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Comprehensive Summary: Side‐chain engineering has emerged as a highly effective strategy for tailoring the aggregation behavior and charge transport properties of non‐fullerene small molecule acceptors (SMAs). In this study, we designed and synthesized two SMAs, namely BTPSi‐Bu and BTPSi‐Pr, respectively incorporating tributylsilyloxy and triisopropylsilyloxy groups in their outer positions. Notably, BTPSi‐Bu exhibited better planarity, crystallization, and favorable phase separation when paired with PM6 donor polymer compared to its counterpart, BTPSi‐Pr. The resulting organic solar cells, utilizing the PM6:BTPSi‐Bu blend, demonstrated a remarkable power conversion efficiency of 17.41% and a high open‐circuit voltage of 0.859 V. These findings underscore the significance of integrating trialkylsilyloxy side chains into SMAs as a rational design approach for enhancing the performance of photovoltaic systems. [ABSTRACT FROM AUTHOR]

The dimerization of small molecule acceptors (SMAs) holds significant potential by combining the advantages of both SMAs and polymer acceptors in realizing high power conversion efficiency (PCE) and operational stability in organic solar cells (OSCs). However, advancements in the selection and innovation of dimeric linkers are still challenging in enhancing their performance. In this study, three new dimeric acceptors, namely DY‐Ar‐4, DY‐Ar‐5, and DY‐Ar‐6 are synthesized, by linking two Y‐series SMA subunits via an “end‐to‐end” strategy using flexible spacers (octyl, decyl, and dodecyl, respectively). The influence of spacer lengths on device performance is systematically investigated. The results indicate that DY‐Ar‐5 exhibits more compact and ordered packing, leading to an optimal morphology. OSCs based on PM6: DY‐Ar‐5 achieves a maximum PCE of 15.76%, attributes to enhance and balance carrier mobility, and reduce carrier recombination. This dimerization strategy using suitable non‐conjugated linking units provides a rational principle for designing high‐performance non‐fullerene acceptors. [ABSTRACT FROM AUTHOR]

Giant molecular acceptors (GMAs) are typically designed through the conjugated linking of individual small molecule acceptors (SMAs). This design imparts an extended molecular size, elevating the glass transition temperature (Tg) relative to their SMA counterparts. Consequently, it effectively suppresses the thermodynamic relaxation of the acceptor component when blended with polymer donors to construct stable polymer solar cells (PSCs). Despite their merits, the optimization of their chemical structure for further enhancing of device performance remains challenge. Different from previous reports utilizing p‐type linkers, here, we explore an n‐type linker, specifically the benzothiadiazole unit, to dimerize the SMA units via a click‐like Knoevenagel condensation, affording BT‐DL. In comparison with B‐DL with a benzene linkage, BT‐DL exhibits significantly stronger intramolecular super‐exchange coupling, a desirable property for the acceptor component. Furthermore, BT‐DL demonstrates a higher film absorption coefficient, redshifted absorption, larger crystalline coherence, and higher electron mobility. These inherent advantages of BT‐DL translate into a higher power conversion efficiency of 18.49 % in PSCs, a substantial improvement over the 9.17 % efficiency observed in corresponding devices with B‐DL as the acceptor. Notably, the BT‐DL based device exhibits exceptional stability, retaining over 90 % of its initial efficiency even after enduring 1000 hours of thermal stress at 90 °C. This work provides a cost‐effective approach to the synthesis of n‐type linker‐dimerized GMAs, and highlight their potential advantage in enhancing intramolecular coupling for more efficient and durable photovoltaic technologies. [ABSTRACT FROM AUTHOR]

Giant molecular acceptors (GMAs) are typically designed through the conjugated linking of individual small molecule acceptors (SMAs). This design imparts an extended molecular size, elevating the glass transition temperature (Tg) relative to their SMA counterparts. Consequently, it effectively suppresses the thermodynamic relaxation of the acceptor component when blended with polymer donors to construct stable polymer solar cells (PSCs). Despite their merits, the optimization of their chemical structure for further enhancing of device performance remains challenge. Different from previous reports utilizing p‐type linkers, here, we explore an n‐type linker, specifically the benzothiadiazole unit, to dimerize the SMA units via a click‐like Knoevenagel condensation, affording BT‐DL. In comparison with B‐DL with a benzene linkage, BT‐DL exhibits significantly stronger intramolecular super‐exchange coupling, a desirable property for the acceptor component. Furthermore, BT‐DL demonstrates a higher film absorption coefficient, redshifted absorption, larger crystalline coherence, and higher electron mobility. These inherent advantages of BT‐DL translate into a higher power conversion efficiency of 18.49 % in PSCs, a substantial improvement over the 9.17 % efficiency observed in corresponding devices with B‐DL as the acceptor. Notably, the BT‐DL based device exhibits exceptional stability, retaining over 90 % of its initial efficiency even after enduring 1000 hours of thermal stress at 90 °C. This work provides a cost‐effective approach to the synthesis of n‐type linker‐dimerized GMAs, and highlight their potential advantage in enhancing intramolecular coupling for more efficient and durable photovoltaic technologies. [ABSTRACT FROM AUTHOR]

A quadra-ridged waveguide transformer (QRWT) is proposed for full-band matching between a standard waveguide and a half-height waveguide, which meets the need for compact waveguide components and the need for multiple sections of irregular transmission lines for better matching in wider operation bands. Unlike conventional matching circuits with monotonically changing impedances, QRWTs form abrupt cross-section changes between transmission line steps. The initial configuration of QRWT is built by CST MICROWAVE STUDIO, a system-level electromagnetic compatibility and general high frequency passive device simulation software, according to the basic electromagnetic (EM) concept and then is optimized by optimization functions from an advanced EM simulator, during the optimization, releasing restrictions as many as possible. To explain the concept, a sample QRWT is designed to match a standard rectangular waveguide WR34 to a half-height waveguide. The reflection coefficient is less than −24 dB in the full operation bandwidth, from 21.7 to 33 GHz. The optimized QRWT has a length of 3.088 mm, 0.218 times the waveguide wavelength at its center operation frequency of 27.35 GHz. For comparison, a two-stage quarter-wave transformer matching circuit is optimized. For similar reflection coefficients in the same bandwidth, the QRWT has a length 57% shorter than the conventional one, and it has an easier manufacturing method using wire-electrode cutting. To verify the design, a back-to-back matching circuit was fabricated using brass material without extra dielectric material. Its measured reflections are less than −16.6 dB, and the insertion loss is less than 0.2 dB. [ABSTRACT FROM AUTHOR]

