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We show the lifespan of a strong solution to the incompressible 3D axially symmetric Euler system in R 3 can be arbitrarily large if the initial swirl is small enough. A precise lower bound of the lifespan, depending on the size of ‖ ∇ × (v 0 , θ e θ) ‖ L ∞ , is given. This extends the conclusion of Danchin (Proc Am Math Soc 141:1979–1993, 2012), in which the domain must be distant from the axis of symmetry. This may help us to have a better understanding of the nonlinear framework and the blowup mechanism inherent in the 3D axisymmetric Euler equations. [ABSTRACT FROM AUTHOR]

In this paper, we solve the Leray's problem for the stationary Navier-Stokes system in a 2D infinite distorted strip with the Navier-slip boundary condition. The existence, uniqueness, regularity and asymptotic behavior of the solution are investigated. Moreover, we discuss how the friction coefficient affects the well-posedness of the solution. Due to the validity of the Korn's inequality, all constants in each a priori estimate are independent of the friction coefficient. Thus our method is also valid for the total-slip and no-slip cases. The main novelty is that the total flux of the velocity can be relatively large (proportional to the slip length) when the friction coefficient of the Navier-slip boundary condition is small, which is essentially different from the 3D case. [ABSTRACT FROM AUTHOR]

In this paper, we obtain a refined temporal asymptotic upper bound of the global axially symmetric solution to the Boussinesq system with no thermal diffusivity. We show the spacial W 1 , p -Sobolev (2 ≤ p < ∞) norm of the velocity can only grow at most algebraically as t → + ∞. Under a signed potential condition imposed on the initial data, we further derive that the aforementioned norm is uniformly bounded at all times. Higher order estimates are also given: We find the H 1 norm of the temperature fluctuation grows sub-exponentially as t → + ∞. Meanwhile, for any m ≥ 1 , we deduce that the H m -temporal growth of the solution is slower than a double exponential function. As a result, these improve the results in [11] where the authors only provided rough temporal asymptotic upper bounds while proving the global well-posedness. [ABSTRACT FROM AUTHOR]

The global well-posedness of the 3D inviscid MHD-Boussinesq system, with large axisymmetric initial data, in the Sobolev space H m is given. To overcome difficulties that arise in the time-uniform H 1 estimate, a reformulated system of good unknowns is discovered and an intermediate estimate is shown. Based on the reformulated system, a Beale-Kato-Majda-type criterion of the inviscid MHD-Boussinesq system is verified. Then higher-order estimates are concluded by the classical energy method and estimates of commutators. At last, we show the H m norm of the global-in-time solution temporally grows no faster than a four times exponential function (∀ m ∈ N) . [ABSTRACT FROM AUTHOR]

In this paper, we derive asymptotic properties of both the velocity and the vorticity fields to the 3-dimensional axially symmetric Navier–Stokes equations at infinity under the generalized D-solution assumption ∫ ℝ 3 | ∇ u | q d x < ∞ for 2 < q < ∞. We do not impose any zero or non-zero constant vector asymptotic assumption to the solution at infinity. Our results generalize those in [H. Choe and B. Jin, Asymptotic properties of axis-symmetric D-solutions of the Navier–Stokes equations, J. Math. Fluid Mech. 11(2) (2009) 208–232; S. Weng, Decay properties of axially symmetric D-solutions to the steady Navier–Stokes equations, J. Math. Fluid Mech. 20(1) (2018) 7–25; B. Carrillo, X. Pan and Q. S. Zhang, Decay and vanishing of some axially symmetric D-solutions of the Navier–Stokes equations, J. Funct. Anal. 279(1) (2020) 108504], where the authors focused on the case q = 2 and the velocity field approaches zero at infinity. Meanwhile, when q → 2 + and the velocity field approaches zero at infinity, our results coincide with the results in [H. Choe and B. Jin, Asymptotic properties of axis-symmetric D-solutions of the Navier–Stokes equations, J. Math. Fluid Mech. 11(2) (2009) 208–232; S. Weng, Decay properties of axially symmetric D-solutions to the steady Navier–Stokes equations, J. Math. Fluid Mech. 20(1) (2018) 7–25; B. Carrillo, X. Pan and Q. S. Zhang, Decay and vanishing of some axially symmetric D-solutions of the Navier–Stokes equations, J. Funct. Anal. 279(1) (2020) 108504]. [ABSTRACT FROM AUTHOR]

In this paper, we give a BKM-type blow-up criterion, which involves only a single component of the velocity, for the inviscid axially symmetric Boussinesq system. More precisely, we will show that if the vorticity of the swirl part of the velocity belongs to L 1 (0 , T ∗ , L ∞) , then the solution is regular up to time T ∗ . At present, our results can not be easily generalized to the classical L t 1 B M O regularity criterion, which will be considered in our further works. [ABSTRACT FROM AUTHOR]

