bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational engineering to enhance the photovoltaic by end‐capped and bridging core alterations: Empowering the future with solar energy through synergistic effect in D‐A materials
Authors: Janjua Muhammad Ramzan Saeed Ashraf , Haroon Muhammad , Hussain Riaz , Usman Muhammad , Khan Muhammad Usman , Gill Waqas Amber
Published: September 2021

Organic photovoltaic solar cells are being designed to offer a low energy photovoltaic (PV) solution. Optimizing the molecular backbone is one the most important technique for improving the photovoltaic characteristic of A‐D‐A type small active layer molecules. Herein, we have designed and theoretical characterized six new molecules by end‐capped and bridging core modifications of recently synthesized molecule BFHIC‐4F. Enhancement in photovoltaic, optoelectronic and physio‐chemical properties of newly designed molecules are seen by doing such modifications. Different advanced quantum chemical techniques have been employed to evaluate the performance of newly planned molecules. Large open circuit voltage and narrow band gap suggested that the designed molecules are efficient aspirants for solar cell applications. Moreover, maximum absorption capability in near‐infra‐red (NIR) region is observed for these newly designed molecules. To sum up, outcomes of all analyses advocated that the designed molecules are efficient candidates for solar cell applications.
Dephasing of Exchange‐Coupled Spins in Quantum Dots for Quantum Computing
Authors: Huang Peihao
Published: September 2021

A spin qubit in semiconductor quantum dots holds promise for quantum information processing for scalability and long coherence time. An important semiconductor qubit system is a double quantum dot trapping two electrons or holes, whose spin states encode either a singlet–triplet qubit or two single‐spin qubits coupled by exchange interaction. In this article, progress on the spin dephasing of two exchange‐coupled spins in a double quantum dot is reported. First, the schemes of two‐qubit gates and qubit encodings in gate‐defined quantum dots or donor atoms based on the exchange interaction are discussed. Then, the progress on spin dephasing of a singlet–triplet qubit or a two‐qubit gate is reported. The methods of suppressing spin dephasing are further discussed. The understanding of the spin dephasing may provide insights into the realization of high‐fidelity quantum gates for spin‐based quantum computing.
Multivariable control based on incomplete models via feedback linearization and continuous‐time derivative estimation
Authors: Rodrigues Diogo , Mesbah Ali
Published: September 2021

Models of nonlinear dynamical systems are typically composed of unknown and known parts due to the existence of mismatch between the true nonlinear system dynamics and their models. This article presents a multivariable control strategy for nonlinear systems that deals explicitly with the existence of incomplete models in a data‐driven framework. The proposed strategy uses feedback linearization and continuous‐time estimation of the unknown derivatives to achieve satisfactory closed‐loop performance for fast sampling applications with simple tuning of design parameters in the absence of a fully known system model. It is shown that this strategy possesses useful steady‐state properties, such as elimination of steady‐state error and rejection of constant input disturbances without any integral term, and ensures exponential convergence to the setpoints. Another contribution of this article is the development of methods for quantitative analysis of the stability and performance of the control strategy in the continuous‐time case. The approach is illustrated via a simulated example of reactor control. The proposed control strategy is broadly applicable and simplifies control design significantly for a large variety of systems.
Adaptive saturated tracking control for spacecraft proximity operations via integral terminal sliding mode technique
Authors: Liu Kang , Wang Yu , Ji Haibo , Wang Shenghui
Published: September 2021

This study presents a tracking control strategy for spacecraft proximity operations subjected to kinematic couplings, input saturation, modeling uncertainties, and external disturbances. First, a coupled six degrees of freedom dynamics is modeled to depict the relative motion between the pursuer and target spacecrafts. To address the input saturation problem, a dead‐zone operator‐based model is introduced. Subsequently, a finite‐time controller is proposed by exploiting the non‐singular integral terminal sliding mode method. By employing the adaptive technique, the proposed control strategy enjoys the feature that it can avoid requiring the prior knowledge of the lumped uncertainty's bounds. Using the Lyapunov theory, the designed controller is proved to guarantee that the translational and rotational tracking errors can converge to the origin within finite time. Finally, numerical simulations are performed to illustrate that the developed control scheme possesses a strong robustness, a fast convergence rate, input saturation elimination as well as chattering suppression.
Distributed asynchronous impulsive consensus of one‐sided Lipschitz nonlinear multi‐agent systems
Authors: Ma Tiedong , Zhang Zhengle , Cui Bing
Published: September 2021

This article investigates the consensus problem of one‐sided Lipschitz nonlinear multi‐agent systems (MASs) with distributed asynchronous impulsive control protocol. Based on the theory of discontinuous Lyapunov stability and impulsive differential equation, some new sufficient criteria about asynchronous impulsive control are derived to guarantee the consensus of one‐sided Lipschitz nonlinear MASs. Different from the existing methods of synchronous impulsive control, the asynchronous impulsive control does not need all agents are controlled simultaneously at one impulsive instant. Compared with the traditional Lipschitz condition, the one‐sided Lipschitz nonlinear function considered in this article can obtain a wider nonlinear range. Finally, some numerical simulation examples are given to verify the correctness of the theoretical analysis.
VDES R‐Mode: Vulnerability analysis and mitigation concepts
Authors: Lázaro Francisco , Raulefs Ronald , Bartz Hannes , Jerkovits Thomas
Published: September 2021