Background: Adenomyosis is a frequent finding in endometrial carcinoma patients. Endometrioid adenocarcinoma is the most common type of endometrial carcinoma; however, endometrioid adenocarcinoma arising from adenomyosis is extremely rare. Case presentation: In this case report, we describe a 69-year-old woman who required surgical treatment for pelvic organ prolapse (POP). The patient had been postmenopausal for 20 years and had no abnormal bleeding after menopause. The patient underwent transvaginal hysterectomy, repair of anterior and posterior vaginal walls, ischium fascial fixation and repair of an old perineal laceration. Histological examination of surgical specimens revealed endometrioid adenocarcinoma of the uterus. Bilateral adnexectomy, pelvic lymphadenectomy and para-aortic lymphadenectomy were then performed. The postoperative histopathological diagnosis was stage IB endometrial cancer (endometrioid carcinoma G2). Conclusions: In summary, endometrioid adenocarcinoma arising from adenomyosis (EC-AIA) is a rare entity and the early diagnosis is difficult. Adequate preoperative assessment and enhanced inquiry of occult clinical symptoms of postmenopausal women before hysterectomy may contribute to the diagnosis of EC-AIA preoperatively. [ABSTRACT FROM AUTHOR]

Advanced ceramics are referred to in various parts of the world as technical ceramics, high-tech ceramics, and high-performance ceramics. Figures Graph: Figure 1 Some representative advanced ceramics developed in recent years: (a) Electronic ceramics, (b) 3-D printed high-strength ceramics, (c) Superconductive ceramics, (d) Various structural ceramics, (e) HAP bioceramics, (f) Nano-ceramic coatings, (g) Fire-resistant glasses. From a general point of view, the advanced ceramics sector comprises the following categories [[1]]: (1) Functional ceramics: Electrical and magnetic ceramics (i.e., dielectrics, piezoelectrics, ferromagnetics), ionic conductors and superconductive ceramics. This special issue contains ten papers that reported the results of several studies on functional ceramics, structural ceramics, ceramic composites, ceramic coatings and special glasses. [Extracted from the article]

Just-in-time evaluation of drug resistance in situ will greatly facilitate the achievement of precision cancer therapy. The rapid elevation of reactive oxygen species (ROS) is the key to chemotherapy. Hence, suppressed ROS production is an important marker for chemotherapy drug resistance. Herein, a NIR-II emission smart nanoprobe (LnNP@ZIF8, consisting of a lanthanide-doped nanoparticle (LnNP) core and metal-organic framework shell (ZIF8)) is constructed for drug delivery and in vivo NIR-II ratiometric imaging of ROS for tumor drug resistance evaluation. The drug-loaded nanoprobes release therapeutic substances for chemotherapy in the acidic tumor tissue. As the level of ROS increases, the LnNPs shows responsively descending fluorescence intensity at 1550 nm excited by 980 nm (F1550, 980Ex), while the fluorescence of the LnNPs at 1060 nm excited by 808 nm (F1060, 808Ex) is stable. Due to the ratiometric F1550, 980Ex/F1060, 808Ex value exhibiting a linear relationship with ROS concentration, NIR-II imaging results of ROS change based on this ratio can be an important basis for determining tumor drug resistance. As the chemotherapy and resistance evaluation are explored continuously in situ, the ratiometric imaging identifies drug resistance successfully within 24 h, which can greatly improve the timeliness of accurate treatment. [ABSTRACT FROM AUTHOR]

A novel hybrid model is proposed to improve the accuracy of ultra-short-term wind speed prediction by combining the improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN), the sample entropy (SE), optimized recurrent broad learning system (ORBLS), and broadened temporal convolutional network (BTCN). First, ICEEMDAN is introduced to smooth the nonlinear part of the wind speed data by decomposing the raw wind speed data into a series of sequences. Second, SE is applied to quantitatively assess the complexity of each sequence. All sequences are divided into simple sequence set and complex sequence set based on the values of SE. Third, based on the typical broad learning system (BLS), we propose ORBLS with cyclically connected enhancement nodes, which can better capture the dynamic characteristics of the wind. The improved particle swarm optimization (PSO) is used to optimize the hyper-parameters of ORBLS. Fourth, we propose BTCN by adding a dilated causal convolution layer in parallel to each residual block, which can effectively alleviate the local information loss of the temporal convolutional network (TCN) in case of insufficient time series data. Note that ORBLS and BTCN can effectively predict the simple and complex sequences, respectively. To validate the performance of the proposed model, we conducted three predictive experiments on four data sets. The experimental results show that our model obtains the best predictive results on all evaluation metrics, which fully demonstrates the accuracy and robustness of the proposed model. [ABSTRACT FROM AUTHOR]

The scattering of flexural waves in piezoelectric thin plates with defects effects the electro-mechanical coupling property. Theoretical analysis for flexural waves is lack of a suitable decoupling function. Here, we have developed a method based on applied electric field to make a solution of the dynamic moment concentration factor (DMCF) for flexural waves scattering problems. The DMCFs of the piezoelectric materials have been found that it is significantly larger than those of the ordinary elastic materials because of electro-mechanical coupling. In the region of low frequency, DMCFs have a dependence on applied electric field and independent on the incident angle. Those opposite phenomena are observed as the frequency increasing. Those results provide theoretical guidance for dynamic analysis and strength design of piezoelectric material structures. [ABSTRACT FROM AUTHOR]

Summary: In the present study, valorization of food and lignocellulosic wastes into biodiesel and 2‐phenylethanol using Metchinikowia pulcherrima isolated from rotten food wastes was evaluated. At the optimum pH of 5.5, food waste hydrolysate (FWH) showed 74.1% higher dry weight than the corresponding synthetic medium. Rice straw (RS) and softwood sawdust (WWA) were used as additional carbon sources to increase the C:N ratio of FWH. WWA enhanced the biomass production by 23.3% and 55.9% over the corresponding RS and FWH, respectively; while RS enhanced lipid accumulation. Due to enhancement of growth, 75 g WWA showed the maximum recorded lipid productivity of 2.49 g L−1 d−1. Interestingly, both hexoses and pentoses were effectively metabolized. Regarding fatty acid profile of M. pulcherrima, RS‐ and WWA‐enriched growth media showed higher saturated fatty acids proportions (56.9% and 98.3%, respectively, over that of FWH), with better biodiesel characteristics. FWH showed the heights significant production of 2‐phenylethanol up to 56.7 mg L−1 after 96 hours. However, FWH enriched with WWA showed the highest gross energy output of 33.98 GJ m−3 y−1. Thus, the present study suggested an integrated approach of M. pulcherrima cultivation on FWH enriched with WWA for efficient biofuel production through waste recycling. [ABSTRACT FROM AUTHOR]

