Overcoming the issue of the stability of tin‐based perovskites is a major challenge for the commercial development of lead‐free perovskite solar cells. To attack this problem, a new organic cation, ...azetidinium (AZ), is incorporated into the crystal structure of formamidinium tin triiodide (FASnI3) to form the mixed‐cation perovskite AZxFA1‐xSnI3. As AZ has a similar size to FA but a larger dipole moment, hybrid AZxFA1‐xSnI3 films exhibit variation in optical and electronic properties on increasing the proportion of AZ. Trifluoromethylbenzene (CF3C6H5) serves as antisolvent to fabricate smooth and uniform perovskite films for the devices with an inverted planar heterojunction structure. The device performance is optimized to produce the greatest efficiency at x=0.15 (AZ15), for which a power conversion efficiency of 9.6 % is obtained when the unencapsulated AZ15 device is stored in air for 100 h. Moreover, the device retains 90 % of its initial efficiency for over 15 days. The significant performance and stability of this device reveal that the concept of mixed cations is a promising approach to stabilize tin‐based perovskite solar cells for future commercialization.
Can we mix it? Yes we can! Mixing 15 % of azetidinium (AZ) inside a FASnI3 perovskite crystal enhances the device performance to attain a power conversion efficiency of 9.6 % with excellent stability for the unencapsulated device, which retains 90 % of its initial performance for over 15 days.
This paper presents a potential approach to settle the problem of surviving major safety accidents in Submerged Floating Tunnel （SFT） that detachable emergency escape devices are set up outside SFT. ...The Computational Fluid Dynamics （CFD） technology is used to investigate the effect of emergency escape devices on the hydrodynamic load acting on SFT in uniform and oscillatory flows and water waves by numerical test. The governing equations, i.e., the Reynolds-Averaged Navier-Stokes （RANS） equations and k - ε standard turbulence equations, are solved by the Finite Volume Method （FVM）. Analytic solutions for the Airy wave are applied to set boundary conditions to generate water wave. The VOF method is used to trace the free surface. In uniform flow, hydrodynamic loads, applied to SFT with emergency escape device, reduce obviously. But, in oscillatory flow, it has little influence on hydrodynamic loads acting on SFT. Horizontal and vertical wave loads of SFT magnify to some extend due to emergency escape devices so that the influence of emergency escape devices on hydrodynamic loads of SFT should be taken into consideration when designed.
Objective To compare the efficacy and safety of medical abortion of different regimens for termination of pregnancy at 8-16 weeks of gestation. Methods Healthy pregnant women requesting medical ...abortion at 8-16 weeks＇ gestation within 12 hospitals in Shanghai were randomly allocated to four treatment groups. Three intervention groups were given mifepristone 200 mg as a single dose then 24 h later misoprostol 600 #g at 3 h intervals vaginally, orally or vaginally followed by orally, respectively. Control group was given mifepristone 100 mg for 2 d, followed at 48 h by initiation of misoprostol 600 μg vaginally every 12 h. The primary outcome measures were the successful abortion rate, the induction-to-abortion interval, vaginal bleeding and side effects. Results Efficacy outcomes were analyzed for 1 112 women （92.67%）, excluding 88 protocol violations. Termination successful rates were similar among the four groups from 97.1% to 97.8%. The average dose of misoprostol and the incidence of side effects in control group were lower than those in three intervention groups. Stratified analysis showed that the interval of induction-to-abortion at gestation of 1116 weeks was decreased in control group. Conclusion The four regimens have the similar termination successful rates in spite of different administration intervals or routes. Control group was recommended for the advantages of reduced dose of misoprostol and fewer side effects.
