bluuebunny/crossref_metadata_2025 huggingface dataset:
Achieving Balanced Crystallinity of Donor and Acceptor by Combining Blade‐Coating and Ternary Strategies in Organic Solar Cells
Authors: Zhang Lin , Xu Xianbin , Lin Baojun , Zhao Heng , Li Tengfei , Xin Jingming , Bi Zhaozhao , Qiu Guanxian , Guo Shengwei , Zhou Ke , Zhan Xiaowei , Ma Wei
Published: October 2018

As a prototype tool for slot‐die coating, blade‐coating exhibits excellent compatibility with large‐area roll‐to‐roll coating. A ternary organic solar cell based on PBDB‐T:PTB7‐Th:FOIC blends is fabricated by blade‐coating and exhibits a power conversion efficiency of 12.02%, which is one of the highest values for the printed organic solar cells in ambient environment. It is demonstrated that blade‐coating can enhance crystallization of these three materials, but the degree of induction is different (FOIC > PBDB‐T > PTB7‐Th). Thus, the blade‐coated PBDB‐T:FOIC device presents much higher electron mobility than hole mobility due to the very high crystallinity of FOIC. Upon the addition of PTB7‐Th into the blade‐coated PBDB‐T:FOIC blends, the crystallinity of FOIC decreases together with the corresponding electron mobility, due to the better miscibility between PTB7‐Th and FOIC. The ternary strategy not only maintains the well‐matched crystallinity and mobilities, but also increases the photocurrent with complementary light absorption as well as the Förster resonant energy transfer. Furthermore, small domains with homogeneously distributed nanofibers are observed in favor of the exciton dissociation and charge transport. This combination of blade‐coating and ternary strategies exhibits excellent synergistic effect in optimizing morphology, showing great potential in the large‐area fabrication of highly efficient organic solar cells.
Tailor‐Made Microporous Metal–Organic Frameworks for the Full Separation of Propane from Propylene Through Selective Size Exclusion
Authors: Wang Hao , Dong Xinglong , Colombo Valentina , Wang Qining , Liu Yanyao , Liu Wei , Wang Xin‐Long , Huang Xiao‐Ying , Proserpio Davide M. , Sironi Angelo , Han Yu , Li Jing
Published: October 2018

Adsorptive separation of olefin/paraffin mixtures by porous solids can greatly reduce the energy consumption associated with the currently employed cryogenic distillation technique. Here, the complete separation of propane and propylene by a designer microporous metal–organic framework material is reported. The compound, Y6(OH)8(abtc)3(H2O)6(DMA)2 (Y‐abtc, abtc = 3,3′,5,5′‐azobenzene‐tetracarboxylates; DMA = dimethylammonium), is rationally designed through topology‐guided replacement of inorganic building units. Y‐abtc is both thermally and hydrothermally robust, and possesses optimal pore window size for propane/propylene separation. It adsorbs propylene with fast kinetics under ambient temperature and pressure, but fully excludes propane, as a result of selective size exclusion. Multicomponent column breakthrough experiments confirm that polymer‐grade propylene (99.5%) can be obtained by this process, demonstrating its true potential as an alternative sorbent for efficient separation of propane/propylene mixtures.
Revealing the Interplay of Structural Phase Transitions and Ferroelectric Switching in Mixed Phase BiFeO3
Authors: Naden Aaron B. , Edwards David , Neumayer Sabine M. , Guy Joseph G. M. , Rodriguez Brian J. , Bassiri‐Gharb Nazanin , Kumar Amit
Published: October 2018

Epitaxially strained BiFeO3 thin films with coexisting tetragonal‐ and rhombohedral‐like phases exhibit a range of intriguing functional properties, often strongly related to the unique microstructure of the film. Here enhancements in electromechanical response are reported during simultaneous nanoscale application of electric field and localized stress. These enhancements manifest in the form of peaks, or humps, in the piezoresponse hysteresis loops obtained under a select polarity of applied electric field, corresponding nominally to a downward polarization. Using a variation of band excitation piezoresponse force spectroscopy to collect electromechanical hysteresis loops and to simultaneously monitor the elastic behavior during switching, a comprehensive picture of the complex interplay of ferroelastic structural transitions and ferroelectric switching and its impact on the overall functional response are developed. Such an understanding is a crucial step toward realizing practical electronic devices, such as pressure sensors, incorporating this promising material.
Clustering and Self‐Recovery of Slanted Hydrogel Micropillars
Authors: Lee Hyemin , Kim Jun‐Hyun , Wu Gaoxiang , Lee Hae‐Min , Kim Jaekyoung , Kwon Dokyeong , Yang Shu , Kim Chang‐Koo , Yoon Hyunsik
Published: October 2018

Slanted high‐aspect‐ratio polymer pillars are studied for their unique properties such as unidirectional spreading of liquid, directional adhesions, or alignment of cells, where the pillars are in constant contact with water or in a humid environment. These pillars, however, tend to cluster upon water evaporation due to the capillary force and lowered modulus of the pillars. Here, spontaneous recovery of clustered slanted hydrogel pillars to their original shape is presented by exploiting the modulus change of hydrogel materials during water evaporation. The clustering and recovery of the slanted hydrogel micropillars are monitored in situ by optical microscopy and environmental scanning electron microscopy. To elucidate sequential clustering and recovery mechanism, the adhesion force between the pillars and the restoring force is compared. Finally, the dynamic change of optical transparency is exploited as the result of switching between clustering and recovery of the slanted micropillars for display. The study of the deformation and recovery of slanted hydrogel pillars will offer insights into geometrical and material designs in water‐based applications.
High Selectivity Gas Separation by Interfacial Diffusion Membranes
Authors: Wang David K. , Bauer Ralph A. , Yan Kelan , Mergos Ioannis A. , Yang Zi , Zhou Yi , Verweij Hendrik
Published: October 2018

