期刊文献+
共找到1,038篇文章
< 1 2 52 >
每页显示 20 50 100
Effects of Using Softwood Pellet Biochar Prepared at Different Temperatures with Grass Chippings on Retention of Heavy Metals in Contaminated Soils
1
作者 Kyari Umar Dunoma Limin Ma +14 位作者 Xingquan Shu Haiyan Yu Weiwei Zhang Chengcheng Bu Yong-Sik Wang Jiahong Luo Guangyao Chen Jinpeng Yu Ru Zhang Yuchen Han Haoyu Zeng Matthew S. Wisseh Amina Grema Mustafa Mohammad Auwal Saidu Mufidat Mamman Khan 《Open Journal of Polymer Chemistry》 2024年第3期146-166,共21页
Heavy metals have been viewed as hazardous environmental pollutants, and anthropogenic activities due to their high toxicity and persistent nature in the environment. Anthropogenic activities such as artisanal mining,... Heavy metals have been viewed as hazardous environmental pollutants, and anthropogenic activities due to their high toxicity and persistent nature in the environment. Anthropogenic activities such as artisanal mining, industrial activities, improper usage of fertilizers and pesticides, and indiscriminate open waste disposal bring about an increase in the presence of heavy metals in the environment. In the Keffi Metropolis, different elements lead to land contamination which debilitates soil quality, plant survival, human well-being, and the environment as a result of extensive dispersion or quantity of heavy metals in the soil and water. In recent years, biochar has emerged as a promising soil amendment for mitigating heavy metal pollution due to its unique physicochemical properties. This paper provides the effects of softwood pellet biochar on the retention of heavy metals in contaminated soils. A microcosm experiment was carried out to investigate the effects of biochar on the retention of heavy metals in contaminated soils. This research aimed to give an overview of the effects of softwood biochar at different temperatures (550˚C and 700˚C) on the retention of heavy metals and metalloids released from the soil during water inundation. The results show that the addition of organic matter (grass chippings) minimizes heavy metal mobilization. Also, biochar at high temperatures is more effective than those at low temperatures. The expected outcome of the research analysis includes providing insights into the role of biochar in retaining heavy metal contamination and further understanding the use of biochar as a sorbent for the management of contaminated soil. 展开更多
关键词 Softwood Biochar Heavy Metal Contaminated Soil Grass Chips Keffi Metropolis MICROCOSM
下载PDF
EFFECT OF STONE POWDER ON STONE CHIPPINGS CONCRETE 被引量:25
2
作者 周明凯 彭少明 +1 位作者 徐健 朱承华 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1996年第4期29-34,共6页
In this paper, the effect and mechanism of calcareous stone powder with size less than 0.074 mm are investigated in stone chippings concrete. The results show that the stone powder can participate in hydration reactio... In this paper, the effect and mechanism of calcareous stone powder with size less than 0.074 mm are investigated in stone chippings concrete. The results show that the stone powder can participate in hydration reaction and acts as crystal nucleus in hydration process, namely, it has hydration activity to an extent. The strength of stone chippings concrete is enhanced and the easy-mixing capacity of the concrete mortar is modified when stone chippings contain a proper amount of stone powder. The stone powder has little effect on the wearability of the concrete. 展开更多
关键词 calcareous stone powder stone chippings CONCRETE cement hydration APPLICATION
下载PDF
GPGPU-parallelised hybrid finite-discrete element modelling of rock chipping and fragmentation process in mechanical cutting 被引量:8
3
