Deep hashing methods utilize an end-to-end framework to mutually learn feature representations and hash codes, thereby achieving a better retrieval performance. Traditional supervised hashing methods ...adopt handcrafted features for hashing function learning and then generate hash codes through classification and quantization. The lack of adaptability and independence of the quantization procedure leads to low retrieval accuracy of supervised hashing methods with handcrafted features in image retrieval. In this study, a non-relaxation deep hashing method for fast image retrieval is proposed. In this method, a differentiable host thresholding function is used to encourage hash-like codes to approach -1 or 1 non-linearly at the output of the convolutional neural, instead of the symbol function for quantization used in the traditional method. The output of the host thresholding function is directly used to compute the network training error, and a loss function is elaborately designed with the norm to constrain each bit of the hash-like code to be as binary as possible. Finally, a symbol function is added outside the trained network model to generate binary hash codes for image storage and retrieval in a low-dimensional binary space. Extensive experiments on two large-scale public datasets show that our method can effectively learn image features, generate accurate binary hash codes, and outperform state-of-the-art methods in terms of the mean average precision.
Thermal conductive polymer composites attract lots of research due to the continuous miniaturization and multi-function of electronic equipment. As a common ceramic, Al2O3 owns relatively high ...thermal conductivity, high electrical resistivity and satisfactory cost performance, which is considered as the high-quality filler to prepare thermal conductive and electrical insulated composites. This paper reviews current progress in the development of Al2O3 reinforced polymer composites. We firstly summarize the preparation methods of spherical Al2O3, then heat conduction mechanisms and main factors affecting thermal conductivity are introduced. Next, we focus on the common research of Al2O3 in improving the thermal conductivity of polymers, including surface modification, filler hybridization and construction of Al2O3 network by various processing methods, and some emerging applications of thermal conductive polymer composites are introduced subsequently. After a critique of recent studies, we identify several outstanding issues must be addressed if higher thermal conductivity is fully realized.
•REEs in cultivated soil and vegetables in vicinity of mining site has been studied.•Farmlands are contaminated seriously due to REEs mining production.•Accumulation levels of REEs differ ...significantly among vegetable species.•Elevated concentration of REEs in human hair and blood is associated with soil.•Local residents around mining site suffer from higher exposure level of REEs.
Contaminated food through dietary intake has become the main potential risk impacts on human health. This study investigated concentrations of rare earth elements (REEs) in soil, vegetables, human hair and blood, and assessed human health risk through vegetables consumption in the vicinity of a large-scale mining area located in Hetian Town of Changting County, Fujian Province, Southeast China. The results of the study included the following mean concentrations for total and bio-available REEs of 242.92±68.98 (135.85–327.56)μgg−1 and 118.59±38.49 (57.89–158.96)μgg−1 dry weight (dw) in agricultural soil, respectively, and total REEs of 3.58±5.28 (0.07–64.42)μgg−1 dw in vegetable samples. Concentrations of total REEs in blood and hair collected from the local residents ranged from 424.76 to 1274.80μgL−1 with an average of 689.74±254.25μgL−1 and from 0.06 to 1.59μgg−1 with an average of 0.48±0.59μgg−1 of the study, respectively. In addition, a significant correlation was observed between REEs in blood and corresponding soil samples (R2=0.6556, p<0.05), however there was no correlation between REEs in hair and corresponding soils (p>0.05). Mean concentrations of REEs of 2.85 (0.59–10.24)μgL−1 in well water from the local households was 53-fold than that in the drinking water of Fuzhou city (0.054μgL−1). The health risk assessment indicated that vegetable consumption would not result in exceeding the safe values of estimate daily intake (EDI) REEs (100−110μgkg−1d−1) for adults and children, but attention should be paid to monitoring human beings health in such rare earth mining areas due to long-term exposure to high dose REEs from food consumptions.
Determination of the key vertical level for cloud condensation nuclei concentration (CCNC) explosions has been a long‐term issue in CCN‐cloud interaction studies. An idealized hailstorm is simulated ...with 37 sensitivity runs, including an initial CCNC grouping vertically from the ground to the cloud top, increasing from 100 to 3,000 mg−1. The results reveal a key zone from 750 to 800 hPa near the median boundary layer, where an explosion of CCNC plays a dominant role in the nonmonotonic response of the hail precipitation rate. The explosion of CCNC in this zone could initially result in the condensation of more water vapor into the clouds, which could be transported to a greater vertical extent to significantly affect the riming collection efficiency. However, the dominant zone for the total precipitation rate is wider at heights of 700–800 hPa due to the lower sensitivity of the riming collection efficiency.
Plain Language Summary
Aerosols can serve as cloud condensation nuclei (CCN) in the atmosphere, affecting convective clouds, including hailstorms; however, due to their uneven vertical distribution, aerosols are a largely uncertain factor when predicting future climate change. Exploration of the key vertical layer induced by CCN during hail precipitation is an increasingly popular research topic to reduce uncertainty in future convection assessments and to operating accurately during weather modification. In this work, by comparing idealized cloud‐resolving numerical experiments with CCNC explosions in different layers, the 750–800 hPa height, that is, near the base of convective clouds, is the most sensitive zone for determining the effects of CCN on hail. This layer is narrower than that for rain, indicating greater difficulty in predicting hail within an uncertain vertical distribution of aerosols compared to rainfall. Thus, this study advances the understanding of how air pollution impacts the hail formation.
