Accurate electrical load forecasting is of great significance to help power companies in better scheduling and efficient management. Since high levels of uncertainties exist in the load time series, ...it is a challenging task to make accurate short-term load forecast (STLF). In recent years, deep learning approaches provide better performance to predict electrical load in real world cases. The convolutional neural network (CNN) can extract the local trend and capture the same pattern, and the long short-term memory (LSTM) is proposed to learn the relationship in time steps. In this paper, a new deep neural network framework that integrates the hidden feature of the CNN model and the LSTM model is proposed to improve the forecasting accuracy. The proposed model was tested in a real-world case, and detailed experiments were conducted to validate its practicality and stability. The forecasting performance of the proposed model was compared with the LSTM model and the CNN model. The Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE) and Root Mean Square Error (RMSE) were used as the evaluation indexes. The experimental results demonstrate that the proposed model can achieve better and stable performance in STLF.
Platycodon grandiflorus (Jacq.) A. DC., the sole species in genus Platycodon A. DC. (Campanulaceae) has a long history of use as a traditional herbal medicine for the treatments of cough, phlegm, ...sore throat, lung abscess, chest pain, dysuria, and dysentery. As a legal medicine and dietary supplement, it is also frequently used as an ingredient in health foods and vegetable dishes. The aim of this review is to provide up-to-date information on the botanical characterization and distribution, ethnopharmacology, phytochemistry, pharmacology, and toxicity of Platycodon grandiflorus based on literature published in recent years. It will build a foundation for further study of the mechanism of action and the development of better therapeutic agents and healthy products from Platycodon grandiflorus.
All of the available information on Platycodon grandiflorus was collected via electronic search (using PubMed, SciFinder Scholar, CNKI, TPL (www.theplantlist.org), Google Scholar, Baidu Scholar, and Web of Science).
A comprehensive analysis of the literature obtained through the above-mentioned sources confirmed that ethno-medical uses of Platycodon grandiflorus have been recorded in China, Japan, Mongolia, and Korea for thousands of years. A phytochemical investigation revealed that this product contains steroidal saponins, flavonoids, polyacetylenes, sterols, phenolics, and other bioactive compounds. Crude extracts and pure compounds isolated from Platycodon grandiflorus exhibited significant anti-inflammatory and immunostimulatory effects. They also showed valuable bioactive effects, such as anti-tumor, anti-oxidant, anti-diabetic, anti-obesity, hepatoprotective and cardiovascular system effects, among others.
In light of its long traditional use and the modern phytochemical and pharmacological studies summarized here, Platycodon grandiflorus has been demonstrated to show a strong potential for therapeutic and health-maintaining uses. Both the extracts and chemical components isolated from the plant showed a wide range of biological activities. Thus, more studies on the pharmacological mechanisms of its main active compounds (e.g., platycodin D, D2) need to be conducted. In addition, as one of the most popular traditional herbal medicines, clinical studies of the main therapeutic aspects, toxicity and adverse effects of Platycodon grandiflorus will also undoubtedly be the focus of future investigation.
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Iridoids are a class of active compounds that widely exist in the plant kingdom. In recent years, with advances in phytochemical research, many compounds with novel structure and outstanding activity ...have been identified. Iridoid compounds have been confirmed to mainly exist as the prototype and aglycone and Ι and II metabolites, by biological transformation. These metabolites have been shown to have neuroprotective, hepatoprotective, anti-inflammatory, antitumor, hypoglycemic, and hypolipidemic activities. This review summarizes the new structures and activities of iridoids identified locally and globally, and explains their pharmacokinetics from the aspects of absorption, distribution, metabolism, and excretion according to the differences in their structures, thus providing a theoretical basis for further rational development and utilization of iridoids and their metabolites.
•Integrative features of cell-wall modification in berry fruit firmness were revealed.•Blackberry fruit firmness lied in levels of hydrolases and degradation of cell walls.•Blackberry fruits of ...similar ripening time exhibited similar initiation of softening.•Cellluase and PG played critical roles at late stages of blackberry fruit softening.
