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When a high-power very low frequency (VLF) communication system is in operation, the end of the antenna is in an alternating strong electric field environment. Due to dielectric loss, abnormal temperature rise may occur at the end of the antenna. To solve the problem, analysis on the electric field distribution and temperature rising effect at the end of the antenna is first carried out in this paper. The factors that affect the electric field distribution and temperature rising, including the amplitude and frequency of the excitation voltage, the diameter of the antenna conductor and the material properties of the outer sheath of the antenna, are studied in detail. A novel approach to improve the electric field distribution and to suppress temperature rising is proposed by designing a dielectric loss eliminator, and the effectiveness of the designed device is verified by simulation.

Menthol, a cyclic terpene alcohol, plays a critical role in overcoming the blood-brain barrier and stratum corneum barrier. Herein, we innovatively propose a menthol nanoliposome (Men-nanoLips) that can dramatically increase lymph node accumulation of the dendritic cell (DC)-based anti-tumor vaccines. Specifically, Men-nanoLips efficiently enhanced lymphatic endothelial cell (EC) barrier permeability by reducing the expression of tight junction proteins. And interestingly, Men-nanoLips not only up-regulated the expression of CCR7 in DCs but also increased the secretion of CCL21 in lymphatic ECs. Moreover, Men-nanoLips promoted DC vaccine maturation as evidenced by increasing the expression of costimulatory molecules and up-regulating the pseudopodia-like protein. With those complementary mechanisms provided by Men-nanoLips, the number of the B16 whole-tumor cell lysate-loaded DCs that target the draining LN enhanced remarkably and significantly boosted the treatment efficacy of DC anti-tumor vaccines. Therefore, we concluded that Men-nanoLips could be instructive for increasing LN homing of DC vaccines.

As the emerging phototheranostic agents, near-infrared (NIR) organic small molecules have drawn more and more attention because of the unique advantages, such as well-defined chemical structure, hi...

Typhoons can have disastrous effects on power systems. They may lead to a large number of power outages for distribution network users. Therefore, this paper establishes a model to predict the power outage quantity of distribution network users under a typhoon disaster. Firstly, twenty-six explanatory variables (called global variables) covering meteorological factors, geographical factors, and power grid factors are considered as the input variables. On this basis, the correlation between each explanatory variable and response variable is analyzed. Secondly, we established a global variable model to predict the power outage quantity of distribution network users based on Random Forest (RF) algorithm. Then the importance of each explanatory variable is mined to extract the most important variables. To reduce the complexity of the model and ease the burden of data collection, eight variables are eventually selected as important variables. Afterward, we predict the power outage quantity of distribution network users again using the eight important variables. Thirdly, we compare the prediction accuracy of a model called the No-model that has been used before, Linear Regression (LR), Support Vector Regression (SVR), Decision Tree Regression (DTR), RF-global variable model, and RF-important variable model. Simulation results show that the RF-important variable model proposed in this paper has a better effect. Since fewer variables can save prediction time and make the model simplified, it is recommended to use the RF-important variable model.

Improving the effective treatment depth of photodynamic therapy (PDT) is an important issue to resolve for its clinical application. In this study, a new biocompatible photosensitizer (PS), namely TQs-PEG4, based on thiadiazolo[3,4-g]quinoxaline (TQ) with ultra-high photoactive property is designed and synthesized. TQs-PEG4 possesses an ultra-high singlet oxygen quantum yield (ΦΔ = 1.04). After encapsulating it with a biodegradable copolymer (DSPE–mPEG2000–cRGD), well distributed organic TQs-PEG4 nanoparticles (NPs) are formed with good water dispersity and excellent active tumor-targeting property. In vitro PDT experiments reveal that TQs-PEG4 NPs present excellent phototoxicities towards different cancer cell lines with an ultra-low dosage (

A low-cost differential mobility spectrometer (DMS) was constructed using polytetrafluoroethylene printed circuit boards with two pairs of gold electrodes. The printed circuit boards were used to c...

