Enhanced mechanical properties and interface structure characterization of W-La₂O₃ alloy designed by an innovative combustion-based approach

Chen, Pengqi,Xu, Xian,Wei, Bangzheng,Chen, Jiayu,Qin, Yongqiang,Cheng, Jigui Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.5

Oxide dispersion strengthening (ODS) tungsten alloys are highly desirable in irradiation applications. However, how to improve the properties of ODS-tungsten alloys efficiently has been worth studying for a long time. Here we report a nanostructuring approach that achieves W-La₂O₃ alloy with a high level of flexural strength and Vickers hardness at room temperature, which have the maximum value of 581 MPa and 703 Hv, respectively. This method named solution combustion synthesis (SCS) can generate 30 nm coating structures W-La₂O₃ composite powders by using Keggin-type structural polyoxometalates as raw materials in a fast and low-cost process. The composite powder can be fabricated to W-La₂O₃ alloy with an optimal microstructure of submicrometric W grains coexisting with nanometric oxide particles in the grain interior, and a stability interface structure of grain boundaries (GBs) by forming transition zones. The method can be used to prepare new ODS alloys with excellent properties in the future.

Magnetic Flux Leakage Image Enhancement using Bidimensional Empirical Mode Decomposition with Wavelet Transform Method in Oil Pipeline Nondestructive Evaluation

Liang Chen,Jingcheng Li,Yakai Zeng,Yongqiang Chen,Wei Liang 한국자기학회 2019 Journal of Magnetics Vol.24 No.3

The magnetic flux leakage (MFL) method is the most widely used and cost-effective inspection technique for oil pipeline. However, noise is inevitable in the process of data collection; thus, the image enhancement method can be more intuitive to identify the defects in an oil pipeline MFL inspection. In this paper, the bidimensional empirical mode decomposition (BEMD) method has been used to study oil pipeline MFL images. The MFL image is decomposed into a finite number of two-dimensional intrinsic mode functions (BIMF) and a residual component by the BEMD. The wavelet transform (WT) was used to remove the noise in the BIMF. The image was then reconstructed by retaining the basic information and removing the noise. The results show that the noise is effectively removed and the detail of the MFL image is well preserved. Thus, the BEMD with WT method for oil pipeline MFL image enhancement is better than the mean filtering method and the WT method.

The Hardware Cost and Computing Accuracy Trade-off in Multipliers using Imprecise 4-2 Compressors for Image Processing Applications

Yongqiang Zhang,Cong He,Xiaoyue Chen,Guangjun Xie 대한전자공학회 2022 IEIE Transactions on Smart Processing & Computing Vol.11 No.3

Approximate computing has been widely used in image processing applications to significantly reduce the hardware cost of circuits; however, this induces a sacrifice in computing accuracy. The compromise between accuracy and hardware cost in approximate multipliers has not been investigated yet. To address this issue, this paper proposes a set of approximate 8×8 Dadda multipliers built by using an efficient imprecise 4-2 compressor. The compressor introduces symmetrical errors into the truth table of the exact design to reach a simpler structure. Furthermore, as an important image processing application, image multiplication is implemented with the proposed multipliers. Synthesis and simulation results show that the overall performance of the multipliers varies depending on the various assessment criteria. Utilization of the modified compressor in the multipliers results in area, delay, and power reductions of 38%-72%, 14%-33%, and 39%-77%, respectively, compared to the exact design, while maintaining acceptable computing accuracy in image multiplication. According to the results, the proposed multipliers achieve a better trade-off between energy efficacy and computing accuracy than the existing designs, which could be certified as options for exact multipliers in image processing.