A one-component regularity criterion for the non-resistive axially symmetric Hall-MHD system is given in this paper. More precisely, we show that strong solutions to a family of axially symmetric initial data, whose velocity and current density have trivial swirl components, could be smoothly extended beyond a possible blow-up time T ∗ if and only if the swirl component of the magnetic field h θ satisfies a Beale-Kato-Majda-type criterion. See (1.5) below. This criterion is not trivial even if the velocity field vanishes since the quantity h θ r satisfies a partial Burgers' equation in this situation. [ABSTRACT FROM AUTHOR]

Let D be the exterior of a cone inside a ball, with its altitude angle at most π / 6 in R 3 , which touches the x 3 axis at the origin. For any initial value v 0 = v 0 , r e r + v 0 , θ e θ + v 0 , 3 e 3 in a C 2 (D ‾) class, which has the usual even-odd-odd symmetry in the x 3 variable and has the partial smallness only in the swirl direction: | r v 0 , θ | ≤ 1 100 , the axially symmetric Navier-Stokes equations (ASNS) with Navier-Hodge-Lions slip boundary condition have a finite-energy solution that stays bounded for all time. In particular, no finite-time blowup of the fluid velocity occurs. Compared with standard smallness assumptions on the initial velocity, no size restriction is made on the components v 0 , r and v 0 , 3. In a broad sense, this result appears to solve 2/3 of the regularity problem of ASNS in such domains in the class of solutions with the above symmetry. Equivalently, this result is connected to the general open question which asks that if an absolute smallness of one component of the initial velocity implies the global smoothness, see e.g. page 873 in Chemin et al. (2017) [6]. Our result seems to give a positive answer in a special setting. As a byproduct, we also construct an unbounded solution of the forced Navier Stokes equation in a special cusp domain that has finite energy. The forcing term, with the scaling factor of −1, is in the standard regularity class, and it can be generated by an electric current in a long and straight wire (i.e. Ampère force). This result confirms the intuition that if the channel of a fluid is very thin, arbitrarily high speed in the classical sense can be attained under a mildly singular, physically reasonable force. [ABSTRACT FROM AUTHOR]

• Continuous Ag films with percolation threshold of 5 nm were realized by Cu seed layer. • Semitransparent PSCs with 6 nm Ag electrodes exhibited PCE of 14.5%, maintaining 88% performance of opaque PSCs. • Average transmittance of PSCs in 800–1200 nm was improved to 58.6% by optical coupling layer. • Tandem solar cells using semitransparent PSCs and c-Si cells were demonstrated. Tandem solar cells with top perovskite solar cells (PSCs) have attracted great attention due to the rapid progress in power conversion efficiency (PCE). Ultrathin silver (Ag) metals with low percolation threshold are promising candidates as transparent electrodes for semitransparent PSCs. In this work, continuous Ag films with percolation threshold lower than 6 nm were realized through Cu seed layer, which guaranteed not only excellent conductivity but also broadband transparency. As a result, semitransparent PSCs with 6 nm Ag electrodes exhibited PCE of 14.5%, maintaining 88% performance of the opaque PSCs. Moreover, the average transmittance of semitransparent PSCs in the range of 800–1200 nm was improved to 58.6% using zinc oxide as optical coupling layer, promising near infrared light absorption by bottom solar cells. Ultimately, four-terminal tandem solar cell using semitransparent PSC and homogenous crystalline silicon solar cell was demonstrated. Furthermore, the strategies of using 5 nm Ag electrodes combined with Ag grids, and optical coupling layers with higher refractive index, were suggested to further increase the PCE of tandem solar cells. The proposed ultrathin Ag transparent electrodes are ease of fabrication as well as good optoelectrical properties, which are promising for application in semitransparent PSCs and tandem solar cells. [ABSTRACT FROM AUTHOR]

Lithium cobalt oxide (LCO) has been widely used as a leading cathode material for lithium-ion batteries in consumer electronics. However, unstable cathode electrolyte interphase (CEI) and undesired phase transitions during fast Li+ diffusivity always incur an inferior stability of the high-voltage LCO (HV-LCO). Here, an ultra-thin amorphous titanium dioxide (TiO2) coating layer engineered on LCO by an atomic layer deposition (ALD) strategy is demonstrated to improve the high-rate and long-cycling properties of the HV-LCO cathode. Benefitting from the uniform TiO2 protective layer, the Li+ storage properties of the modified LCO obtained after 50 ALD cycles (LCO-ALD50) are significantly improved. The results show that the average Li+ diffusion coefficient is nearly tripled with a high-rate capability of 125 mAh g−1 at 5C. An improved cycling stability with a high-capacity retention (86.7%) after 300 cycles at 1C is also achieved, far outperforming the bare LCO (37.9%). The in situ XRD and ex situ XPS results demonstrate that the dense and stable CEI induced by the surface TiO2 coating layer buffers heterogenous lithium flux insertion during cycling and prevents electrolyte, which contributes to the excellent cycling stability of LCO-ALD50. This work reveals the mechanism of surface protection by transition metal oxides coating and facilitates the development of long-life HV-LCO electrodes. [ABSTRACT FROM AUTHOR]

