Emre Gener  Gary R. Burniske  Otto C. Doering  Wallace E. Tyner  Rakesh Agrawal  W. Nicholas Delgass  Gebisa Ejeta  Maureen C. McCann  Nicholas C. Carpita 《Biofuels, Bioproducts and Biorefining》2020,14(4):725-733

Nitrogen is the most limiting plant nutrient. Inexpensive natural gas has substantially reduced costs of ammonia fertilizer for intensive agriculture in the developed world, but its excessive use negatively impacts downstream ecosystems. By contrast, the availability of ammonia fertilizer is a major economic bottleneck for agriculture in developing countries. A dedicated lignocellulosic biomass crop could supply sufficient substrate to generate optimal nitrogen fertilizer on less than 5% of a grower's food crop acreage. Reimagining ammonia generation using biomass could significantly enhance sustainable agricultural productivity in developing countries when combined with emerging catalytic technologies. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd  相似文献   

    

Robert F. Smith  Emily C. Neideigh  Alex M. Rittle  John R. Wallace 《河流研究与利用》2020,36(1):79-90

Stream restoration projects utilize a variety of approaches to improve conditions for aquatic organisms or enhance ecosystem function. Alterations to abiotic conditions to enhance certain ecosystems services may not lead to concurrent changes in the benthic macroinvertebrate community indicative of improved stream health. Big Spring Run was the location of a novel restoration project to recreate an anabranching “wet meadow” habitat typical of precolonization conditions without the primary goal of restoring a macroinvertebrate community characteristic of single‐channel lotic systems. We examined the effect of the restoration on the macroinvertebrate community using a multivariate analysis of assemblage composition, a before‐after‐control‐impact (BACI) approach, and an assessment of potential aerial migrants. We also examined subsets of the data using a BACI approach that represented restricted sampling designs often employed in stream restoration projects. Benthic macroinvertebrates were collected in the Spring twice prior to restoration (2010 and 2011) and 3 years after restoration (2012–2014). Adult stream insects were collected in 2014. Analyses of benthic macroinvertebrates and adult insects using the full dataset suggested that restoration had no effect on the macroinvertebrate community due to poor in‐stream conditions likely from sediment deposition following restoration. Dispersal barriers are likely acting as a secondary constraint on recolonization. Analyses using subsets of the data demonstrated that reference site quality and sampling extent can alter conclusions from a BACI approach. We found that a holistic approach using multiple lines of evidence required a nuanced approach to interpreting the data but was also informative for assessing project success. Robust monitoring protocols are likely the best approach for producing convincing results through a single line of evidence. The additional BACI analyses performed for this study, however, allowed the modest sampling regime employed to generate a broad narrative demonstrating that the macroinvertebrate assemblage did not respond to this type of restoration. Thus, we believe the holistic approach we employed can strengthen assessments of stream restoration projects when resources for monitoring are limited.  相似文献   

    

Rodrick Wallace 《连接科学》2020,32(3):264-279

The asymptotic limit theorems of information theory, and related formalism from punctuated equilibrium evolutionary theory, allow exploration of the dynamics of real-time, multi-component, hierarchical, cognitive enterprises – institutional, machine, or man/machine hybrid – under constraints of time, material resources, internal communication, situational awareness, and adversarial intent. Surprisingly direct argument shows such enterprises can almost always be confounded by an opponent with comparatively limited resources, provided it has sufficient situational understanding, adaptive capacity, and resolve. Consequently, there can be no free lunch for AI combat systems, driverless cars on intelligent roads, or other such entities, tasked with the control of real-time critical processes. Intelligent adversaries, resource limitations, “design flaws”, inattentional blindness, command stupidity, coevolutionary dynamics, and the like confront all real-time, multi-component cognitive processes. AI systems will not be spared simply by being labelled “high tech” in marketing campaigns.  相似文献   

    

Wenhui Li  Qian Liu  Yuniu Zhang  Chang'an Li  Zhenfei He  Wallace C. H. Choy  Paul J. Low  Prashant Sonar  Aung Ko Ko Kyaw 《Advanced materials (Deerfield Beach, Fla.)》2020,32(33):2001591

There is little question that the “electronic revolution” of the 20th century has impacted almost every aspect of human life. However, the emergence of solid-state electronics as a ubiquitous feature of an advanced modern society is posing new challenges such as the management of electronic waste (e-waste) that will remain through the 21st century. In addition to developing strategies to manage such e-waste, further challenges can be identified concerning the conservation and recycling of scarce elements, reducing the use of toxic materials and solvents in electronics processing, and lowering energy usage during fabrication methods. In response to these issues, the construction of electronic devices from renewable or biodegradable materials that decompose to harmless by-products is becoming a topic of great interest. Such “green” electronic devices need to be fabricated on industrial scale through low-energy and low-cost methods that involve low/non-toxic functional materials or solvents. This review highlights recent advances in the development of biodegradable materials and processing strategies for electronics with an emphasis on areas where green electronic devices show the greatest promise, including solar cells, organic field-effect transistors, light-emitting diodes, and other electronic devices.  相似文献   

    

Yu‐Chuan Lin  Brian M. Bersch  Rafik Addou  Ke Xu  Qingxiao Wang  Christopher M. Smyth  Bhakti Jariwala  Roger C. Walker  Susan K. Fullerton‐Shirey  Moon J. Kim  Robert M. Wallace  Joshua A. Robinson 《Advanced Materials Interfaces》2020,7(18)