作者 Mojtaba Mohammadnejad Sevda Dehkhoda +2 位作者 Daisuke Fukuda Hongyuan Liu Andrew Chan 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2020年第2期310-325,共16页
Mechanical cutting provides one of the most flexible and environmentally friendly excavation methods.It has attracted numerous efforts to model the rock chipping and fragmentation process,especially using the explicit... Mechanical cutting provides one of the most flexible and environmentally friendly excavation methods.It has attracted numerous efforts to model the rock chipping and fragmentation process,especially using the explicit finite element method(FEM) and bonded particle model(BPM),in order to improve cutting efficiency.This study investigates the application of a general-purpose graphic-processing-unit parallelised hybrid finite-discrete element method(FDEM) which enjoys the advantages of both explicit FEM and BPM,in modelling the rock chipping and fragmentation process in the rock scratch test of mechanical rock cutting.The input parameters of FDEM are determined through a calibration procedure of modelling conventional Brazilian tensile and uniaxial compressive tests of limestone,A series of scratch tests with various cutting velocities,cutter rake angles and cutting depths is then modelled using FDEM with calibrated input parameters.A few cycles of cutter/rock interactions,including their engagement and detachment process,are modelled for each case,which is conducted for the first time to the best knowledge of the authors,thanks to the general purpose graphic processing units(GPGPU) parallelisation.The failure mechanism,cutting force,chipping morphology and effect of various factors on them are discussed on the basis of the modelled results.Finally,it is concluded that GPGPU-parallelised FDEM provides a powerful tool to further study rock cutting and improve cutting efficiencies since it can explicitly capture different fracture mechanisms contributing to the rock chipping as well as chip formation and the separation process in mechanical cutting.Moreover,it is concluded that chipping is mostly owed to the mix-mode Ⅰ-Ⅱ fracture in all cases although mode Ⅱ cracks and mode Ⅰ cracks are the dominant failures in rock cutting with shallow and deep cutting depths,respectively.The chip morphology is found to be a function of cutter velocdty,cutting depth and cutter rake angle. 展开更多
关键词 Numerical simulation Finite-discrete element method(FDEM) ROCK CUTTING chipping Cracking
下载PDF
Hard rock tunnel boring machine penetration test as an indicator of chipping process efficiency 被引量:4
4
作者 M.C. Villeneuve 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2017年第4期611-622,共12页
The transition from grinding to chipping can be observed in tunnel boring machine(TBM) penetration test data by plotting the penetration rate(distance/revolution) against the net cutter thrust(force per cutter) over t... The transition from grinding to chipping can be observed in tunnel boring machine(TBM) penetration test data by plotting the penetration rate(distance/revolution) against the net cutter thrust(force per cutter) over the full range of penetration rates in the test.Correlating penetration test data to the geological and geomechanical characteristics of rock masses through which a penetration test is conducted provides the ability to reveal the efficiency of the chipping process in response to changing geological conditions.Penetration test data can also be used to identify stress-induced tunnel face instability.This research shows that the strength of the rock is an important parameter for controlling how much net cutter thrust is required to transition from grinding to chipping.It also shows that the geological characteristics of a rock will determine how efficient chipping occurs once it has begun.In particular,geological characteristics that lead to efficient fracture propagation,such as fabric and mica contents,will lead to efficient chipping.These findings will enable a better correlation between TBM performance and geological conditions for use in TBM design,as a basis for contractual payments where penetration rate dominates the excavation cycle and in further academic investigations into the TBM excavation process. 展开更多