A new generation of inorganic/organic polymeric interfacial diffusion membranes is presented that have unprecedented combinations of high selectivity and flux. The membranes consist of an inorganic scaffold, with pores that are filled with a thermoplastic polymer that crystallizes in the pore space while a nm thin interfacial area remains amorphous. The polyetherimide, present on top of the α‐Al2O3 scaffold as a 3.9 µm amorphous layer, and inside the near‐surface area of the scaffold over ≈130 nm, is partly crystallized. Combinations of extremely high gas selectivities are found of >2200 for CO2/N2 and >4000 for H2/N2, combined with CO2 and H2 permeances of 2.2 × 10−10 and 4.0 × 10−10 [mol (m2 Pa s)−1], respectively. For CO2 (5–50%) and N2 dry and water‐saturated gas mixtures, only CO2 permeance is detected. The presence of water appears to affect CO2 permeances very little at both 22 and 57 °C. Selective molecular transport is blocked in the crystalline areas and takes place exclusively in the amorphous interfacial area. It is governed by a combination of affinity, mobility, and size‐exclusion. Conservative estimates of the membrane permeability indicate that their properties by far exceed the Robeson boundary.
Curvature Elasticity‐Driven Leaflet Asymmetry and Interleaflet Raft Coupling in Supported Membranes
Authors: Ryu Yong‐Sang , Jordan Luke R. , Wittenberg Nathan J. , Kim Sang Moon , Yoo Daehan , Jeong Cherlhyun , Warrington Arthur E. , Rodriguez Moses , Oh Sang‐Hyun , Lee Sin‐Doo
Published: October 2018

Membrane curvature is closely associated with spatial distribution of lipids and curvature can influence the formation of lipid rafts in biological membranes. However, it is still unclear how the curvature elasticity plays a role on the asymmetric distribution of lipids across the membrane leaflets, especially, during the process of the raft domain growth. Using supported lipid membranes on wedge‐shaped substrates with alternating positive and negative curvatures, curvature‐mediated asymmetry of lipid raft domains is observed across the membrane leaflets accompanied by glycolipid receptor (GM1 and GT1b) localization. The raft domains initially appear only in a membrane leaflet possessing negative curvatures. In the presence of the interleaflet coupling, they evolve to generate the transverse registry across the membrane bilayer. It is shown that a human recombinant antibody rHIgM12 is co‐localized with the rafts formed at the peaks and valleys of the wedge substrate, indicating that the spatial distribution of its receptor (GT1b) is indeed manifested by the site‐specific formation of asymmetric raft domains through the curvature elasticity. The platform can be used to explore the mechanism for the leaflet asymmetry and lipid sorting in terms of the membrane curvature, the composition, and the receptor presentation.
High Energy Density CNT/NaI Composite Cathodes for Sodium‐Ion Batteries
Authors: Kim Sanghyeon , Li Xiangming , Sang Lingzi , Yun Young Soo , Nuzzo Ralph G. , Gewirth Andrew A. , Braun Paul V.
Published: October 2018

The Na‐iodine system has potential as a positive electrode in sodium‐ion batteries due to its fast reaction kinetics and high energy density. Here, the fabrication of a NaI‐loaded carbon nanotube (CNT) mat cathode is presented and the use of NaI as a Na‐ion battery cathode is reported for the first time. Freestanding electrodes show a capacity retention of 92% after 100 cycles at 100 mA h g−1 and a high specific energy density (≈473 W h kg−1, second discharge basis vs Na metal) and small hysteresis (0.03 V). Adding a CNT mat interlayer between the NaI composite cathode and the separator, and fluoroethylene carbonate to the electrolyte significantly suppresses shuttling of active materials during cycling. Using ex situ X‐ray photoelectron spectroscopy and Raman data, an understanding of the relevant processes occurring during cycling of the CNT/NaI cathode is developed.
Toward Fully Manufacturable, Fiber Assembly–Based Concurrent Multimodal and Multifunctional Sensors for e‐Textiles
Authors: Kapoor Ashish , McKnight Michael , Chatterjee Kony , Agcayazi Talha , Kausche Hannah , Bozkurt Alper , Ghosh Tushar K.
Published: October 2018

Soft polymer‐based sensors as an integral part of textile structures have attracted considerable scientific and commercial interest recently because of their potential use in healthcare, security systems, and other areas. While electronic sensing functionalities can be incorporated into textiles at one or more of the hierarchical levels of molecules, fibers, yarns, or fabrics, arguably a more practical and inconspicuous means to introduce the desired electrical characteristics is at the fiber level, using processes that are compatible to textiles. Here, a prototype multimodal and multifunctional sensor array formed within a woven fabric structure using bicomponent fibers with ordered insulating and conducting segments is reported. The multifunctional characteristics of the sensors are successfully demonstrated by measuring tactile, tensile, and shear deformations, as well as wetness and biopotential. While the unobtrusive integration of sensing capabilities offers possibilities to preserve all desirable textile qualities, this scaled‐up fiber‐based approach demonstrates the potential for scalable and facile manufacturability of practical e‐textile products using low‐cost roll‐to‐roll processing of large‐area flexible sensor systems and can be remarkably effective in advancing the field of e‐textiles.
Functional Liquid Metal Nanoparticles Produced by Liquid‐Based Nebulization
Authors: Tang Shi‐Yang , Qiao Ruirui , Lin Yiliang , Li Yuhuan , Zhao Qianbin , Yuan Dan , Yun Guolin , Guo Jinhong , Dickey Michael D. , Huang Tony Jun , Davis Thomas P. , Kalantar‐Zadeh Kourosh , Li Weihua
Published: October 2018