Separation of oil/water mixtures, especially for the emulsified oil/water mixtures, is important because of the frequent occurrence of oil spill accidents. Utilizing superwetting porous membrane has ...become a promising approach to separate either surfactant-free or surfactant-stabilized emulsions. Herein we report a facile and versatile strategy for preparing hydrophobic/under-oil superhydrophobic membranes by coating the skeletons of the membranes with the poly（3,3,3- trifluoropropyl）methylsiloxane （PTFPMS） nanoparticles. The obtained membranes could be used to separate various water- in-oil emulsions with high flux and separation efficiency. In addition, owning to the outstanding resistance of PTFPMS to the most organic solvents or oils, the modified membranes exhibited the excellent reusability and the antifouling properties that were critical in the practical applications. Many commercially available membranes can be modified by such a simple method.
The purpose of this study is to fabricate a composite film of bristling few-layer graphite on an octagonal shaped diamond-tip array and to measure the field emission characteristics. The composite ...film of bristling few-layer graphite on an octagonal shaped diamond-tip array is firstly proposed to improve the field emission effect and lifetime because of the high pitch height ratio of bristling few-layer graphite and the high stability of diamond.
The microcrystalline and ultra-nano-crystalline diamond-tip arrays with the shape of an octagonal cone are formed by microwave plasma-enhanced chemical vapor deposition on a silicon substrate. Changing the flow rates of gasses when the bristling few-layer graphite are deposited on the diamond film leads to different results and find out the ideal fabrication parameters for improving field emission. The diamond-tip arrays and bristling few-layer graphite morphology are then examined by Raman spectroscopy and scanning electron microscopy. The field emission effect with different few-layer graphite/diamond composite arrays is also examined.
In this study, the composite film of bristling few-layer graphite structures on diamond-tip arrays grown by N2/H2/CH4=40/80/20 showed excellent field emission stability and high field emission characteristics with low turn-on field of 2.60V/μm and the field enhancement factor of 1921.
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•The octagonal silicon tip made by lithography process is firstly proposed.•The novel bristling few-layer graphite/diamond tip composite film is fabricated.•The flakes are composited with diamond core covered by multilayer graphite.•The best field emission properties with the lowest turn-on field of 2.60V/μm•The largest β is 1921 and has excellent field emission stability.
This paper proposes a robot peer reciprocal learning system in which robot peers can not only cooperatively accomplish a difficult task but also help each other to learn better. In this system, each ...robot is an independent individual and has the ability to make individual decisions. They can communicate about image information, individual decisions, and current state to formulate mutual decisions and motions. For learning a new concept, we propose a mutual learning method, which allows the robots to learn from each other by exchanging weights in their neural network concept learning system. The simulation results show that the robots can learn from each other to build general concepts from limited training, while improving both of their performances at the same time. Finally, we design two cooperative tasks, which require the robots to formulate mutual sequential motions and keep communicating to manage their motions. The robotic experiments demonstrate that the proposed robot peer reciprocal learning system can help robots achieve difficult tasks in appropriate and cooperative ways, just as humans do.
This paper presents a potential approach to settle the problem of surviving major safety accidents in Submerged Floating Tunnel (SFT) that detachable emergency escape devices are set up outside SFT. ...The Computational Fluid Dynamics (CFD) technology is used to investigate the effect of emergency escape devices on the hydrodynamic load acting on SFT in uniform and oscillatory flows and water waves by numerical test. The governing equations, i.e., the Reynolds-Averaged Navier-Stokes (RANS) equations and k – ɛ standard turbulence equations, are solved by the Finite Volume Method (FVM). Analytic solutions for the Airy wave are applied to set boundary conditions to generate water wave. The VOF method is used to trace the free surface. In uniform flow, hydrodynamic loads, applied to SFT with emergency escape device, reduce obviously. But, in oscillatory flow, it has little influence on hydrodynamic loads acting on SFT. Horizontal and vertical wave loads of SFT magnify to some extend due to emergency escape devices so that the influence of emergency escape devices on hydrodynamic loads of SFT should be taken into consideration when designed.
