Shear-relative distributions of four types of precipitation/convection in tropical cyclones (TCs) are statistically analyzed using 14 years of Tropical Rainfall Measuring Mission (TRMM) Precipitation ...Radar (PR) data. The dataset of 1139 TRMM PR overpasses of tropical storms through category-2 hurricanes over global TC-prone basins is divided by future 24-h intensity change. It is found that increased and widespread shallow precipitation (defined as where the 20-dBZradar echo height <6 km) around the storm center is a first sign of rapid intensification (RI) and could be used as a predictor of the onset of RI. The contribution to total volumetric rain and latent heating from shallow and moderate precipitation (20-dBZecho height between 6 and 10 km) in the inner core is greater in RI storms than in non-RI storms, while the opposite is true for moderately deep (20-dBZecho height between 10 and 14 km) and very deep precipitation (20-dBZecho height ≥14 km). The authors argue that RI is more likely triggered by the increase of shallow–moderate precipitation and the appearance of more moderately to very deep convection in the middle of RI is more likely a response or positive feedback to changes in the vortex. For RI storms, a cyclonic rotation of frequency peaks from shallow (downshear right) to moderate (downshear left) to moderately and very deep precipitation (upshear left) is found and may be an indicator of a rapidly strengthening vortex. A ring of almost 90% occurrence of total precipitation is found for storms in the middle of RI, consistent with the previous finding of the cyan and pink ring on the 37-GHz color product.
Background
This study examines the predictive value of a novel systemic immune‐inflammation index (SII, platelet × neutrophil/lymphocyte ratio) in coronary artery disease (CAD) patients.
Methods
A ...total of 5602 CAD patients who had undergone a percutaneous coronary intervention (PCI) were enrolled. They were divided into two groups by baseline SII score (high SII vs low SII) to analyse the relationship between SII groups and the long‐term outcome. The primary outcomes were major cardiovascular events (MACE) which includes nonfatal myocardial infarction (MI), nonfatal stroke and cardiac death. Secondary outcomes included a composite of MACE and hospitalization for congestive heart failure.
Results
An optimal SII cut‐off point of 694.3 × 109 was identified for MACE in the CAD training cohort (n = 373) and then verified in the second larger CAD cohort (n = 5602). Univariate and multivariate analyses showed that a higher SII score (≥694.3) was independently associated with increased risk of developing cardiac death (HR: 2.02; 95% CI: 1.43‐2.86), nonfatal MI (HR: 1.42; 95% CI: 1.09‐1.85), nonfatal stroke (HR: 1.96; 95% CI: 1.28‐2.99), MACE (HR: 1.65; 95% CI: 1.36‐2.01) and total major events (HR: 1.53; 95% CI: 1.32‐1.77). In addition, the SII significantly improved risk stratification of MI, cardiac death, heart failure, MACE and total major events than conventional risk factors in CAD patients by the significant increase in the C‐index (P < .001) and reclassification risk categories by significant NRI (P < .05) and IDI (P < .05).
Conclusions
SII had a better prediction of major cardiovascular events than traditional risk factors in CAD patients after coronary intervention.
•The inherent features of metal–organic frameworks (MOFs) for improving the performance of electrochromic (EC) materials are presented.•The electronic conductivity and ion diffusion in MOFs are ...briefly introduced.•An overview of MOF-based EC materials is described.•Four types of MOF-based EC films with different color-changing principles are systematically summarized.•MOF-based multifunctional EC devices are briefly reviewed.•The challenges and future prospect of the development of MOF-based EC materials are suggested.