Extreme sea surface temperatures (SSTs) attract much attention in recent years. However, the detailed spatial and temporal pattern of the extreme SSTs in China Seas has not been well understood. Using the daily SST data set of OISST v2 from January 1, 1982 to December 31, 2013, and based on four extreme SST indices, the frequency and intensity of SST extremes in the China Seas were examined. The analysis showed that the annual mean SST exhibited cooling trend, on pace with a trend of − 0.34 °C/decade during 1998–2013, confirming the previous studies that China Seas also experienced the recent global warming hiatus. But during this recent global warming hiatus, there was a notable asymmetric pattern of greater cooling trends in cold SSTs as compared to the hot SSTs in this region. During 1998–2013, the cold days (CDs) frequency increased significantly by 13 days per decade and cold SST extremes which were below the 10th percentile of each year (SST10p) notably decreased by 0.4 °C per decade. Hot days (HD) and hot SST extremes which were above the 90th percentile of each year (SST90p) slowed down, but without any distinct tendency. Meanwhile, the rates of SST10p and CDs were highly heterogeneous in space. Cold extremes in the near-shore areas are much more sensitive to the global warming hiatus than these in the eastern of the Kuroshio Current. Importantly, hot extremes do not reveal any distinct cooling tendency during 1998–2013, there were more frequent hot days and more intense hot SSTs in this region comparing with 1982–1997. These hot extremes could push some marine organisms, fisheries and ecosystems beyond the limits of their resilience, with cascading impacts on economies and societies. [ABSTRACT FROM AUTHOR]

In this paper, a broadband and compact oversized rectangular waveguide transition is proposed. Employing novel quadruple-ridged waveguide technology, two quadruple-ridged waveguides achieve an extreme compactness interconnection from a standard rectangular waveguide to an oversized rectangular waveguide. This design can be used as an alternative way to create a new oversized rectangular waveguide transition. The length of the transition is only 0.3λ, where λ is the TE10 mode wavelength at the center frequency. For verification purpose, a back-to-back transition was designed, fabricated, and measured. Measured results show that the return loss is greater than 20 dB and the insertion loss is less than 0.2 dB in the operating frequency band. Therefore, we can infer that the return loss and insertion loss of single transition are around 25 dB and 0.1 dB, respectively. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) have been confirmed to play a crucial part in oncogenesis. Several studies suggested that MiR-3174 act as a tumor promoter in various Malignant neoplasm. However, the biological function of miR-3174 in hepatocellular carcinoma (HCC) still highly unexplored. We screened differentially over-expressed miRNAs by The Cancer Genome Atlas (TCGA) and the GEO databases. The expression of miR-3174 in HCC cells and tissues was detected by qRT-PCR. The cellular behaviors of transfected cells were respectively examined by colony formation assays, EdU Assays and flow cytometry. Forkhead box O1 transcription factor (FOXO1) was predicted and confirmed as a direct target of miR-3174 by bioinformatics analysis and dual-luciferase reporter gene assay. MiR-3174 was up-regulated in HCC tissues and cells, and the expression level of it was highly associated with tumor size and Edmondson grade. Our study pioneering validates that upregulated miR-3174 promote cell proliferation and inhibit cell apoptosis in vitro and in vivo. Meanwhile, our study verified that miR-3174 regulate Bim, P21, cyclin D1 and c-MYC expression by directly targeting FOXO1. The upregulated miR-3174 promote cell proliferation and inhibit cell apoptosis by downregulating FOXO1 expression in HCC. MiR-3174 may be a novel candidate for targeted delivery of miRNA therapeutics for HCC patients. • Combination of TCGA and GEO database sorts out novel miRNA candidates for HCC therapy. • MiR-3174 expression is significantly up-regulated in HCC tissues and cells. • Upregulation of miR-3174 plays a vital role in promoting proliferation in HCC cells. • FOXO1 is validated to be a tissue-specific target of miR-3174 in HCC. [ABSTRACT FROM AUTHOR]

In this paper, we study a chemotaxis system with signal-dependent motility, indirect signal production and generalized logistic source in a smooth bounded domain. By using a priori estimates, some important inequalities and the well-known standard Alikakos–Moser iteration, we establish the global existence of the solution for such kind of chemotaxis system. More precisely, we show that if l > max n 2 , 1 , λ ∈ R , μ > 0 and δ > 0 , then for all sufficiently smooth initial data the system u t = Δ (γ (v) u) + λ u - μ u l , x ∈ Ω , t > 0 , v t = Δ v - v + w , x ∈ Ω , t > 0 , w t = - δ w + u , x ∈ Ω , t > 0 , possesses a unique global-in-time solution. Moreover, the solution is shown to approach λ + μ 1 l - 1 , 1 δ λ + μ 1 l - 1 , 1 δ λ + μ 1 l - 1 in the large time limit under some extra hypotheses, where λ + = max { λ , 0 } . [ABSTRACT FROM AUTHOR]

To investigate the effects of varying right-angle corner locations inside the L-shaped tube on self-ignition induced by high-pressure hydrogen release, a series of experiments were carried out on L-shaped tubes with different right-angle corner locations and a straight tube was adopted for comparison. It is found that compared with the straight tube, the propagation of shock wave in the L-shaped tubes becomes more complicated due to the existence of reflected shock wave. The pressure profiles detected by pressure transducers before the right-angle corner will undergo secondary rapid rise. The varying right-angle corner locations inside the L-shaped tube have a significant influence on self-ignition of hydrogen. The closer the right-angle corner is to the burst disk, the lower the critical pressure that causes hydrogen self-ignition is. Three possible mechanisms of self-ignition inside the L-shaped tubes are discussed. Nevertheless, different right-angle corner locations have no obvious effects on development process of out-tube jet flame, only the velocity of flame tip and the length and width of jet flame have slight differences. • The effect of varying right-angle corner locations on self-ignition is investigated. • The relationship between the reflected shock wave and burst pressure in L-shaped tube is discussed. • Self-ignition is easy to occur in L-shaped tube of smaller distance from corner to diaphragm. • Three possible mechanisms of self-ignition in L-shaped tube are proposed. [ABSTRACT FROM AUTHOR]

The article presents a case study of an 18-year-old female diagnosed with chronic myeloid leukemia (CML) who rapidly progressed to the blast phase despite treatment with tyrosine kinase inhibitors (TKIs). Topics discussed include the identification of recurrent fusion genes in CML-blast phase, their potential role in disease progression and drug resistance, and the need for further research to understand their prevalence and clinical implications.