Fruit flesh firmness plays a critical role in controlling blackberry (Rubus spp.) postharvest shelf life. This work aimed to identify the underlying characteristics in pericarp morphology, cell wall hydrolase activity and cell wall composition that account for flesh firmness in soft-fruited ‘Boysen’ and firm-fruited ‘Arapaho’ cultivars that have a similar ripening time of 39 days after flowering (DAF). The fruit firmness of both fruits decreased noticeably at the onset of color change, and this decrease hastened from 33 DAF to ripening despite considerable differences in their temporal changes. The evaluation of pericarp cellular morphology revealed that the disassembly of the cell wall in both fruits was likely initiated at 33 DAF, followed by extreme degradation at 39 DAF. Cell wall hydrolase activity assays indicated that increases in polygalacturonase (PG) and cellulase activity also dramatically occurred in the late softening stages of both fruits. Notably, appreciably higher levels of cellulase, and significant increases in pectin methylesterase (PME), α-L-arabinofuranosidase (α-L-Af) and xyloglucan endotransglycosylase (XET) were only detected in the late ripening stages of ‘Boysen’. In terms of cell wall components, the levels of cell wall material (CWM), cellulose and hemicellulose declined similarly during ripening in both fruits. Comparatively, lower levels of CWM, chelator soluble pectin (CSP), sodium carbonate soluble pectin (SSP), and hemicellulose as well as higher levels of water soluble pectin (WSP) were found in ‘Boysen’ than those in ‘Arapaho’ during maturation and ripening. Overall, the loss of fruit firmness during ripening in blackberry fruit is correlated closely with biochemical changes in cell wall fractions that involve hydrolytic processes, resulting in the breakdown of cell-wall polymers. The low firmness of ‘Boysen’, as determined by cell wall degradation, could be of particular relevance to the function of cell wall degrading enzymes and to the more drastic degradation of cell wall components than that in the firm cv. ‘Arapaho’.
species find widespread application in food and pharmaceutical products owing to their large polyphenol content. The main polyphenols in Chinese
species are phenolic acids and flavonoids, which ...exhibit anti-oxygenation, anti-ischemia-reperfusion injury, anti-thrombosis, anti-tumour, and other therapeutic effects. However, there are few peer-reviewed studies on polyphenols in Chinese
species, especially flavonoids. This review is a systematic, comprehensive collation of available information on the biosynthesis, chemistry, and pharmacology of Chinese
species. We believe that our study makes a significant contribution to the literature because this review provides a detailed literary resource on the currently available information on various polyphenolic components of Chinese
species, including their bioactivities and structures. In addition, the study provides information that would encourage further investigation of this plant material as a natural resource with potential for a broad range of applications in various industries, such as the food and pharmaceutical industries.
Student Dropout Prediction (SDP) is pivotal in mitigating withdrawals in Massive Open Online Courses. Previous studies generally modeled the SDP problem as a binary classification task, providing a ...single prediction outcome. Accordingly, some attempts introduce survival analysis methods to achieve continuous and consistent predictions over time. However, the volatility and sparsity of data always weaken the models' performance. Prevailing solutions rely heavily on data pre-processing independent of predictive models, which are labor-intensive and may contaminate authentic data. This paper proposes a Survival Analysis based Volatility and Sparsity Modeling Network (SAVSNet) to address these issues in an end-to-end deep learning framework. Specifically, SAVSNet smooths the volatile time series by convolution network while preserving the original data information using Long-Short Term Memory Network (LSTM). Furthermore, we propose a Time-Missing-Aware LSTM unit to mitigate the impact of data sparsity by integrating informative missingness patterns into the model. A survival analysis loss function is adopted for parameter estimation, and the model outputs monotonically decreasing survival probabilities. In the experiments, we compare the proposed method with state-of-the-art methods in two real-world MOOC datasets, and the experiment results show the effectiveness of our proposed model.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper presents a flexible 2.45-GHz wireless power harvesting wristband that generates a net dc output from a -24.3-dBm RF input. This is the lowest reported system sensitivity for systems ...comprising a rectenna and impedance-matching power management. A complete system has been implemented comprising: a fabric antenna, a rectifier on rigid substrate, a contactless electrical connection between rigid and flexible subsystems, and power electronics impedance matching. Various fabric and flexible materials are electrically characterized at 2.45 GHz using the two-line and the T-resonator methods. Selected materials are used to design an all-textile antenna, which demonstrates a radiation efficiency above 62% on a phantom irrespective of location, and a stable radiation pattern. The rectifier, designed on a rigid substrate, shows a best-in-class efficiency of 33.6% at -20 dBm. A reliable, efficient, and wideband contactless connection between the fabric antenna and the rectifier is created using broadside-coupled microstrip lines, with an insertion loss below 1 dB from 1.8 to over 10 GHz. A self-powered boost converter with a quiescent current of 150 nA matches the rectenna output with a matching efficiency above 95%. The maximum end-to-end efficiency is 28.7% at -7 dBm. The wristband harvester demonstrates net positive energy harvesting from -24.3 dBm, a 7.3-dB improvement on the state of the art.