In this paper, we derive Schauder estimates to the solutions of the following uniformly elliptic equation with a inverse-square potential and nonhomogeneous term (0.1) − a i j ( x ) ∂ i j u ( x ) + A | x | 2 u ( x ) = f ( x ) , in B , which lead to the existence and sharp regularity results of the classical solutions. More precisely, we prove that u ∈ C n + 2 , γ provided f ∈ C n , γ , a i j ∈ C n , γ and A > Λ ( 2 + n + γ ) ( d + n + γ ) . [ABSTRACT FROM AUTHOR]

We prove Hölder continuity of weak solutions of the uniformly elliptic and parabolic equations (0.1) ∂ i ( a i j ( x ) ∂ j u ( x ) ) − A | x | 2 + β u ( x ) = 0 ( A > 0 , β ≥ 0 ) , (0.2) ∂ i ( a i j ( x , t ) ∂ j u ( x , t ) ) − A | x | 2 + β u ( x , t ) − ∂ t u ( x , t ) = 0 ( A > 0 , β ≥ 0 ) , with critical or supercritical 0-order term coefficients which are beyond De Giorgi–Nash–Moser's Theory. We also prove, in some special cases, weak solutions are even differentiable. Previously P. Baras and J. A. Goldstein [3] treated the case when A < 0 , ( a i j ) = I and β = 0 for which they show that there does not exist any regular positive solution or singular positive solutions, depending on the size of | A | . When A > 0 , β = 0 and ( a i j ) = I , P. D. Milman and Y. A. Semenov [7,8] obtain bounds for the heat kernel. [ABSTRACT FROM AUTHOR]

The corrosion of rebars will change the mechanical properties of the reinforced concrete structure, leading to the decline in the structural strength, which seriously threatens the safety and stability of buildings and power equipment foundations. Hence, it is of great significance to detect the internal corrosion of reinforced concrete structures. In this paper, a nondestructive detection method for detecting the corrosion in reinforced concrete structures based on microwave was proposed, and the corrosion state of rebar can be evaluated by the change of microwave information. Compared with other detection methods, microwave nondestructive detection has the advantages of low energy consumption, strong penetration, no contact, and small equipment volume and weight. In order to verify the effectiveness of the method, a microwave nondestructive detection simulation test platform was built and reinforced concrete test models with different corrosion lengths and depths were made. The influences of concrete parameters, the microwave frequency, and the lifting distance of the waveguide were analyzed. The frequency sweeping and moving scanning detection methods of the waveguide were carried out for the test models with different corrosion defects, and the changes of microwave S-parameters under different corrosion defects were obtained. The results show that when the waveguide is placed horizontally by the frequency sweeping detection method, the corrosion length detection effect of rebar is better. When the waveguide is placed vertically by the frequency sweeping detection method, the corrosion depth can be identified and the amplitude of transmission coefficient increases with the increase in the corrosion depth. The corrosion length of rebars can be identified quantitatively by the moving scanning detection method of the waveguide. [ABSTRACT FROM AUTHOR]

In the paper Koch et al. (2009), the authors make the following conjecture: any bounded ancient mild solution of the 3D axially symmetric Navier–Stokes equations is constant. And it is proved in the case that the solution is swirl free. Our purpose of this paper is to improve their result by allowing that the solution can grow with a power smaller than 1 with respect to the distance to the origin. Also, we will show that such a power is optimal to prove the Liouville type theorem since we can find counterexamples for the Navier–Stokes equations such that the Liouville theorem fails if the solution can grow linearly. [ABSTRACT FROM AUTHOR]

Background: Neonatal hyperbilirubinemia (NNH) is a common disease in newborns. This research study aimed to assess the associations between uridine diphospho-glucuronate-glucuronosyltransferase 1A1 (UGT1A1, c.-3279 T > G) polymorphisms and NNH risk. Methods: We searched PubMed, the Cochrane Library, and the Embase electronic databases. All published eligible studies before July 1, 2019, were searched for this meta-analysis. Results: We identified 7 independent studies including 1560 cases. The data showed that in the general population, compared with the GT + GG vs TT and GG vs TT, c.-3279 T > G (rs4124874) was significantly related to a higher NNH risk (GG vs TT: OR = 1.865, 95% CI: 1.031–3.373, P = 0.039; GT + GG vs TT: OR = 1.331, 95% CI: 1.055–1.679, P = 0.016). Although not statistically significant, the data showed that c.3279 T > G had a tendency to be associated with NNH under the allele model and GG vs GT + TT in the overall population (G vs T: OR = 1.288, 95% CI: 0.982–1.689, P = 0.067; GG vs TT + GT: OR = 1.583, 95% CI: 0.947–2.647, P = 0.080). Conclusion: The UGT1A1 gene c.-3279 T > G (rs4124874) polymorphism increased susceptibility to NNH, especially for the comparison of GT + GG vs TT and GG vs TT. In the future, we can use homozygous state of the UGT1A1 gene c.-3279 T > G (rs4124874) polymorphism for the diagnosis and screening of molecular biomarkers in NNH patients. [ABSTRACT FROM AUTHOR]