Thermal stress fatigue failure caused by mismatch in the coefficients of thermal expansion (CTE) between the metal layer and ceramic sheet during a high and low temperature cycle is considered as the big issue of high-power ceramic substrates. The aim of this study is to explore the thermal fatigue mechanism of nano Cu/Ti–Si 3 N 4 ceramic substrates after thermal fatigue test. Thermal fatigue test has been performed by thermal cycles experiment from −30 °C to 150 °C. After thermal cycles, the microstructure of the interface is observed by SEM and TEM. The results show after 400 thermal cycles, the nano-Cu metal layer oxidizes severely. Various oxides are found in the corrosion zone, such as CuO, CuAlO 2 and CuAl 2 O 4. Higher dislocation density and nanoscale-twins are observed in Cu or Cu 2 O, which indicate that Cu and Cu 2 O alleviates thermal stress. As the number of thermal cycles increases, CuO CuAlO 2 , CuAl 2 O 4 as a corrosion layer in the corrosion zone were formed. The corrosion layer is difficult to alleviate interfacial thermal stress, and easy to form cracks in the joint zone. [ABSTRACT FROM AUTHOR]

He had a 30-year history of vitiligo without treatment which started from the back of the neck and had progressed to a universal vitiligo with whole-body depigmentation and focal hair depigmentation for over 1 year. In our patient, the very severe universal vitiligo has been in continuously gradual remission post allo-HSCT. Due to the common preservation of melanocyte stem cells among hair follicle stem cells, vitiligo lesions can repigment, and repigmentation usually starts with a perifollicular pattern, just as in our patient. [Extracted from the article]

Phosphatase and tensin homolog (PTEN), one of the most frequently mutated tumor suppressor genes in human cancer, is pivotal in the progression of colorectal cancer. Therefore, the regulation of PTEN has emerged as a theme of intense research in tumor biology. This study aims to show that long noncoding RNA (lncRNA) Linc02023 aberrant downregulation in colorectal cancer correlates positively with the expression of PTEN and CDKN2B but negatively with the tumor size in patients and xenografted mouse models. The gain- and loss-of-function investigation reveals that Linc02023 suppresses the proliferation of colorectal cancer cells in vitro and in vivo with apoptosis promotion and cell cycle rearrangement. Mechanistically, Linc02023 specifically binds to PTEN and blocks its interaction with and ubiquitination by WWP2, stabilizing it and suppressing its downstream expression. In conclusion, this study demonstrates that lncRNA Linc02023 may serve as a novel therapeutic target by restoring the PTEN tumor suppressor activity. [ABSTRACT FROM AUTHOR]

A novel wideband eight-way radial waveguide power combiner has been proposed in this paper. The proposed radial waveguide power combiner consists of a commercial N-type connector, a regular-octagon waveguide cavity, eight matching circuits, and eight coaxial-to-ridge waveguide transitions. The introduction of matching circuits is used to improve matching performance in the regular-octagon waveguide cavity. Besides, in order to guarantee the bandwidth performance and facilitate applications, eight coaxial-to-ridge transitions as output ports were also designed to connect ridge ports of the radial waveguide power combiner. Therefore, the overall performance of the proposed waveguide power combiner is enhanced over the wideband range. For validation, a sample eight-way radial waveguide power combiner has been designed, fabricated, and measured. The measured results show that the return loss (S11) and insertion loss (S21) are better than 20 dB and 0.5 dB, respectively, in the whole frequency range from 4 to 8 GHz (with 66.6% fractional bandwidth). The measured results reasonably agree well with the simulation ones. Compared with some other radial waveguide power combiners, the completed radial waveguide power combiner exhibits lower return loss, lower insertion loss, more compact size, and prominent bandwidth performance. [ABSTRACT FROM AUTHOR]

• A dynamic pricing strategy based on deep reinforcement learning is developed to improve FCST profit and EV charging satisfaction. • A prediction method for charging demand distribution is developed with analyzing the spatial–temporal relations of traffic network. • An EV satisfaction model with proposing both charging and opportunity costs is used to make charging decisions for EV users under the dynamic price and traffic environment. • The potential influence of dynamic charging prices on traffic flows and EV charging behaviors is transformed into Markov decision process to build the learning environment. With the rapid development of electric vehicles (EVs) and charging infrastructures, the unbalanced utilization rate of fast charging stations (FCSTs) and the long waiting time for charging have aroused considerable attention. The incurred low operation profit of FCSTs and low satisfaction of EVs impose difficulties on the further development of EV industry. Existing literature ignored the influence of real-time charging price changes on traffic flow variation and EV charging determination during the dynamic price regulating process. This paper focuses on solving these crucial issues in the dynamic pricing for FCSTs with deep reinforcement learning (DRL). Firstly, considering the spatial–temporal interactions of different roads, a traffic flow prediction model is proposed based on the LSTM combined with the GNN-FiLM. Then, the Origin-Destination (OD) estimation is used to estimate the charging requirements of EVs based on the predicted traffic flow, and a charging demand prediction method for FCSTs is developed by converting the EV satisfaction into economic costs with different dimensions. Then, the vehicle–road learning environment is built with the Markov decision process (MDP), and a dynamic pricing strategy based on the Deep Deterministic Policy Gradient (DDPG) learning is proposed to achieve the optimal charging prices of FCSTs with maximum operation profit. Moreover, during the learning process, the real-time charging price is renewed based on the predicted charging demand, and the future charging demand is further predicted under the renewed charging price until the optimal price is achieved. Finally, simulation results validate that the proposed dynamic pricing strategy effectively improves the profit of FCSTs, alleviates the road congestion, and improves the users' satisfaction. [ABSTRACT FROM AUTHOR]

A novel TE01-TE20 mode converter is designed and fabricated by 3-D printing in this paper. It can realize high-efficiency (>97.5%) mode conversion in broadband from 27 to 40 GHz. Its weight is 0.011 kg only, and its coupling cavity normalized length is 0.39λ. An out-of-phase power divider is designed to verify the mode converter by observing the difference of output phase and flat frequency characteristics when connected to the mode converter. A sample converter with a power divider was then tested. Flat frequency characteristics for power dividing and anti-phase outputs are obtained in the working bandwidth to verify the mode converter with a good performance of mode conversion. [ABSTRACT FROM AUTHOR]

The effect of the temperature and time of spark plasma sintering (SPS) of a nickel powder on the structure of obtained samples of porous nickel was studied, and their mechanical strength under compression was evaluated. Based on the results of the experiments, it was found that spark plasma sintering the nickel powder at a temperature of 480°C with a holding time of 4 minutes enables to obtain samples with a porosity of 78.8%, having a structural performance and a compressive strength exceeding 1 MPa. [ABSTRACT FROM AUTHOR]

Cracking of concrete is one of the critical parameters for the structural safety evaluation of building components after high-temperature exposure. In this paper, a method was developed to detect the cracks of concrete after exposure to high temperature. The gray-scale images of the cross-sections of concrete were binarized with a local-binarization algorithm, and then the isolate cracks were extracted to analyze the geometric attributes, including length, average width, and area. The factor of circle of each isolate crack was used to filter the noise and fake cracks. The proposed method was applied to the real images of both cross-sections and surfaces of high-temperature-damaged concrete to test the effectiveness. Moreover, based on the detection results, the effects of four parameters, i.e. local window size ( S w ), step size ( S step ), local threshold ratio ( R t ) and upper limit of factor of circle ( F c,lmt ), in the proposed method were discussed to decide the optimal option. The results indicate that with the optimal parameters ( S w  = 10 pixels, S step  = 0.5, R t  = 0.85 for cross-sections and 0.95 for surface, F c,lmt  = 0.3), the proposed method can detect the cracks on both the surface and cross-section of concrete effectively. Some unclear cracks which were not detected with the optimal parameters can be detected out by combining the results from different groups of parameters. [ABSTRACT FROM AUTHOR]

