A new terpolymer acceptor is presented, comprising various ratios of the same dithienothienopyrrolobenzothiadiazole (BTP) core with different side chains—alkoxy side chains (BTPO-IC) and alkyl side chains (BTP-IC)—and thiophene units, for use in all-polymer organic photovoltaics. Devices incorporating binary blends of this terpolymer and the polymer PM6 as the active layer displayed open-circuit voltages (VOC) that increase linearly upon increasing the molar ratio of BTPO-IC. For example, the optimized device incorporating PM6:PY-0.2OBO (i.e., with 20 mol% of BTPO-IC) (1:1.2 wt.%) blend, with the smallest domain sizes but largest coherence length and combined face-on and edge-on orientation fractions among all blends, have a champion power conversion efficiency (PCE) of 16.7% (VOC = 0.97 V; JSC = 25.2 mA cm−2; FF = 0.68), whereas the device containing a similar blend ratio of the PM6:PY-OD:PY-OBO ternary blend (1:0.96:0.24 wt.%) displayed a PCE of 8.6% (VOC = 0.969 V; JSC = 18.7 mA cm−2; FF = 0.48). The device with PM6:PY-0.2OBO displays better thermal stability than the devices with PM6: PY-OD or PY-OBO. Thus, employing terpolymer acceptors with differently functionalized side-chain units can be an effective approach for simultaneously optimizing the aggregation domain and enhancing the PCEs and thermal stabilities of all-polymer devices. 相似文献
In this study we address the automatic segmentation of selected muscles of the thigh and leg through a supervised deep learning approach.
Material and methods
The application of quantitative imaging in neuromuscular diseases requires the availability of regions of interest (ROI) drawn on muscles to extract quantitative parameters. Up to now, manual drawing of ROIs has been considered the gold standard in clinical studies, with no clear and universally accepted standardized procedure for segmentation. Several automatic methods, based mainly on machine learning and deep learning algorithms, have recently been proposed to discriminate between skeletal muscle, bone, subcutaneous and intermuscular adipose tissue. We develop a supervised deep learning approach based on a unified framework for ROI segmentation.
Results
The proposed network generates segmentation maps with high accuracy, consisting in Dice Scores ranging from 0.89 to 0.95, with respect to “ground truth” manually segmented labelled images, also showing high average performance in both mild and severe cases of disease involvement (i.e. entity of fatty replacement).
Discussion
The presented results are promising and potentially translatable to different skeletal muscle groups and other MRI sequences with different contrast and resolution.
This paper proposes a form of MPC in which the control variables are moved asynchronously. This contrasts with most MIMO control schemes, which assume that all variables are updated simultaneously. MPC outperforms other control strategies through its ability to deal with constraints. This requires on-line optimization, hence computational complexity can become an issue when applying MPC to complex systems with fast response times. The Multiplexed MPC (MMPC) scheme described in this paper solves the MPC problem for each subsystem sequentially, and updates subsystem controls as soon as the solution is available, thus distributing the control moves over a complete update cycle. The resulting computational speed-up allows faster response to disturbances, which may result in improved performance, despite finding sub-optimal solutions to the original problem. This paper describes nominal and robust MMPC, states some stability results, and demonstrates the effectiveness of MMPC through two examples. 相似文献
This paper highlights the importance of protecting an organization's vital business information assets by investigating several fundamental considerations that should be taken into account in this regard. Based on this, it is illustrated that information security should be a priority of executive management, including the Board and CEO and should therefore commence as a corporate governance responsibility. This paper, therefore, motivates that there is a need to integrate information security into corporate governance through the development of an information security governance (ISG) framework. This paper further proposes such a framework to aid an organization in its ISG efforts. 相似文献
Retractable membrane roof covering the court yard of the town hall in Vienna. In September 2000 the retractable membrane roof covering the court yard of the Vienna town hall was inaugurated. Giving shelter against rain and sun, the new structure with an area of 34 m ∞ 32 m replaces the former tents sheltering numerous events which take place here every summer. The transverse orientated steel‐cables are anchored at carriages, which can be moved along tracks orientated perpendicularly to the cables. The membrane spans between the transverse ridge and valley cables, causing practically only warp stresses in the membrane. Thick walled tubes are used to weigh down the valley cables, resisting the small wind uplift forces in the courtyard and ensuring the accordion like folding process during retraction. 相似文献