Key Points
Hail precipitation is highly sensitive to the explosion of cloud condensation nuclei concentration in different vertical layers
The exploded cloud condensation nuclei concentration near the median boundary layer controls the sensitivity of hail precipitation
The dominant vertical zone of the cloud condensation nuclei concentration effect on hail is narrower than that on rain
Left bundle branch area pacing (LBBAP), a new pacing approach, lacks adequate evaluation.
To assess the feasibility, safety, and acute effect of permanent LBBAP in patients with atrioventricular ...block (AVB).
A total of 33 AVB patients with indications for ventricular pacing were recruited. Electrocardiograms, pacing parameters, echocardiographic measurements, and complications associated with LBBAP were evaluated perioperatively and at 3-month follow-up. Successful LBBAP was defined as a paced QRS morphology of right bundle branch block pattern in lead V
and QRS duration (QRSd) less than 130 ms.
LBBAP was successfully performed in 90.9% (30/33) of patients (mean age: 55.1 ± 18.5 years; 66.7% male). The mean capture threshold was similar during the procedure (0.76 ± 0.26 V at 0.4 ms) and at the 3-month follow-up (0.64 ± 0.20 V at 0.4 ms). The paced QRSd was 112.8 ± 10.9 ms during the procedure and 116.8 ± 10.4 ms at the 3-month follow-up. Baseline left or right bundle branch block was corrected (intrinsic QRSd 153.3 ± 27.8 ms vs paced QRSd 122.2 ± 9.9 ms) with a success rate of 68.7% (11/16). One ventricular septal lead perforation occurred soon after the procedure with characteristics of pacing failure, and lead revision was successful. Cardiac function and left ventricular synchronization by 2-dimensional echocardiographic strain imaging at the 3-month follow-up slightly improved compared with that at baseline.
Permanent LBBAP yielded a stable threshold, a narrow QRSd, and preserved left ventricular synchrony with few complications. Our preliminary results indicate that LBBAP holds promise as an attractive physiological pacing strategy for AVB.
Elevated glycolysis remains a universal and primary character of cancer metabolism, which deeply depends on dysregulated metabolic enzymes. Lactate dehydrogenase A (LDHA) facilitates glycolytic ...process by converting pyruvate to lactate. Numerous researches demonstrate LDHA has an aberrantly high expression in multiple cancers, which is associated with malignant progression. In this review, we summarized LDHA function in cancer research. First, we gave an introduction of structure, location, and basic function of LDHA. Following, we discussed the transcription and activation mode of LDHA. Further, we focused on the function of LDHA in cancer bio‐characteristics. Later, we discussed the clinical practice of LDHA in cancer prevention and treatment. What we discussed gives a precise insight into LDHA especially in cancer research, which will contribute to exploring cancer pathogenesis and its handling measures.
LDHA contributes to diverse bio‐characteristics of tumors via numerous mechanisms. LDHA has been used as a tumor biomarker for clinical diagnosis and treatment and is considered as a potential anticancer target.
Effective heat dissipation has become a critical issue for electronic devices. In this study, the silicone rubber (SR)/vertically aligned boron nitride (BN) composites were prepared and the thermal ...conductivity of the composites was systematically investigated. The vertically aligned BNs constructed effective vertical thermal conductive pathways in the SR matrix, and the SR/ABN composites exhibited much higher through-plane thermal conductivity compared to the non-orientated SR/BN composite. The through-plane thermal conductivity of SR/ABN150 reached 5.4 W m−1 K−1, which was ~6.3 and ~33 times higher than those of SR/BN150 and pure SR, respectively. In addition, the surface thermal infrared analysis also indicates that the vertically aligned SR/ABN composites possess excellent heat transfer capacity during the heating and cooling processes. The obtained results exhibit the potential for the design and preparation of thermal interface materials (TIMs) with high through-plane thermal conductivity to be applied in thermal conductive and electrical insulating field.
Display omitted
•Through-plane aligned boron nitrides were constructed in silicone rubber matrix.•High through-plane thermal conductivity of silicone rubber composites was obtained.•Excellent heat dissipation and good electrical insulation were achieved for silicone rubber/aligned boron nitride composites.
Maximum power transfer is an important index for an inductive power transfer (IPT) system to make full use of its power transfer capability, and such a capability is usually realized by impedance ...matching. Traditionally, impedance matching is implemented by placing a power electronics converter such as a dc-dc converter at the secondary side of an IPT system. However, the power electronics converter and its operation mode directly affect its impedance-matching range, which is very limited if a traditional power converter only operates at continuous conduction mode (CCM). To extend the impedance-matching range, this paper proposes a novel impedance matching method based on combined CCM and discontinuous conduction mode (DCM) operation of an impedance matching converter. The impedance-matching range is fully analyzed for CCM and DCM operation, respectively, by taking variation of coupling coefficient into consideration. The analysis results show that the impedance-matching range can be extended by more than double that of the traditional impedance matching method. In addition, a maximum power transfer tracking method is developed using the proposed impedance-matching range extension method, and the experimental results have verified the feasibility of the tracking method.
PDF