关键词 Penetration rate GRINDING chipping Geological characteristics Face stability
下载PDF
超宽带穿墙雷达压缩感知成像中chipping序列的设计
5
作者 潘龙 晋良念 《大众科技》 2014年第4期12-16,共5页
在超宽带穿墙雷达压缩感知成像中,常常使用Rademacher序列作为模拟信息转换器的chipping序列。而这种序列的功率谱类似于高斯白噪声的功率谱,它与回波信号的功率谱不匹配,导致低速采样前信号的信噪比偏低,最终影响了成像效果。文章... 在超宽带穿墙雷达压缩感知成像中,常常使用Rademacher序列作为模拟信息转换器的chipping序列。而这种序列的功率谱类似于高斯白噪声的功率谱,它与回波信号的功率谱不匹配,导致低速采样前信号的信噪比偏低,最终影响了成像效果。文章从低速采样前的平均信噪比最大化入手,构建设计匹配chipping序列的优化算法以导出其成立的条件,给出一种使用马尔科夫链游程长度受限(RLL)序列来设计匹配chipping序列的解决方案。仿真结果表明,使用马尔科夫链RLL序列设计匹配chipping序列的成像结果优于Rademacher序列,其图像的信噪比提高2~3dB。 展开更多
关键词 超宽带穿墙雷达 压缩感知 chipping序列 功率谱匹配
下载PDF
Study on disc cutter chipping of TBM based on field data and particle flow code simulation
6
作者 Yadong Xue Yongqiang Fan +2 位作者 Xing Li Kai Shen Jiaxuan Wang 《Underground Space》 SCIE EI CSCD 2023年第2期122-139,共18页
Using tunnel boring machines to excavate high-strength intact rock masses is becoming more common.Due to the interactions between disc cutters and rocks,abnormal wear of disc cutters,especially cutter chipping,has bec... Using tunnel boring machines to excavate high-strength intact rock masses is becoming more common.Due to the interactions between disc cutters and rocks,abnormal wear of disc cutters,especially cutter chipping,has become a common phenomenon.Existing research has mainly focused on normal wear of disc cutters without addressing abnormal wear cases.This study used the disc cutter consumption data of a tunnel project in China to investigate the abovementioned problem based on field research.According to the fail-ure patterns and fracture surface characteristics,the cutter chipping patterns were mainly categorized into four types:granule chipping,patch chipping,primary collapse,and secondary collapse.To further simulate the evolution of disc cutter chipping,based on the linear plastic bond model,a new contact model called the modified plastic bond(MPB)model was proposed to solve the metal simulation prob-lem in Particle Flow Code software.To this end,a set of uniaxial tensile and compressive tests were initially conducted to verify the applicability of the MPB model.Then,a series of three-dimensional rock-cutting simulation tests were conducted to reflect the evolu-tionary processes involved in each type of cutter chipping.The cutter chipping mechanism and morphological characteristics were clas-sified and summarized in detail.The results revealed that the cutting speed and penetration growth led to a rising trend in the probability and intensity of the cutter chipping.The presence of initial defects also induced an adverse effect on the service life of the cutter.The results indicated suitable working conditions for the cutter and suggested ways to control tunneling parameters and avoid frequent cutter chipping cases. 展开更多
关键词 Tunnel boring machine Disc cutter Cutter chipping Particle flow code Modified plastic bond model
原文传递
CHIP相关基因与MPN患者心脑血管事件的风险分析
7
作者 韩雪 白贝贝 +2 位作者 冯翠翠 赵森 陈烨 《中国实验血液学杂志》 CSCD 北大核心 2024年第1期190-196,共7页