Typhoons have substantial impacts on power systems and may result in major power outages for distribution network users. Developing prediction models for the number of users going through typhoon power outages is a high priority to support restoration planning. This study proposes a data-driven model to predict the number of distribution network users that may experience power outages when a typhoon passes by. To improve the accuracy of the prediction model, twenty six explanatory variables from meteorological factors, geographical factors and power grid factors are considered. In addition, the authors compared the application effect of five different machine learning regression algorithms, including linear regression, support vector regression, classification and regression tree, gradient boosting decision tree and random forest (RF). It turns out that the RF algorithm shows the best performance. The simulation indicates that the accuracy of the optimal model error within ±30% can reach up to 86%. The proposed method can improve the prediction accuracy through continuous learning on the existing basis. The prediction results can provide efficient guidance for emergency preparedness during typhoon disaster, and can be used as a basis to notify the distribution network users who are likely to lose power.

Improving the effective treatment depth of photodynamic therapy (PDT) is an important issue to resolve for its clinical application. In this study, a new biocompatible photosensitizer (PS), namely TQs-PEG4, based on thiadiazolo[3,4

Over the past five years, oxygen-based nanocarriers (NCs) to boost anti-tumor therapy attracted tremendous attention from basic research and clinical practice. Indeed, tumor hypoxia, caused by elevated proliferative activity and dysfunctional vasculature, is directly responsible for the less effectiveness or ineffective of many conventional therapeutic modalities. Undeniably, oxygen-generating NCs and oxygen-carrying NCs can increase oxygen concentration in the hypoxic area of tumors and have also been shown to have the ability to decrease the expression of drug efflux pumps (e.g., P-gp); to increase uptake by tumor cells; to facilitate the generation of cytotoxic reactive oxide species (ROS); and to evoke systematic anti-tumor immune responses. However, there are still many challenges and limitations that need to be further improved. In this review, we first discussed the mechanisms of tumor hypoxia and how it severely restricts the therapeutic efficacy of clinical treatments. Then an up-to-date account of recent progress in the fabrications of oxygen-generating NCs and oxygen-carrying NCs are systematically introduced. The improved physicochemical and surface properties of hypoxia alleviating NCs for increasing the targeting ability to hypoxic cells are also elaborated with special attention to the latest nano-technologies. Finally, the future directions of these NCs, especially towards clinical translation, are proposed. Therefore, we expect to provide some valued enlightenments and proposals in engineering more effective oxygen-based NCs in this promising field in this comprehensive overview.

The biological applications of multi-walled carbon nanotubes (MWCNTs) may lead to their exposure to human blood vessels, but the influence of their physicochemical properties on toxicity to endothelial cells is incompletely known. Here, human umbilical vein endothelial cells (HUVECs) were exposed to three commercially available MWCNTs, namely XFM4, XFM22, and XFM34 (diameters XFM4 XFM22 XFM34), to understand the possible role of their diameter on toxicity. Based on the same mass concentration, XFM4 induced significantly higher level of cytotoxicity than the other two MWCNTs, and HUVECs internalized more XFM4. Cytokine release, monocyte adhesion, and intracellular reactive oxygen species levels were significantly induced only after XFM4 treatment. The exposure to XFM4 significantly reduced the expression of autophagic genes autophagy-related 7 (ATG7), autophagy-related 12 (ATG12), and beclin 1 (BECN1) and increased the expression of endoplasmic reticulum (ER) stress genes DNA damage inducible transcript 3 (DDIT3) and X-box binding protein 1 spliced (XBP-1s). Moreover, the modulation of autophagy-ER stress by chemicals resulted in a significant increase in the cytotoxicity of XFM4 but had minimal impact on the cytotoxicity of XFM34. These data indicate that the diameter of MWCNTs may influence their toxicity to HUVECs, probably through autophagy dysfunction and ER stress.