[Display omitted] • A facile palette strategy was proposed to achieve multicolor afterglow. • The afterglow also exhibited excitation wavelength and time-dependent characteristics. • Anti-counterfeiting 3D aerogel and multilevel encryption system were fabricated. Achieving multicolor afterglow modulation from single conventional chromophore-based room temperature phosphorescence (RTP) materials is attractive but challenging. Herein, a facile palette strategy based on physical doping of red afterglow-emitted chromophore (N8) into sodium alginate (SA) is proposed to achieve large range of multicolor afterglow modulation for single conventional chromophore-based RTP materials. As well as being a key luminous component in the color palette, SA with cyan afterglow (upon 254 nm UV irradiation) can also activate the red afterglow of N8 via strong hydrogen bond interactions. Through regulating the doping ratios of N8 to SA, cyan to red afterglows have been achieved in the formed amorphous N8/SA films. Significantly, the afterglow of N8/SA also exhibits excitation wavelength- and time-dependent characteristics, which further extend the range and tunability of afterglow color. Besides, the phosphorescence lifetime of N8-based SA films could be further improved by chemically grafting N8 to SA, with a lifetime of 464.9 ms. Considering the excellent multicolor afterglow tunability and hygrothermal responsiveness, these smart SA-based materials demonstrate great application prospects in information encryption, anti-counterfeit ink painting, and 3D afterglow aerogel. [ABSTRACT FROM AUTHOR]

Background: Natural orifice specimen extraction (NOSE) surgery has been widely implemented in colorectal cancer surgery due to its good short‐term efficacy. However, anastomotic leakage (AL) is a serious postoperative complication in colorectal cancer, and the risk factors for this complication after NOSE surgery have rarely been investigated. The aim of this study was to explore the predictive factors for AL after laparoscopic resection with transrectal NOSE for rectal cancer and sigmoid colon cancer. Methods: A total of 208 patients who underwent total laparoscopic resection with transrectal NOSE for rectal cancer and sigmoid colon cancer from January 2014 to June 2019 were systematically reviewed. Univariate and multivariate analyses were performed to identify the relevant risk factors. Results: The rate of AL was 10.1% (21 of 208 patients). The univariate analyses showed that male sex (85.7% vs 57.8%, P =.013), the distance from the anal verge (10.5 vs 14.5 cm, P =.011), and a duration of operation ≥140 min (71.4% vs 29.4%, P<.001) were associated with an increased incidence of AL. The multivariate analysis showed that a duration of operation ≥140 min (OR = 5427, 95% CI = 1.355‐21.727, P =.017) was an independent risk factor for AL. Conclusion: A duration of operation ≥140 min is a possible risk factor for AL after total laparoscopic resection with transrectal NOSE for colorectal cancer. [ABSTRACT FROM AUTHOR]

In addition to evaluate the morphologic characteristics of intracranial aneurysms, the dimension of the aneurysm is an important parameter for selecting treatment strategies, determining follow-up period, and predicting the risk of rupture. High-resolution vessel wall imaging has an increasingly dominant role in measuring aneurysm size and assessing the risk of rupture accurately. The size of saccular intracranial aneurysm may play an important role as a predictor of the rupture risk. With the rapid improvement in radiological techniques, different noninvasive imaging methods have respective characteristics in saccular intracranial aneurysms (sIA) measurement and morphologic description. Although most studies believe that the larger the aneurysm, the higher the risk of rupture, there is still a synergistic effect of multiple factors (such as location, morphology, history of aneurysmal subarachnoid hemorrhage, and even patient factors) to explain the rupture of small aneurysms. A literature search was performed of intracranial aneurysm size and risk of rupture. The specificity and sensitivity of different imaging methods for evaluating intracranial aneurysms varied based on sizes. Rupture risk of aneurysms was associated with multiple factors. A comprehensive assessment that considered aneurysm size in conjunction with other relevant factors would be helpful in guiding options of management. Accurate measurement of the dimension of sIA is an important basis in the selection of appropriate treatment including intravascular intervention or surgical clipping, as well as for determining the follow-up cycles for conservative or postoperative treatment. A uniform definition of sIA size is recommended to facilitate the integration of similar studies and to accomplish rapid and effective screening of cases in sIA treatment. [ABSTRACT FROM AUTHOR]

