO2 compact layer. Herein, we prepared Mg doped modified SnO2 film at high temperature, combined it with TiO2 to form a composite compact layer, and then applied PSCs with the mesoporous structure. Compared with the pristine SnO2 compact layer, the composite compact layer has excellent interface contact with perovskite and higher electronic extraction capacity. Moreover, the defect free contact between TiO2 and FTO provides stronger hole blocking ability. Devices based on composite compact layers have almost no hysteresis effect. With the composite compact layer, the devices achieved a champion PCE of 13.01%, which is a 9.79% increase compared to the pristine SnO2 compact layer device.

A Ag-doped double-layer composite film with TiO2nanoparticles (P25) as the underlayer and TiO2nanotube (TNT) arrays with the Ag-doped nanoparticles as the overlayer was fabricated as the photoanode in dye-sensitized solar cells (DSSCs). Five different concentrations of Ag-doped TNT arrays photoelectrode were compared with the pure TNT arrays composite photoelectrode. It is found that the photoelectric conversion efficiency of the TNT arrays composite photoanode is gradually improved from 3.00% of the pure TNT arrays composite photoanode to 6.12% of the Ag-doped TNT arrays photoanode with the increasing of the doping concentration, reaching up to the maximum in the 0.04 mol/L AgNO3solution, and then slightly decreased to 5.43% after continuing to increase the doping concentration. The reason is mainly that the cluster structure of the Ag nanoparticles with large surface area contributes to dye adsorption and the Surface Plasmon Resonance Effect of the Ag nanoparticles improved the photocatalytic ability of the TNT arrays film.

Traffic congestion varies spatially and temporally. The observation of the formation, propagation and dispersion of network traffic congestion can lead to insights about the network performance, the bottleneck dynamics etc. While many researchers use the traffic flow data to reconstruct the congestion profile, the data missing problem is bypassed. Current methods either omit the missing data or supplement the missing part by average etc. Great error may be introduced during these processes. Rather than simply discarding the missing data, this research regards the data missing event as a result of either the severe congestion which prevent the floating vehicle from entering the congested area, or a type of feature of the resulting traffic flow time series. Hence a new traffic flow operational index time series similarity measurement is expected to be established as a basis of identifying the dynamic network bottleneck. The method first measures the traffic flow operational similarity between pairs of neighboring links, and then the similarity results are used to cluster the spatial-temporal congestion. In order to get the similarity under missing data condition, the measurement is implemented in a two-stage manner: firstly the so called first order similarity is calculated given that the traffic flow variables are bounded both upside and downside; then the first order similarity is aggregated to generate the second order similarity as the output. We implement the method on part of the real-world road network; the results generated are not only consistent with empirical observation, but also provide useful insights.

Highly ordered TiO2nanotube arrays (TNT arrays) were fabricated by two-step anodization process. In order to further improve the performance of DSSCs, TNT arrays were optimized by changing the anodization conditions to meet the requirements of high-performance photoanode. The photoelectric conversion properties of DSSCs based on P25/TNT arrays double-layer film with different anodization time were investigated and compared. The results show that the conversion efficiency of 4.20% was achieved in double-layer photoanode at 18 h, with an open-circuit voltage (Voc) of 0.65 V and short-circuit current density (Jsc) of 9.98 mA cm−2.

Herein, the low-cost and eco-friendly zinc cation (Zn2+) is used to replace part of the lead cation (Pb2+) in methylammonium lead iodide (CH3NH3PbI3). The modified perovskite material, CH3NH3PbxZn1-xI3, is then obtained and successfully applied in the construction of hole-conductor-free perovskite solar cells (PSCs) based on carbon counter electrodes. The obtained PSCs with 1 mol% Zn doping dramatically facilitate the formation of dense, high surface coverage perovskite films with large grain size and superior crystallinity. Especially, the power conversion efficiency is up to 15.37%, which is a 14.8% increase, compared to the pristine PSCs. This work finds a superior way to further research lead-reduced PSCs.