The utility of electronically conductive metal–organic frameworks (EC‐MOFs) in high‐performance devices has been limited to date by a lack of high‐quality thin film. The controllable thin‐film ...fabrication of an EC‐MOF, Cu3(HHTP)2, (HHTP=2,3,6,7,10,11‐hexahydroxytriphenylene), by a spray layer‐by‐layer liquid‐phase epitaxial method is reported. The Cu3(HHTP)2 thin film can not only be precisely prepared with thickness increment of about 2 nm per growing cycle, but also shows a smooth surface, good crystallinity, and high orientation. The chemiresistor gas sensor based on this high‐quality thin film is one of the best room‐temperature sensors for NH3 among all reported sensors based on various materials.
A wafer‐thin sensor: The preparation of a crystalline, highly‐oriented, and thickness‐controlled thin film with an electronically conductive MOF is reported. Chemiresistive sensors based on these thin films show a high response, excellent selectivity, fast response speed, and good long‐term stability towards NH3 gas at room temperature.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The construction of hydrophobic nanochannel with hydrophilic sites for bionic devices to proximally mimick real bio‐system is still challenging. Taking the advantages of MOF chemistry, a highly ...oriented CuTCPP thin film has been successfully reconstructed with ultra‐thin nanosheets to produce abundant two‐dimensional interstitial hydrophobic nanochannels with hydrophilic sites. Different from the classical active‐layer material with proton transport in bulk, CuTCPP thin film represents a new type of active‐layer with proton transport in nanochannel for bionic proton field‐effect transistor (H+‐FETs). The resultant device can reversibly modulate the proton transport by varying the voltage on its gate electrode. Meanwhile, it shows the highest proton mobility of ≈9.5×10−3 cm2 V−1 s−1 and highest on‐off ratio of 4.1 among all of the reported H+‐FETs. Our result demonstrates a powerful material design strategy for proximally mimicking the structure and properties of bio‐systems and constructing bionic electrical devices.
A MOF thin film‐based bionic proton field‐effect transistor (H+‐FET) has been fabricated for the first time. It displays the highest proton mobility and highest on–off ratio among all reported H+‐FETs.
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Challenges remain in the development of novel multifunctional electrocatalysts and their industrial operation on low‐electricity pair‐electrocatalysis platforms for the carbon cycle. Herein, an ...enzyme‐inspired single‐molecular heterojunction electrocatalyst ((NHx)16‐NiPc/CNTs) with specific atomic nickel centers and amino‐rich local microenvironments for industrial‐level electrochemical CO2 reduction reaction (eCO2RR) and further energy‐saving integrated CO2 electrolysis is designed and developed. (NHx)16‐NiPc/CNTs exhibit unprecedented catalytic performance with industry‐compatible current densities, ≈100% Faradaic efficiency and remarkable stability for CO2‐to‐CO conversion, outperforming most reported catalysts. In addition to the enhanced CO2 capture by chemisorption, the sturdy deuterium kinetic isotope effect and proton inventory studies sufficiently reveal that such distinctive local microenvironments provide an effective proton ferry effect for improving local alkalinity and proton transfer and creating local interactions to stabilize the intermediate, ultimately enabling the high‐efficiency operation of eCO2RR. Further, by using (NHx)16‐NiPc/CNTs as a bifunctional electrocatalyst in a flow cell, a low‐electricity overall CO2 electrolysis system coupling cathodic eCO2RR with anodic oxidation reaction is developed to achieve concurrent feed gas production and sulfur recovery, simultaneously decreasing the energy input. This work paves the new way in exploring molecular electrocatalysts and electrolysis systems with techno‐economic feasibility.
An enzyme‐inspired single‐molecular heterojunction electrocatalyst with accurate amino‐rich microenvironments around the active sites is uniquely designed to enable efficient CO2 capture and fast proton ferrying during CO2 electroreduction, which achieves concurrent CO production at the cathode and sulfur recovery at the anode with industrial‐level current density and lower energy consumption.