Novel Robust High Dynamic Range Image Watermarking Algorithm Against Tone Mapping

( Yongqiang Bai ),( Gangyi Jiang ),( Hao Jiang ),( Mei Yu ),( Fen Chen ),( Zhongjie Zhu ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.9

High dynamic range (HDR) images are becoming pervasive due to capturing or rendering of a wider range of luminance, but their special display equipment is difficult to be popularized because of high cost and technological problem. Thus, HDR images must be adapted to the conventional display devices by applying tone mapping (TM) operation, which puts forward higher requirements for intellectual property protection of HDR images. As the robustness presents regional diversity in the low dynamic range (LDR) watermarked image after TM, which is different from the traditional watermarking technologies, a concept of watermarking activity is defined and used to distinguish the essential distinction of watermarking between LDR image and HDR image in this paper. Then, a novel robust HDR image watermarking algorithm is proposed against TM operations. Firstly, based on the hybrid processing of redundant discrete wavelet transform and singular value decomposition, the watermark is embedded by modifying the structure information of the HDR image. Distinguished from LDR image watermarking, the high embedding strength can cause more obvious distortion in the high brightness regions of HDR image than the low brightness regions. Thus, a perceptual brightness mask with low complexity is designed to improve the imperceptibility further. Experimental results show that the proposed algorithm is robust to the existing TM operations, with taking into account the imperceptibility and embedded capacity, which is superior to the current state-of-art HDR image watermarking algorithms.

A Compensated Software Reliability Model Based on Unascertained Rational Number

Yongqiang Zhang,Wen Chen,Huizhen Yan 한국멀티미디어학회 2006 한국멀티미디어학회 국제학술대회 Vol.2006 No.-

The software reliability model based on unascertained ration number has unique superiority. It does not have any assumption about software fault process. Moreover, its algorithm is simple, and it avoids derivation of nonlinear equations set. But the characteristic of the algorithm itself determines that the estimation of this model is the pessimistic estimation. In this view, this paper makes some improvement to this model, and puts forward the compensated software reliability model based on unascertained rational number, which make the model have wider applicability and suit the reliability growth feature better.

Proteome Analysis on Lethal Effect of l2 in the Sex-linked Balanced Lethal Strains of Silkworm, Bombyx mori

Jine Chen,Baolong Niu,Yongqiang Wang,Yan Liu,Peigang Liu,Zhiqi Meng,Boxiong Zhong 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.2

The sex-linked balanced lethal (SLBL) strains of silkworm serve as an effective system for sex-control in silkworm. To gain comprehensive insight into the effect of one sex-linked balanced lethal gene l2, comparative proteomic analysis was carried out between the survival embryos (W +l 1 Z l 1 +l 2 ) and lethal embryos (W +l 1 Z l 1 +l 2 ) before the lethal stage. The lethal stage of l2 was confirmed by observing the typical dead embryo morphology. The two genotype embryos before lethal stage were distinguished using polymorphic simple sequence repeats (SSR) markers closely linked to l2 on the sex chromosome. Finally, 11 differentially expressed protein spots were successfully identified by MALDI-TOF/TOF mass spectrometry (MS). Among them,only 1 protein identified as heat shock protein 20.4(HSP20.4) was up-regulated in the lethal embryos, while the other 10 were down-regulated. The up-regulation of HSP20.4 suggests that there may be abnormal polypeptides produced in the lethal embryos. The gene ontology (GO)annotation indicated those down-regulated proteins are involved in important biological processes including embryo development, nucleoside metabolism, tRNA splicing, translation and protein folding. The biological pathway analysis showed that those down-regulated proteins are mainly involved in spindle assemblage and morphogenesis. Based on our results, we suggest that the l2 may be the mutant expressing abnormal polypeptides. Its expression has a negative effect on mitosis and morphogenesis processes. The death of the embryos may be caused by the accumulation of abnormal polypeptides and the handicap of cell proliferation and morphogenesis.