Electrochromic (EC) materials can reversibly transform their optical properties, including the transmittance, reflectance, absorptance, and color, under an external voltage bias, showing lot of potential for applications in smart devices. Metal-organic frameworks (MOFs) are organic–inorganic hybrid porous materials composed of metal centers and organic linkers through coordination bonds. Considering the unlimited possibility of inorganic and organic components, large specific surface area, unique permanent porosity, facile structural and surface properties, MOFs have the characteristics of organic–inorganic hybridization and rich nanoporous structure, which inherently meets the requirements for improving the performance of EC materials, and is expected to become a new generation of excellent EC materials. In this review, the electrical conductivity of MOFs and ion diffusion in MOFs are briefly introduced. The latest advances in MOFs-based EC materials are then systematically summarized, including four types: MOFs with redox active linkers, MOFs with redox active metal centers, MOFs with entrapped redox active guest molecules in their pores or channels, and MOF derivatives. The MOF-based multifunctional EC devices are also briefly reviewed. This review could encourage more researchers to enrich the MOF-based EC materials to fully release the application potential of MOFs as EC materials, and provide assistance for the future smart devices.
This paper considers channel estimation and system performance for the uplink of a single-cell massive multiple-input multiple-output system. Each receiver antenna of the base station is assumed to ...be equipped with a pair of one-bit analog-to-digital converters to quantize the real and imaginary part of the received signal. We first propose an approach for channel estimation that is applicable for both flat and frequency-selective fading, based on the Bussgang decomposition that reformulates the nonlinear quantizer as a linear function with identical first- and second-order statistics. The resulting channel estimator outperforms previously proposed approaches across all SNRs. We then derive closed-form expressions for the achievable rate in flat fading channels assuming low SNR and a large number of users for the maximal ratio and zero forcing receivers that takes channel estimation error due to both noise and one-bit quantization into account. The closed-form expressions, in turn, allow us to obtain insight into important system design issues such as optimal resource allocation, maximal sum spectral efficiency, overall energy efficiency, and number of antennas. Numerical results are presented to verify our analytical results and demonstrate the benefit of optimizing system performance accordingly.
Data to field operations of construction resources (personnel, equipment, materials) is vast, but the effort of collecting, analyzing, and visualizing is hardly ever taken. One main reason that ...limits higher quality in project site management decision making especially in resource intensive and complex operations is access to real-time information and subsequent technology that enables effortless data collection, processing, and visualization. Although recent developments in remote data sensing and intelligent data processing supplement manual data recording and analyze practices, few data on visualization tools in construction exist that gather data from dynamic resources and stream it to a field-realistic virtual reality environment in real-time. State-of-the-art technology in the field of real-time data collection and visualization is reviewed. A novel framework is presented that explains the method of streaming data from real-time positioning sensors to a real-time data visualization platform. Three case studies are presented which highlight its methods for recording data and visualizing information of construction activities in a (1) simulated virtual construction site, (2) outdoor construction setting, and (3) worker training environment. The results demonstrate that important construction information related to both safety and activity in field operations can be automatically monitored and visualized in real-time, thus offering benefits such as increased situational awareness to workers, equipment operators, or decision makers anywhere on a construction project or from a remote location.
Display omitted
► Current efforts to collect field data of constructions operations are very limited. ► Many virtual reality/immersive 3D visualization environments are not real-time. ► Technology for real-time data collection, processing, and visualization is shown. ► Case studies (workers, equipment operators, decision makers) are presented. ► Real-time situational awareness of construction information is made possible.
Expression of a high concentration of H2S is closely related to the formation of colon cancer tumors. However, only a few H2S‐triggered theranostics agents for colon cancer have been reported to ...date. Now, a turn‐on theranostics agent was developed by utilizing the in situ reaction of Cu2O and endogenous H2S at colon tumor sites. Based on in vitro and in vivo experiments, excellent photoacoustic imaging and photothermal therapy were both confirmed by this in situ reaction‐activated colon cancer theranostics method. This work established a simple and efficient strategy for both diagnosis and treatment of colon cancer with a novel trigger mechanism, which provides a new route for colon cancer theranostics based on the in situ reactions at the tumor sites.