Fly ash geopolymer concrete (FAGC) and ordinary Portland cement concrete (OPCC) specimens were immersed in 5% MgSO4 solution undergoing 32 wetting-drying and heating-cooling cycles. Their compressive behavior was investigated after every 8 cycles. Several microstructure analysis techniques were applied on the samples to identify the materials formed due to magnesium sulfate attack, including XRD, FTIR, SEM, and EDS. Experimental results elucidated that the compressive strength loss ratio in the heating group of FAGC was 12.7%, while that of OPCC was 17.8%, which means that FAGC had better magnesium sulfate resistance than OPCC. The compressive strength loss of OPCC was due to the formation of gypsum under the magnesium sulfate attack exposed to wetting-drying and heating-cooling cycles. The deterioration mechanisms of FAGC against MgSO4 solution were discovered to be that sodium aluminum silicate hydrate (N-A-S-H) gels reacted with MgSO4, leading to the creation of low strength magnesium aluminum silicate hydrate (M-A-S-H) gels. [ABSTRACT FROM AUTHOR]

Temperature effects on the mobility of < c + a > dislocations on pyramidal planes are characterized by molecular dynamics simulations. On the first-order pyramidal planes, near-edge dislocations always decompose, while the critical resolved shear stress (CRSS) for near-screw dislocations increases with increasing temperatures. On the second-order pyramidal planes, the CRSS decreases to a minimum at ~ 400 K, then increases with temperatures. This indicates that first-order pyramidal slip is favorable at low temperatures, while at elevated temperatures both pyramidal slip planes are active, leading to profuse plasticity. [ABSTRACT FROM AUTHOR]

Utilization of phenol formaldehyde foams is becoming increasingly widespread, especially in floral bouquets, generating toxic microplastics in the environment. The present study evaluated phenols recovery from floral foam waste (FFW) of floral bouquets through optimization of pyrolysis conditions. Compared to the biomass portion in the floral bouquet, FFW showed 55.1% higher carbon content, 56.9% lower nitrogen content, and 44.6% lower oxygen content, with the highest recorded calorific value of 27.43 MJ kg−1. Thermogravimetric analysis showed the relative thermal stability of FFW with gradual weight loss and numerous small peaks at 70 °C (representing short chain volatiles such as formaldehyde and phenol), 450 and 570 °C (due to phenolic and aromatic products release), indicating the richness of FFW with phenolic compounds. Optimization of pyrolysis conditions showed the highest significant biocrude yield of 36.0% at 700 °C for 20 min using FFW load of 2.5 g. However, optimization of phenolic production suggested 520 °C, 30 min, and 3.49 g FFW load as optimum conditions for high biocrude yield with enhanced phenolic proportion. Experimental results using the aforementioned conditions showed phenolics potential of 0.22 g phenolics/g FFW, with 78.8% phenolic compounds composed mainly of phenol and its methyl derivatives. [Display omitted] • Pyrolysis of floral foam waste (FFW) was optimized for enhanced phenols recovery. • Among all components, FFW showed the highest calorific value (27.43 MJ kg-1). • Biocrude recovery of 36.0% was achieved at 700 °C. • Maximum phenolics potential of 0.22 g phenolics/g FFW was obtained at 520 °C. • The main phenolic compounds were phenol and its methyl derivatives (78.8% in total). [ABSTRACT FROM AUTHOR]

This paper describes and analyzes the appearance, phase, and photocurrent of titanium film surfaces after exposure to water vapor at 100-1000 °C. The experimental results show that water vapor at higher than 300 °C can cause measurable oxidation of the titanium surface, and the oxidation product is changed into rutile from anatase in a gradual phase transformation with temperature. In the reaction, the product produced at 500-900 °C is a mixed phase of rutile and anatase. The titanium film surface appearance can change regularly with temperature, and an acicular rutile oxidation product can be produced on the surface at 800 °C. The photocurrent density on titanium surface increases with reaction temperature, and comes to a maximum value at 800 °C. However, with further increase in reaction temperature, the density decreases. [ABSTRACT FROM AUTHOR]

• The influence of various alkali on hydration and microstructure of HPGP was investigated. • Two opposite effects of alkali resulted by neutralization effect and ion strength effect on hydration of HPGP were observed. • Gypsum crystal morphology was significantly affected in alkaline environment except of excessive lime. • The influence effect of alkaline environment is related to its alkalinity and the impurity content in HPG. Although lime neutralization is widely recommended for raw phosphogypsum pretreatment, the influence mechanism of alkaline environment on hydration of hemihydrate phosphogypsum (HPG) is not clear. In the present paper, effect of alkaline environment created by different kinds of alkali including Mg(OH) 2 , NH 3 ·H 2 O, NaOH and Ca(OH) 2 with variable contents on hydration and microstructure of HPG were investigated. Abnormal setting and strength degradation were observed in the low-alkaline environment, while the setting time was normalized and crystal size developed in the high-alkaline environment regardless of the alkali category. Interestingly, the strength of HPG in the alkali environment only increased with excessive Ca(OH) 2. It is verified that the formation of Ca 3 (PO 4) 2 from neutralization reaction in the low-alkaline environment served as retarder, and the excessive alkali beyond the threshold value of neutralization reaction played as accelerator in the high-alkaline environment, while only excessive lime particles promoted the development of gypsum crystal at c axis probably due to its absorption of Ca 3 (PO 4) 2. This finding would promote the application of HPG in an alkaline environment and thus improve the utilization rate of phosphogypsum. [ABSTRACT FROM AUTHOR]

Surface runoff decrease (SRD) and sediment concentration change (SCC) are accountable for sediment reduction by anti-erosion strategies. Using a design of horizontal stages, contour trenches, fish-scale pits, as well as their combinations, this study evaluated the two components for sediment reduction after the implementation of various land management strategies on steep spoil tips. The study highlighted the interactions between SRD and SCC in reducing sediment, and characterized the temporal variations of sediment-reducing capacity by SRD and SCC. Results showed that slope erosion was well controlled with control ratios of sediment yield ranging from 0.4 to 0.59, 0.2 to 0.22, for horizontal stage- and contour trench-based strategies, respectively. Sediment-reducing benefit by SRD accounted for 52%–77% of the total sediment reduction and highly determined the performance of SCC. Quadratic relationships between sediment-reducing capacity by SCC and that by SRD were observed. The function of SCC only operated when the sediment-reducing capacity by SRD reached a certain threshold. These thresholds varied greatly in the range of 0.75 kg m−3–0.91 kg m−3 and 0.61 kg m−3–0.66 kg m−3 for horizontal stage- and contour trench-based strategies, respectively. The upper limits for sediment-reducing capacity by SCC varied in the range of 0.32 kg m−3–0.44 kg m−3 and 0.63 kg m−3–0.76 kg m−3 for horizontal stage- and contour trench-based strategies, respectively. An efficiency coefficient of 55% and an M - N ratio of 1:1 indicated that sediment-reducing benefits by SRD and SCC were effectively exerted by combining contour trenches and fish-scale pits. The findings emphasized that the application of land management strategies must be considered based on particular goals to restore spoil tips. In practice, if targeted to enhancing sediment-reducing efficiency, contour trenches and fish-scale pits should be primarily considered. However, if the aim is to decrease water consumed for sediment control, then horizontal stages should be principally considered. • Surface runoff decrement is responsible for the majority part of sediment reduction. • Contour trench-based measures performed better in managing sediment flow behavior. • The balance between soil- and water-conserving must be considered in practice. [ABSTRACT FROM AUTHOR]