We recently synthesized ZnO nanomaterials (denoted as ZnO nanorods [NRs] and Mini-NRs) and suggested that their cytotoxicity could be related with the activation of endoplasmic reticulum (ER) stress apoptosis. However, in a complex biological microenvironment, the ER stress-apoptosis pathway could also be modulated by biological molecules, such as free fatty acids, leading to unpredicted biological effects. In this study, we investigated the combined toxicity of ZnO NRs/Mini-NRs and palmitate (PA) to THP-1 macrophages. PA influenced the zeta potential and solubility of ZnO NRs and ZnO Mini-NRs in water, which indicated a change of colloidal stability. Exposure to ZnO NRs and Mini-NRs dose-dependent decreased cellular viability and release of soluble monocyte chemotactic protein 1 (sMCP-1), and these effects were significantly promoted with the presence of PA. However, ZnO NR- and Mini-NR-induced intracellular Zn ions or reactive oxygen species were not significantly affected by PA. ZnO NRs and ZnO Mini-NRs significantly promoted the expression of ER stress genes HSPA5, DDIT3, XBP-1s and apoptotic gene CASP3, whereas PA also modestly promoted the expression of HSPA5, DDIT3 and CASP3. Interestingly, the ER stress inducer thapsigargin showed a similar effect as PA to promote the cytotoxicity of ZnO NRs and ZnO Mini-NRs. It is suggested that PA might promote the cytotoxicity of ZnO NRs and ZnO Mini-NRs possibly by promoting ER stress.

Pollution flashover accident seriously threatens the security and stability of power grid. It is very important to clean the contaminated insulator to avoid pollution flashover accident. In view of the shortcomings of the traditional cleaning methods, a novel method of 1064 nm pulse laser cleaning insulator contamination is proposed in this paper. The finite element simulation model of laser cleaning insulator contamination is established and the numerical simulation calculation is carried out. The distribution characteristics of temperature field in the process of laser cleaning are obtained by simulation. The results show that the temperature in the center of the laser spot is the highest. When the laser power is 50 W, the maximum temperature of the contamination layer reaches to 411 K. The temperature gradually decreases along the radial direction, and decreases to 312 K at the edge of the spot. The temperature decreases rapidly in the depth direction. The influence of laser power on the distribution of temperature field is analyzed and the maximum temperature of the contamination layer is linearly related to the laser power.

The antenna end of the tethered balloon-type high-power VLF communication system will be exposed to an extremely strong alternating electric field environment when it is in operation. Due to dielectric loss, an abnormal temperature rise may occur at the antenna end, which may lead to an antenna fracture in serious cases. It is an effective measure to install a corona ring at the end of the antenna to prevent such accidents. In this paper, the structural parameters of the corona ring, including ring radius, tube radius, and ring depth, are optimized based on intelligent optimization algorithm to significantly improve the electric field distribution and restrain the temperature rise to the maximum extent. The effectiveness of the optimization results is verified by simulation.

As a new technology, laser cleaning can be applied to the on-line cleaning of insulators. There is still a potential risk of damage to the substrate of insulators under laser irradiation. The finite element method is used to simulate the laser-induced damage of porcelain insulators in this paper. The results show that the thermal stress is unevenly distributed in the longitudinal direction. When the laser power is 750W, the maximum tensile stress of the glaze layer exceeds its tensile strength, and the glaze layer will be cracked. The inherent defects will affect the laser damage threshold of the material. When there are pit defects in the glaze layer, the laser damage threshold is reduced to 350W. Different pit sizes would also have a certain impact on the laser damage threshold. The smaller the pit sizes, the easier it is for the laser to damage the material and the lower the laser damage threshold.

The deregulation of electricity market enables residential customers to select or switch to a suitable plan with low expenditure. We proposed an optimal pricing strategy for electricity providers by considering customers’ willingness to switch to another plan and competition from other electricity providers. Firstly, plan-oriented clustering is investigated. Then, new competitive plans are put forward based on objective customers classes and current plans using Weber-Fechner law. In the end, promising numerical results of profit in different objective customer classes and different situations demonstrate that the proposed strategy could effectively provide electricity providers with more competitive plans.