In this paper, FePO 4 ∙2H 2 O and FePO 4 have been successfully accomplished by utilizing titanium white by-product ferrous sulfate via two-step synthesis method, which is further employed to react with Li 2 CO 3 via carbothermal reduction to prepare LiFePO 4 cathode materials. The composition and structure characteristics of obtained samples are studied in detail by TG-DSC, XRD, XPS, FESEM and TEM, and the electrochemical performances of prepared LiFePO 4 are also carefully investigated. The results indicate that the discharge specific capacity of LiFePO 4 synthesized from FePO 4 achieves 162.4 and 153.7 mAh∙g−1 at 0.1C and 1C, which is 2.2 and 2.9 mAh∙g−1 higher than that from FePO 4 ∙2H 2 O, and the capacity retention rate reaches as high as 97.5 % after 450 cycles at 1C, correspondingly 94.8 % for LiFePO 4 from FePO 4 ∙2H 2 O. It is mainly ascribed to the smaller particle size of LiFePO 4 synthesized from FePO 4 , and the intimately ordered interface structure between the carbon layer and LiFePO 4 , which greatly promotes the migration of lithium ions in the lithiation and delithiation process. • Titanium white by-product ferrous sulfate has been utilized to synthesize LiFePO 4. • The max discharge specific capacity of LiFePO 4 achieves 162.4 mAh∙g−1 at 0.1C. • Smaller grain size and intimate interface structure lead to superior performances. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three kinds of NBD-incorporated naphthalene diimide derivatives were designed and synthesized. • Compound 1NND and 3NND exhibited fluorescent "turn-off" property toward G-quadruplex. • Dissociation constant (K d) of ligands against G-quadruplex could be measured directly by fluorescence titration assay. • Compound 1NND exhibited great cytotoxic activity against cancer cell MIA PaCa-2 and strong affinity to the G-quadruplex. Nitrobenzoxadiazole (NBD)-incorporated naphthalene diimide derivatives were designed and synthesized as candidates of antitumor agents with cytotoxicity against human pancreatic cancer cell MIA PaCa-2. Among these, compounds 1NND and 3NND exhibited fluorescent "turn-off" property toward human telomeric G-quadruplex (G4), which allows the direct measurement of dissociation constant (K d) of ligands against G4 by fluorescence titration method. Notably, the compound 1NND not only exhibited great cytotoxic activity against MIA PaCa-2 with a half maximal inhibitory concentration (IC 50) of 77.9 nM, but also exhibited high affinity against G4 with K d of 1.72 μM. Furthermore, the target binding properties were investigated by circular dichroism (CD) spectra and further studied by molecular docking methods. [ABSTRACT FROM AUTHOR]

Abstract: Condensation heat transfer has been studied in the past century due to its wide applications in energy and power systems. The key scientific issue is the thick liquid thickness near the tube wall along the condenser tube length. The fabricated microstructures on the inner wall are the conventional technique to improve the performance. Here a passive phase separation concept was proposed to create distinct phase distribution. An empty cylinder made of a single layer of mesh pore surface was suspended in a tube, dividing the tube into an annular region and an inner region. The mesh pore surface prevents gas phase entering the inner region but sucks liquid towards the inner region. Thus largest possibility for gas directly contacted with the inner wall surface is ensured. An air/water two-phase flow experiment was performed and the stratified flow pattern modulation was investigated. When the liquid level in the horizontal tube is relatively higher, the liquid can be thoroughly within the mesh cylinder to form the “gas-floating-liquid” mode. The whole inner tube wall surface is covered by the gas phase. If the liquid content is relatively smaller, partial liquid can be sucked into the mesh cylinder. The contact area between the inner tube wall and gas is increased. The stratified flow pattern modulation is expected to significantly enhance the condensation heat transfer under low mass fluxes which is being verified by our continuous experiment. [Copyright &y& Elsevier]

Abstract: A passive phase separation concept was proposed to modulate flow pattern in a condenser tube. An empty mesh cylinder is suspended in the condenser tube. The miniature mesh pores prevent gas bubble entering the mesh cylinder but capture liquid into the mesh cylinder, ensuring largest possibility for cold tube wall directly contacted with gas to form the perfect thin liquid film condensation heat transfer. We performed the air–water two-phase flow experiment. It was found that for a relatively higher liquid height in the horizontal tube, all liquid can be captured by the mesh cylinder to form the “gas-floating-liquid” mode. If the liquid height is small in the horizontal tube, partial liquid can be sucked by the mesh cylinder, the contact area between tube wall and gas is increased. When plug flow reaches the mesh cylinder surface, elongated saddle bubbles are formed in the annular region to envelop the mesh cylinder surface. When bubbly flow in the horizontal tube approaches the mesh cylinder area, miniature bubbles can merge to form large bubbles in the annular region. For the later two cases, all the gas flow rate is flowing in the annular region and the inside mesh cylinder is the liquid. [Copyright &y& Elsevier]

In this paper, we study the hedging effectiveness of crude oil futures on the basis of the lower partial moments (LPMs). An improved kernel density estimation method is proposed to estimate the optimal hedge ratio. We investigate crude oil price hedging by contributing to the literature in the following twofold: First, unlike the existing studies which focus on univariate kernel density method, we use bivariate kernel density to calculate the estimated LPMs, wherein the two bandwidths of the bivariate kernel density are not limited to the same, which is our main innovation point. According to the criterion of minimizing the mean integrated square error, we derive the conditions that the optimal bandwidths satisfy. In the process of derivation, we make a distribution assumption locally in order to simplify calculation, but this type of local distribution assumption is far better than global distribution assumption used in parameter method theoretically and empirically. Second, in order to meet the requirement of bivariate kernel density for independent random variables, we adopt ARCH models to obtain the independent noises with related to the returns of crude oil spot and futures. Genetic algorithm is used to tune the parameters that maximize quasi-likelihood. Empirical results reveal that, at first, the hedging strategy based on the improved kernel density estimation method is of highly efficiency, and then it achieves better performance than the hedging strategy based on the traditional parametric method. We also compare the risk control effectiveness of static hedge ratio vs. time-varying hedge ratio and find that static hedging has a better performance than time-varying hedging. [ABSTRACT FROM AUTHOR]