VDES R‐Mode aims at providing a contingency maritime positioning and navigation system when the operation of Global Navigation Satellite Systems (GNSS) is disrupted. However, VDES R‐Mode, similarly to GNSS, can itself also be subject to different types of attacks, such as jamming or spoofing. In this paper, we evaluate the vulnerabilities of VDES R‐Mode and discuss the effectiveness and cost of different types of countermeasures. The outcome of this cost‐benefit analysis is a recommendation to introduce authentication for the navigation messages of R‐Mode using the Timed Efficient Stream Loss‐Tolerant Authentication (TESLA) protocol.
Informing power and sample size calculations when using inverse probability of treatment weighting using the propensity score
Authors: Austin Peter C.
Published: September 2021

Propensity score weighting is increasingly being used in observational studies to estimate the effects of treatments. The use of such weights induces a within‐person homogeneity in outcomes that must be accounted for when estimating the variance of the estimated treatment effect. Knowledge of the variance inflation factor (VIF), which describes the extent to which the effective sample size has been reduced by weighting, allows for conducting sample size and power calculations for observational studies that use propensity score weighting. However, estimation of the VIF requires knowledge of the weights, which are only known once the study has been conducted. We describe methods to estimate the VIF based on two characteristics of the observational study: the anticipated prevalence of treatment and the anticipated c‐statistic of the propensity score model. We considered five different sets of weights: those for estimating the average treatment effect (ATE), the average treated effect in the treated (ATT), and three recently described sets of weights: overlap weights, matching weights, and entropy weights. The VIF was substantially smaller for the latter three sets of weights than for the first two sets of weights. Once the VIF has been estimated during the design phase of the study, sample size and power calculations can be done using calculations appropriate for a randomized controlled trial with similar prevalence of treatment and similar outcome variable, and then multiplying the requisite sample size by the estimated VIF. Implementation of these methods allows for improving the design and reporting of observational studies that use propensity score weighting.
Sensitive Detection of Protamine Based on a Yellow Emission Fluorophore
Authors: Wu Jichun , Dai Jianan , Zhao Yu , Li Jingmin , Ju Minzi , Zhang Xing , Shen Baoxing
Published: September 2021

In this study, a novel p‐hydroxybenzylidene‐imidazolidone derivatives‐based probe CBX (abbreviation of the synthetic probe) is designed and synthesized for sensitive detection of protamine. CBX emits fluorescence at 569 nm and a large Stokes shift of 114 nm is observed. Since protamine can induce the aggregation of negatively charged CBX, the designed probe shows excellent fluorescent response to protamine. Due to stronger electrostatic interactions between heparin and protamine, protamine prefers to unite with heparin rather than the probe after the addition of heparin, so the fluorescence of CBX decreases and realizes the detection of heparin. Comparing to other reported probes, CBX shows lower background interference, better sensitivity and higher stability. Limit of detection for protamine and heparin is calculated as 0.034 and 0.028 μg mL−1, respectively. Moreover, the detection of protamine by CBX is not interfered by other glycosaminoglycans.
Thione Derivatives as Medicinally Important Compounds
Authors: Das Aparna , Ashraf Muhammad Waqar , Banik Bimal Krishna
Published: September 2021

Like nitrogen‐containing heterocycles, sulfur‐containing heterocyclic compounds also have a lot of significant applications. These sulfur heterocycles are mainly used as a core for the synthesis of different heterocyclic compounds with various biological applications. It also occupies a huge part of natural products. In this review, we focus on the thiones‐the analogous of ketones. Syntheses of thiones as well as their applications as biologically active compounds are discussed in great detail. We have considered seven different classes of thiones such as Benzimidazole thiones, Triazole thiones, Pyrimidine thiones, Thiadiazine thiones, Thiazoline thiones, Thiazolidine thiones, and Quinazoline thiones.
Anti‐Inflammatory Nanotherapeutics by Targeting Matrix Metalloproteinases for Immunotherapy of Spinal Cord Injury
Authors: Shen Kui , Sun Guodong , Chan Leung , He Lizhen , Li Xiaowei , Yang Shuxian , Wang Baocheng , Zhang Hua , Huang Jiarun , Chang Minmin , Li Zhizhong , Chen Tianfeng
Published: September 2021

Neuroinflammation is critically involved in the repair of spinal cord injury (SCI), and macrophages associated with inflammation propel the degeneration or recovery in the pathological process. Currently, efforts have been focused on obtaining efficient therapeutic anti‐inflammatory drugs to treat SCI. However, these drugs are still unable to penetrate the blood spinal cord barrier and lack the ability to target lesion areas, resulting in unsatisfactory clinical efficacy. Herein, a polymer‐based nanodrug delivery system is constructed to enhance the targeting ability. Because of increased expression of matrix metalloproteinases (MMPs) in injured site after SCI, MMP‐responsive molecule, activated cell‐penetrating peptides (ACPP), is introduced into the biocompatible polymer PLGA‐PEI‐mPEG (PPP) to endow the nanoparticles with the ability for diseased tissue‐targeting. Meanwhile, etanercept (ET), a clinical anti‐inflammation treatment medicine, is loaded on the polymer to regulate the polarization of macrophages, and promote locomotor recovery. The results show that PPP‐ACPP nanoparticles possess satisfactory lesion targeting effects. Through inhibited consequential production of proinflammation cytokines and promoted anti‐inflammation cytokines, ET@PPP‐ACPP could decrease the percentage of M1 macrophages and increase M2 macrophages. As expected, ET@PPP‐ACPP accumulates in lesion area and achieves effective treatment of SCI; this confirmed the potential of nano‐drug loading systems in SCI immunotherapy.
Capacity‐Limited Na–M foil Anode: toward Practical Applications of Na Metal Anode
Authors: Han Jiatong , He Guang
Published: September 2021