目的:分析骨髓增殖性肿瘤(MPN)患者不确定潜能的克隆性造血(CHIP)相关基因突变谱和临床特征,探讨CHIP相关基因与其心脑血管事件(CCE)的相关性及可能作用机制。方法:回顾性分析2019年8月-2022年7月首都医科大学附属北京安贞医院血液科收... 目的:分析骨髓增殖性肿瘤(MPN)患者不确定潜能的克隆性造血(CHIP)相关基因突变谱和临床特征,探讨CHIP相关基因与其心脑血管事件(CCE)的相关性及可能作用机制。方法:回顾性分析2019年8月-2022年7月首都医科大学附属北京安贞医院血液科收治的73例MPN患者的临床资料和二代测序结果,采用Logistic回归分析CHIP相关基因、炎症细胞因子对MPN患者CCE的影响。结果:55例(75.3%)MPN患者检出CHIP相关基因,原发性血小板增多症(ET)和真性红细胞增多症(PV)患者CHIP相关基因各突变频率差异无统计学意义。CHIP相关基因突变以单基因形式为主,检出率从高至低依次为JAK2V617F(63.0%,46/73)、ASXL1(16.4%,12/73)、TET2(11.0%,8/73)、DNMT3A(9.6%,7/73)、SRSF2(6.9%,5/73)、SF3B1(4.1%,3/73)、TP53(1.4%,1/73)和PPMID(1.4%,1/73)。年龄>60岁患者CHIP相关基因检出率明显高于≤60岁者[91.7%(33/36)vs 59.5%(22/37)]。27例(37.0%)MPN患者伴CCE(MPN/CCE),2次CCE者5例,均为动脉事件。CCE组患者年龄(62.8±12.8 vs 53.9±15.8岁,P=0.015)、IL-1β水平(17.7±26.0vs 4.3±8.6,P=0.012)、IL-8水平(360.7±598.6 vs 108.3±317.0,P=0.045)、血栓形成史(29.6%vs 2.2%,P=0.020)和CHIP相关基因检出率(88.9%vs 67.4%,P=0.040)高于无CCE组。多因素Logistic回归分析结果显示,年龄(OR=0.917,95%CI:0.843-0.999,P=0.047)、血栓形成史(OR=34.148,95%CI:2.392-487.535,P=0.009)、任何1个CHIP相关基因突变(OR=16.065,95%CI:1.217-212.024,P=0.035)和IL-1β水平升高(OR=0.929,95%CI:0.870-0.992,P=0.027)均是MPN/CCE的独立危险因素;CHIP相关单基因突变与MPN/CCE无关,但DNMT3A(OR=88.717,95%CI:2.690-292.482,P=0.012)、ASXL1(OR=7.941,95%CI:1.045-60.353,P=0.045)突变是PV/CCE的独立危险因素。结论:MPN患者CHIP相关基因突变率高,尤其是60岁以上患者;高龄、血栓形成史、CHIP相关基因突变和IL-1β水平升高是MPN发生CCE的独立危险因素。DNMT3A、ASXL1单基因突变是PV患者CCE的独立危险因素。CHIP相关基因突变及炎症细胞因子IL-1β升高是MPN新的CCE危险因素。 展开更多
关键词 骨髓增殖性肿瘤 CHIP相关基因 心脑血管事件 炎症细胞因子
下载PDF
替普瑞酮通过E3泛素连接酶CHIP减轻LPS引起的心肌炎症反应和心功能障碍
8
作者 徐丽婷 刘颖文 +8 位作者 李健玲 林婉 王淼 余蕾 张雪 李航 王华东 吕秀秀 王一阳 《中国病理生理杂志》 CAS CSCD 北大核心 2024年第5期862-871,共10页
目的:探究替普瑞酮又称香叶基香叶基丙酮,GGA)对脂多糖(LPS)诱导的心功能障碍的治疗作用及机制。方法:(1)取8周龄C57BL/6雄性野生型小鼠和热休克蛋白70(HSP70)羧基末端相互作用蛋白(CHIP)基因敲除小鼠,随机分为对照组、LPS组、LPS+GGA组... 目的:探究替普瑞酮又称香叶基香叶基丙酮,GGA)对脂多糖(LPS)诱导的心功能障碍的治疗作用及机制。方法:(1)取8周龄C57BL/6雄性野生型小鼠和热休克蛋白70(HSP70)羧基末端相互作用蛋白(CHIP)基因敲除小鼠,随机分为对照组、LPS组、LPS+GGA组和GGA组,每组8只。用腹腔注射LPS(25 mg/kg)的方法建立模型,于LPS刺激后1 h给予小鼠腹腔注射GGA(100 mg/kg)。利用小动物超声系统评估小鼠心脏功能;采集各组小鼠血清,检测血清肌酸激酶同工酶(CK-MB)和乳酸脱氢酶(LDH)水平;HE染色观察病理学改变;ELISA检测心脏组织中炎症因子肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)的水平;Western blot检测各组心脏组织HSP70、CHIP、核转运蛋白α2(KPNA2)、髓过氧化物酶(MPO)、血管细胞黏附分子(VCAM)和细胞间黏附分子(ICAM)的蛋白表达以及细胞核NF-κB的水平。(2)利用小鼠心肌细胞HL-1,建立LPS刺激的离体细胞炎症模型。ELISA检测细胞上清中TNF-α和IL-6的水平;Western blot检测心肌细胞中HSP70、CHIP和KPNA2蛋白表达;免疫荧光染色观察细胞核NF-κB的表达。结果:(1)GGA有效改善LPS刺激小鼠的心脏功能,显著提高射血分数和左室短轴缩短率(P<0.01),减少血清CK-MB和LDH含量(P<0.01),减轻心肌损伤。(2)GGA显著减少LPS引起的TNF-α和IL-6炎症因子的释放(P<0.01),以及NF-κB的入核,降低心肌组织中KPNA2、MPO、VCAM和ICAM蛋白表达,增加心肌组织和细胞HSP70的水平(P<0.01)。(3)在CHIP基因敲除的心肌细胞和小鼠中,GGA不能抑制LPS引起的炎症反应,失去了改善LPS刺激小鼠心脏功能的作用。结论:GGA能够减轻LPS引起的心功能障碍,其作用机制与升高HSP70的表达,促进CHIP的活化,减少NF-κB的入核,抑制炎症因子的释放有关。CHIP的敲除使GGA丧失了减轻LPS诱导的炎症反应和心肌损伤的作用。 展开更多
关键词 替普瑞酮 脂多糖 心功能障碍 CHIP蛋白 炎症
下载PDF
湖羊lncRNA-269的鉴定及转录调控分析
9
作者 舒嘉傲 曹少先 +6 位作者 孟春花 钱勇 张俊 张建丽 丁强 李隐侠 李齐发 《南京农业大学学报》 CAS CSCD 北大核心 2024年第1期174-182,共9页
[目的]本文旨在研究湖羊长链非编码RNA-269(long no-coding RNA-269,lncRNA-269)序列特征、表达模式和转录调控,为后续开展lncRNA-269的功能研究提供理论基础。[方法]以湖羊为研究对象,采用5′/3′RACE结合PCR扩增方法获得其序列全长,利... [目的]本文旨在研究湖羊长链非编码RNA-269(long no-coding RNA-269,lncRNA-269)序列特征、表达模式和转录调控,为后续开展lncRNA-269的功能研究提供理论基础。[方法]以湖羊为研究对象,采用5′/3′RACE结合PCR扩增方法获得其序列全长,利用RT-qPCR方法鉴定其在湖羊组织中的表达模式,并利用PCR方法扩增其启动子区,鉴定其启动子区特征,分析其转录调控情况。[结果]湖羊lncRNA-269全长3 146 bp,组织表达谱显示其在湖羊各组织中广泛表达,且在健康卵泡中显著高表达,其表达水平与NR5A1 mRNA水平和血清中雌二醇(E_(2))水平呈正相关。荧光素酶活性分析发现在lncRNA-269启动子区的-359~-17 nt有1个转录激活基序,在-1 485~-942 nt有1个转录抑制基序。JASPAR软件预测发现在lncRNA-269转录抑制启动子区域存在FOXO3、PDX1等转录因子结合位点,在转录激活区域有SMAD4、YY1等转录因子结合位点。过表达SMAD4可显著提升lncRNA-269启动子区荧光素酶活性,染色质免疫沉淀(ChIP)-PCR试验进一步确认了SMAD4特异性与lncRNA-269启动子区结合。[结论]湖羊lncRNA-269在健康卵泡中显著高表达,其启动子区存在一个转录激活区域和一个转录抑制区域,转录因子SMAD4可通过与lncRNA-269启动子区结合显著上调lncRNA-269的启动子活性。 展开更多
关键词 湖羊 卵巢卵泡 lncRNA-269 5′/3′RACE 染色质免疫沉淀(ChIP)
下载PDF
Advances in microfluidic-based DNA methylation analysis 被引量:1
10
作者 Jiwen Li Tiechuan Li Xuexin Duan 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第1期116-134,共19页
