Publications by authors named "ZeKun Chen"

In recent years, perovskite has been widely adopted in series-connected monolithic tandem solar cells (TSCs) to overcome the Shockley-Queisser limit of single-junction solar cells. Perovskite-organic TSCs, comprising a wide-bandgap (WBG) perovskite solar cell (pero-SC) as the front cell and a narrow-bandgap organic solar cell (OSC) as the rear cell, have recently drawn attention owing to the good stability and potential high power conversion efficiency (PCE). However, WBG pero-SCs usually exhibit higher voltage losses than regular pero-SCs, which limits the performance of TSCs.

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Organic solar cells (OSCs) processed with non-halogenated solvents usually suffer from excessive self-aggregation of small molecule acceptors (SMAs), severe phase separation and higher energy loss (E), leading to reduced open-circuit voltage (V) and power conversion efficiency (PCE). Regulating the intermolecular interaction to disperse the aggregation and further improve the molecular packing order of SMAs would be an effective strategy to solve this problem. Here, we designed and synthesized two SMAs L8-PhF and L8-PhMe by introducing different substituents (fluorine for L8-PhF and methyl for L8-PhMe) on the phenyl end group of the inner side chains of L8-Ph, and investigated the effect of the substituents on the intermolecular interaction of SMAs, E and performance of OSCs processed with non-halogenated solvents.

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Nanoengineered metal@zeolite materials have recently emerged as a promising class of catalysts for several industrially relevant reactions. These materials, which consist of small transition metal nanoclusters confined within three-dimensional zeolite pores, are interesting because they show higher stability and better sintering resistance under reaction conditions. While several such hybrid catalysts have been reported experimentally, key questions such as the impact of the zeolite frameworks on the properties of the metal clusters are not well understood.

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Electron-deficient heteroarenes based on dithienopyrrolobenzothiadiazole (BTP) have been highly attractive due to their fascinating packing structures, broad absorption profiles, and promising applications in non-fullerene organic solar cells. However, the control of their crystal structures for superior charge transport still faces big challenges. Herein, a conformation engineering strategy is proposed to rationally manipulate the single crystal structure of BTP-series heteroarenes.

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Digital green innovation (DGI) is crucial for high-pollution enterprises to improve green performance. However, there is a paradox regarding the impact of environmental regulations on DGI, primarily due to the varied effects of diverse regulatory tools. To resolve this paradox, based on Neoclassical Economics and the Porter Hypothesis, we empirically examine the influence of heterogeneous environmental regulations on DGI using a sample of high-pollution enterprises in China.

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Objective: To determine the diagnostic and therapeutic value of contrast-enhanced ultrasound-guided endoscopic retrograde appendicitis treatment (ERAT) in patients with uncomplicated appendicitis.

Methods: A retrospective analysis was performed on clinical and ultrasound data collected from 105 pediatric patients with uncomplicated appendicitis between January 2020 and December 2023. The ultrasound findings before and after treatment, as well as postoperative follow-up and recurrence rates, were summarized and analyzed.

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Article Synopsis
  • Data from Demographic and Health Surveys showed that out of over 600,000 children, about 3% died before age 5, with unsatisfied family planning being the strongest risk factor.
  • The presence of multiple risk factors significantly increases the risk of U5M, with those exposed to all five leading risks having over five times higher mortality odds.
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Background: Prolonged exclusive breastfeeding (PEB) for children older than six months old is a threat to appropriate complementary feeding practices. This study aims to examine the trend of PEB among children aged 6-23 months in India.

Methods: We adopted five waves of National Family Health Survey (NFHS) data between 1992-93 and 2019-21.

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Background: The appropriateness of hypertension thresholds for triggering action to prevent cardiovascular and renal complications among non-White populations in the UK is subject to question. Our objective was to establish ethnicity-specific systolic blood pressure (SBP) cutoffs for ethnic minority populations and assess the efficacy of these ethnicity-specific cutoffs in predicting adverse outcomes.

Methods: We analyzed data from UK Biobank, which included 444,418 participants from White, South Asian, Black Caribbean, and Black African populations with no history of cardiorenal complications.

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This study investigated the non-inferiority of feeding term healthy infants with enriched formula milk powder containing 1,3-dioleoyl-2-palmitoylglycerol (OPO) and milk fat globular membrane (MFGM), compared to breast milk, in terms of the formation of gut microbiota, neurodevelopment and growth. Infants were divided into three groups: breast milk group (BMG, = 50), fortified formula group (FFG, = 17), and regular formula group (RFG, = 12), based on the feeding pattern. Growth and development information was collected from the infants at one month, four months, and six months after the intervention.

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Organic molecules are of great interest for gas sensing applications. However, achieving high-performance gas sensors with high sensitivity, fast response, low consumption, and workability in humid conditions is still challenging. Herein, we report the rational design and synthesis of an ion-in-conjugation polymer, PADC (poly-4,4'-azodianiline-croconamide), obtained by the condensation of croconic acid with 4-4'diaminoazobenzene for gas sensing under humid conditions.

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Article Synopsis
  • Intimate partner violence (IPV) remains a significant issue in low and middle-income countries, hindering efforts to achieve the United Nations' Sustainable Development Goal 5.2, which aims to eliminate violence against women and girls.
  • The study analyzed data from population-based surveys conducted from 2000 to 2021, focusing on women aged 15-49 who had experienced IPV, and investigated the relationship between women's empowerment and IPV prevalence.
  • Findings indicated that 37.2% of women reported experiencing some form of IPV, with a slight overall decline observed over the years at an average rate of -0.2% annually, suggesting possible improvements in addressing this issue.
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Antimony sulfide (SbS) photodetectors (PDs) have great potential in commercial applications. The performances are affected by photocarrier distribution and recombination. Here, the gate-controlled SbS thin film PD is fabricated on the TiO/SiO/Si substrate by the vacuum method.