The practical applications of Na metal anodes are severely plagued by unstable Na plating/stripping. Here the fabrication of Na‐rich Na–M (M = Au, Sn, and In) alloy anodes is reported as promising alternatives to address this issue. As compared to metallic Na foil anodes, the alloy foils exhibit improved electrolyte/electrode interface and provide abundant sodiophilic sites for efficient Na plating, while the self‐evolved porous Na‐M structures accommodate volume variation on cycling. Among three alloy foils, the Na–Au system shows the most promising performance. Under practical conditions such as capacity‐limited anodes (5 mAh cm−2) and large stripping/plating capacity (1.0 mAh cm−2), the Na0.9Au0.1 anodes demonstrate stable plating/stripping over 350 h. The proof‐of‐concept full cells assembled with hard carbon or Prussian blue materials and this thin Na0.9Au0.1 anode also have much elongated cycling life than for pristine Na metal anodes. These findings confirm that the rational design of Na–M alloy anodes can be a promising strategy to promote the development of Na metal batteries.
Reduction‐Sensitive Fluorinated‐Pt(IV) Universal Transfection Nanoplatform Facilitating CT45‐Targeted CRISPR/dCas9 Activation for Synergistic and Individualized Treatment of Ovarian Cancer
Authors: Lu Hongtong , Zhang Qingfei , He Shasha , Liu Sha , Xie Zhigang , Li Xiaoyuan , Huang Yubin
Published: September 2021

Compared to traditional clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR‐associated protein 9 (Cas9) system, CRISPR/dead Cas9 (dCas9) system can precisely regulate endogenous gene expression without damaging the host gene, representing a greater potential for cancer therapy. Cancer/testis antigen 45 (CT45) is proved to enhance platinum‐based chemosensitivity for individualized ovarian cancer therapy. However, the development of a single nanocarrier codelivering CRISPR/dCas9 system and chemotherapeutics for synergistic cancer therapy still faces challenges. Herein, a reduction‐sensitive fluorinated‐Pt(IV) universal transfection nanoplatform (PtUTP‐F) is developed for the CT45‐targeted CRISPR/dCas9 activation to achieve synergistic and individualized treatment of ovarian cancer. Overcoming multiple physiological barriers, PtUTP‐F condensed gene can efficiently transfect into different cells including 293T cells, A2780, SKOV3, A549, and A2780/cisplatin (DDP) cancer cells, which is superior to Lipofectamine 6000. With the responsive release of gene and Pt(II) in the intracellular reducing microenvironment, PtUTP‐F/dCas9‐CT45 can generate CRISPR/dCas9 activation of CT45 expression for protein phosphatase 4C (PP4C) activity inhibition to hinder the DNA repair pathway and thus enhances the sensitivity to Pt(II) drugs for individualized A2780 tumor therapy. The PtUTP‐F not only represents a powerful nanoplatform for CRISPR/dCas9 system delivery but also initiates a novel strategy for synergistic and individualized treatment of CRISPR/dCas9‐based gene therapy with chemotherapy.
Recent Advances in 2D Material‐Mediated Immuno‐Combined Cancer Therapy
Authors: Ma Baojin , Bianco Alberto
Published: September 2021

In the last years, cancer immunotherapy has started to attract a lot of attention, becoming one of the alternatives in the clinical treatment of cancer. Indeed, one of the advantages of immunotherapy is that both primary and distant tumors can be efficiently eradicated through a triggered immune response. Due to their large specific surface area and unique physicochemical properties, 2D materials have become popular in cancer immunotherapy, especially as efficient drug carriers. They have been also exploited as photothermal platforms, chemodynamic agents, and photosensitizers to further enhance the efficacy of the therapy. In this review, the focus is on the recent development of 2D materials as new tools to combine immunotherapy with chemotherapy, photothermal therapy, photodynamic therapy, chemodynamic therapy, radiotherapy, and radiodynamic therapy. These innovative synergistic approaches intend to go beyond the classical strategies based on a simple delivery function of immune modulators by nanomaterials. Furthermore, the effects of the 2D materials themselves and their surface properties (e.g., chemical modification and protein corona formation) on the induction of an immune response will be also discussed.
An Amorphous–Crystalline Nanosheet Arrays Structure for Ultrahigh Electrochemical Performance Supercapattery
Authors: Jiang Jing , Hu Yalin , He Xinrui , Li Zhipeng , Li Fu , Chen Xing , Niu Yi , Song Jie , Huang Pei , Tian Guiyun , Wang Chao
Published: September 2021

Hybrid supercapacitors (HSCs), also called supercapattery, which can substitute for low power density batteries have attracted extensive interest. However, when HSCs comes to commercial applications, there is still space for improvement in energy density. It seems that designing of electrode with high capacity is an effective measure. Herein, amorphous–crystalline MoO3‐Ni3S2/NF‐0.5 nanosheet arrays are developed as battery‐type electrodes. Specifically, the sheet‐like structure of crystalline Ni3S2 can achieve rich structural nanocrystallization, improving the redox reaction efficiency. Meanwhile, the disordered structure and irregular surface of the amorphous MoO3 are conducive to maximize the contact between the electrode and electrolyte, slowing down the volume change caused by the continuous charge–discharge process. As a result, it displays an ultrahigh areal specific capacity of 8.52 C cm−2 at 5 mA cm−2, and superior lifespan up to 7500 cycles with 90.0% retention. Further, when assembled into HSCs, the specific capacity reaches 1.47 C cm−2, corresponding to an energy density of 4.18 mWh cm−2 at a power density of 0.34 mW cm−2. Totally, the design of the unique structure displays a valuable measure for rational development of high energy density hybrid energy storage devices that are not limited to supercapacitors.
Copper/Carbon Heterogenous Interfaces for Enhanced Selective Electrocatalytic Reduction of CO2 to Formate
Authors: Du Juan , Xin Yu , Dong Minghua , Yang Junjuan , Xu Qingling , Liu Huizhen , Han Buxing
Published: September 2021