DNA methylation has been extensively investigated in recent years,not least because of its known relationship with various diseases.Progress in analytical methods can greatly increase the relevance of DNA methylation ... DNA methylation has been extensively investigated in recent years,not least because of its known relationship with various diseases.Progress in analytical methods can greatly increase the relevance of DNA methylation studies to both clinical medicine and scientific research.Microflu-idic chips are excellent carriers for molecular analysis,and their use can provide improvements from multiple aspects.On-chip molecular analysis has received extensive attention owing to its advantages of portability,high throughput,low cost,and high efficiency.In recent years,the use of novel microfluidic chips for DNA methylation analysis has been widely reported and has shown obvious superiority to conventional methods.In this review,wefirst focus on DNA methylation and its applications.Then,we discuss advanced microfluidic-based methods for DNA methylation analysis and describe the great progress that has been made in recent years.Finally,we summarize the advantages that microfluidic technology brings to DNA methylation analysis and describe several challenges and perspectives for on-chip DNA methylation analysis.This review should help researchers improve their understanding and make progress in developing microfluidic-based methods for DNA methylation analysis. 展开更多
关键词 Microfluidic chip DNA methylation analysis Molecular analysis High throughput Low cost
下载PDF
AcWRKY28 mediated activation of AcCPK genes confers salt tolerance in pineapple(Ananas comosus)
11
作者 Qiao Zhou Samaranayaka Vidana Gamage Nirosha Priyadarshani +11 位作者 Rongjuan Qin Han Cheng Tiantian Luo Myat Hnin Wai Mohammad Aqa Mohammadi Yanhui Liu Chang Liu Hanyang Cai Xiaomei Wang Yeqiang Liu Yuan Qin Lulu Wang 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第2期398-412,共15页
Unfavorable environmental cues severely affect crop productivity resulting in significant economic losses to farmers. In plants, multiple regulatory genes, such as the WRKY transcription factor (TF) family, modulate t... Unfavorable environmental cues severely affect crop productivity resulting in significant economic losses to farmers. In plants, multiple regulatory genes, such as the WRKY transcription factor (TF) family, modulate the expression of defense genes. However, the role of the pineapple WRKY genes is poorly understood. Here, we studied the pineapple WRKY gene, AcWRKY28, by generating AcWRKY28 over-expressing transgenic pineapple plants. Overexpression of AcWRKY28 enhanced the salt stress resistance in transgenic pineapple lines. Comparative transcriptome analysis of transgenic and wild-type pineapple plants showed that “plant-pathogen interaction” pathway genes, including 9calcium-dependent protein kinases (CPKs), were up-regulated in AcWRKY28 over-expressing plants. Furthermore, chromatin immunoprecipitation and yeast one-hybrid assays revealed AcCPK12, AcCPK3, AcCPK8, AcCPK1, and AcCPK15 as direct targets of AcWRKY28. Consistently, the study of AcCPK12 over-expressing Arabidopsis lines showed that AcCPK12 enhances salt, drought, and disease resistance. This study shows that AcWRKY28 plays a crucial role in promoting salt stress resistance by activating the expression of AcCPK genes. 展开更多
关键词 PINEAPPLE AcWRKY AcCPK Transcription factor Salt stress CHIP
下载PDF
Simulation and fabrication of in vitro microfluidic microelectrode array chip for patterned culture and electrophysiological detection of neurons
12
作者 Yan Yang Shihong Xu +7 位作者 Yu Deng Yaoyao Liu Kui Zhang Shiya Lv Longze Sha Qi Xu Xinxia Cai Jinping Luo 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第2期1-10,共10页