Extraction of valuable components from coal gangue through thermal activation and HNO3 leaching

Shuang Shao,Baozhong Ma,Chengyan Wang,Yongqiang Chen 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.113 No.-

Coal gangue has the dual attributes of hazard and resource. With the increasing awareness of resourcesconservation and ecological sustainability, the high-value utilization of coal gangue has attracted activeattention. In this research, thermal activation followed by HNO3 leaching were performed to extract valuablecomponents from coal gangue. Firstly, the activation behavior and phase transformation mechanismduring thermal activation were revealed through the Gibbs free energy calculation and experimentalresearch. After activation, inert kaolinite was converted to active metakaolinite. Subsequently, thepotential-pH diagrams analyses confirmed that the strategy of extracting Al, Ga, and Li into the leachliquor while precipitating Fe into the leach residue was feasible. Meanwhile, systematic leaching experimentsshowed that 95.2% of Al, 56.4% of Ga, and 80.5% of Li were extracted, while only 2.1% of Fe wasdissolved at the optimal conditions. The leaching behavior of each component agreed well with the thermodynamicanalysis. Finally, the raw ore, activated product, and leach residue were analyzed via a suiteof characterization techniques. In contrast to the raw ore and activated product, the leach residue hadlarge BET surface area and high available Si content, and was a promising Si fertilizer source. This studyprovides a useful reference for the high-value utilization of coal gangue.

Effects of heat stress on body temperature, milk production, and reproduction in dairy cows: a novel idea for monitoring and evaluation of heat stress — A review

Jiangjing Liu,Lanqi Li,Xiaoli Chen,Yongqiang Lu,DONG WANG 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.9

Heat stress exerts a substantial effect on dairy production. The temperature and humidity index (THI) is widely used to assess heat stress in dairy operations. Herein, we review the effects of high temperature and humidity on body temperature, feed intake, milk production, follicle development, estrous behavior, and pregnancy in dairy cows. Analyses of the effects of THI on dairy production have shown that body temperature is an important physiological parameter in the evaluation of the health state of dairy cows. Although THI is an important environmental index and can help to infer the degree of heat stress, it does not reflect the physiological changes experienced by dairy cows undergoing heat stress. However, the simultaneous measurement of THI and physiological indexes (e.g., body temperature) would be very useful for improving dairy production. The successful development of automatic detection techniques makes it possible to combine THI with other physiological indexes (i.e., body temperature and activity), which could help us to comprehensively evaluate heat stress in dairy cows and provide important technical support to effectively prevent heat stress.

Factors Associated with Echinococcosis-Induced Perioperative Anaphylactic Shock

Jianrong Ye,Qin Zhang,Yan Xuan,Siyu Chen,Long Ma,Yongqiang Zhang,Hong Zheng 대한기생충학열대의학회 2016 The Korean Journal of Parasitology Vol.54 No.6

An effective method for directly extracting lithium from a-spodumene by activated roasting and sulfuric acid leaching

Yuqing Zhang,Baozhong Ma,Yingwei Lv,Chengyan Wang,Yongqiang Chen 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.122 No.-

The global trend toward electrification has encouraged lithium’s market position to grow prominently. Spodumene is the focus of lithium extraction owing to its abundant lithium resources. In this study, anovel lithium extraction method was proposed for a-spodumene by combining activated roasting andsulfuric acid leaching. First, the thermodynamics of the roasting process demonstrated that aspodumenewas converted into b-spodumene, which reacted with CaO to produce acid-solubleLiAlSiO4 and CaSiO3 concurrently. The addition of CaO reduced the melting temperature, which promotedthe structural transformation of b-spodumene and further acid leaching. Then, the influences of variousfactors on lithium extraction were investigated by a single-factor test. A lithium leaching yield of 96.18%was obtained under optimum conditions: 20% CaO, roasting temperature of 1200 C, holding time of1.5 h, H2SO4 concentration of 120 g/L, liquid–solid ratio of 7:1 mL/g, leaching temperature of 80 Cand leaching time of 1.5 h. Finally, Li entered into leach liquor by the action of sulfuric acid, and the maincomponents of the leach residue were silicate and calcium sulfate. Compared to the conventional acidapproach, this method has a higher lithium recovery and lower energy and acid consumption (decreaseby approximately 0.42 kg/ kg).