Electrochemical reduction of CO2 (CO2RR) to formate is a promising route to prepare value‐added chemical. Developing low‐cost and efficient electrocatalysts with high product selectivity is still a grand challenge. Herein, a novel Cu anchored on hollow carbon spheres catalysts (HCS/Cu‐x, x represents the mass of CuCl2 added in the system) is designed with controllable copper/carbon heterogenous interfaces. Rich copper/carbon heterogenous interfaces and hollow structure of optimized HCS/Cu‐0.12 catalyst are beneficial to charge transmission. Compared with the CO2RR occurred in aqueous electrolyte over Cu‐based catalyst that has been reported to date, it exhibits highest formate Faradaic efficiency (FE) of 82.4% with a current density of 26 mA cm−2 and remarkable stability in a H‐cell.
3D Hydrazone‐Functionalized Covalent Organic Frameworks as pH‐Triggered Rotary Switches
Authors: Zhao Wenjuan , Yu Chengyang , Zhao Jie , Chen Fengqian , Guan Xinyu , Li Hui , Tang Bin , Yu Guangtao , Valtchev Valentin , Yan Yushan , Qiu Shilun , Fang Qianrong
Published: September 2021

The property expansion of 3D functionalized covalent organic frameworks (COFs) is important for developing their potential applications. Herein, the first case of 3D hydrazone‐decorated COFs as pH‐triggered molecular switches is reported, and their application in the stimuli‐responsive drug delivery system is explored. These functionalized COFs with hydrazone groups on the channel walls are obtained via a multi‐component bottom–up synthesis strategy. They exhibit a reversibleE/Zisomerization at various pH values, confirmed by UV–vis absorption spectroscopy and proton conduction. Remarkably, after loading cytarabine (Ara‐C) as a model drug molecule, these pH‐responsive COFs show an excellent and intelligent sustained‐release effect with an almost fourfold increase in the Ara‐C release at pH = 4.8 than at pH = 7.4, which will effectively improve drug‐targeting. Thus, these results open a way toward designing 3D stimuli‐responsive functionalized COF materials and promote their potential application as drug carriers in the field of disease treatment.
Sensitive, High‐Speed, and Broadband Perovskite Photodetectors with Built‐In TiO2 Metalenses
Authors: Xiao Ting , Zhao Jie , Sun Peng , Li Peng , Zhang Yaokang , Zhao Ni , Ren Zhiwei , Li Gang , Huang Zhifeng , Zheng Zijian
Published: September 2021

Monolithic integration of nanostructured metalenses with broadband light transmission and good charge transport can simultaneously enhance the sensitivity, speed, and efficiency of photodetectors. The realization of built‐in broadband metalenses in perovskite photodetectors, however, has been largely challenged by the limited choice of materials and the difficulty in nanofabrication. Here a new type of broadband‐transmitting built‐in TiO2 metalens (meta‐TiO2) is devised, which is readily fabricated by one‐step and lithograph‐free glancing angle deposition. The meta‐TiO2, which comprises of sub‐100 nm TiO2 nanopillars randomly spaced with a wide range of sub‐wavelength distances in 5–200 nm, shows high transmittance of light in the wavelength range of 400–800 nm. The meta‐TiO2 also serves as an efficient electron transporting layer to prevent the exciton recombination and facilitate the photoinduced electron extraction and transport. Replacing the conventional mesoporous TiO2 with the meta‐TiO2 comprehensively leads to enhancing the detection speed by three orders of magnitude to a few hundred nanoseconds, improving the responsivity and detectivity by one order of magnitude to 0.5 A W−1 and 1013 Jones, respectively, and extending the linear dynamic range by 50% to 120 dB.
A Polysulfides‐Confined All‐in‐One Porous Microcapsule Lithium–Sulfur Battery Cathode
Authors: Liu Jinyun , Zhu Mengfei , Shen Zihan , Han Tianli , Si Ting , Hu Chaoquan , Zhang Huigang
Published: September 2021

Developing emerging materials for high energy‐density lithium–sulfur (Li–S) batteries is of great significance to suppress the shuttle effect of polysulfides and to accommodate the volumetric change of sulfur. Here, a novel porous microcapsule system containing a carbon nanotubes/tin dioxide quantum dots/S (CNTs/QDs/S) composite core and a porous shell prepared through a liquid‐driven coaxial microfluidic method as Li–S battery cathode is developed. The encapsulated CNTs in the microcapsules provide pathways for electron transport; SnO2 QDs on CNTs immobilize the polysulfides by strong adsorption, which is verified by using density functional theory calculations on binding energies. The porous shell of the microcapsule is beneficial for ion diffusion and electrolyte penetration. The void inside the microcapsule accommodates the volumetric change of sulfur. The Li–S battery based on the porous CNTs/QDs/S microcapsules displays a high capacity of 1025 mAh g−1 after 100 cycles at 0.1 C. When the sulfur loading is 2.03 mg cm−2, the battery shows a stable cycling life of 700 cycles, a Coulombic efficiency exceeding 99.9%, a recoverable rate‐performance during repeated tests, and a good temperature tolerance at both −5 and 45 °C, which indicates a potential for applications at different conditions.
Conjugated Polymers: Optical Toolbox for Bioimaging and Cancer Therapy
Authors: Wei Jinchao , Liu Ying , Yu Jie , Chen Ling , Luo Mai , Yang Lele , Li Peng , Li Shengliang , Zhang Xiao‐Hong
Published: September 2021