Functional liquid metal nanoparticles (NPs), produced from eutectic alloys of gallium, promise new horizons in the fields of sensors, microfluidics, flexible electronics, catalysis, and biomedicine. Here, the development of a vapor cavity generating ultrasonic platform for nebulizing liquid metal within aqueous media for the one‐step production of stable and functional liquid metal NPs is shown. The size distribution of the NPs is fully characterized and it is demonstrated that various macro and small molecules can also be grafted onto these liquid metal NPs during the liquid‐based nebulization process. The cytotoxicity of the NPs grafted with different molecules is further explored. Moreover, it is shown that it is possible to control the thickness of the oxide layer on the produced NPs using electrochemistry that can be embedded within the platform. It is envisaged that this platform can be adapted as a cost‐effective and versatile device for the rapid production of functional liquid metal NPs for future liquid metal‐based optical, electronic, catalytic, and biomedical applications.
1D/2D TiO2/MoS2 Hybrid Nanostructures for Enhanced Photocatalytic CO2 Reduction
Authors: Xu Feiyan , Zhu Bicheng , Cheng Bei , Yu Jiaguo , Xu Jingsan
Published: October 2018

Photocatalytic reduction of CO2 into solar fuels is recognized an attractive approach to solve the environmental and energy crisis. MoS2, a type of 2D transition metal dichalcogenides, has attracted significant attention in photoelectronics, sensors and photo/electrocatalytic water splitting owing to its remarkable properties. Nevertheless, to date, MoS2 is barely used as (co)catalyst for CO2 photoreduction. Herein, novel 1D/2D TiO2/MoS2 nanostructured hybrid with TiO2 fibers covered by MoS2 nanosheets by hydrothermal transformation method is fabricated. The MoS2 sheet arrays show a lateral size of ≈80 nm and a thickness of down to 2 nm, vertically and uniformly standing upon the TiO2 fibers. X‐ray photoelectron spectroscopy (XPS) results and density functional theory (DFT) calculation imply the intimate chemical interaction between MoS2 and TiO2 upon hybridization, which can facilitate electron–hole separation upon photoexcitation. In addition, the hierarchical TiO2/MoS2 nanostructure shows enhanced optical absorption and CO2 adsorption, therefore, a superior photocatalytic activity for reducing CO2 into methane and methanol is achieved over the hybrid as compared to pristine TiO2. Isotope (13C) tracer test confirms that the products are produced from the photocatalytic reduction of the CO2 source instead of any organic contaminants. This work offers an alternative approach to rationally design and synthesize TiO2‐based photocatalysts toward high‐efficiency photoreduction of CO2.
Broadband Metamaterial Absorbers
Authors: Yu Peng , Besteiro Lucas V. , Huang Yongjun , Wu Jiang , Fu Lan , Tan Hark H. , Jagadish Chennupati , Wiederrecht Gary P. , Govorov Alexander O. , Wang Zhiming
Published: October 2018

The recent rise of metamaterials opens new opportunities for absorbers due to their designed electrodynamic properties and effects, allowing the creation of materials with effective values of permittivity and permeability that are not available in naturally occurring materials. Since their first experimental demonstration in 2008, recent literature has offered great advances in metamaterial perfect absorbers (MMPAs) operating at frequencies from radio to optical. Broadband absorbers are indispensable in thermophotovoltaics, photodetection, bolometry, and manipulation of mechanical resonances. Although it is easy to obtain MMPAs with single band or multiband, achieving broadband MMPA (BMMPA) remains a challenge due to the intrinsically narrow bandwidth of surface plasmon polaritons, localized surface plasmon resonances generated on metallic surfaces at nanoscale or high Q‐factor in GHz region. To guide future development of BMMPA, recent progress is reviewed here: the methods to create broadband absorption and their potential applications. The four mainstream methods to achieve BMMPAs are introduced, including planar and vertical element arrangements, their welding with lumped elements and the use of plasmonic nanocomposites, accompanied by the description of other, less common approaches. Following this, applications of BMMPA in solar photovoltaics, photodetection, bolometry, and manipulation of mechanical resonances are reviewed. Finally, challenges and prospects are discussed.
Illumination‐Induced Halide Segregation in Gradient Bandgap Mixed‐Halide Perovskite Nanoplatelets
Authors: Zhou Chunhua , Ou Qingdong , Chen Weijian , Gan Zhixing , Wang James , Bao Qiaoliang , Wen Xiaoming , Jia Baohua
Published: October 2018

Efficient energy funneling has exhibited great contribution to the high performance of perovskite‐based optoelectronic devices. Here, formamidinium (FA+, HC(NH2)2+) lead mixed‐halide nanoplatelets (FAPb(BrxI1−x)3) with gradient bandgap are fabricated using chemical vapor deposition followed with bromide–iodide substitution by exposure to FABr vapor. The as‐fabricated perovskite nanoplatelets exhibit pure bromide phase in the thin nanoplatelet (tens of nanometers) and a gradual bromide–iodide composite, thus with gradient bandgap (2.29–1.56 eV), in the thick nanoplatelet (more than hundreds of nanometers). Accordingly, photoluminescence (PL) spectra are observed at 540, 560/610, and 735/790 nm, respectively. In such gradient bandgap structures, photogenerated carriers can effectively transfer and emit in the low‐bandgap region by energy funneling. With illumination, the PL spectrum of Br‐rich phase exhibits blueshift and therefore 610 nm band disappears. In contrast, redshift is observed in I‐rich phase due to the decrease of 735 nm band while an increase of 790 nm band. It is demonstrated that irreversible and stable phases are formed with illumination in both Br‐rich and I‐rich nanoplatelets. This investigation develops a method to fabricate gradient bandgap perovskites with designed energy funneling, and also provides significant insight into the halide segregation in such special perovskites, which greatly benefits their future optoelectronic applications.
Efficient Prediction of Structural and Electronic Properties of Hybrid 2D Materials Using Complementary DFT and Machine Learning Approaches
Authors: Tawfik Sherif Abdulkader , Isayev Olexandr , Stampfl Catherine , Shapter Joe , Winkler David A. , Ford Michael J.
Published: October 2018