Cerebellar intermittent theta burst stimulation (iTBS) modulates the excitability of the cerebral cortex and may enhance attentional performance. To date, few studies have conducted iTBS on healthy subjects for one week and used electroencephalography (EEG) to investigate the effect of multiple stimulation sessions on resting-state functional brain networks and the daily stimulation effect on attentional performance. 16 healthy subjects participated in a one-week experiment, receiving bilateral cerebellar iTBS or sham stimulation and engaging in multi-task attentional training. The primary measures were the one-week attentional performance and pre- and post-experiment resting-state EEG activities. Amplitude Envelope Correlation (AEC) was used to construct the functional connectivity in the eye-open (EO) and eye-closed (EC) phases. At least three sessions of iTBS were required to enhance multi-task performance significantly, whereas only one or two sessions failed to elicit the improvement. Compared with the control group, iTBS induced significant changes in PSD, AEC functional connectivity, and AEC network properties during the EO phase, while it had little effect during the EC phase. During the EO phase, the network property changes of the iTBS subject were correlated with improved attentional performance. The multi-task performance requires multiple stimulations to enhance. iTBS affects the resting-state alpha band brain activities during the EO rather than the EC phase. The AEC network properties may serve as a biomarker to assess the attentional potential of healthy subjects. • At least three sessions of iTBS were required to improve multi-task performance. • One-week iTBS has little effect on resting-state brain activity during the EC phase. • For iTBS subjects, more AEC network properties changes lead to better performance. • iTBS causes no adverse effect as functional connectivity are evenly distributed. [ABSTRACT FROM AUTHOR]

The adsorbed and dissolved oil in the shale reservoirs can be produced during CO 2 injection. However, the effects of different factors on the adsorption and dissolution behaviors of CO 2 and oil mixtures in the shale were unclear, such as the oil composition, shale properties and temperature. In this study, a series of adsorption and dissolution tests of CO 2 and different n-alkane mixtures in organic-rich shales were performed under different condition. The effects of the alkane type, shale properties and temperature on the adsorption and dissolution amount of mixtures and the replace ability of CO 2 to n-alkane were discussed, respectively. The results indicate that the dissolution amount was decreased with the chain length of alkane and increased with TOC and temperature. The adsorption amount of the mixtures in shale was low and only account for 3–16% of total adsorption and dissolution amount, which mainly depended on the specific surface area of the shale samples. Additionally, the replace ability of CO 2 to dissolved n-alkane was decreased with the chain length of alkane and temperature. However, there are no obvious rules between the replace ability with TOC of shale. This study can provide useful information for EOR of shale oil reservoirs by CO 2 injection and the geological storage of CO 2 in shale oil reservoir. [ABSTRACT FROM AUTHOR]

• Rheological behaviors of polysaccharides with different substituents have been studied. • Both the saccharide side chain and acetyl substituents improve the gelation of polysaccharide solutions at 25 °C. • The relationship between the apparent viscosity and concentration of GG conforms to the exponential equation. • The stability of gel structure containing longer saccharide side chains shows lower temperature/salt sensitivity. • Deacylated GG solutions transform into hydrogels in the presence of DTAB. Rheological behaviors of microbial polysaccharides with different substituents in aqueous solutions have been systematically investigated. Both the saccharide side chains and acetyl substituents improve the gelation of welan gum (WG), diutan gum (DG) and gellan gum (GG) in pure water at 25 °C. For the polysaccharides with saccharide side chains (WG and DG), the relationship between the apparent viscosity and concentration conforms to the linear equation, while that of the polysaccharide with acetyl (GG) is exponential. More importantly, the roles of substituents on the stability of the molecular conformation of polysaccharides are significantly depended on the surrounding environment. Disaccharide side chains promote the stability of helical conformation and gel aggregates of GG at high temperature (85 °C) or in the presence of inorganic salts with the ionic strength of 2.0 mol L−1. The stability of gel structure containing acetyl (GG) shows higher temperature/salt sensitivity. Additionally, deacylated gellan gum (GG(d)) solutions transform into hydrogels in the presence of dodecyltrimethylammonium bromide (DTAB). This study will help to obtain a better understanding on the rheological properties of polysaccharides with respect to the conformation and applications. [ABSTRACT FROM AUTHOR]

As natural adjuvants, the bacterial outer membrane vesicles (OMV) hold great potential in cancer vaccines. However, the inherent immunotoxicity of OMV and the rarity of tumor-specific antigens seriously hamper the clinical translation of OMV-based cancer vaccines. Herein, metal-phenolic networks (MPNs) are used to attenuate the toxicity of OMV, meanwhile, provide tumor antigens via the chemodynamic effect induced immunogenic cell death (ICD). Specifically, MPNs are assembled on the OMV surface through the coordination reaction between ferric ions and tannic acid. The iron-based "prison" is locally collapsed in the tumor microenvironment (TME) with both low pH and high ATP features, and thus the systemic toxicity of OMV is significantly attenuated. The released ferric ions in TME promote the ICD of cancer cells through Fenton reaction and then the generation of abundant tumor antigens, which can be used to fabricate in-situ vaccines by converging with OMV. Together with the immunomodulatory effect of OMV, potent tumor repression on a bilateral tumor model is achieved with good biosafety. • Metal-phenolic network is first used for not only attenuating the toxicity of OMV but also fabricating in situ vaccines. • The smart synergism of in situ vaccines with TME reprogramming leads to robust tumor repression and immunological memory. • This convenient and reliable engineering strategy can be popularized in the construction of different bioactive formulations. [ABSTRACT FROM AUTHOR]

