During sequential tripping of dc hybrid circuit breakers (HCBs), the energy-absorbing metal-oxide varistors (MOVs) are inserted one after the other rather than simultaneously. This tripping scheme ...has been demonstrated to be effective in reducing the peak fault current and fault interruption time. However, the voltage overshoots during the sequential tripping process need to be suppressed and the fault energy among the MOVs needs to be balanced. Therefore, this article proposes, first, a simple overvoltage suppression method and second, a modified sequential tripping algorithm for HCBs. The former method is realized by increasing the turn- off gate resistance of the semiconductor devices, for which an analytical expression relating the HCB peak overvoltage and the semiconductor switch's gate resistance is provided. The latter algorithm is able to evenly distribute the MOV energy absorption under different grid conditions with the least number of switching events via a predefined tripping scheme and an energy feedback loop. Verification results from both time-domain simulation and a 1.2 kV circuit breaker hardware corroborate the efficacies of the proposed strategies, which will improve the performance of the sequentially tripped HCBs.
A superior Na3V2(PO4)3‐based nanocomposite (NVP/C/rGO) has been successfully developed by a facile carbothermal reduction method using one most‐common chelator, disodium ethylenediamintetraacetate ...Na2(C10H16N2O8), as both sodium and nitrogen‐doped carbon sources for the first time. 2D‐reduced graphene oxide (rGO) nanosheets are also employed as highly conductive additives to facilitate the electrical conductivity and limit the growth of NVP nanoparticles. When used as the cathode material for sodium‐ion batteries, the NVP/C/rGO nanocomposite exhibits the highest discharge capacity, the best high‐rate capabilities and prolonged cycling life compared to the pristine NVP and single‐carbon‐modified NVP/C. Specifically, the 0.1 C discharge capacity delivered by the NVP/C/rGO is 116.8 mAh g−1, which is obviously higher than 106 and 112.3 mAh g−1 for the NVP/C and pristine NVP respectively; it can still deliver a specific capacity of about 80 mAh g−1 even at a high rate up to 30 C; and its capacity decay is as low as 0.0355 % per cycle when cycled at 0.2 C. Furthermore, the electrochemical impedance spectroscopy was also implemented to compare the electrode kinetics of all three NVP‐based cathodes including the apparent Na diffusion coefficients and charge‐transfer resistances.
Go nano! A Na3V2(PO4)3‐based nanocomposite (NVP/C/rGO) has been prepared by using Na2EDTA (disodium ethylenediamintetraacetate) as both sodium‐ and nitrogen‐doped carbon sources and employing reduced graphene oxide as the conductor. The double‐carbon‐modified NVP/C/rGO exhibits much improved properties compared to the single‐carbon modified NVP/C and pristine NVP when used as a cathode for sodium‐ion batteries (see figure).
The compression of the industrialization process has forced China to confront the double pressure of greenhouse gas emissions and air pollution. This paper constructs an energy system optimization ...model for China’s power industry; establishes four energy consumption scenarios with different constraints; and forecasts and analyses the energy consumption structure, power consumption demand and production composition of China’s power industry from 2020 to 2050. Furthermore, based on synergistic effects, the emission characteristics, emission reduction potential and costs of CO2 and air pollutants are quantitatively analysed, and the obtained synergistic emission reduction effect and influencing factors are decomposed based on technical effect and structural effect. Finally, a low-carbon emission reduction path that can realize the synergistic control of CO2 and traditional air pollutants in China’s power industry is obtained. The results show that in the future, China’s power industry will continue to grow at a greater rate than primary energy consumption and the focus of power demand will gradually shift from industry to transportation and construction. The power industry can introduce and maximize the application of optimal control technologies while optimizing the energy consumption structure in order to realize synergistic emission reduction for CO2 and traditional air pollutants in China’s power industry. While saving energy, the corresponding cost of emission reduction will remain relatively low. After CO2 emissions peak in the power industry, the main way to reduce CO2 emissions will be to optimize the structure and upgrade the technology for CO2 self-governance. For the reduction of air pollutants, the promotion effect is limited only by the implementation and promotion of structural emission reduction measures focused on non-fossil energy.
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•A bottom-up energy system optimization model for China’s electric power industry.•Energy consumption scenarios with different constraints.•Synergistic control path by structure optimization and control technology upgrading.•Emissions characteristics, reduction potential and cost are quantitatively analysed.•Synergistic emission reduction effect and influencing factors are decomposed.
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•Positively charged PEGylated nanomedicines exhibit shorter blood circulation and lower tumor accumulation than their neutral and anionic counterparts.•Positively charged PEGylated ...nanomedicines exhibit superior extravasation and penetration in tumors.•Positively charged PEGylated nanomedicines show higher cellular uptake in disaggregated tumors.•Positively charged PEGylated nanomedicines exhibit enhanced antitumour efficacy in a variety of tumor models.