The total sulphur dioxide (SO2) concentration of beers decreases during storage, essentially following first-order kinetics. Beers differ in the rate at which they lose SO2. Half-lives for total SO2 loss in 22 commercial beers stored at 25°C ranged from 37·7 days to more than 1000 days. The rate of loss could be predicted from beer compositional data using partial least squares (PLS) regression modelling. Initial concentrations of total SO2, sugars and ions were important factors in the models. 相似文献
Although there is a substantial literature on the role of parenting in adolescent substance use, most parenting effects have been small in magnitude and studied outside the context of genetically informative designs, raising debate and controversy about the influence that parents have on their children (D. C. Rowe, 1994). Using a genetically informative twin-family design, the authors studied the role of parental monitoring on adolescent smoking at age 14. Although monitoring had only small main effects, consistent with the literature, there were dramatic moderation effects associated with parental monitoring: At high levels of parental monitoring, environmental influences were predominant in the etiology of adolescent smoking, but at low levels of parental monitoring, genetic influences assumed far greater importance. These analyses demonstrate that the etiology of adolescent smoking varies dramatically as a function of parenting. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
Mass balance studies at a number of calibrated watersheds in eastern North America suggest that large losses of Ca from soil have occurred due to acid deposition. However, there is considerable controversy over whether losses have occurred from the exchangeable pool or whether there are other sources of Ca that have not been considered. Mass balance calculations at a small, calibrated catchment (PC1) in south-central Ontario also indicate that large losses of Ca have occurred over the past 2 decades. If the exchangeable Ca pool has declined by approximately 40% between 1983/1984 and 1998/1999 but the exchangeable Mg pool has remained relatively stable, these changes should be evident in streamwater chemistry. The slope of the buffer curve relating Ca to (sigma)acid anions (F(Ca)) decreased significantly over the study period. We estimate that F(Ca) decreased by 12-24% between 1983 and 1999, although the level of decrease is affected by changes in hydrology. During the same period, there was no significant change in F(Mg), and the annual volume-weighted Ca:Mg (equiv/equiv) ratio in streamwater decreased from approximately 2.8 to approximately 2.1. Measured changes in streamwater chemistry translate into Ca losses from the exchangeable pool of approximately 250-570 mequiv/m2 over the study period, which is similar to estimated losses based on soil measurements (approximately 425 mequiv/m2) and mass balance calculations (approximately 380-430 mequiv/m2). The magnitude of Ca loss cannot be explained by decreases in Ca deposition or decreased Ca weathering. Large Ca losses from the soil exchangeable pool have serious implications for future forest health and the recovery of streamwater from acid deposition. 相似文献
Motorcyclists and a matched group of non-motorcycling car drivers were assessed on behavioral measures known to relate to accident involvement. Using a range of laboratory measures, we found that motorcyclists chose faster speeds than the car drivers, overtook more, and pulled into smaller gaps in traffic, though they did not travel any closer to the vehicle in front. The speed and following distance findings were replicated by two further studies involving unobtrusive roadside observation. We suggest that the increased risk-taking behavior of motorcyclists was only likely to account for a small proportion of the difference in accident risk between motorcyclists and car drivers. A second group of motorcyclists was asked to complete the simulator tests as if driving a car. They did not differ from the non-motorcycling car drivers on the risk-taking measures but were better at hazard perception. There were also no differences for sensation seeking, mild social deviance, and attitudes to riding/driving, indicating that the risk-taking tendencies of motorcyclists did not transfer beyond motorcycling, while their hazard perception skill did. 相似文献