There are now, in principle, a limitless number of hybrid van der Waals (vdW) heterostructures that can be built from the rapidly growing number of 2D layers. The key question is how to explore this vast parameter space in a practical way. Computational methods can guide experimental work. However, even the most efficient electronic structure methods such as density functional theory, are too time consuming to explore more than a tiny fraction of all possible hybrid 2D materials. A combination of density functional theory (DFT) and machine learning techniques provide a practical method for exploring this parameter space much more efficiently than by DFT or experiments. As a proof of concept, this methodology is applied to predict the interlayer distance and band gap of bilayer heterostructures. The methods quickly and accurately predict these important properties for a large number of hybrid 2D materials. This work paves the way for rapid computational screening of the vast parameter space of vdW heterostructures to identify new hybrid materials with useful and interesting properties.
The Recent Advance in Fiber‐Shaped Energy Storage Devices
Authors: Liao Meng , Ye Lei , Zhang Ye , Chen Taiqiang , Peng Huisheng
Published: October 2018

Wearable electronic devices that can be directly worn on the human body or combined with daily textiles have experienced a booming development with the rapid development of mobile electronics. These wearable electronic devices strongly demand indispensable, high performance power systems with small size, high flexibility, and adaptability to comfort frequent deformations during usage. Fabricating high‐performance energy storage systems in a 1D shape like fiber is recognized as a promising strategy to address the above issues. These fiber‐shaped power systems with diameters from tens to hundreds of micrometers can adapt to various deformations for stable operation in close contact with the human body. It is also possible to further weave such 1D energy storage devices into breathable textiles with matching electrochemical performances for the wearable electronics. Here, the key advancements related to fiber‐shaped energy storage devices are reviewed, including the synthesis of materials, the design of structures, and the optimization of properties for the most explored energy storage devices, i.e., supercapacitors, aprotic lithium‐based batteries, as well as novel aqueous battery systems. The remaining challenges are finally discussed to highlight the future direction of the development of fiber‐shaped energy storage devices.
Thermally Enhanced n‐Type Thermoelectric Behavior in Completely Organic Graphene Oxide‐Based Thin Films
Authors: Cho Chungyeon , Bittner Noah , Choi Woongchul , Hsu Jui‐Hung , Yu Choongho , Grunlan Jaime C.
Published: October 2018

Air‐stable n‐type organic thermoelectric (TE) materials with high power factor are needed to produce efficient, lightweight devices that could be self‐powered by harnessing waste heat. Here, a completely organic n‐type TE nanocomposite is achieved by depositing layers of double‐walled carbon nanotubes (DWNT) stabilized with polyethylenimine (PEI) and graphene oxide (GO) in a layer‐by‐layer fashion from aqueous solutions. A 30 bilayer (BL) film (≈610 nm thick), comprised of this DWNT‐PEI/GO sequence, exhibits electrical conductivity of 27.3 S cm−1 and a Seebeck coefficient of −30 µV K−1, producing a power factor of 2.5 µW m−1 K−2. Low temperature thermal reduction (150 °C for 30 min) of this composite thin film significantly improves its thermoelectric performance. An electrical conductivity of 460 S cm−1 and Seebeck coefficient of −93 µV K−1 are achieved. A 30 BL DWNT‐PEI/reduced graphene oxide (rGO) film (≈480 nm thick) exhibits a power factor as large as 400 µW m−1 K−2, which is one of the highest values reported for an organic n‐type material. By depositing layers containing montmorillonite clay on top, these n‐type nanocomposites exhibit excellent air stability. This combination of air stability and high power factor could enable efficient thermoelectric devices on flexible substrates (e.g., clothing).
Patterning Vertically Grown Gold Nanowire Electrodes for Intrinsically Stretchable Organic Transistors
Authors: Zhu Bowen , Gong Shu , Lin Fenge , Wang Yan , Ling Yunzhi , An Tiance , Cheng Wenlong
Published: October 2018

Advances in large‐area organic electronics for sensor arrays and electronic skins demand highly stretchable, patternable, and conformal electrodes to minimize contact resistance when sensing devices are mechanically deformed. Gold is an excellent electrode material with work function matching well with p‐type organic transistors. However, it is non‐trivial to fabricate highly stretchable gold electrodes for stretchable organic electronics. Here, by combining the advantages of both top‐down patterning and bottom‐up synthesis, a new materials platform of patterned vertically grown gold nanowires (AuNWs) for constructing intrinsically stretchable electrodes, with high conductivity of 1288 S cm−1 at 0% and 152 S cm−1 at 170% strain, is introduced. Such patterned vertical AuNWs can be embedded in an elastomer matrix, leading to stretchable electrodes that are mechanically robust and durable. The interface between AuNWs electrodes and poly(3‐hexylthiophene) thin film shows ohmic contact for the entire strain regime from 0% to 100%, indicating low contact resistance. A stretchable organic transistor with ion gel as the dielectric is demonstrated, which can survive up to 100% strain without much performance degradation. The results indicate that our methodology may be extended to other organic semiconducting materials, hence, offering a general electrode materials platform for devising high performance intrinsically stretchable organic transistors.
Surface Doping to Enhance Structural Integrity and Performance of Li‐Rich Layered Oxide
Authors: Liu Shuai , Liu Zepeng , Shen Xi , Li Weihan , Gao Yurui , Banis Mohammad Norouzi , Li Minsi , Chen Kai , Zhu Liang , Yu Richeng , Wang Zhaoxiang , Sun Xueliang , Lu Gang , Kong Qingyu , Bai Xuedong , Chen Liquan
Published: October 2018