Physiochemical properties of nanomedicines determine their in vivo fate and ultimate therapeutic efficacy. Establishing correlations between nanoparticle properties and their physiological response is vitally important for nanomedicine design and optimization. To date, the correlation between surface charge, a fundamental property of a nanomedicine, and its therapeutic efficacy remains poorly understood. Here, we systematically investigated the influence of surface charge on the pharmacokinetics, tumor accumulation, penetration, and antitumor efficacy of nanoparticles constructed from PEG-b-PLA, loaded with docetaxel, and tuned by various lipids to yield three groups of ∼100nm nanoparticles with positive, neutral or negative charge. Our results indicate that cationic PEGylated nanoparticles, although slightly inferior in blood circulation time and tumor accumulation, outperform their anionic or neutral counterparts in inhibiting tumor growth in five different tumor models. Docetaxel-loaded cationic nanoparticles significantly suppressed tumor growth with an inhibition ratio of ∼90%, compared with the ∼60% achieved by their anionic or neutral counterparts. Further studies reveal that better tumor penetration and 2.5-fold higher cellular uptake of cationic PEGylated nanoparticles is responsible for their superior treatment efficacy. This fundamental study provides a foundation for engineering the next generation of nano-delivery systems for in vivo applications.
GRB 050709 was the first short Gamma-ray Burst (sGRB) with an identified optical counterpart. Here we report a reanalysis of the publicly available data of this event and the discovery of a ...Li-Paczynski macronova/kilonova that dominates the optical/infrared signal at t>2.5 days. Such a signal would arise from 0.05 r-process material launched by a compact binary merger. The implied mass ejection supports the suggestion that compact binary mergers are significant and possibly main sites of heavy r-process nucleosynthesis. Furthermore, we have reanalysed all afterglow data from nearby short and hybrid GRBs (shGRBs). A statistical study of shGRB/macronova connection reveals that macronova may have taken place in all these GRBs, although the fraction as low as 0.18 cannot be ruled out. The identification of two of the three macronova candidates in the I-band implies a more promising detection prospect for ground-based surveys.
The present study was performed to evaluate the effects of seed priming. This was done by soaking the seeds of two rapeseed cultivars, namely, ZY15 (tolerant to low temperature and drought) and HY49 ...(sensitive to low temperature and drought), for 12 h in varying solutions: distilled water, 138 mg/L salicylic acid (SA), 300 mg/L gibberellic acid (GA), 89.4 mg/L sodium nitroprusside (SNP), 3000 mg/L calcium chloride (CaCl2), and 30 mg/L abscisic acid (ABA). Primed and non-primed seeds were left to germinate at 15°C and -0.15 MPa (T15W15) and at 25°C and 0 MPa (T25W0), respectively. The results showed that SA, GA, SNP, CaCl2, and ABA significantly improved the germination potential (GP), germination rate (GR), germination index (GI), stem fresh weight (SFW), stem dry weight (SDW), root length (RL), stem length (SL), and seed vigor index (SVI) under T15W15. For ZY15 seeds under T25W0, GA, SNP, CaCl2, and ABA priming reduced the average germination time (96% after 5 days) compared to that of the control (88% after 5 days). For ZY15 seeds under T15W15, SA, SNP, CaCl2, and ABA priming, with respect to the control and water-treated groups, shortened the average germination time (92% after 5 days) compared to that of the control (80% after 5 days). For HY49 seeds under T25W0, GA, SNP, CaCl2, and ABA priming reduced the average germination time (92% after 5 days) compared to that of the control (85% after 5 days). Similarly, for HY49 seeds under T15W15, GA priming shortened the average germination time (89% after 5 days) compared to that of the control (83% after 5 days). These priming agents increased the net photosynthesis, stomatal conductivity, and transpiration rate of rape seedlings under conditions of low temperature and drought stress, while also decreasing intercellular carbon dioxide (CO2) concentrations. Additionally, SA, GA, SNP, CaCl2, and ABA increased superoxide dismutase concentrations (SOD) and ascorbic peroxidase (APX) activities of rape seedlings under stress conditions, while decreasing catalase (CAT) and peroxidase (POD) activities in ZY15 seedlings. In HY49, which is sensitive to low temperature and drought, all priming solutions, except for SNP, led to an increase in SOD activity levels and a decrease in CAT activity levels. Overall, SA, GA, SNP, and CaCl2 increased the concentrations of indoleacetic acid (IAA), GA, ABA, and cytokinin (CTK) in seedlings under stress conditions. Moreover, compared to SA, CaCl2, and ABA, GA (300 mg/L) and SNP (300 mol/L) showed improved priming effects for ZY15 and HY49 under stress conditions.