The defect-free channels were frequently observed in irradiated materials, i.e. copper, as a result of the stacking fault tetrahedron (SFT) interactions with dislocations. However, the underlying mechanisms for this process are still unclear to date. To address them, a comprehensive study on the interactions between SFTs and mixed dislocations was performed using molecular dynamics simulations. In particular, eight interaction geometries were considered, in terms of the dislocation Burgers vector directions, dislocation gliding directions and intersection positions on SFT. Various interaction outcomes were revealed after dislocation detachment. (1) SFT is fully absorbed through the transformation into Lomer dislocations, and subsequently moves out of free surfaces along the dislocation. (2) SFT is partially absorbed with the absorbed SFT base moving out of free surfaces along the dislocation. (3) SFT is not absorbed but sheared with ledges left on the SFT faces. (4) SFT is unaffected by the mixed dislocation. The current simulations, especially the full SFT absorption, provide important insights into the forming mechanisms of defect-free channels in irradiated materials. [ABSTRACT FROM AUTHOR]

• New solar chimney design is proposed for aged care centers to avoid cross-infection. • Solar chimney performance present power function with typical design factors. • Its viability in avoiding cross-infection in aged care centers was confirmed. • It performs 6.4–14.8 air change per hour which fulfills the requirement by the WHO. • A theoretical model was developed for solar chimney in aged care center or similar. Natural ventilation is considered the first suggestion for COVID-19 prevention in buildings by the World Health Organization (WHO). Solar chimney's viability in aged care centers or similar facilities was analyzed numerically and theoretically. A new solar chimney design was proposed to reduce the cross-infection risk of COVID-19 based on an airflow path through window, ceiling vent, attic, and then chimney cavity. Solar chimney performance, quantified by the natural ventilation rate, presented power function with window area, ceiling vent area, cavity height, and solar radiation. The ceiling vent is suggested to be closer to the corridor to enhance the performance and ventilation coverage of the room. A cavity gap of 1.0 m is recommended to balance the ventilation performance and construction cost. A theoretical model was also developed for aged care centers with multiple rooms and a joint attic. Its predictions obey reasonably well with the numerical results. Solar chimney's viability in aged care center is confirmed as a 7.22 air change per hour (ACH) ventilation can be achieved even under a low solar radiation intensity of 200 W/m2, where its performance fulfills the minimal ventilation requirement (i.e. , 6 ACH) suggested by the WHO for airborne infection isolation rooms. This study offers a new design and a guideline for the future implementation of solar chimney in aged care centers or similar facilities. [ABSTRACT FROM AUTHOR]

The activity of sewage sludge ash (SSA) is not high; ground granulated blast slag (GGBS) has a high calcium oxide content that can accelerate polymerization rates and exhibit better mechanical performance. In order to improve the engineering application of SSA–GGBS geopolymer, it is necessary to conduct a comprehensive evaluation of its performance and benefits. In this study, the fresh properties, mechanical performance and benefits of geopolymer mortar with different SSA/GGBS, modulus and Na2O contents were studied. Taking the economic and environmental benefits, working performance and mechanical performance of mortar as evaluation indexes, the entropy weight TOPSIS (Technique for Order Performance by Similarity to Ideal Solution) comprehensive evaluation method is used to evaluate the geopolymer mortar with different proportions. The results show that as SSA/GGBS increases, the workability of mortar decreases, the setting time first increases and then decreases, and the compressive strength and flexural strength decrease. By appropriately increasing the modulus, the workability of the mortar decreases and more silicates are introduced, resulting in increased strength in the later stage. By appropriately increasing the Na2O content, the volcanic ash activity of SSA and GGBS is better stimulated, the polymerization reaction is accelerated, and the early strength increases. The highest I c (integrated cost index, C t f c 28 ) of geopolymer mortar is 33.95 CNY/m3/MPa, and the lowest is 16.21 CNY/m3/MPa, which is at least 41.57% higher than that of ordinary Portland cement (OPC). The minimum I e (embodied CO2 index, E c f c 28 ) is 6.24 kg/m3/MPa, rising up to 14.15 kg/m3/MPa, which is at least 21.39% lower than that of OPC. The optimal mix ratio is a water–cement ratio of 0.4, a cement–sand ratio of 1.0, SSA/GGBS of 2/8, a modulus content of 1.4, and an Na2O content of 10%. [ABSTRACT FROM AUTHOR]

Steel fiber reinforced geopolymer concrete (SFRGC) shows excellent mechanical properties comparable to steel fiber reinforced concrete. However, research on the durability of SFRGC is scarce. This paper presents the carbonation performances of SFRGC, including the carbonation depth and strength variation during carbonation. The results show that the permeability and carbonation depth of SFRGC are close to those of plain geopolymer concrete (GC). Their carbonation depths are much deeper than those of cement concrete because of the lower alkali content of the geopolymer matrix. Carbonation hardly influences the final flexural strength of plain GC, but the flexural strength of SFRGC declines significantly during carbonation because of the decrease in steel fiber-geopolymer matrix bond strength. The scanning electron microscope results show that the failure mode in uncarbonated SFRGC specimens is fiber rupture, while in carbonated SFRGC specimens, fiber pullout is the failure mode. These findings suggest that using SFRGC in the atmosphere is not recommended. [ABSTRACT FROM AUTHOR]

Using construction and demolition waste composites (CDWC) and fly ash (FA) to replace cement to produce concrete can reduce CO2 emissions. However, the CDWC-based geopolymer materials have two imperfections: the compressive strength is prone to decrease with the increase of curing age (strength shrinkage) under heat curing conditions, and the strength develops slowly under ambient curing conditions. To solve the problems of these materials, on the one hand, we designed an experiment of preparing CDWC-based geopolymer concrete (CDWGC) with pretreated CDWC at different high temperatures. We analyzed the influence of different pretreatment temperatures on the mechanical properties of CDWGC through compressive strength, SEM-EDS and XRD. On the other hand, we added CaO to improve the mechanical properties of CDWC-based geopolymer paste (CDWGP) under ambient curing conditions. Further, the CO2 emissions of pretreating CDWC and adding CaO were calculated by life cycle assessment (LCA). The results show that: (1) Pretreatment of CDWC can effectively solve the problem of CDWGC strength shrinkage. (2) The compressive strength of CDWGP cured at ambient can be significantly improved by adding CaO, and the compressive strength can be increased by 180.9% when the optimum content is 3%. (3) Adding CaO had less impact on CO2 emissions, a low-carbon way to improve its strength effectively. [ABSTRACT FROM AUTHOR]