The Li‐rich layer‐structured oxides are regarded as one of the most promising cathode materials for their high energy density but suffer from severe problems such as capacity fading, poor rate performance, and continuous potential dropping. These issues are addressed here by surface doping of niobium (Nb) and other heavy ions in a Li‐rich Mn‐based layered oxide, Li1.2Mn0.54Ni0.13Co0.13O2. The doped ions are verified to be located in the Li‐layer near the oxide surface; they bind the slabs via the strong NbO bonds and “inactivate” the surface oxygen, enhancing the structural stability. The specific capacity of the modified oxide reaches 320 mAh g−1 in the initial cycle, 94.5% of which remains after 100 cycles. More importantly, the average discharge potential drops only by 136 mV in this process. The findings of this study illustrate the importance of inactivating the surface oxygen in suppressing the cation mixing in the bulk, providing an effective strategy for designing high‐performance Li‐rich cathode materials.
Surface Passivation and Carrier Collection in {110}, {100} and Circular Si Microwire Solar Cells
Authors: Ro Yun Goo , Chen Renjie , Liu Ren , Li Nan , Williamson Theodore , Yoo Jinkyoung , Sim Sangwan , Prasankumar Rohit P. , Dayeh Shadi A.
Published: October 2018

Surface recombination is a major bottleneck for realizing highly efficient micro/nanostructure solar cells. Here, parametric studies of the influence of Si microwire (SiMW) surface‐facet orientation (rectangular with flat‐facets, {110}, {100} and circular), with a fixed height of 10 µm, diameter (D = 1.5–9.5 µm), and sidewall spacing (S = 2.5–8.5 µm), and mesh‐grid density (1–16 mm−2) on recombination and carrier collection in SiMW solar cells with radial p‐n junctions are reported. An effective surface passivation layer composed of thin thermally grown silicon dioxide (SiO2) and silicon nitride (SiNx) layers is employed. For a fixed D of 1.5 µm, tight SiMW spacing results in improved short‐circuit current density (Jsc = 30.1 mA cm−2) and sparse arrays result in open‐circuit voltages (Voc = 0.552 V) that are similar to those of control Si planar cells. For a fixed S, smaller D results in better light trapping at shorter wavelengths and higher Jsc while larger D exhibits better light trapping at larger wavelengths and a higher Voc. With a mesh‐grid electrode the power conversion efficiency increases to 15.3%. These results provide insights on the recombination mechanisms in SiMW solar cells and provide general design principles for optimizing their performance.
Understanding the Exceptional Performance of Lithium‐Ion Battery Cathodes in Aqueous Electrolytes at Subzero Temperatures
Authors: Ramanujapuram Anirudh , Yushin Gleb
Published: October 2018

Lithium‐ion batteries with aqueous electrolytes can be excellent candidates for battery applications at low temperatures. In contrast to a common misconception, aqueous lithium ion batteries can operate at several tens of degrees below the freezing point of water when high concentration electrolyte solutions are utilized. Furthermore, it is reported here that the performance of intercalation cathodes in aqueous electrolytes is quite remarkable and superior to that in common organic electrolytes at very low temperatures down to about −40 °C. Here in the performance of water‐based electrolyte solutions‐based on three low‐cost inorganic salts (LiNO3, Li2SO4, and LiCl) and that of the corresponding aqueous battery systems is studied in order to understand the rate‐limiting step at sub‐zero temperatures. It is found that the charge transfer resistance is the largest impedance contributor at low temperatures. However, layered cathodes in aqueous electrolytes do not exhibit a significant increase in the charge‐transfer resistance, or a reduction in the accessible capacity during charging until the temperature is close to the solution freezing point. This is in sharp contrast to their behavior in organic electrolytes that do not support any performance below −20 °C. This different behavior explains the dramatically superior performance of lithium ion battery cathodes in water‐based electrolytes at lower temperatures.
K‐Birnessite Electrode Obtained by Ion Exchange for Potassium‐Ion Batteries: Insight into the Concerted Ionic Diffusion and K Storage Mechanism
Authors: Gao Ang , Li Min , Guo Nannan , Qiu Daping , Li Yan , Wang Senhao , Lu Xia , Wang Feng , Yang Ru
Published: October 2018

Novel and low‐cost rechargeable batteries are of considerable interest for application in large‐scale energy storage systems. In this context, K‐Birnessite is synthesized using a facile solid‐state reaction as a promising cathode for potassium‐ion batteries. During synthesis, an ion exchange protocol is applied to increase K content in the K‐Birnessite electrode, which results in a reversible capacity as high as 125 mAh g−1 at 0.2 C. Upon K+ exchange the reversible phase transitions are verified by in situ X‐ray diffraction (XRD) characterization. The underlying mechanism is further revealed to be the concerted K+ ion diffusion with quite low activation energies by first‐principle simulations. These new findings provide new insights into electrode process kinetics, and lay a solid foundation for material design and optimization of potassium‐ion batteries for large‐scale energy storage.
Heat integration and operational optimization of an austenitization furnace using concentric‐tube radiant recuperators
Authors: Ganesh Hari S. , Ezekoye Ofodike A. , Edgar Thomas F. , Baldea Michael
Published: October 2018