To enable the detection and modulation of modularized neural networks in vitro,this study proposes a microfluidic microelectrode array chip for the cultivation,compartmentalization,and control of neural cells.The chip... To enable the detection and modulation of modularized neural networks in vitro,this study proposes a microfluidic microelectrode array chip for the cultivation,compartmentalization,and control of neural cells.The chip was designed based on the specific structure of neurons and the requirements for detection and modulation.Finite-element analysis of the chip’s flow field was conducted using the COMSOL Multiphysics software,and the simulation results show that the liquid within the chip can flow smoothly,ensuring stable flow fields that facilitate the uniform growth of neurons within the microfluidic channels.By employing MEMS technology in combination with nanomaterial modification techniques,the microfluidic microelectrode array chip was fabricated successfully.Primary hippocampal neurons were cultured on the chip,forming a well-defined neural network.Spontaneous electrical activity of the detected neurons was recorded,exhibiting a 23.7%increase in amplitude compared to neuronal discharges detected on an open-field microelectrode array.This study provides a platform for the precise detection and modulation of patterned neuronal growth in vitro,potentially serving as a novel tool in neuroscience research. 展开更多
关键词 Microfluidic Microelectrode array In vitro Neural chip
下载PDF
GPU-accelerated OCT imaging: Real-time data processing and artifact suppression for enhanced monitoring of 3D bioprinted tissues and vascular-like networks
13
作者 Shanshan Yang Jinhao Zhou +2 位作者 Hao Guo Ling Wang Mingen Xu 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2024年第6期67-82,共16页
Optical coherence tomography(OCT)imaging technology has significant advantages in in situ and noninvasive monitoring of biological tissues.However,it still faces the following challenges:including data processing spee... Optical coherence tomography(OCT)imaging technology has significant advantages in in situ and noninvasive monitoring of biological tissues.However,it still faces the following challenges:including data processing speed,image quality,and improvements in three-dimensional(3D)visualization effects.OCT technology,especially functional imaging techniques like optical coherence tomography angiography(OCTA),requires a long acquisition time and a large data size.Despite the substantial increase in the acquisition speed of swept source optical coherence tomography(SS-OCT),it still poses significant challenges for data processing.Additionally,during in situ acquisition,image artifacts resulting from interface reflections or strong reflections from biological tissues and culturing containers present obstacles to data visualization and further analysis.Firstly,a customized frequency domainfilter with anti-banding suppression parameters was designed to suppress artifact noises.Then,this study proposed a graphics processing unit(GPU)-based real-time data processing pipeline for SS-OCT,achieving a measured line-process rate of 800 kHz for 3D fast and high-quality data visualization.Furthermore,a GPU-based realtime data processing for CC-OCTA was integrated to acquire dynamic information.Moreover,a vascular-like network chip was prepared using extrusion-based 3D printing and sacrificial materials,with sacrificial material being printed at the desired vascular network locations and then removed to form the vascular-like network.OCTA imaging technology was used to monitor the progression of sacrificial material removal and vascular-like network formation.Therefore,GPU-based OCT enables real-time processing and visualization with artifact suppression,making it particularly suitable for in situ noninvasive longitudinal monitoring of 3D bioprinting tissue and vascular-like networks in microfluidic chips. 展开更多
关键词 SS-OCT GPU acceleration artifact noise 3D bioprinted microfluidic chip.