In recent years, the ecological damage caused by human activities has been intensified, and typhoon disasters have been increasingly frequent, which has brought huge structural damage to the power system. Therefore, this paper summarizes the research on power grid loss prediction and early warning under typhoon disaster from three aspects: power grid loss prediction under typhoon disaster, power grid loss early warning under typhoon disaster and construction of power outage defense system. Some instructive conclusions are obtained in this paper.

The development of smart grids and worldwide spread of smart meters enable a great opportunity to develop the demand-side management. How to apply the analysis of household smart meter data to improve energy efficiency and implement demand response schemes has become a new hot field. This paper presents an overview of the literature on the most recent methods of smart meter data clustering analysis. Mainly includes the latest applications of hierarchical, k-means clustering, self-organizing maps, principal and components analysis and other algorithms in smart meter data analysis. Furthermore, this paper reviews the application of smart meter data analysis in demand response potential estimation and candidate selection, the action analysis and scheme management of demand response. Through the literature review, we find the crucial points in the existing literature. Due to the characteristics of data, data feature extraction and form conversion are required before clustering. To ensure the effectiveness of demand response schemes, power companies need to overcome the random characteristics of users and conduct various feasibility studies around customers. Through a comprehensive review in this paper, we believe that with the solution of these crucial points, the application of smart meter data will have broad prospects.

The fouling phenomenon of the insulation equipment outside the substation will affect the safety and reliable operation of the substation. Traditional cleaning methods have been unable to meet the requirements. In this paper, the continuous laser is applied to insulator cleaning and a finite element model is established for laser cleaning of porcelain insulator. Three factors influencing the effect of laser cleaning have been discussed, including the power density of pulse laser, the radius of the laser spot and the scanning velocity of laser. The simulation results show that the power density and radius of the laser spot are positively correlated with the highest temperature of the pollution surface, while the scanning velocity is negatively correlated with the pollution surface temperature. Furthermore, the variation tendency and the influence of the above three factors on the surface temperature are analyzed.

A water-soluble photosensitizer, PQs-PEG5, based on a novel pyrazino[2,3-g]quinoxaline (PQ) prototype compound (PQs-5), was designed and synthesized. It has strong linear absorption within 400–600 nm and a desirable two-photon absorption cross section (100–1290 GM) within 740–1000 nm, and it exhibits both a high fluorescence quantum yield (∼0.55) and singlet oxygen quantum yield (∼0.47). By carrying out in vitro cell imaging and photodynamic therapy (PDT) experiments on PQs-PEG5 with HeLa and 4T1 cells, it was demonstrated that PQs-PEG5 can present outstanding bioimaging performance and PDT efficacies simultaneously. Under one-photon excitation (1PE) of a 635 nm diode laser (60 mW cm−2, 5 min) or two-photon excitation (2PE) of an 820 nm fs laser (100 mW, 80 MHz, 140 fs, 5 min), PQs-PEG5 (10 μM) could cause HeLa and 4T1 cell death effectively, which indicated its great potential as a novel photosensitizer for both 1PE- and 2PE-PDT applications.

The remanence (residual flux) in the core of power transformers needs to be determined in advance to eliminate the inrush current during the process of re-energization. In this paper, a novel method is proposed to determine the residual flux based on the relationship between residual flux and the measured magnetizing inductance. The paper shows physical, numerical, and analytical explanations on the phenomenon that the magnetizing inductance decreases with the increase of residual flux under low excitation. Numerical simulations are performed by EMTP (Electro-Magnetic Transient Program) on a 1 kVA power transformer under different amounts of residual flux. The inductance&ndash, remanence curves are nearly the same when testing current changes. Laboratory experiments conducted on the same transformer are in line with the numerical simulations. Furthermore, numerical simulation results on a 240 MVA are reported to demonstrate the effectiveness of the proposed method.