This paper presents a model‐based study of the impact of implementing radiant (radiation‐dominated) concentric‐tube recuperators on fuel use in an indirectly‐fired industrial heat treating (austenitization/quench hardening) furnace. The recuperators recover some of the waste heat from the burner exhaust to preheat the inlet air to the burners, thus reducing the amount of fuel required for combustion. The novelty of this work consists of developing a physics‐based model of a recuperator, which captures local gas‐to‐surface convective heat transfer and long‐range surface‐to‐surface radiation interactions, and using the model to analyze and optimize the energy use of the furnace. An iterative algorithm is proposed to solve the poorly‐conditioned energy balance equations. The steady‐state system operation is optimized using surrogate models. Extensive simulation studies demonstrate that heat integration reduces fuel consumption significantly without affecting product quality. © 2018 American Institute of Chemical Engineers AIChE J, 65: e16414 2019
Evolution of leaf structure and drought tolerance in species of Californian Ceanothus
Authors: Fletcher Leila R. , Cui Hongxia , Callahan Hilary , Scoffoni Christine , John Grace P. , Bartlett Megan K. , Burge Dylan O. , Sack Lawren
Published: October 2018

Premise of the Study

Studies across diverse species have established theory for the contribution of leaf traits to plant drought tolerance. For example, species in more arid climates tend to have smaller leaves of higher vein density, higher leaf mass per area, and more negative osmotic potential at turgor loss point (πTLP). However, few studies have tested these associations for species within a given lineage that have diversified across an aridity gradient.

Methods

We analyzed the anatomy and physiology of 10 Ceanothus (Rhamnaceae) species grown in a common garden for variation between and within “wet” and “dry” subgenera (Ceanothus and Cerastes, respectively) and analyzed a database for 35 species for leaf size and leaf mass per area (LMA). We used a phylogenetic generalized least squares approach to test hypothesized relationships among traits, and of traits with climatic aridity in the native range. We also tested for allometric relationships among anatomical traits.

Key Results

Leaf form, anatomy, and drought tolerance varied strongly among species within and between subgenera. Cerastes species had specialized anatomy including hypodermis and encrypted stomata that may confer superior water storage and retention. The osmotic potentials at turgor loss point (πTLP) and full turgor (πo) showed evolutionary correlations with the aridity index (AI) and precipitation of the 10 species’ native distributions, and LMA with potential evapotranspiration for the 35 species in the larger database. We found an allometric correlation between upper and lower epidermal cell wall thicknesses, but other anatomical traits diversified independently.

Conclusions

Leaf traits and drought tolerance evolved within and across lineages of Ceanothus consistently with climatic distributions. The πTLP has signal to indicate the evolution of drought tolerance within small clades.
Rates of human–macaque interactions affect grooming behavior among urban‐dwelling rhesus macaques (Macaca mulatta)
Authors: Kaburu Stefano S. K. , Marty Pascal R. , Beisner Brianne , Balasubramaniam Krishna N. , Bliss‐Moreau Eliza , Kaur Kawaljit , Mohan Lalit , McCowan Brenda
Published: October 2018

Objectives

The impact of anthropogenic environmental changes may impose strong pressures on the behavioral flexibility of free‐ranging animals. Here, we examine whether rates of interactions with humans had both a direct and indirect influence on the duration and distribution of social grooming in commensal rhesus macaques (Macaca mulatta).

Materials and Methods

Data were collected in two locations in the city of Shimla in northern India: an urban setting and a temple area. We divided these two locations in a series of similar‐sized physical blocks (N = 48) with varying rates of human–macaque interactions. We conducted focal observations on three free‐ranging rhesus macaque groups, one in the urban area and two in the temple area.

Results

Our analysis shows that macaques engaged in shorter grooming bouts and were more vigilant while grooming in focal sessions during which they interacted with people more frequently, suggesting that humans directly affected grooming effort and vigilance behavior. Furthermore, we found that in blocks characterized by higher rates of human–macaque interactions grooming bouts were shorter, more frequently interrupted by vigilance behavior, and were less frequently reciprocated.

Discussion

Our work shows that the rates of human–macaque interaction had both a direct and indirect impact on grooming behavior and that macaques flexibly modified their grooming interactions in relation to the rates of human–macaque interaction to which they were exposed. Because grooming has important social and hygienic functions in nonhuman primates, our work suggests that human presence can have important implications for animal health, social relationships and, ultimately, fitness. Our results point to the need of areas away from people even for highly adaptable species where they can engage in social interactions without human disruption.
From Laboratory Press to Spins with Giant Effects
Authors: Weihrich Richard , Pöttgen Rainer , Pielnhofer Florian
Published: October 2018

Parallelly aligned spins in Co‐Kagome nets have provided several reasons for researchers to celebrate: Liu et al. and Wang et al. have reported discoveries of unique combinations of properties: Sn2Co3S2=Co3Sn2S2=SnCo3/2S exhibits giant anomalous Hall effects that exceed those of known materials by orders of magnitude. For this laboratory curiosity, a specific electronic topology has been discovered in the predicted half‐metal ferromagnetic S=
state that makes it a fascinating example of the novel group of magnetic Weyl semimetals. We present a chemical view on this compound that was little understood for a long time, but that is now also studied with respect to skyrmion lattices and thermoelectrics.
DFT and TD‐DFT study of iridium complexes with low‐color‐temperature and low‐efficiency roll‐off properties
Authors: Qin Zheng‐Kun , He Ke‐Chuan , Lü Peng , Song Ming‐Xing , Zhang Yong‐Ling , Wang Chun‐Xu , Song Shu‐Yan , Lü Shi‐Quan , Bai Fu‐Quan , Zhang Hong‐Jie
Published: October 2018