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Abstract
Peach is a typical climacteric fruit that releases ethylene during fruit ripening. Several studies have been conducted on the transcriptional regulation of ethylene biosynthesis in peach ...fruit. Herein, an ethylene response factor, PpERF.A16, which was induced by exogenous ethylene, could enhance ethylene biosynthesis by directly inducing the expression of
1-aminocyclopropane-1-carboxylic acid synthase
(
PpACS1
) and
1-aminocyclopropane-1-carboxylic acid oxidase
(
PpACO1
) genes. Moreover, the NAM/ATAF1/2/CUC2 (NAC) transcription factor (TF)
PpNAC.A59
was coexpressed with
PpERF.A16
in all tested peach cultivars. Interestingly, PpNAC.A59 can directly interact with the promoter of
PpERF.A16
to induce its expression but not enhance
LUC
activity driven by any promoter of
PpACS1
or
PpACO1
. Thus, PpNAC.A59 can indirectly mediate ethylene biosynthesis via the NAC-ERF signaling cascade to induce the expression of both
PpACS1
and
PpACO1
. These results enrich the genetic network of fruit ripening in peach and provide new insight into the ripening mechanism of other perennial fruits.
Minimal Gated Unit for Recurrent Neural Networks Zhou, Guo-Bing; Wu, Jianxin; Zhang, Chen-Lin ...
International journal of automation and computing,
06/2016, Volume:
13, Issue:
3
Journal Article
Peer reviewed
Open access
Recurrent neural networks （RNN） have been very successful in handling sequence data. However, understanding RNN and finding the best practices for RNN learning is a difficult task, partly because ...there are many competing and complex hidden units, such as the long short-term memory （LSTM） and the gated recurrent unit （GRU）. We propose a gated unit for RNN, named as minimal gated unit （MCU）, since it only contains one gate, which is a minimal design among all gated hidden units. The design of MCU benefits from evaluation results on LSTM and GRU in the literature. Experiments on various sequence data show that MCU has comparable accuracy with GRU, but has a simpler structure, fewer parameters, and faster training. Hence, MGU is suitable in RNN＇s applications. Its simple architecture also means that it is easier to evaluate and tune, and in principle it is easier to study MGU＇s properties theoretically and empirically.
Towards Safe Weakly Supervised Learning Li, Yu-Feng; Guo, Lan-Zhe; Zhou, Zhi-Hua
IEEE transactions on pattern analysis and machine intelligence,
01/2021, Volume:
43, Issue:
1
Journal Article
Peer reviewed
In this paper, we study weakly supervised learning where a large amount of data supervision is not accessible. This includes i) incomplete supervision, where only a small subset of labels is given, ...such as semi-supervised learning and domain adaptation; ii) inexact supervision, where only coarse-grained labels are given, such as multi-instance learning and iii) inaccurate supervision, where the given labels are not always ground-truth, such as label noise learning. Unlike supervised learning which typically achieves performance improvement with more labeled examples, weakly supervised learning may sometimes even degenerate performance with more weakly supervised data. Such deficiency seriously hinders the deployment of weakly supervised learning to real tasks. It is thus highly desired to study safe weakly supervised learning, which never seriously hurts performance. To this end, we present a generic ensemble learning scheme to derive a safe prediction by integrating multiple weakly supervised learners. We optimize the worst-case performance gain and lead to a maximin optimization. This brings multiple advantages to safe weakly supervised learning. First, for many commonly used convex loss functions in classification and regression, it is guaranteed to derive a safe prediction under a mild condition. Second, prior knowledge related to the weight of the base weakly supervised learners can be flexibly embedded. Third, it can be globally and efficiently addressed by simple convex quadratic or linear program. Finally, it is in an intuitive geometric interpretation with the least square loss. Extensive experiments on various weakly supervised learning tasks, including semi-supervised learning, domain adaptation, multi-instance learning and label noise learning demonstrate our effectiveness.