A turn‐on theranostics agent was developed by utilizing the in situ reaction of Cu2O (see picture: brown) and endogenous H2S (yellow) at colon tumor sites. Based on in vitro and in vivo experiments, excellent photoacoustic imaging and photothermal therapy were both confirmed after being triggered by this in situ reaction. Cu9S8 shown in green.
Using 16-yr Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) observations, rainfall properties in the inner-core region of tropical cyclones (TCs) and the relative importance of ...stratiform and convective precipitation are examined with respect to the evolution of rapid intensification (RI) events. The onset of RI follows a significant increase in the occurrence and azimuthal coverage of stratiform rainfall in all shear-relative quadrants, especially upshear left. The importance of the increased stratiform occurrence in RI storms is further confirmed by the comparison of two groups of slowly intensifying (SI) storms with one group that underwent RI and the other that did not. Statistically, SI storms that do not undergo RI during their life cycle have a much lower percent occurrence of stratiform rain within the inner core. The relatively greater areal coverage of stratiform rain in RI cases appears to be related to the moistening/humidification of the inner core, particularly in the upshear quadrants. In contrast to rainfall frequency, rainfall intensity and total volumetric rain do not increase much until several hours after RI onset, which is more likely a response or positive feedback rather than the trigger of RI. Despite a low frequency of occurrence, the overall contribution to total volumetric rain by convective precipitation is comparable to that of stratiform rain, owing to its intense rain rate.
Perovskite quantum dots (PVQDs) have been demonstrated to be favorable materials for opto-electronic devices regardless of the generally required complicated preparation processes including solvent ...exchanges. Here, we report a novel convenient and efficient approach to produce CsSnI3 PVQDs through one-pot synthesis. Specifically, the produced PVQD solutions were clear and stable at room temperature after 90 days due to the antioxidant solvent additive (ASA) triphenyl phosphite (TPPi). Interestingly, the corresponding CsSnI3 PVQD-based solar cells achieved the maximum power conversion efficiency (PCE) of 5.03%, which is the highest performance for all-inorganic lead-free perovskite solar cells reported so far.
An asymmetric intermolecular, three-component radical-initiated dicarbofunctionalization of 1,1-diarylalkenes with diverse carbon-centered radical precursors and electron-rich heteroaromatics by a ...copper(I) and chiral phosphoric acid cooperative catalysis strategy has been developed, providing straightforward access to chiral triarylmethanes bearing quaternary all-carbon stereocenters with high efficiency as well as excellent chemo- and enantioselectivity. The key to success is not only the introduction of a sterically demanding chiral phosphoric acid to favor radical difunctionalization over the otherwise remarkable side reactions but also the in situ generation of carbocation intermediates from benzylic radical to realize asymmetric induction with the aid of a removable hydroxy directing group via cooperative interactions with chiral phosphate. Density functional theory calculations elucidated the critical chiral environment created by the hydrogen-bonding and ion-pair interactions between the chiral phosphoric acid catalyst and substrates, which leads to the enantioselective C–C bond formation.
Abstract
Electroreduction of carbon dioxide (CO
2
) into multicarbon products provides possibility of large-scale chemicals production and is therefore of significant research and commercial ...interest. However, the production efficiency for ethanol (EtOH), a significant chemical feedstock, is impractically low because of limited selectivity, especially under high current operation. Here we report a new silver–modified copper–oxide catalyst (dCu
2
O/Ag
2.3%
) that exhibits a significant Faradaic efficiency of 40.8% and energy efficiency of 22.3% for boosted EtOH production. Importantly, it achieves CO
2
–to–ethanol conversion under high current operation with partial current density of 326.4 mA cm
−2
at −0.87 V vs reversible hydrogen electrode to rank highly significantly amongst reported Cu–based catalysts. Based on in situ spectra studies we show that significantly boosted production results from tailored introduction of Ag to optimize the coordinated number and oxide state of surface Cu sites, in which the
*
CO adsorption is steered as both atop and bridge configuration to trigger asymmetric C–C coupling for stablization of EtOH intermediates.
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