A series of heteroleptic cyclometalated Ir (III) complexes with low‐color‐temperature and low‐efficiency roll‐off properties, which cause a fast reduction in efficiency when the drive current increases, for organic light‐emitting devices are investigated theoretically to explore their electronic structures and spectroscopic properties. The geometries, electronic structures, lowest‐lying singlet absorptions and triplet emissions of (ptpy)2Ir(acac), and the theoretically designed models (ptpy)2Ir(tpip), (F‐ptpy)2Ir(acac), (F‐ptpy)2Ir(tpip), (F2‐ptpy)2Ir(acac) and (F2‐ptpy)2Ir(tpip), are investigated with density functional theory approaches, where ptpy denotes 4‐phenylthieno [3,2‐c] pyridine, acac denotes acetylacetonate, tpip denotes tetraphenylimido‐diphosphinate, F‐ptpy denotes 4‐(3‐fluorophenyl) thieno [3,2‐c] pyridine, and F2‐ptpy denotes 4‐(2,4‐difluorophenyl) thieno [3,2‐c] pyridine.
Facilitating a high‐performance photocatalyst for Suzuki reaction: Palladium nanoparticles immobilized on reduced graphene oxide‐doped graphitic carbon nitride
Authors: Zhao Xiaohua , Xie Jiateng , Liu Xin , Liu Xiang
Published: October 2018

We prepared a non‐covalently coupled hybrid of reduced graphene oxide (rGO)‐doped graphitic carbon nitride (g‐C3N4) by freezing‐assisted assembly and calcination. Fourier transform infrared, Raman and X‐ray photoelectron spectroscopies and transmission electron microscopy confirmed that rGO was incorporated into the bulk g‐C3N4, which was an ideal support for loading Pd nanoparticles. The Pd nanoparticles with an average size of 4.57 nm were uniformly dispersed on the rGO‐doped g‐C3N4 surface. The layered structure provided large contact area of g‐C3N4 with rGO, further accelerating the electron transfer rate and inhibiting electron–hole recombination. Consequently, compared with Pd/rGO/g‐C3N4 and Pd/g‐C3N4, the Pd/rGO‐doped g‐C3N4 showed a prominent catalytic activity for visible‐light‐driven photocatalytic Suzuki–Miyaura coupling at ambient temperature. The Pd/rGO‐doped g‐C3N4 exhibited very high stability after six consecutive cycles with minimal loss of catalytic activity.
Monodentate aminophosphine nickel(II)‐ and palladium(II)‐catalyzed ethylene oligomerization and norbornene polymerization
Authors: Rong Chunyong , Li Weimin , Tan Chen
Published: October 2018

Nickel(II) and palladium(II) complexes of monodentate aminophosphine ligands were prepared and characterized. In ethylene oligomerization and subsequent Friedel–Crafts alkylation of toluene, the Ni(II) complexes Ni‐1 and Ni‐2 were activated with aluminium co‐catalysts and generated tandem catalysts with high activities (up to 1.1 × 106 g (mol Ni)−1 h−1) which are comparable with those of previously reported bidentate Ni(II) catalysts. The Pd(II) precatalyst Pd‐1 showed high activities (up to 2.0 × 105 g (mol Pd)−1 h−1) in the polymerization of norbornene.
Biomechanical Study of the Development of Long Bones: Finite Element Structure Synthesis of the Human Second Proximal Phalanx Under Growth Conditions
Authors: Lipphaus Andreas , Witzel Ulrich
Published: October 2018

Torsional loads are a possible mechanical explanation for the architecture of long bone. Finite element structure synthesis (FESS) has previously successfully been used as a deductive technique using Wolff's Law by applying expected loads to an unspecific homogeneous solid and eliminating stress free parts to verify muscle forces. The extended approach presented in this article includes further mechanobiological rules to model the development from a cartilage model to a finger bone. In contrast to former computational models, simulation of processes leading to both external growth and internal differentiation are included. Combined axial and torsional loads synthesize a complete human secondary proximal phalanx model comparable to form and internal structure to that observedin vivo. While the computational model is very sensitive to initial alterations of loads, changes after growth have a minor effect as observed in animal models. Predictions of cartilage growth and ossification during FESS showed significant similarities to ontogeny indicating the importance of mechanical factors for the morphogenesis of bone during growth. Anat Rec, 302:1389–1398, 2019. © 2018 Wiley Periodicals, Inc.
Targeted Inhibition of Aggrecanases Prevents Articular Cartilage Degradation and Augments Bone Mass in the STR/Ort Mouse Model of Spontaneous Osteoarthritis
Authors: Kanakis Ioannis , Liu Ke , Poulet Blandine , Javaheri Behzad , van ’t Hof Rob J. , Pitsillides Andrew A. , Bou‐Gharios George
Published: October 2018

Objective

Cartilage destruction in osteoarthritis (OA) is mediated mainly by matrix metalloproteinases (MMPs) and ADAMTS. The therapeutic candidature of targeting aggrecanases has not yet been defined in joints in which spontaneous OA arises from genetic susceptibility, as in the case of the STR/Ort mouse, without a traumatic or load‐induced etiology. In addition, we do not know the long‐term effect of aggrecanase inhibition on bone. We undertook this study to assess the potential aggrecanase selectivity of a variant of tissue inhibitor of metalloproteinases 3 (TIMP‐3), called [‐1A]TIMP‐3, on spontaneous OA development and bone formation in STR/Ort mice.