• Effects of polyether surfactants on improving oil–CO 2 miscibility are investigated. • Miscible degree parameter is defined to assess oil–CO 2 miscibility in MD simulation. • PO chain length of polyether exerts huge impacts on improving oil–CO 2 miscibility. • Micro-mechanism of polyether surfactant promoting oil–CO 2 miscibility is proposed. Accomplishing the high miscibility of CO 2 and crude oil under reservoir conditions is critical for achieving the most efficient recovery process by CO 2 injection into low-porosity and low-permeability reservoirs. In this study, the effects of nonionic polyether surfactants on improving the miscibility of CO 2 –hydrocarbon systems were investigated. The influence of polyether structure on the reduction of miscibility pressure between CO 2 and hydrocarbons was evaluated by experiments. The results showed that the miscibility pressure of CO 2 and C 16 could be reduced by 4.8% to 10.2% after adding 0.04 mol polyethers with different structures per kg CO 2. The capability of polyethers to improve oil–gas miscibility exhibited a first growing then diminishing trend with increasing polyoxypropylene chain length and decreased with increasing alkyl chain length. Moreover, the microscopic influence mechanism of polyether on the miscible processes of CO 2 –hydrocarbon systems was investigated by molecular dynamics simulations. The miscible degree parameter was defined in the simulation to quantitatively estimate oil–gas miscibility. The distributions of different molecules and potential interactions during the miscible process were analyzed. The simulation results showed that the solubilization of CO 2 molecules among polyoxypropylene chains in the oil phase caused by the local aggregation of nonionic polyether surfactants enhanced the vdW interactions between hydrocarbons and CO 2 and then improved the oil–gas miscibility. Furthermore, simulation results suggested that the number of polyoxypropylene groups in the nonionic polyether surfactant should be maintained at 8 to achieve the highest amount of CO 2 solubilization and the best potential in improving the oil–gas miscibility. The study results provide guidance for understanding the miscible behavior among CO 2 , additives, and hydrocarbons, as well as designing the appropriate additive structures for improving oil–gas miscibility. [ABSTRACT FROM AUTHOR]

• A quantitative evaluation method of additive promoting miscibility was proposed. • Polyoxypropylene alkyl ethers significantly improved oil–gas miscibility. • Low molecular weight surfactants with high PO groups exhibited the best effect. • Solubilization of CO 2 in oil resulted in a reduction of miscibility pressures. Certain unique reservoir conditions and technical difficulties have greatly limited the use of CO 2 miscible injection in unconventional reservoirs. Lowering the miscibility pressure to realize the miscibility of CO 2 and crude oil is critical for achieving the most efficient recovery process. In this study, we investigated whether nonionic polyether surfactants could improve the miscibility of CO 2 and hydrocarbons. And an improved experimental method for a quantitative evaluation of additive efficiencies in lowering the miscibility pressure was introduced for the first time. The dissolution behaviors of nonionic polyether surfactants in CO 2 and phase behaviors of CO 2 –hydrocarbon systems with and without surfactant additives were conducted. The effects of surfactant structure and concentration and temperature on the solubility of nonionic polyether surfactants in CO 2 along with the efficiency of miscibility pressure reduction for CO 2 –hydrocarbon systems were analyzed. The results showed that the polyoxypropylene alkyl ethers exhibited excellent potential for improving the miscibility of the CO 2 and hydrocarbons, especially when low molecular weight surfactant molecules with high polyoxypropylene group content were used. The first-contact miscibility pressure (FCMP) of the mixed oil and CO 2 could be reduced by as much as 22.51% with 3 wt% C 4 (PO) 3 addition. Furthermore, a mechanistic understanding showed that the solubilization of the CO 2 caused by polyether reverse micelles resulted in a reduction of miscibility pressures for CO 2 –hydrocarbon systems. The study results and the novel evaluation method provided guidance for designing and selecting appropriate additive structures to reduce miscibility pressures of CO 2 –oil systems and meet the CO 2 miscible injection technology requirements. [ABSTRACT FROM AUTHOR]

Abstract: Self-assembled three-dimensional (3D) hierarchical Bi2WO6 microspheres built from 2D nanoplates alignment were successfully prepared by the sol–gel–hydrothermal route. Based on X-ray diffraction and scanning electron microscopy observation of the products at different reaction time periods, the formation mechanism of 3D hierarchical Bi2WO6 microspheres was proposed. UV–vis diffuse reflectance spectra indicated that the obtained 3D hierarchical Bi2WO6 microspheres had enhanced absorption in both UV and visible light regions. The photocatalytic activities of the as-prepared products were evaluated by monitoring the degradation of methylene blue solution under visible light irradiation. Due to the structural feature and good optical quality, Bi2WO6 prepared by the sol–gel–hydrothermal route possessed the highest photocatalytic activity than those of Bi2WO6 samples prepared by hydrothermal and sol–gel routes. [Copyright &y& Elsevier]