Atomically thin tungsten diselenide (WSe₂) is a promising 2D semiconductor for nanoelectronics and optoelectronics. Using UV ozone and low‐power O₂ plasma treatments, it is demonstrated that the formation of WSe_2(1−x)O_2x (WSe_yO_x) leads to hysteretic behavior in vertical transport measurements and also enables to an improvement in the p‐type transfer characteristics in lateral transport measurements. The amount of oxidation correlates well with the resistive switch behavior in oxidized WSe₂/graphene, and WSe_yO_x formation under the electrical contact of the horizontal devices leads to increased p‐branch on/off by 100×. In addition to its effect for residue removal, oxidation on field effect transistor channel also helps mitigate n‐type dominated transfer characteristics of WSe₂ commonly seen on sapphire. It is demonstrated that light oxidation of WSe₂ is a multifunctional post‐growth treatment that enables vertical resistive switch junctions, contact improvement, and continuous tuning of transistor transport properties.  相似文献   

    

Hugh Lu Zhu  Junyan Xiao  Jian Mao  Hong Zhang  Yong Zhao  Wallace C. H. Choy 《Advanced functional materials》2017,27(11)

While Sn? Pb alloyed perovskites have been considered as an effective approach to broaden the absorption spectrum, it is still challenging to modify the crystallization (and thus morphology, crystallinity, and orientation) in a controllable manner and thus boost the efficiency of Sn? Pb alloyed perovskite solar cells. Here, it is unveiled that controlling the crystallization of CH₃NH₃Sn_0.25Pb_0.75I₃ films can be simply realized by adjusting the amount of dimethyl sulfoxide in precursors, which has not been reported in Sn? Pb alloyed perovskite systems. The remarkable perovskite crystallinity enhancement by the 20‐fold enhanced (110) plane intensity in the X‐ray diffraction spectrum of CH₃NH₃Sn_0.25Pb_0.75I₃ and the preferred (110) orientation with the texture coefficient enhanced by 2.6 times to reach 0.88 are demonstrated. Importantly, it is discovered that the introduction of dimethyl sulfoxide avoids the formation of the colloidal coagulation observed in prolonged‐storage precursors and ameliorates inhomogeneous Sn/Pb distributions in resultant perovskite films. Through optimizing perovskite films and device structures, hysteresis‐free planar‐heterojunction CH₃NH₃Sn_0.25Pb_0.75I₃ solar cells with the efficiency reaching 15.2%, which are the most efficient Sn? Pb alloy‐based perovskite solar cells, are achieved.  相似文献   

    

Hong Zhang  Jiaqi Cheng  Dan Li  Francis Lin  Jian Mao  Chunjun Liang  Alex K.‐Y. Jen  Michael Grätzel  Wallace C. H. Choy 《Advanced materials (Deerfield Beach, Fla.)》2017,29(13)

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Tao Liu  Xuexue Pan  Xiangyi Meng  Yu Liu  Donghui Wei  Wei Ma  Lijun Huo  Xiaobo Sun  Tack Ho Lee  Minjuan Huang  Hyosung Choi  Jin Young Kim  Wallace C. H. Choy  Yanming Sun 《Advanced materials (Deerfield Beach, Fla.)》2017,29(6)

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Xiaopeng Xu  Zhaozhao Bi  Wei Ma  Zishuai Wang  Wallace C. H. Choy  Wenlin Wu  Guangjun Zhang  Ying Li  Qiang Peng 《Advanced materials (Deerfield Beach, Fla.)》2017,29(46)

In this work, highly efficient ternary‐blend organic solar cells (TB‐OSCs) are reported based on a low‐bandgap copolymer of PTB7‐Th, a medium‐bandgap copolymer of PBDB‐T, and a wide‐bandgap small molecule of SFBRCN. The ternary‐blend layer exhibits a good complementary absorption in the range of 300–800 nm, in which PTB7‐Th and PBDB‐T have excellent miscibility with each other and a desirable phase separation with SFBRCN. In such devices, there exist multiple energy transfer pathways from PBDB‐T to PTB7‐Th, and from SFBRCN to the above two polymer donors. The hole‐back transfer from PTB7‐Th to PBDB‐T and multiple electron transfers between the acceptor and the donor materials are also observed for elevating the whole device performance. After systematically optimizing the weight ratio of PBDB‐T:PTB7‐Th:SFBRCN, a champion power conversion efficiency (PCE) of 12.27% is finally achieved with an open‐circuit voltage (V _oc) of 0.93 V, a short‐circuit current density (J _sc) of 17.86 mA cm^?2, and a fill factor of 73.9%, which is the highest value for the ternary OSCs reported so far. Importantly, the TB‐OSCs exhibit a broad composition tolerance with a high PCE over 10% throughout the whole blend ratios.  相似文献   

    

Maamar Al Tobi  Geraint Bevan  Peter Wallace  David Harrison  Kenneth Eloghene Okedu 《Computational Intelligence》2021,37(1):21-46

This paper presents a comparative study of two artificial intelligent systems, namely; Multilayer Perceptron (MLP) and support vector machine (SVM), to classify six fault conditions and the normal (nonfaulty) condition of a centrifugal pump. A hybrid training method for MLP is proposed for this work based on the combination of Back Propagation (BP) and Genetic Algorithm (GA). The two training algorithms are tested and compared separately as well. Features are extracted using Discrete Wavelet Transform (DWT), both approximations, details, and two mother wavelets were used to investigate their effectiveness on feature extraction. GA is also used to optimize the number of hidden layers and neurons of MLP. In this study, the feature extraction, GA‐based hidden layers, neurons selection, training algorithm, and classification performance, based on the strengths and weaknesses of each method, are discussed. From the results obtained, it is observed that the DWT with both MLP‐BP and SVM produces better classification rates and performances.  相似文献