Conjugated polymers (CPs) are capable of coordinating the electron coupling phenomenon to bestow powerful optoelectronic features. The light‐harvesting and light‐amplifying properties of CPs are extensively used in figuring out the biomedical issues with special emphasis on accurate diagnosis, effective treatment, and precise theranostics. This review summarizes the recent progress of CP materials in bioimaging, cancer therapeutics, and introduces the design strategies by rationally tuning the optical properties. The recent advances of CPs in bioimaging applications are first summarized and the challenges to clear the future directions of CPs in the respective area are discussed. In the following sections, the focus is on the burgeoning applications of CPs in phototherapy of the tumor, and illustrates the underlying photo‐transforming mechanism for further molecular designing. Besides, the recent progress in the CPs‐assistant drug therapy, mainly including drug delivery, gene therapeutic, the optical‐activated reversion of tumor resistance, and synergistic therapy has also been discussed elaborately. In the end, the potential challenges and future developments of CPs on cancer diagnosis and therapy are also illuminated for the improvement of optical functionalization and the promotion of clinical translation.
Lanthanide Upconverted Microlasing: Microlasing Spanning Full Visible Spectrum to Near‐Infrared under Low Power, CW Pumping
Authors: Yang Xiang‐Fei , Lyu Ze‐Yu , Dong Hao , Sun Ling‐Dong , Yan Chun‐Hua
Published: September 2021

The miniaturization of lasers holds promise in ultradense data storage and biosensing, but greater pump power is required to reach the lasing thresholds to overcome increased optical losses with reduced resonant cavity sizes. Here, the whispering galley mode (WGM) of Yb3+/Tm3+ doped upconversion nanoparticles (UCNPs) coupled with microcavities (≈5 µm) is used to achieve ultralow threshold upconverted lasing at 800 nm with excitation fluences as low as 4 W cm−2. The continuous‐wave (CW) upconverted lasing, with a Q factor on the order of 103, can remain stable for more than 6 h. In addition, ultralow threshold upconverted microlasers spanning the full visible spectrum from Yb3+/Er3+, Yb3+/Ho3+, and Yb3+/Tm3+ doped UCNPs are obtained with the same WGM cavity design. These upconverted microlasers working under low power CW 980 nm laser will enable promising applications in biosensing and imaging.
Bioinspired Photonic Ionogels as Interactively Visual Ionic Skin with Optical and Electrical Synergy
Authors: Lyu Quanqian , Wang Shanzhen , Peng Bolun , Chen Xiaodong , Du Shuo , Li Miaomiao , Zhang Lianbin , Zhu Jintao
Published: September 2021

With the ever‐growing demands for flexible smart interactive electronics, it remains highly desirable yet challenging to design and fabricate interactive ionic skin with multiple signal synergistic outputs. Herein, high‐performance photonic ionogels (PIGs) with excellent stability and synergy sensitivity are designed by locking a non‐volatile and non‐hygroscopic ionic liquid (IL), that is, 1‐ethyl‐3‐methylimidazolium bis‐(trifluoromethylsulfonyl)imide ([EMIm][TFSI]), into photonic elastomers based on polymer networks of poly(ethylene glycol) phenyl ether acrylate (PEGPEA). Through manipulating the degree of crosslinking, PIGs exhibit high sensitivity that can output distinct and intuitive color change in visual with the mechanochromic sensitivity of ≈1.76 nm per percent strain and clear electrical signal with the gauge factor of 1, in response to a tiny stretch of millimeter scale. Thanks to the stable photonic elastomers and IL employed, the PIGs developed in this study exhibit good performance under harsh and complex environmental conditions, including high/low temperature (from −35 °C to 100 °C), dry/wet air, and high vacuum. This study provides a novel strategy for developing integrated, stable, and multifunctional photonic ionogels for ionic skin sensors and flexible interactive devices with synergistically optical and electrical output.
Ultralight‐Weight Graphene Aerogels with Extremely High Electrical Conductivity
Authors: dos Santos‐Gómez Lucía , García José R. , Montes‐Morán Miguel A. , Menéndez José Angel , García‐Granda Santiago , Arenillas Ana
Published: September 2021

The integration of 2D graphene sheets into a porous and macroscopic structure is extremely attractive for application in several electrochemical fields. In this regard, for the first time, the synthesis of 3D graphene aerogels is reported by using a rapid, easy, cost‐effective, and scalable at industrial level methodology. These aerogels integrate the intrinsic properties of graphene with a high pore volume. To achieve this ultraporous graphene network, resorcinol/formaldehyde polymer with controllable porosity is employed as a binder and a cross‐linker material, and a graphene oxide solution provides the graphene building blocks. Two series of materials with and without catalyst for resorcinol/formaldehyde reaction and with different synthesis conditions and graphene contents are studied. The resulting graphene aerogels present low density, large macroporosity, and electrical conductivity values as high as 852 S m−1, with 97.58% of porosity, which is the highest value of electrical conductivity reported so far in the literature for ultralight‐weight graphene aerogels.
Near‐Field Energy Transfer into Silicon Inversely Proportional to Distance Using Quasi‐2D Colloidal Quantum Well Donors
Authors: Humayun Muhammad Hamza , Hernandez‐Martinez Pedro Ludwig , Gheshlaghi Negar , Erdem Onur , Altintas Yemliha , Shabani Farzan , Demir Hilmi Volkan
Published: September 2021