Methods

Using the background of STR/Ort mice, which develop spontaneous OA, we generated transgenic mice that overexpress [‐1A]TIMP‐3, either ubiquitously or conditionally in chondrocytes. [‐1A]TIMP‐3 has an extra alanine at the N‐terminus that selectively inhibits ADAMTS but not MMPs. We analyzed a range of OA‐related measures in all mice at age 40 weeks.

Results

Mice expressing high levels of [‐1A]TIMP‐3 were protected against development of OA, while those expressing low levels were not. Interestingly, we also found that high levels of [‐1A]TIMP‐3 transgene overexpression resulted in increased bone mass, particularly in females. This regulation of bone mass was at least partly direct, as adult mouse primary osteoblasts infected with [‐1A]TIMP‐3 in vitro showed elevated rates of mineralization.

Conclusion

The results provide evidence that [‐1A]TIMP‐3–mediated inhibition of aggrecanases can protect against cartilage degradation in a naturally occurring mouse model of OA, and they highlight a novel role that aggrecanase inhibition may play in increased bone mass.
Students’ Views on Difficulties in Learning Histology
Authors: García Magdalena , Victory Noemí , Navarro‐Sempere Alicia , Segovia Yolanda
Published: October 2018

The aim of this study was to provide a better understanding of the main difficulties hindering undergraduate biology students in learning histology. The study utilized a self‐administered questionnaire which included three closed‐ended and two open‐ended questions: (1) if students had difficulty in learning about each tissue type; (2) what might be the problem in learning about the tissue at hand; (3) which topics were the most difficult; (4) what were the possible reasons that made image identification of tissue types difficult; and (5) how to improve the course curriculum from a student perspective. The survey was administered to 139 undergraduate biology students enrolled in a histology course, of which 101 surveys were completed and analyzed both qualitatively and quantitatively. The topics that students experienced the most difficulties with were: nervous tissue, plant tissues, bone tissues, and glandular epithelial tissue. The main reasons students experienced difficulties with these tissue types, according to the students themselves, were the nature of the topic, grasping the terminology used, and insufficient teaching time. Students suggested the adoption of strategies such as: teaching based on practical tasks; reducing the content of the histology curriculum; adding anatomy subjects; and making histology education more interesting.
Expression and production of recombinant scorpine as a potassium channel blocker protein in Escherichia coli
Authors: Seyfi Roghayyeh , Babaeipour Valiollah , Mofid Mohammad Reza , Kahaki Fatemeh Abarghooi
Published: October 2018

Scorpine is a cationic protein from the venom of Pandinus imperator, belonging to potassium channel blocker family, which has been shown to have antibacterial, antiviral, and antiplasmodia activities. In the present study, a pET‐44a vector containing scorpine synthetic gene with T7 Promoter (pET 44a‐His6‐Nus‐His6‐tev‐scorpine) was transferred into Escherichia coli Rosetta‐gami B (DE3) for soluble expression of the protein in the cytoplasm and its overproduction. After confirming recombinant scorpine peptide expression using SDS–PAGE and Western blot, augmentation of production was performed during two stages. At first, effects of three parameters including carbon source concentration of medium, temperature, and induction time were investigated in terrific broth (TB) medium. Afterward, the overexpression was performed by response surface methodology in TB + glucose. Under the optimized conditions, the highest production of 3.5 g/L in the TB + glucose medium (7.5 g/L glucose, induction at OD600 = 3.5 and 25 °C) was increased to 4.1 g/L in TB medium (2.5 g/L glycerol, induction at OD600 = 0.7 and 25 °C). Then, in order to increase the amount of protein production, effects of carbon concentration in the fermenter under the primary optimized condition was investigated. The amount of produced recombinant protein increased from 0.12 to 2.1 g/L.H. The results were similar to previous studies on optimizing and increasing the production of recombinant protein and in particular recombinant scorpine.
Effects of generally recognized as safe (GRAS) and dietary compounds on phenylephrine metabolism in LS180 human intestinal cells
Authors: Zhang Zhenxian , Gerk Phillip M.
Published: October 2018

Phenylephrine (PE) has low and variable oral bioavailability in humans, due in part to presystemic metabolism by sulfation. LS180 cells were used as a model of the human intestinal epithelium to examine phenylephrine metabolism and its inhibition by generally recognized as safe (GRAS) and dietary compounds. Curcumin, zingerone, resveratrol, guaiacol, pterostilbene and isoeugenol significantly inhibited phenylephrine disappearance, while vanillin, propylparaben and eugenol did not. However, when propylparaben was combined with either vanillin or eugenol, the phenylephrine disappearance was significantly inhibited. These data suggest that these compounds or combinations thereof may have potential to improve phenylephrine oral bioavailability.
Chemiluminescence‐based aptasensors for various target analytes
Authors: Sun Yue , Lu Jianzhong
Published: October 2018

Aptamers (DNA or RNA) have complex three‐dimensional shapes that can bind to specific targets. Relative to antibodies, aptamers benefit from their low cost of production, easy chemical modification, high chemical stability, reproducibility, and low levels of immunogenicity and toxicity. However, the true value of aptamers lies in their simplicity by which these molecules can be engineered into sensors as bio‐recognition elements in diagnostics, drug discovery and therapy, environmental monitoring and food quality testing, etc. Many different types of techniques, such as optical, electrochemical, radiochemical and piezoelectronic methods, have been applied for the design of aptamer‐based methods, in which chemiluminescence (CL) detection techniques have become very popular in recent years. This review focuses on the recent advances in the development of aptamer‐based CL sensors for different target detection. We highlight specific examples that showcase the use of aptamers in practical applications, and provide the challenges and opportunities in this promising field.