Abstract
As a sodium superionic conductor, Mn‐rich phosphate of Na
3.4
Mn
1.2
Ti
0.8
(PO
4
)
3
is considered as one of the promising cathodes for sodium‐ion batteries owing to its good thermodynamic ...stability and high working voltage. However, Na
3.4
Mn
1.2
Ti
0.8
(PO
4
)
3
is faced with low electronic conductivity, poor cycling stability and complex phase transition caused by multi‐electron transfers, which limits its practical application. Herein, an anion‐regulated strategy is proposed to optimize the Mn‐rich Na
3.4
Mn
1.2
Ti
0.8
(PO
4
)
3
phosphate cathode. After introducing F anions into the lattice, the rate performance is improved from 60.5 to 72.8 mAh g
−1
at 20 C. Ascribed to unique structure design, the reaction kinetics of Na
3.4
Mn
1.2
Ti
0.8
(PO
4
)
3
are significantly improved, as demonstrated by cyclic voltammetry at varied scan rates and galvanostatic intermittent titration technique. The generated M‐F bond inhibits Jahn–Teller effect with an improved cycle stability (85.8 mAh g
−1
after 1000 cycles at 5 C with 94.3% capacity retention). Interestingly, reaction mechanism of Na
3.4
Mn
1.2
Ti
0.8
(PO
4
)
3
with the complex two‐phase and solid solution reactions changes to the whole solid solution reaction after fluorine substitution, and leads to a smaller volume change of 5.41% during reaction processes, which is verified by in situ X‐ray diffraction. This anion regulation strategy provides a new method for designing the high‐performance phosphate cathode materials of sodium‐ion batteries.
Modulating effector immune cells via monoclonal antibodies (mAbs) and facilitating the co-engagement of T cells and tumor cells via chimeric antigen receptor- T cells or bispecific T cell-engaging ...antibodies are two typical cancer immunotherapy approaches. We speculated that immobilizing two types of mAbs against effector cells and tumor cells on a single nanoparticle could integrate the functions of these two approaches, as the engineered formulation (immunomodulating nano-adaptor, imNA) could potentially associate with both cells and bridge them together like an 'adaptor' while maintaining the immunomodulatory properties of the parental mAbs. However, existing mAbs-immobilization strategies mainly rely on a chemical reaction, a process that is rough and difficult to control. Here, we build up a versatile antibody immobilization platform by conjugating anti-IgG (Fc specific) antibody (αFc) onto the nanoparticle surface (αFc-NP), and confirm that αFc-NP could conveniently and efficiently immobilize two types of mAbs through Fc-specific noncovalent interactions to form imNAs. Finally, we validate the superiority of imNAs over the mixture of parental mAbs in T cell-, natural killer cell- and macrophage-mediated antitumor immune responses in multiple murine tumor models.
Multi-stage Tesla valves in the reversed flow state can be applied during the hydrogen decompression process between the high pressure hydrogen storage vessel and the fuel cell. Under high-pressure ...turbulent hydrogen flow, severe aerodynamic noise may be caused and large energy loss inside Tesla valves may be generated, which can cause uncomfortable noise in vehicles. In this paper, the valve stage number and the pressure ratio between the inlet and the outlet are analyzed to investigate the possibility of the occurrence of aerodynamic noise and energy loss inside Tesla valves, and Mach number, turbulent dissipation rate, and exergy loss are used and evaluated as the criterion. The results show that both Mach number and exergy loss increase with the increasing of pressure ratio, but with the decrease of valve stage number, Mach number increases and exergy loss decreases. In addition, large turbulent dissipation rate at each valve stage appears near the bifurcation and the confluence between the straight channel and the bend channel of multi-stage Tesla valves. The correlation between the valve stage number, the pressure ratio, and the maximum Mach number is fitted, which can be used to estimate the possibility of the occurrence of aerodynamic noise.
•Multi-stage Tesla valves are applicable for hydrogen decompression.•Mach number is used to represent the occurrence of aerodynamic noise.•Impacts of valve stage number under different pressure ratios are investigated.•Small valve stage number results in higher Mach number.•Higher pressure ratio and large valve stage number lead to high exergy loss.
Activation of the phagocytosis of macrophages to tumor cells is an attractive strategy for cancer immunotherapy, but the effectiveness is limited by the fact that many tumor cells express an ...increased level of anti‐phagocytic signals (e.g., CD47 molecules) on their surface. To promote phagocytosis of macrophages, a pro‐phagocytic nanoparticle (SNPACALR&aCD47) that concurrently carries CD47 antibody (aCD47) and a pro‐phagocytic molecule calreticulin (CALR) is constructed to simultaneously modulate the phagocytic signals of macrophages. SNPACALR&aCD47 can achieve targeted delivery to tumor cells by specifically binding to the cell‐surface CD47 and block the CD47‐SIRPα pathway to inhibit the “don't eat me” signal. Tumor cell‐targeted delivery increases the exposure of recombinant CALR on the cell surface and stimulates an “eat me” signal. Simultaneous modulation of the two signals enhances the phagocytosis of 4T1 tumor cells by macrophages, which leads to significantly improved anti‐tumor efficacy in vivo. The findings demonstrate that the concurrent blockade of anti‐phagocytic signals and activation of pro‐phagocytic signals can be effective in macrophage‐mediated cancer immunotherapy.
The phagocytosis of tumor cells by macrophages requires both the coordinated disruption of “don't eat me” signals and simultaneous activation of “eat me” signals. Herein, a nanoparticle‐enabled strategy is proposed to concurrently modulate the cell surface levels of calreticulin (CALR) and CD47 to improve macrophage phagocytosis for improved cancer immunotherapy.
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