Silicon is the most prevalent material system for light‐harvesting applications; however, its inherent indirect bandgap and consequent weak absorption limits its potential in optoelectronics. This paper proposes to address this limitation by combining the sensitization of silicon with extraordinarily large absorption cross sections of quasi‐2D colloidal quantum well nanoplatelets (NPLs) and to demonstrate excitation transfer from these NPLs to bulk silicon. Here, the distance dependency, d, of the resulting Förster resonant energy transfer from the NPL monolayer into a silicon substrate is systematically studied by tuning the thickness of a spacer layer (of Al2O3) in between them (varied from 1 to 50 nm in thickness). A slowly varying distance dependence of d−1 with 25% efficiency at a donor–acceptor distance of 20 nm is observed. These results are corroborated with full electromagnetic solutions, which show that the inverse distance relationship emanates from the delocalized electric field intensity across both the NPL layer and the silicon because of the excitation of strong in‐plane dipoles in the NPL monolayer. These findings pave the way for using colloidal NPLs as strong light‐harvesting donors in combination with crystalline silicon as an acceptor medium for application in photovoltaic devices and other optoelectronic platforms.
Engineering Tough Metallosupramolecular Hydrogel Films with Kirigami Structures for Compliant Soft Electronics
Authors: Yu Hai Chao , Hao Xing Peng , Zhang Chuan Wei , Zheng Si Yu , Du Miao , Liang Songmiao , Wu Zi Liang , Zheng Qiang
Published: September 2021

A simple and effective approach is demonstrated to fabricate tough metallosupramolecular hydrogel films of poly(acrylic acid) by one‐pot photopolymerization of the precursor solution in the presence of Zr4+ ions that form coordination complexes with the carboxyl groups and serve as the physical crosslinks of the matrix. Both as‐prepared and equilibrated hydrogel films are transparent, tough, and stable over a wide range of temperature, ionic strength, and pH. The thickness of the films can be easily tailored with minimum value of ≈7 μm. Owing to the fast polymerization and gelation process, kirigami structures can be facilely encoded to the gel films by photolithographic polymerization, affording versatile functions such as additional stretchability and better compliance of the planar films to encapsulate objects with sophisticated geometries that are important for the design of soft electronics. By stencil printing of liquid metal on the hydrogel film with a kirigami structure, the integrated soft electronics shows good compliance to cover curved surfaces and high sensitivity to monitor human motions. Furthermore, this strategy is applied to diverse natural and synthetic macromolecules containing carboxyl groups to develop tough hydrogel films, which will open opportunities for the applications of hydrogel films in biomedical and engineering fields.
Precise Control of Customized Macrophage Cell Robot for Targeted Therapy of Solid Tumors with Minimal Invasion
Authors: Dai Yuguo , Bai Xue , Jia Lina , Sun Hongyan , Feng Yanmin , Wang Luyao , Zhang Chaonan , Chen Yuanyuan , Ji Yiming , Zhang Deyuan , Chen Huawei , Feng Lin
Published: September 2021

Injecting micro/nanorobots into the body to kill tumors is one of the ultimate ambitions for medical nanotechnology. However, injecting current micro/nanorobots based on 3D‐printed biocompatible materials directly into blood vessels for targeted therapy is often difficult, and mistakes in targeting can cause serious side effects, such as blood clots, oxidative stress, or inflammation. The natural affinity of macrophages to tumors, and their natural phagocytosis and ability to invade tumors, make them outstanding drug delivery vehicles for targeted tumor therapy. Hence, a magnetically controlled cell robot (MCR) based on a macrophage drug carrier is proposed. Here, living macrophages are converted into MCRs through endocytosis of specially‐designed magnetic nanoparticles loaded with doxorubicin and indocyanine green. Following this, the MCRs can be transported to tumors through the blood vessels using external magnetic fields, and penetrate the blood vessels into the interior of the tumor due to their deformability. With the MCR's cascaded drug release, targeted killing of tumors in mice is demonstrated, with minimal effects on the normal surrounding tissue. The ability to impart precise drug doses onto natural cells, such as macrophages, and load various functional components into the MCRs, offers an efficient method for precise targeted therapy.
Creating Fluorine‐Doped MoS2 Edge Electrodes with Enhanced Hydrogen Evolution Activity
Authors: Zhang Ruihua , Zhang Mengru , Yang Hao , Li Gen , Xing Shuming , Li Mengyan , Xu Yiling , Zhang Qiuyue , Hu Sheng , Liao Honggang , Cao Yang
Published: September 2021

The edge sites of MoS2 are catalytically active for hydrogen evolution reactions (HER). However, pristine edge sites usually contain only intrinsic atoms or defects, limiting the tuning of on‐site hydrogen species adsorption and desorption, the critical steps for HER. In addition, the number of atoms on pristine edges is small compared to that of electrochemically inert atoms in bulk. Thus, it is desirable to develop a scalable technique of creating a large number of highly HER‐active edge sites. Here, a plasma etching strategy is developed for creating MoS2 edge electrodes with a controllable number of active sites that enable the quantitative characterization of their HER activity using a local probe method. Fluorine atoms with large electronegativity are doped on the MoS2 edge sites that lead to a fivefold activity enhancement compared to that from pristine edges and is attributed to the more moderate binding energy for hydrogen species. The scalability of such a method is further demonstrated by activating MoS2 catalyst in macroscopic quantities with enhanced HER performance and stability. The work provides two‐dimensional materials as a platform for understanding the doping effect on the edge sites at atomic‐level, and offers a novel route for the design of efficient catalysts.
Nanostructured Metal Borides for Energy‐Related Electrocatalysis: Recent Progress, Challenges, and Perspectives
Authors: Pu Zonghua , Liu Tingting , Zhang Gaixia , Liu Xianhu , Gauthier Marc. A. , Chen Zhangxing , Sun Shuhui
Published: September 2021