Abstract: ZnO with hierarchical microspheres and hexagonal prisms structures were successfully synthesized by hydrothermal microemulsion route. Based on X-ray diffraction and scanning electron microscopy observation of the products at the different reaction time periods, the formation mechanism of three-dimensional hierarchical ZnO microspheres was proposed. Ultraviolet and visible diffuse reflectance spectra indicated that as-synthesized ZnO microspheres had enhanced absorption in both ultraviolet and visible light areas. The photocatalytic activities of as-synthesized products were evaluated by monitoring the degradation of methylene blue solution. Due to the synergistic effects of the high crystallization and special hierarchical structure, the hierarchical ZnO microsphere exhibited the highest photocatalytic activity. [Copyright &y& Elsevier]

Highlights: [•] A phase separation concept was proposed to modulate flow patterns for vertical upflows. [•] The tube was divided into an annular region and a core region. [•] The gas bubbles flow in the annular region and liquid majorly flows in the core region. [•] Thin liquid film and pulsating flow have the potential to enhance the heat transfer. [Copyright &y& Elsevier]

[Display omitted] A novel Dansyl-nucleoside surrogate (Dns) based on (±)- trans -4-(hydroxymethyl) piperidin-3-ol was designed and synthesized. The Dns exhibited excellent solvatochromic properties. About 90 nm of red-shift accompanied color change from green to orange could be achieved with an increase of solvent polarity. The Dns was incorporated into oligodeoxynucleotide by phosphoroamidite chemistry. Two kinds of Dns -incorporated fluorescent DNA probes were designed and synthesized for sensing variation of DNA duplexes based on color-changing manner. As a result, the color-changing DNA probe not only can detect complementary oligonucleotide, but also can distinguish mismatch flanked in Dansyl/nucleobase pair by naked eye. Moreover, the change of fluorescence color of sample solutions could be captured by smartphone, and the photographs could be digitalized by image-processing software. Thus, the Dns -incorporated fluorescent DNA probe is expected to open the way to point-of-care assays in the future. [ABSTRACT FROM AUTHOR]

The Luobusa ophiolite in the Indus—Yarlung Zangbo suture of southern Tibet hosts the largest known chromite deposit in China. The podiform chromitites occur in a well-preserved mantle sequence consisting of harzburgite with abundant lenses of dunite. The harzburgites have relatively uniform bulk-rock compositions with mg-numbers [100 Mg/(Mg + Fe)] ranging from 89 to 91 and show flat, unfractionated, chondrite-normalized platinum group element (PGE) patterns. Their accessory chromite varies widely in cr-number [100Cr/(Cr + Al)] (18–66). These rocks are essentially residua left after extraction of mid-ocean ridge basalt (MORB)-type magmas. The podiform chromitites display nodular, massive, disseminated and banded textures and typically have dunite envelopes that grade into the surrounding harzburgite and diopsidic harzburgite with increasing pyroxene contents. They consist of relatively uniform chromite with high cr-numbers (74–82), have strongly fractionated, chondrite-normalized PGE patterns with enrichment in Os, Ir and Ru relative to Rh, Pt and Pt, and are believed to have formed from a boninitic magma produced by a second stage of melting. Dunites contain accessory chromite intermediate in composition between those of harzburgite and chromitite and are believed to be the products of reaction between new boninitic magmas and old MORB-type peridotites. The melt-rock reaction removed pyroxene from the peridotites and precipitated oli-vine, forming dunite envelopes around the chromitite pods. The melts thus became more boninitic in composition and chromite saturated, leading to precipitation of chromite alone. The interplay of melt-rock interaction, chromite fractionation and magma mixing should lead to many fluctuations in melt composition, producing both massive and disseminated chromitites and phase layering within individual podiform bodies observed in the Luobusa ophiolite. [ABSTRACT FROM AUTHOR]

Energy storage system (ESS) has been advocated as one of the key elements for the future energy system by the fast power regulation and energy transfer capabilities. In particular, for distribution networks with high penetration of renewables, ESS plays an important role in bridging the gap between the supply and demand, maximizing the benefits of renewables and providing various types of ancillary services to cope the intermittences and fluctuations, consequently improving the resilience, reliability and flexibility. To solve the voltage fluctuations caused by the high permeability of renewables in distribution networks, an optimal capacity allocation strategy of ESS is proposed in this paper. Taking the life cycle cost, arbitrage income and the benefit of reducing network losses into consideration, a bilevel optimization model of ESS capacity allocation is established, the coordination between active/reactive power of associate power conversion system is considered, and the large scale nonlinear programming problem is solved using genetic algorithm, simulated annealing and mixed integer second-order cone programming method. The feasibility and effectiveness of the proposed algorithm have been verified. [ABSTRACT FROM AUTHOR]