下载PDF
Simplified quantitative analysis method and its application in the insitu synthesized copper-based azide chips
14
作者 Jie Ren Yunfeng Li +3 位作者 Mingyu Li Xingyu Wu Jiabao Wang Qingxuan Zeng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期309-316,共8页
Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ ... Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems. 展开更多
关键词 Copper-based azide chips SPECTROPHOTOMETRY Separation method Quantitative analysis Ignition ability
下载PDF
A novel integrated microfluidic chip for on-demand electrostatic droplet charging and sorting
15
作者 Jinhui Yao Chunhua He +5 位作者 Jianxin Wang Canfeng Yang Ye Jiang Zhiyong Liu Guanglan Liao Tielin Shi 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第1期31-42,共12页
On-demand droplet sorting is extensively applied for the efficient manipulation and genome-wide analysis of individual cells.However,state-of-the-art microfluidic chips for droplet sorting still suffer from low sortin... On-demand droplet sorting is extensively applied for the efficient manipulation and genome-wide analysis of individual cells.However,state-of-the-art microfluidic chips for droplet sorting still suffer from low sorting speeds,sample loss,and labor-intensive preparation procedures.Here,we demonstrate the development of a novel microfluidic chip that integrates droplet generation,on-demand electrostatic droplet charging,and high-throughput sorting.The charging electrode is a copper wire buried above the nozzle of the microchannel,and the deflecting electrode is the phosphate buffered saline in the microchannel,which greatly simplifies the structure and fabrication process of the chip.Moreover,this chip is capable of high-frequency droplet generation and sorting,with a frequency of 11.757 kHz in the drop state.The chip completes the selective charging process via electrostatic induction during droplet generation.On-demand charged microdroplets can arbitrarilymove to specific exit channels in a three-dimensional(3D)-deflected electric field,which can be controlled according to user requirements,and the flux of droplet deflection is thereby significantly enhanced.Furthermore,a lossless modification strategy is presented to improve the accuracy of droplet deflection or harvest rate from 97.49% to 99.38% by monitoring the frequency of droplet generation in real time and feeding it back to the charging signal.This chip has great potential for quantitative processing and analysis of single cells for elucidating cell-to-cell variations. 展开更多
关键词 Copper wire Droplet generation Droplet sorting Microfluidic chips On-demand charging
下载PDF
On-chip quantum NOON state sensing for temperature and humidity
16
作者 Weihong Luo Chao Wu +5 位作者 Yuxing Du Chang Zhao Miaomiao Yu Pingyu Zhu Kaikai Zhang Ping Xu 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期15-20,共6页
A maximal photon number entangled state,namely NOON state,can be adopted for sensing with a quantum enhancedprecision.In this work,we designed silicon quantum photonic chips containing two types of Mach-Zehnder interf... A maximal photon number entangled state,namely NOON state,can be adopted for sensing with a quantum enhancedprecision.In this work,we designed silicon quantum photonic chips containing two types of Mach-Zehnder interferometerswherein the two-photon NOON state,sensing element for temperature or humidity,is generated.Compared with classicallight or single photon case,two-photon NOON state sensing shows a solid enhancement in the sensing resolution andprecision.As the first demonstration of on-chip quantum photonic sensing,it reveals the advantages of photonic chips forhigh integration density,small-size,stability for multiple-parameter sensing serviceability.A higher sensing precision isexpected to beat the standard quantum limit with a higher photon number NOON state. 展开更多
关键词 quantum sensing NOON state photonic chip
下载PDF
Single event effects evaluation on convolution neural network in Xilinx 28 nm system on chip
17
作者 赵旭 杜雪成 +4 位作者 熊旭 马超 杨卫涛 郑波 周超 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期638-644,共7页
Convolutional neural networks(CNNs) exhibit excellent performance in the areas of image recognition and object detection, which can enhance the intelligence level of spacecraft. However, in aerospace, energetic partic... Convolutional neural networks(CNNs) exhibit excellent performance in the areas of image recognition and object detection, which can enhance the intelligence level of spacecraft. However, in aerospace, energetic particles, such as heavy ions, protons, and alpha particles, can induce single event effects(SEEs) that lead CNNs to malfunction and can significantly impact the reliability of a CNN system. In this paper, the MNIST CNN system was constructed based on a 28 nm systemon-chip(SoC), and then an alpha particle irradiation experiment and fault injection were applied to evaluate the SEE of the CNN system. Various types of soft errors in the CNN system have been detected, and the SEE cross sections have been calculated. Furthermore, the mechanisms behind some soft errors have been explained. This research will provide technical support for the design of radiation-resistant artificial intelligence chips. 展开更多