The discovery of durable, active, and affordable electrocatalysts for energy‐related catalytic applications plays a crucial role in the advancement of energy conversion and storage technologies to achieve a sustainable energy future. Transition metal borides (TMBs), with variable compositions and structures, present a number of interesting features including coordinated electronic structures, high conductivity, abundant natural reserves, and configurable physicochemical properties. Therefore, TMBs provide a wide range of opportunities for the development of multifunctional catalysts with high performance and long durability. This review first summarizes the typical structural and electronic features of TMBs. Subsequently, the various synthetic methods used thus far to prepare nanostructured TMBs are listed. Furthermore, advances in emerging TMB‐catalyzed reactions (both theoretical and experimental) are highlighted, including the hydrogen evolution reaction, the oxygen evolution reaction, the oxygen reduction reaction, the carbon dioxide reduction reaction, the nitrogen reduction reaction, the methanol oxidation reaction, and the formic acid oxidation reaction. Finally, challenges facing the development of TMB electrocatalysts are discussed, with focus on synthesis and energy‐related catalytic applications, and some potential strategies/perspectives are suggested as well, which will profit the design of more efficient TMB materials for application in future energy conversion and storage devices.
Superferromagnetic Nanoparticles Enable Order‐of‐Magnitude Resolution & Sensitivity Gain in Magnetic Particle Imaging
Authors: Tay Zhi Wei , Savliwala Shehaab , Hensley Daniel W. , Fung K.L. Barry , Colson Caylin , Fellows Benjamin D. , Zhou Xinyi , Huynh Quincy , Lu Yao , Zheng Bo , Chandrasekharan Prashant , Rivera‐Jimenez Sindia M. , Rinaldi‐Ramos Carlos M. , Conolly Steven M.
Published: September 2021

Magnetic nanoparticles have many advantages in medicine such as their use in non‐invasive imaging as a Magnetic Particle Imaging (MPI) tracer or Magnetic Resonance Imaging contrast agent, the ability to be externally shifted or actuated and externally excited to generate heat or release drugs for therapy. Existing nanoparticles have a gentle sigmoidal magnetization response that limits resolution and sensitivity. Here it is shown that superferromagnetic iron oxide nanoparticle chains (SFMIOs) achieve an ideal step‐like magnetization response to improve both image resolution & SNR by more than tenfold over conventional MPI. The underlying mechanism relies on dynamic magnetization with square‐like hysteresis loops in response to 20 kHz, 15 kAm−1 MPI excitation, with nanoparticles assembling into a chain under an applied magnetic field. Experimental data shows a “1D avalanche” dipole reversal of every nanoparticle in the chain when the applied field overcomes the dynamic coercive threshold of dipole‐dipole fields from adjacent nanoparticles in the chain. Intense inductive signal is produced from this event resulting in a sharp signal peak. Novel MPI imaging strategies are demonstrated to harness this behavior towards order‐of‐magnitude medical image improvements. SFMIOs can provide a breakthrough in noninvasive imaging of cancer, pulmonary embolism, gastrointestinal bleeds, stroke, and inflammation imaging.
Atmospheric Pressure Dry Etching of Polysilicon Layers for Highly Reverse Bias‐Stable TOPCon Solar Cells
Authors: Kafle Bishal , Mack Sebastian , Teßmann Christopher , Bashardoust Sattar , Clochard Laurent , Duffy Edward , Wolf Andreas , Hofmann Marc , Rentsch Jochen
Published: September 2021

Single‐sided etching (SSE) of a‐Si/poly‐Si is typically considered a challenge for realizing a cost‐efficient TOPCon production sequence, as there is a certain degree of unwanted wrap‐around for poly‐Si deposition technologies such as low pressure chemical vapor deposition, plasma‐enhanced chemical vapor deposition, and atmospheric pressure chemical vapor deposition. To date, alkaline or acidic wet‐chemical solutions in either inline or batch configurations are used for this purpose. Herein, an alternative SSE process is proposed using an inline dry etching tool, which applies molecular fluorine as the etching gas under atmospheric pressure conditions. The developed etching process performs complete etching of both as‐deposited amorphous silicon and annealed polycrystalline silicon layers, either intrinsic or doped, and with measured etch rates of >3 μm min−1 at 10% F2 concentration allows etching of a typical layer thickness of 200 nm in just a few seconds. The etching process is also configured to perform excellent edge isolation while maintaining a low wrap‐around etching (d
rear < 500 μm) at the opposing‐side. The etching process is successfully transferred to the industrial TOPCon solar cell architecture, yielding high parallel resistances (S
shunt,avg. > 1500 kΩ cm2), low reverse current density (J
rev,avg < 0.8 mA cm−2) measured at a bias voltage of −12 V, and independently certified conversion efficiencies of up to 23.3%.
Passivating Contact with Phosphorus‐Doped Polycrystalline Silicon‐Nitride with an Excellent Implied Open‐Circuit Voltage of 745 mV and Its Application in 23.88% Efficiency TOPCon Solar Cells
Authors: Yang Qing , Liu Zunke , Lin Yiran , Liu Wei , Liao Mingdun , Feng Mengmeng , Zhi Yuyan , Zheng Jingming , Lu Linna , Ma Dian , Han Qingling , Cheng Hao , Yang Zhenhai , Ding Kaining , Duan Weiyuan , Chen Hui , Wang Yuming , Zeng Yuheng , Yan Baojie , Ye Jichun
Published: September 2021