In this paper, porous polyimide composites (PPIC) for electromagnetic interference (EMI) shielding were rationally designed and fabricated by using polyimide (PI) matrix, polyaniline modified ...graphene oxide (PANI-g-GO) and multiwalled carbon nanotube (MWCNT) as hybrid fillers through innovatively combining in-situ polymerization process and thermally assisted non-solvent induced phase separation (TNIPS) method. The polyimide matrix and porous structure endow the composites with good heat resistance and lightweight, and hybrid fillers can form effective conductive networks in the PI matrix, which results in the enhancement of EMI shielding performance. The porous polyimide composite with a hybrid filler content of 12 wt% (PPIC12) exhibited a low density of 0.56 g/cm3, high T10 of 554.81 °C, excellent EMI shielding effectiveness up to 28.2 dB at a thickness of 2 mm. Therefore, the novel porous polyimide composites are promising polymer-based EMI shielding materials with lightweight and good heat resistance.
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•A facile strategy is proposed to prepare porous polyimide composite.•The composite exhibits lightweight due to the formation of porous structure.•Effective conductive networks formed by hybrid fillers result in high EMI SE.•The composite shows high EMI SE with strong absorption loss characteristics.
Borophene is a novel two-dimensional material with abundant crystal structure and photoelectric properties. We focus on the effect of co-doping on the electronic structure and optical properties of ...borophene using the first-principles method. The results show that the structure of Al and Ga co-doped borophene is obviously distorted because Al and Ga atoms have formed bonds with a bond length of 2.378 Å, and the two B atoms that bond together with Al and Ga are no longer formed bonds. However, it is also a two-dimensional planar structure after co-doping. After co-doping, the band gap width of the borophene system is narrowed from 1.409 eV to 1.376 eV, and the band gap is narrowed by 0.033 eV. Mulliken population analysis shows an obvious charge transfer between Al-B and Ga-B atoms in the co-doped borophene. The calculation of optical properties shows that the static dielectric constant ε1 (0) increases from 5.08 to 7.01, and ε2 (ω) is larger than that of the undoped sample in the low-energy range. Thus, the co-doping of Al and Ga can enhance the electromagnetic energy storage capacity and the visible light absorption ability. Although the reflectance of borophene is reduced by co-doping (the peak of the reflectivity can be decreased from 71% to 61% at E = 2.94 eV), it still presents metallic reflection characteristics. The static refractive index n0 can be increased from 2.25 to 2.65 by co-doping. The extinction coefficient shows strong band edge absorption at the low-energy range with an absorption edge of 0.85 eV. The light loss is limited to a very narrow energy range of approximately 7.30 eV, which indicates that borophene co-doped with Al and Ga can also be used as a light storage material. The optical conductivity reaches its maximum at E = 1.78 eV and 2.52 eV, which correspond to the light irradiation with a wavelength of 698 nm (red light) and 492 nm (cyan light), respectively. The results show that the Al-Ga co-doped borophene is sensitive to cyan light and red light, so it can be used to make photosensitive devices. The results can hopefully fill the gap in the application of borophene in semiconductor photoelectric devices and provide a theoretical basis for its application.
It is important to study the role and mechanism of arbuscular mycorrhizal fungi (AMF) on plants in arsenic-contaminated soil phytoremediation. In this paper, it was introduced that the ways of AMF ...acting on arsenic hyperaccumulator and non-hyperaccumulator were different; then the mechanism of AMF acting on plants was discussed from five aspects: (1) AMF improved the absorption of nutrients; (2) AMF would have participated in the reduction process of As (V) to As (III) and changed the form of As in plant; (3) AMF would have participated in the transformation process of inorganic arsenic to organic arsenic; (4) AMF absorbed and assimilates arsenic; and (5) AMF could improve the rhizosphere soil environment, thus affecting the arsenic absorption and accumulation of plants. Finally, the shortcomings and future of the research were prospected to promote the relevant research progress.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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