关键词 single event effects convolutional neural networks alpha particle system on chip fault injection
下载PDF
A Fully-Integrated Memristor Chip for Edge Learning
18
作者 Yanhong Zhang Liang Chu Wenjun Li 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第9期123-127,共5页
It is still challenging to fully integrate computing in memory chip as edge learning devices.In recent work published on Science,a fully-integrated chip based on neuromorphic memristors was developed for edge learning... It is still challenging to fully integrate computing in memory chip as edge learning devices.In recent work published on Science,a fully-integrated chip based on neuromorphic memristors was developed for edge learning as artificial neural networks with functionality of synapses,dendrites,and somas.A crossbar-array memristor chip facilitated edge learning including hardware realization,learning algorithm,and cycle-parallel sign-and threshold-based learning(STELLAR)scheme.The motion control and demonstration platforms were executed to improve the edge learning ability for adapting to new scenarios. 展开更多
关键词 Computing in memory Edge learning Fully-integrated chip
下载PDF
Rapid fabrication of modular 3D paper-basedmicrofluidic chips using projection-based 3D printing
19
作者 Mingjun Xie Zexin Fu +5 位作者 Chunfei Lu Sufan Wu Lei Pan Yong He Yi Sun Ji Wang 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第5期611-623,共13页
Paper-based microchips have different advantages,such as better biocompatibility,simple production,and easy handling,making them promising candidates for clinical diagnosis and other fields.This study describes ametho... Paper-based microchips have different advantages,such as better biocompatibility,simple production,and easy handling,making them promising candidates for clinical diagnosis and other fields.This study describes amethod developed to fabricate modular three-dimensional(3D)paper-based microfluidic chips based on projection-based 3D printing(PBP)technology.A series of two-dimensional(2D)paper-based microfluidic modules was designed and fabricated.After evaluating the effect of exposure time on the accuracy of the flow channel,the resolution of this channel was experimentally analyzed.Furthermore,several 3D paper-based microfluidic chips were assembled based on the 2D ones using different methods,with good channel connectivity.Scaffold-based 2D and hydrogel-based 3D cell culture systems based on 3D paper-based microfluidic chips were verified to be feasible.Furthermore,by combining extrusion 3D bioprinting technology and the proposed 3D paper-based microfluidic chips,multiorgan microfluidic chips were established by directly printing 3D hydrogel structures on 3D paperbased microfluidic chips,confirming that the prepared modular 3D paper-based microfluidic chip is potentially applicable in various biomedical applications. 展开更多
关键词 Paper-based microfluidic chip Projection-based 3D printing(PBP) Modularization Cell culture
下载PDF
Efficient stochastic parallel gradient descent training for on-chip optical processor
20
作者 Yuanjian Wan Xudong Liu +4 位作者 Guangze Wu Min Yang Guofeng Yan Yu Zhang Jian Wang 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第4期5-15,共11页
In recent years,space-division multiplexing(SDM)technology,which involves transmitting data information on multiple parallel channels for efficient capacity scaling,has been widely used in fiber and free-space optical... In recent years,space-division multiplexing(SDM)technology,which involves transmitting data information on multiple parallel channels for efficient capacity scaling,has been widely used in fiber and free-space optical communication sys-tems.To enable flexible data management and cope with the mixing between different channels,the integrated reconfig-urable optical processor is used for optical switching and mitigating the channel crosstalk.However,efficient online train-ing becomes intricate and challenging,particularly when dealing with a significant number of channels.Here we use the stochastic parallel gradient descent(SPGD)algorithm to configure the integrated optical processor,which has less com-putation than the traditional gradient descent(GD)algorithm.We design and fabricate a 6×6 on-chip optical processor on silicon platform to implement optical switching and descrambling assisted by the online training with the SPDG algorithm.Moreover,we apply the on-chip processor configured by the SPGD algorithm to optical communications for optical switching and efficiently mitigating the channel crosstalk in SDM systems.In comparison with the traditional GD al-gorithm,it is found that the SPGD algorithm features better performance especially when the scale of matrix is large,which means it has the potential to optimize large-scale optical matrix computation acceleration chips. 展开更多
关键词 optical communications optical signal processing channel descrambling optical neural network chip silicon photonics
下载PDF
上一页 1 2 52 下一页 到第
使用帮助 返回顶部