A P‐doped polycrystalline silicon‐nitride (n‐poly‐SiNx) as the electron selective collection layer in a tunnel oxide passivated contact (TOPCon) solar cell is reported. The nitrogen content is controlled by the active gas ratio ofR = NH3/(SiH4 + NH3) during the plasma‐enhanced chemical vapor deposition (PECVD) process. The effects ofRratio on the material's composition, crystallinity, surface passivation, and contact resistivity are investigated. The poly‐SiNxcontact exhibits improved surface passivation in comparison with the reference poly‐Si without N incorporation. The best double‐sided passivated n‐type alkaline‐polished crystalline silicon wafer with the n‐poly‐SiNx/SiOxmanifests the highest implied open‐circuit voltage (iVoc) of ≈745 mV, with the corresponding single‐sided saturated current density of 1.7 fA cm−2and the effective lifetime (τeff) of 10 ms at the injection level of ≈1 × 1015 cm−3. In contrast, the controlled sample with an n‐poly‐Si/SiOxpassivation contact has a maximal iVocof 738 mV. However, the primary drawback of the N doping is to raise the contact resistivity, but which is still in an acceptable range and shows little effect on the performance of solar cell with full‐area contact. The proof‐of‐concept TOPCon solar cell using the n‐poly‐SiNx/SiOxpassivating contact has achieved an efficiency of 23.88%, indicating the potential of the n‐poly‐SiNxfor high‐efficiency TOPCon solar cells.
Effect of Preheating on the Microstructure, Impact Properties, and Fracture Mechanisms of a Laser Surface‐Hardened High‐Carbon–Chromium Steel
Authors: Li Zhen-Xing , Li Bo , Yao Zhe-He , Zhang Qun-Li , Yao Jian-Hua , Dong Gang , Ye Zhong
Published: September 2021

To optimize the toughness and hardness of laser surface‐hardened high‐carbon–chromium (52100) steel, the effect of preheating on microstructure evolution and impact property is studied, and the impact fracture mechanism is analyzed. The results indicate that preheating deepens the hardened depth, facilitating grain coarsening and cementite dissolution near the surface. Regardless of preheating, the size distribution of cementite follows a typical lognormal distribution. Laser surface hardening leads to a decrease in impact absorbed energy. Preheating at 160 °C increases the impact absorbed energy by ≈25%, at which point the maximum hardness is still as high as 860 HV0.3. The impact absorbed energy of spheroidized microstructure tends to be larger before laser hardening and reduces after laser hardening. The impact toughness is the combined result of the brittleness of the hardened layer, residual stress, and substrate microstructure. Under the impact load, microcracks nucleate near the surface of the hardened layer and propagate in the form of intergranular fracture and then propagate in the form of transgranular fracture toward the inside of the hardening layer and substrate. Herein, a novelty research work on optimizing the impact properties during laser hardening through preheating and adjusting initial microstructure is provided.
Influence of an Increasing Alloying Content on the Microstructure of a High‐Speed Steel in the Laser‐Powder Bed Fusion Process
Authors: Kunz Johannes , Köhler Marie Luise , Herzog Simone , Kaletsch Anke , Broeckmann Christoph
Published: September 2021

Tool steels being processed by laser powder bed fusion (LPBF) receive increasing attention in research. High hardness and low toughness lead to a challenging crack susceptibility of these alloys. Latest advancements in process technology have shown promising results toward crack‐free build‐up of additive manufactured tools. Detailed microstructure analysis is carried out to understand the mechanisms of solidification as an influencing factor for cracking. These findings can provide insights toward an alloy optimization regarding a higher intrinsic crack resistance while maintaining the typical mechanical properties of tool steels. PMHS 6–5–3–8 high‐speed steel shows directional dendritic solidification with carbides mainly precipitating in enriched interdendritic areas. Increasing the alloying content by additions of PMHS 7–7–7–11 leads to a shift toward a less‐pronounced texture. The positive effect of texture reduction is superimposed by a highly increased crack formation due to carbide networks.
Arpeggio – die Hauptbrücke der neuen Hisingsbron in Göteborg
Authors: Walser Peter , Savery Trojaborg Steen , Darholm Thomas , Kollén Magnus , Stockmann Rico
Published: September 2021

Es wird über den Wettbewerb, die Detailplanung, die Ausschreibung und die Bauausführung des Arpeggio, der Hauptbrücke der Hisingsbronquerung in Göteborg, berichtet. Diese Hubbrücke wird die alternde Klappbrücke aus dem Jahre 1939 ersetzen und für eine bessere Anbindung von Straße, Straßenbahn sowie Geh‐ und Radwegen der nördlich gelegenen Bereiche an die Stadtmitte beitragen. Durch die Absenkung der Gradiente wurde es möglich, die Länge der Querung kürzer zu gestalten und somit wertvolle Flächen zur weiteren Entwicklung der Stadt zu gewinnen.
Formulation of Rice and Wheat Based Snacks with Modulated Starch Digestibility by Altering the Dietary Composition
Authors: Bhatt Yogita , Aswathanarayana Setty Jyothi Lakshmi
Published: September 2021

Diabetes and other metabolic disorders are increasing at an alarming rate worldwide. This study aims to formulate rice‐based and wheat‐based snack khakhra, a pan‐baked snack, with macronutrient distribution for diabetics, as per the guidelines issued by the American Diabetes Association. Protein, fiber, and fat‐rich ingredients are used to modulate the starch hydrolysis pattern with 50–52%, 28–32%, and 16–20% of energy from carbohydrate, fat, and protein, respectively. It is observed that upon nutrient enrichment, the estimated glycemic index reduces by 8.5% in wheat‐based khakhra and 11% in rice‐based khakhra. Significant changes (p < 0.05) are observed in viscosity, swelling power, solubility, and thermal properties of khakhra flours. Changes in FTIR spectra are also observed, particularly in rice based samples. The khakhra, thus, formulated shows good sensory acceptability in both qualitative descriptive analysis and consumer acceptability tests. These findings suggest that a simple modulation in macronutrient content can be an effective tool in developing a healthy snack at both the domestic and industrial levels.