Methylammonium (MA) and formamidinium (FA) mixed perovskites have been widely utilized in invert planar perovskite solar cell (PSC) applications due to their great potentials such as solution processing, high power conversion efficiency, high absorption, and low cost. To commercialize the PSCs, further improving the device performance without detrimentally changing the device configuration is important at present. Herein, small amount (5%) of CsI is introduced to form a pinhole-free mixed perovskite light absorption layer in a flexible photovoltaic system with enhanced main photovoltaic parameters of the device, resulting in a ~ 36% enhancement of power conversion efficiency (PCE) from 8.9% to 12.1% (from 11.3% to 14.6% for rigid device). The origins of the enhancement have been studied by exploring the crystal structures, optical absorption, and crystal morphlogies of the synthesised perovskite layers and charge carrier behaviors of the devices. Through small perturbation transient photovoltage (TPV) measurements, the lifetime of the charge carriers are found remarkably increased after the small amount of CsI doping. These characteristics make cation doping of the mixed perovskite layer a promising method in facile tuning of the film quality of the perovskite layer for efficient charge carriers transporting and further boosting the PCE of the devices.

When entering circulation, multi-walled carbon nanotubes (MWCNTs) will inevitably adsorb proteins, which can consequently influence their toxicity to cells lining human blood vessels. In this study, we investigated the influence of pre-incubation with bovine serum albumin (BSA) on internalization, cytotoxicity, oxidative stress and inflammation induced by pristine/carboxylated MWCNTs to human umbilical vein endothelial cells (HUVECs). Atomic force microscopy (AFM) indicated the adsorption of proteins onto the surface of MWCNTs, which consequently increased the diameter. Pre-incubation with BSA did not obviously influence the hydrodynamic sizes, but decreased the zeta potential of MWCNTs. Transmission electron microscopy (TEM) indicated the internalization of both types of MWCNTs into HUVECs, whereas pre-incubation with BSA appeared to enhance the internalization. MWCNT exposure induced cytotoxicity and oxidative stress, as well as a modest inflammatory response shown as an increased THP-1 adhesion to HUVECs, but not release of interleukin 6 (IL-6) or tumor necrosis factor (TNFα). Exposure to MWCNTs pre-incubated with BSA induced less cytotoxicity to HUVECs, associated with increased intracellular glutathione (GSH). However, MWCNTs induced IL-6 and TNFα release, as well as THP-1 adhesion to HUVECs, were enhanced after pre-incubation with BSA. In summary, these data indicated that pre-incubation with BSA could enhance the internalization of MWCNTs to HUVECs, which consequently reduces the cytotoxicity and oxidative stress, but enhances the inflammatory response of MWCNTs. The reduced cytotoxicity and oxidative stress, and enhanced inflammatory responses are likely due to a combined effect of BSA and MWCNTs, which suggests that when assessing the biological effects of MWCNTs in circulation, it is necessary to consider the interactions between MWCNTs and serum proteins.

Large-format prismatic lithium-ion batteries (LIBs) with 52 Ah capacity and Verband Der Automobilindustrie (VDA) standard dimensions were cycled under a preloading force of 2.5 kN at 25 °C. When cycled, the LIBs exhibited a two-stage degradation behavior characterized by a first linear degradation stage and a second nonlinear degradation stage. The two-stage behavior which is also called rollover failure is investigated by post-mortem analysis. When the jelly roll was unfolded, lithium plating and delamination of cathode materials were found in the curved areas. From the scanning electron microscopy (SEM) images, the graphite particles in the curved areas were deformed and cracked. The LIB under a higher preloading force of 5.5 kN was found to have shorter cycle life, indicating mechanical force is one of the factors that lead to the rollover failure. The degradation mechanism was thoroughly illustrated by applying shift voltage-resistance voltage (SV-RV), differential voltage (DV) and electrochemical impedance spectroscopy (EIS) measurements. The SV-RV analysis suggests that lithium plating occurs after around 300 cycles. The shifting to low capacity and broadening of peaks in dV/dQ curves indicate that the second nonlinear degradation stage could be caused by combining loss of active materials (LAM) and loss of lithium inventory (LLI). In the nonlinear degradation stage, ohmic resistance (Rs) and charge transfer resistance (Rct) is dramatically increased as characterized by EIS measurement. The increased Rs and Rct further support the conclusion that LLI and LAM are the dominating degradation mechanism in the nonlinear degradation stage.