Highlights: [•] The fatigue strength of welded joints in the corrugated steel web beams is evaluated. [•] The effect of transition curvature on the fatigue failure of the joints is identified. [•] The interaction of feature parameters on the joint stress concentration is analyzed. [•] An analytical approach for combined stresses is proposed to assess such joints. [Copyright &y& Elsevier]

Highlights: [•] Anatase-TiO2 doped with Gd, C, N and P was prepared by a sol–solvothermal method. [•] Enhanced photoactivity is ascribed to a synergetic effect of the quaternary doping. [•] Enhanced visible light absorption is due to its band-gap narrowed by N and P codoping. [•] The cooperative action of Gd and P further inhibits the charge carrier recombination. [•] The quaternary doped TiO2 has a superior photostability under sunlight irradiation. [ABSTRACT FROM AUTHOR]

Highlights: [•] High-performance Sm, N, P-tridoped TiO2 was prepared by a sol–solvothermal process. [•] Enhanced photoactivity is ascribed to a synergetic effect of Sm, N, P-tridoping. [•] Sm and P in TiO2 lattice further inhibit the recombination of photogenerated e−/h+. [•] OH in the solution is main reactive species in Sm, N, P-tridoped TiO2 suspension. [•] Sm, N, P-tridoped TiO2 photocatalyst exhibits superior photochemical stability. [ABSTRACT FROM AUTHOR]

Abstract: It was frequently observed in experiments that stacking fault tetrahedron (SFT) can be completely absorbed by dislocation and generate defect-free channels in irradiated materials, but the mechanism is still open. In this paper, molecular dynamics (MD) was used to explore the dislocation mechanism of reaction between SFT and screw dislocation in copper. Our computational results reveal that, at high temperature, the SFT is completely absorbed by screw dislocation with the help of Lomer–Cottrell (LC) lock transforming into Lomer dislocation. This complete absorption mechanism is very helpful to understand the defect-free channels in irradiated materials. [Copyright &y& Elsevier]

Although a combination of various (or types of) solar chimneys (SCs) can overcome the limitations of a solo system, the interactions, designing factors and overall performance in one building are still not known. Therefore, a combined wall and roof SCs were investigated both numerically and theoretically through this study. After being coupled with a roof SC, the performance of the wall SC is generally enhanced, which is quite stable when the designs of the roof solar chimney keep changing. The optimal designs of the wall SC are basically the same with those without coupling a roof SC. Furthermore, the window area shows an obvious impact on the roof SC but not the wall SC. Solar radiation offers an obviously positive effect on both the wall SC and the overall performance, while its impacts on the roof SC are relatively less obvious. The optimized design of the combined system can be achieved with specific designs, such as possibly big absorption walls for both chimneys, a big window, an appropriate level of cavity gap and air inlet height for the wall SC, a relatively small cavity gap for the roof SC, and a closer wall and roof SCs. A theoretical model is also developed to predict the airflow rates through both the wall and roof SCs. A coefficient, namely α, is proposed to describe the percentage of the airflow from the window to the wall SC. The predictions based on fixed α obey well with those numerical results. • Interaction between wall and roof solar chimneys (SCs) in a building is addressed. • Airflow bifurcation from the window to different chimney cavities is studied. • The impacts from the main influencing factors on SCs' performance were addressed. • Theoretical model is developed to predict the performance of both wall and roof SCs. • About 72% of the incoming airflow from the window enter the wall solar chimney. [ABSTRACT FROM AUTHOR]

• The hydration process of HPG in alkaline environment were analyzed by a muti-technique approach. • Both the dissolution of hemihydrate and crystallization of gypsum were frustrated in alkaline environment. • As an increase in pH, HPG plaster sets slow with a fall in strength. • The morphology of gypsum crystal in hydrated HPG plaster were modified contributing to loose microstructure. The hydration of hemihydrate phosphogypsum in the alkaline environment was investigated aiming to recycle phosphogypsum-a promising gypsum resource in gypsum-based materials that generally incorporated alkaline binders. Isothermal conduction calorimetry and transmission electron microscopy showed that the hydration reaction of hemihydrate phosphogypsum was significantly changed by alkali. Both the dissolution of hemihydrate particles and crystallization of gypsum were impeded, as a result of phosphate precipitation from neutralization reaction. Consequently, the setting times decreased with the increase of pH and the time span of heat liberation was extended. The impurities in hemihydrate phosphogypsum, especially phosphate, served as setting retarders and crystal modifiers in alkaline environment, contributing to loose crystal microstructure with lower strength. This important finding called for the extra attention to the utilization of hemihydrate phosphogypsum in an alkaline environment. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents experimental research on reinforced concrete (RC) beams with external flexural and flexural–shear strengthening by fibre reinforced polymer (FRP) sheets consisting of carbon FRP (CFRP) and glass FRP (GFRP). The work carried out has examined both the flexural and flexural–shear strengthening capacities of retrofitted RC beams and has indicated how different strengthening arrangements of CFRP and GFRP sheets affect behaviour of the RC beams strengthened. Research output shows that the flexural–shear strengthening arrangement is much more effective than the flexural one in enhancing the stiffness, the ultimate strength and hardening behaviour of the RC beam. In addition theoretical calculations are developed to estimate the bending and shear capacities of the beams tested, which are compared with the corresponding experimental results. [Copyright &y& Elsevier]

With increasing energy consumption in urban rail transit systems, researchers have paid significant attention to energy-saving train control. In this paper, we propose an effective train trajectory optimization method to reduce the energy consumption based on coasting control, in which coasting control regimes are added to balance running time and energy consumption. For better determining the starting points of coasting control regimes, the whole train running process is divided into several subintervals. Then, aiming to achieve energy efficiency, coasting regimes are added to the subintervals with high energy-saving effects, in which more energy consumption can be reduced with the same running time addition. Based on this, a coasting control method is proposed to generate energy-saving trajectories considering train dynamics, safety, and punctuality. In addition, the proposed method can solve the multisection energy-saving train trajectory optimization problem to obtain optimal running time schemes and related trajectories. Finally, numerical examples based on one of the Beijing metro lines are implemented to verify the effectiveness of the proposed method. The results show that, for the single-section train control problem, the proposed coasting control algorithm can achieve significant energy-saving effects compared to the practical trajectory and calculate energy-saving trajectory in shorter computation times compared to the dynamic programming method. Meanwhile, for the multisection train control problem, energy consumption can be further reduced by optimizing trajectories and running times integratedly. [ABSTRACT FROM AUTHOR]