Cytokine-induced killer (CIK) cells are immune effector cells characterized by co-expression of CD3 and CD56 molecules. We examined the quantities of CIK cells and the changes of these cell ...expressing NK cell receptors in HIV-1-positive children infected via mother-to-child transmission. The percentage of CIK cells was quantified and the changes in the surface cell receptor profiles in 18 HIV-1-infected children were examined. We found that CIK cell percentages were dramatically increased in HIV-1-infected children. Furthermore, the expressions of CD16, NKp30, NKp44, NKp46, NKp80 and CD244 on CIK cells were decreased, while the expressions of KIR3DL1 and NKG2D on CIK cells were increased in HIV-1-infected children. However, the expressions of KIR2D and NTB-A on CIK cells did not change in the HIV-1-infected children. CIK cells possessed the characteristics of promoting the maturation of dendritic cells and killing functions in HIV-1-infected children. Moreover, serum concentrations of IL-4 and IFN-γ were significantly increased in HIV-1-infected children compared with the HIV-negative controls. These changes likely occurred as a protective mechanism against transmission of maternal HIV-1 virus and thereby helped to limit viral spread, eliminate infected cells and help HIV-1-infected patients to slow the progression to AIDS.
Natural killer (NK) cells are believed to play a role in the progression of human immunodeficiency virus 1 (HIV-1) disease, and NK cell levels are reduced in individuals with chronic HIV-1 infection. ...To assess the effects on quantity of NK cells and the changes of NK cell receptors in HIV-1 infected children via mother-to-child transmission, the percentage of NK cells is quantified and the changes in the NK cell receptor profiles in 20 HIV-1 infected children who are not progressing into AIDS were examined. The results showed that NK cell percentage was decreased in the HIV-1 infected children. The expression of NKp30 on NK cells was increased, while the expressions of CD16, NKp44, NKp46, NKp80, NTB-A, CD244, KIR2D, KIR3DL1 and NKG2D on NK cells were decreased in the HIV-1 infected children. NK cell cytolytic activity was elevated in HIV-1 infected children. These results indicate that the acute changes in NK cell percentage and NK cell receptors in HIV-1 infected children are different from the HIV-1 infected adult individuals. Moreover, serum concentrations of IL-18 were elevated in HIV-infected children compared to HIV-uninfected controls. These differences probably play a role in protecting against transmission of maternal HIV-1 virus and guiding the therapeutic strategies for HIV-1 infected children.
Dendritic cells (DCs) play a pivotal role in the pathogenesis of human immunodeficiency virus-1 (HIV-1). Reduced numbers of blood DCs have been observed in individuals with chronic HIV-1 infection. ...In the present study, we analyzed the expression levels of monocytes, myeloid dendritic cell (mDC) precursors, mDCs, and plasmacytoid dendritic cells (pDCs), in HIV-1-infected patients in China who were infected via different routes of transmission, including heterosexual and homosexual sexual contact, and blood transmission through importation of blood or blood products, to further elucidate their role in HIV. Compared with HIV-negative individuals (n = 40), relative levels of CD11c+CD14⁻mDCs, CD11c++CD123(low) mDCs, and CD11c⁻CD123+ pDCs in total peripheral blood mononuclear cells (PBMCs) were significantly lower in all HIV patients (n = 93), and in those with blood transmission (n = 26) and heterosexual transmission (n = 43), while relative levels of CD11c+CD14⁻mDCs were significantly lower in HIV patients infected via homosexual transmission (n = 24). The results of correlation analysis demonstrated a significant negative correlation between CD4+ T-cell counts and the relative levels of CD11c++CD123(low) mDCs in HIV-I patients infected via blood transmission. There was no significant correlation between CD4+ T-cell counts and the expression level of other DC subpopulations in PBMCs from HIV patients. The results of this study suggest that HIV-1 patients with different routes of transmission exhibit altered expression levels of blood DC subpopulations, which contributes to dysregulated immune responses and pathogenesis of HIV-1.
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