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Circulating tumor cells (CTCs) are important biomarkers in cancer diagnosis. However, the specific labeling of CTCs with high capture efficiency in whole blood remains a problem. Herein, a dual-source-driven nanomotor coupled with dual-targeting ligands (CD@NM) was designed for efficient capture, specific imaging and quantitative detection of CTCs.

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The slow charge transfer and high energy barrier are the key restrictions of cost-effective electrocatalysts for hydrogen production. A hierarchical heterostructure of MoN@NiFe-layered double hydroxides (LDH) is developed, with NiFe-LDH nanosheets supported on MoN nanowire arrays. The as-prepared MoN@NiFe-LDH exhibits a remarkably high performance on hydrogen production in alkaline medium, which is close to the benchmark Pt/C.

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The stability of rock pillar is crucial for ensuring the construction safety of twin tunnels with small clearance, especially when transitioning from the traditional left-right tunnel layouts to the up-down configurations due to complex and variable site constraints. However, there are limited researches on the evaluation and comparative study of the stability of these two types of rock pillars in twin tunnels. This paper introduces the yield approach index (YAI) as a measure to assess the stability of rock pillar in twin tunnels with small clearance, and various influencing factors including side pressure coefficient (SPC), stress release rate (SRR), and the thickness of rock pillar (characterised by the ratio of rock pillar thickness to tunnel diameter, RPT/TD) are considered in the analysis.

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Two perylenediimide (PDI) regioisomers with the central core substituted at the (Y-αPDI) and bay (Y-βPDI) areas of the PDIs were successfully prepared. The regioisomeric effects on the physicochemical and charge-transport properties were thoroughly investigated. The results unravel that Y-βPDI shows ambipolar transport with higher mobilities compared to its -counterpart, which is due to its favourable molecular geometry, stronger intermolecular interaction and improved electron-withdrawing ability.

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Lightweight, flexible, and noncombustible thermo-acoustic insulating (TAI) materials have great potential in vehicles, cold-chain transportation, and aerospace engineering, where weight and space savings are critical. However, the TAI capabilities of many commodities are hindered by the lack of diverse and reasonable resonant cavities with broadband and highly efficient acoustic responsiveness. This study demonstrates a layer-by-layer freeze-casting method for superelastic cellular aerogel construction from varied nanofibers and ice particulates with widely distributed resonant cavities from 0.

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Solitary waves are unique in nonlinear systems, but their formation and propagation in the nonlinear fluid-structure interactions have yet to be further explored. As a typical nonlinear system, the buckling of solid thin films is fundamentally related to the film-substrate interface that is further vulnerable to environments, especially when fluids exist. In this work, we report an anomalous, solitary-wave-like blister (SWLB) mode of MoS thin films in a humid environment.

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High efficiency organic solar cells (OSCs) based on A-DA'D-A type small molecule acceptors (SMAs) were mostly fabricated by toxic halogenated solvent processing, and power conversion efficiency (PCE) of the non-halogenated solvent processed OSCs is mainly restricted by the excessive aggregation of the SMAs. To address this issue, we developed two vinyl π-spacer linking-site isomerized giant molecule acceptors (GMAs) with the π-spacer linking on the inner carbon (EV-i) or out carbon (EV-o) of benzene end group of the SMA with longer alkyl side chains (ECOD) for the capability of non-halogenated solvent-processing. Interestingly, EV-i possesses a twisted molecular structure but enhanced conjugation, while EV-o shows a better planar molecular structure but weakened conjugation.

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Two-dimensional covalent organic frameworks (2D COFs) are promising for gas sensing owing to the large surface area, abundant active sites, and their semiconducting nature. However, 2D COFs are usually produced in the form of insoluble micro-crystallites. Their poor contacts between grain boundaries severely suppress the conductivity, which are too low for chemresistive gas sensing.

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Background: There is abundant evidence showing that iron deficiency is closely linked with delayed brain development, worse school performance, and behavioral abnormalities. However, evidence on the impact of iron supplementation among children and adolescents in low- and middle-income countries (LMICs) has been inconsistent. This study aims to examine the effect of oral iron supplementation on cognitive function among children and adolescents in LMICs.

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Context: The influences of diabetes duration and glycemic control and their potential interplays on the risk of heart failure (HF) remain unclear.

Objective: This work aimed to investigate the association of diabetes duration and glycemic control with the risk of HF.

Methods: A total of 23 754 individuals with diabetes but without HF during the baseline recruitment of UK Biobank were included in this study.

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Purpose: To explore the applicability of the Tei index combined with lung ultrasound score (LUS) in the evaluation of the lung condition and the right ventricular function of patients with neonatal pulmonary hypertension (PH).

Methods: Thirty healthy neonates and 75 neonates with PH were included. Two-dimensional, M-mode, and double Doppler ultrasound were used to detect RVFAC, TAPSE, TAPSV, and double Doppler Tei index (DD-Tei index).

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Background: Numerous studies have suggested that age at first birth (AFB) is inversely associated with metabolic diseases, but positively associated with liver cancer in women. Non-alcoholic fatty liver disease (NAFLD) is a canonical example of metabolic dysfunction and inflammation-based liver disease, while the association between AFB and the risk of NAFLD remains unclear. We aimed to investigate the association between AFB and the odds of NAFLD in women.

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