Geopolymeric recycled concrete (GRC) is a new low-carbon building material that uses both construction and industrial solid waste to replace natural aggregate and cement. GRC is similar to geopolymeric concrete (GPC) in that it has good mechanical properties but needs to be improved in terms of frost resistance. Previous studies have shown that polyoxymethylene fiber (POM fiber) can improve the shrinkage and durability of concrete and is superior to other commonly used fibers. Therefore, this paper explores adding POM fiber to GRC to improve its frost resistance. In this paper, the influence of different volumes and lengths of POM fiber on the frost resistance of geopolymeric recycled concrete (PRGRC) is studied. By measuring the changes in mass loss rate, relative dynamic elastic modulus, and compressive strength of PRGRC under different cycles, the improvement effect of POM fiber on the freeze-thaw damage of GRC is analyzed, and the strength attenuation model of PRGRC is established. The results show that the increase in POM fiber content can effectively slow down the mass loss of PRGRC in the freeze-thaw cycles, the reduction rate of relative dynamic elastic modulus, and the reduction rate of compressive strength. This shows that POM fiber can effectively improve the frost resistance of PRGRC, and the effect of 6 mm POM fiber on the freeze-thaw damage of PRGRC is better than 12 mm POM fiber. According to the test results, the existing strength attenuation model is further modified, the attenuation model of PRGRC compressive strength under the freeze-thaw cycle is obtained, and the model fitting effect is good. The strengthening mechanism of POM fiber is explained by the structural relationship between POM fiber and concrete matrix in the SEM micrograph of PRGRC. The research results provide a scientific basis for the applicability of POM fiber in geopolymeric cementitious materials and improving the frost resistance of PRGRC. [ABSTRACT FROM AUTHOR]

[Display omitted] • The spectral reshaping intermediate structure on silicon substrate with simple fabrication process. • The hierarchical Si NW absorber exhibits an excellent optical absorption performance from 220 nm to 1100 nm and a lower emittance above 1100 nm. • The Si-W-SiN/SiNO multilayer emitter shows a selective narrowband absorption (i.e., emission) peak in the target wavelength and low thermal radiation loss in long wave range. • The overall efficiency of the whole STPV system is precisely optimized by varying emitter parameters and system parameters. • At achievable light concentration intensity of 1000, the STPV system efficiency can exceed 29% using this integrated silicon-based intermediate structure. Solar thermophotovoltaics (STPV) system is a technique that uses absorber and emitter to remold wide-band solar radiation into narrowband infrared emission and then convert it into electric energy in order to get high energy conversion efficiency. In this study, we fabricated an integrated silicon-based intermediate structure to enable the spectral reshaping. The absorber is a hierarchical Si NW structure, which exhibits excellent absorption performance of over 95 % in the spectral range of 220–1100 nm and a low heat loss in the long-wavelength band. The emitter is planar Si-W-SiN/SiNO structure, exhibiting a selective narrowband absorption (i.e., emission) peak in the target wavelength. When the emission peak of emitter is at 1800 nm, the overall efficiency of the STPV system based on this silicon-based intermediate structure can theoretically exceed 29 % with an achievable solar concentration of 1000 and an emitter-to-absorber area ratio of 4. We also test the prepared spectral reshaping intermediate structures on real systems and discuss further optimizations. [ABSTRACT FROM AUTHOR]

Thermal emitters with properties of wavelength-selective and narrowband have been highly sought after for a variety of potential applications due to their high energy efficiency in the mid-infrared spectral range. In this study, we theoretically and experimentally demonstrate the tunable narrowband thermal emitter based on fully planar Si-W-SiN/SiNO multilayer, which is realized by the excitation of Tamm plasmon polaritons between a W layer and a SiN/SiNO-distributed Bragg reflector. In conjunction with electromagnetic simulations by the FDTD method, the optimum structure design of the emitter is implemented by 2.5 periods of DBR structure, and the corresponding emitter exhibits the nearly perfect narrowband absorption performance at the resonance wavelength and suppressed absorption performance in long wave range. Additionally, the narrowband absorption peak is insensitive to polarization mode and has a considerable angular tolerance of incident light. Furthermore, the actual high-quality Si-W-SiN/SiNO emitters are fabricated through lithography-free methods including magnetron sputtering and PECVD technology. The experimental absorption spectra of optimized emitters are found to be in good agreement with the simulated absorption spectra, showing the tunable narrowband absorption with all peak values of over 95%. Remarkably, the fabricated Si-W-SiN/SiNO emitter presents excellent high-temperature stability for several heating/cooling cycles confirmed up to 1200 K in Ar ambient. This easy-to-fabricate and tunable narrowband refractory emitter paves the way for practical designs in various photonic and thermal applications, such as thermophotovoltaic and IR radiative heaters. [ABSTRACT FROM AUTHOR]

A marine heatwave (MHW) can significantly harm marine ecosystems and fisheries. Based on a remotely sensed sea surface temperature (SST) product, this study investigated MHWs behaviors in the South China Sea (SCS) throughout the warm season (May to September) from 1982 to 2020. The distributions of the three MHW indices used in this study showed significant latitudinal variations: more frequent, longer, and more intense MHWs appear in the northern SCS, and less frequent, shorter, and weaker MHWs appear in the southern SCS. Using the empirical orthogonal function (EOF) method, we found that the first leading modes of the three MHW indices account for more than half of the total variance. The first leading modes reveal uniform anomalies throughout the SCS, with the maximum in the deep central portion and its surroundings. Their corresponding time series showed significant interdecadal variations, with a turning point around 2009. Since 2010, the SCS has seen an increase in the frequency, length, and severity of MHWs. The incidence of MHWs has been linked to the presence of stable near-surface anticyclonic anomalies, which reduced cloud cover and increased solar radiation. This abnormal pattern was usually accompanied by the intensification and westward shift of the western North Pacific subtropical high (WNPSH). The findings imply that MHWs in the SCS may be predictable on interannual and decadal scales. [ABSTRACT FROM AUTHOR]

A high‐efficiency millimetre‐wave spatial power combining structure that is a waveguide power combining network is proposed. High phase and amplitude consistency and isolation between the output ports are the key factors for the high‐efficiency power combining structure. The phase and amplitude consistency is guaranteed by the symmetry of this structure. As a sample, an eight‐way power splitting and combining network in the Ka‐band is designed, fabricated and measured. In a fractional bandwidth of 20% around a centre frequency of 33 GHz, the measured results show that the phase and amplitude differences between the output ports are smaller than ±1.5° and ±0.1 dB, isolation between the output ports is higher than 17 dB, insertion loss is lower than 0.1 dB, and the return loss of the input and output ports is better than 18 dB. The proposed broadband eight‐way power combining network can improve the spatial power combining efficiency to a great extent with excellent performance. [ABSTRACT FROM AUTHOR]