The tiger frog (Hoplobatrachus rugulosus) is listed as a national Class II protected species in China. In the context of global warming, the sex ratio of amphibians will be affected, and the ...development of the population will be limited. Therefore, considering the potential for a decrease in the number of amphibians, studying sex evolution and molecular regulation of gonadal development in H. rugulosus, phenomenon that are currently unclear, is of great significance. Here, H. rugulosus was used to explore the mechanisms regulating gonadal development in amphibians. Illumina HiSeq 3000 was used to sequence the gonadal transcriptome of male and female H. rugulosus at two growth stages to identify genes related to gonadal development and analyze expression differences in the gonads. This analysis indicated that cyp17alpha, hsd3beta, hsd11beta1, cyp19alpha, and hsd17beta12 perform vital functions in sex development in amphibians. Specifically, the expression of cyp3alpha, cyp17alpha, hsd3beta, hsd11beta1, sox2, sox9, sox30, soat, cyp19alpha, hsd17beta12, and hspalpha1s was correlated with gonadal development and differentiation in H. rugulosus, as determined using the quantitative reverse transcriptase-polymerase chain reaction. Significant differences were found in the gonadal gene expression levels in H. rugulosus of both sexes, and we identified a steroid hormone synthesis pathway in this species and analyzed related gene expression, but the changes during sex differentiation were still unclear. To our knowledge, this report presents the first analysis of the H. rugulosus gonadal transcriptome and lays the foundation for future research.
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A new metal-organic framework with excellent water stability, {H(N(CH3)4)2Gd3(NIPA)6}·3H2O (1, H2NIPA = 5-nitroisophthalic acid), displays a proton conductivity of 7.17 × 10-2 S cm-1 (at 75 °C and ...98% relative humidity), which is among the highest values for proton-conducting MOFs.
Proton conductivity research on single crystals is essential to elucidate their conduction mechanism and guide the unidirectional crystal growth to improve the performance of electrolyte materials. ...Herein, we report a highly anisotropic proton-conductive 2D metal–organic framework (MOF) Cu2(Htzehp)2(4,4′-bipy)·3H2O (1·3H 2 O, H3tzehp = N-2-(1H-tetrazol-5-yl)ethyl-l-hydroxyproline) with definite crystal structures showing single-crystal to single-crystal transformation between the anhydrate (1) and trihydrate (1·3H 2 O) phases. The hydrogen bonded chains consisted of well-defined lattice water molecules and hydroxyl functional groups of the Htzehp2– ligand array inside the 2D interlayer spaces along the crystallographic a-axis (100 direction) in 1·3H 2 O. Temperature- and humidity-dependent proton conductivity was achieved along the 100 and 010 directions, respectively. The anisotropic proton conductivity of σ100/σ010 in a single crystal of 1·3H 2 O was as high as 2 orders of magnitude. The highest proton conductivity of 1.43 × 10–3 S cm–1 of 1·3H 2 O at 80 °C and 95% relative humidity was observed among the reported 2D MOF crystals. The relation between the proton conductivity and structure was also revealed. The hydrogen bonded chain in 1·nH 2 O plays a significant role in the proton transport. The time-dependent proton conductivity and single-crystal X-ray diffraction measurements demonstrated that 1·3H 2 O is temperature- and humidity-stable and acts as an underlying electrolyte material for fuel cell applications.
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Image retargeting aims to adapt images to displays of small sizes and different aspect ratios. Effective retargeting requires emphasizing the important content while retaining surrounding context ...with minimal visual distortion. In this paper, we present such an effective image retargeting method using saliency-based mesh parametrization. Our method first constructs a mesh image representation that is consistent with the underlying image structures. Such a mesh representation enables easy preservation of image structures during retargeting since it captures underlying image structures. Based on this mesh representation, we formulate the problem of retargeting an image to a desired size as a constrained image mesh parametrization problem that aims at finding a homomorphous target mesh with desired size. Specifically, to emphasize salient objects and minimize visual distortion, we associate image saliency into the image mesh and regard image structure as constraints for mesh parametrization. Through a stretch-based mesh parametrization process we obtain the homomorphous target mesh, which is then used to render the target image by texture mapping. The effectiveness of our algorithm is demonstrated by experiments.
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