期刊文献+
共找到2,406篇文章
< 1 2 121 >
每页显示 20 50 100
3D printing encouraging desired in-situ polypyrrole seed-polymerization for ultra-high energy density supercapacitors
1
作者 Tiantian Zhou Shangwen Ling +6 位作者 Shuxian Sun Ruoxin Yuan Ziqin Wu Mengyuan Fu Hanna He Xiaolong Li Chuhong Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期117-125,I0004,共10页
The tireless pursuit of supercapacitors with high energy density entails the parallel advancement of wellsuited electrode materials and elaborately engineered architectures.Polypyrrole(PPy)emerges as an exceedingly co... The tireless pursuit of supercapacitors with high energy density entails the parallel advancement of wellsuited electrode materials and elaborately engineered architectures.Polypyrrole(PPy)emerges as an exceedingly conductive polymer and a prospective pseudocapacitive materials for supercapacitors,yet the inferior cyclic stability and unpredictable polymerization patterns severely impede its real-world applicability.Here,for the first time,an innovative seed-induced in-situ polymerization assisted 3D printing strategy is proposed to fabricate PPy-reduced graphene oxide/poly(vinylidene difluoride-cohexafluoropropylene)(PVDF-HFP)(PPy-rGO/PH)electrodes with controllable polymerization behavior and exceptional areal mass loading.The preferred active sites uniformly pre-planted on the 3D-printed graphene substrates serve as reliable seeds to induce efficient polypyrrole deposition,achieving an impressive mass loading of 185.6 mg cm^(-2)(particularly 79.2 mg cm^(-2)for polypyrrole)and a superior areal capacitance of 25.2 F cm^(-2)at 2 mA cm^(-2)for a 12-layer electrode.In agreement with theses appealing features,an unprecedented areal energy density of 1.47 mW h cm^(-2)for a symmetrical device is registered,a rarely achieved value for other PPy/rGO-based supercapacitors.This work highlights a promising route to preparing high energy density energy storage modules for real-world applications. 展开更多
关键词 3d printing Seed-induced polymerization SUPERCAPACITOR POLYPYRROLE high energy density
下载PDF
Three‐dimensional(3D)‐printed MXene high‐voltage aqueous micro‐supercapacitors with ultrahigh areal energy density and low‐temperature tolerance
2
作者 Yuanyuan Zhu Qingxiao Zhang +6 位作者 Jiaxin Ma Pratteek Das Liangzhu Zhang Hanqing Liu Sen Wang Hui Li Zhong‐Shuai Wu 《Carbon Energy》 SCIE EI CAS CSCD 2024年第8期36-48,共13页
The rapid advancement in the miniaturization,integration,and intelligence of electronic devices has escalated the demand for customizable microsupercapacitors(MSCs)with high energy density.However,efficient microfabri... The rapid advancement in the miniaturization,integration,and intelligence of electronic devices has escalated the demand for customizable microsupercapacitors(MSCs)with high energy density.However,efficient microfabrication of safe and high‐energy MXene MSCs for integrating microelectronics remains a significant challenge due to the low voltage window in aqueous electrolytes(typically≤0.6 V)and limited areal mass loading of MXene microelectrodes.Here,we tackle these challenges by developing a highconcentration(18mol kg^(−1))“water‐in‐LiBr”(WiB)gel electrolyte for MXene symmetric MSCs(M‐SMSCs),demonstrating a record high voltage window of 1.8 V.Subsequently,additive‐free aqueous MXene ink with excellent rheological behavior is developed for three‐dimensional(3D)printing customizable all‐MXene microelectrodes on various substrates.Leveraging the synergy of a highvoltage WiB gel electrolyte and 3D‐printed microelectrodes,quasi‐solid‐state MSMSCs operating stably at 1.8 V are constructed,and achieve an ultrahigh areal energy density of 1772μWhcm^(−2) and excellent low‐temperature tolerance,with a long‐term operation at−40℃.Finally,by extending the 3D printing protocol,M‐SMSCs are integrated with humidity sensors on a single planar substrate,demonstrating their reliability in miniaturized integrated microsystems. 展开更多
关键词 3d printing aqueous electrolyte high voltage micro‐supercapacitors MXene
下载PDF
A hierarchical salt-rejection strategy for sustainable and high-efficiency solar-driven desalination
3
作者 Zhengyi Mao Xuliang Chen +7 位作者 Yingxian Chen Junda Shen Jianpan Huang Yuhan Chen Xiaoguang Duan Yicheng Han Kannie Wai Yan Chan Jian LU 《Nano Materials Science》 EI CAS CSCD 2024年第1期38-43,共6页
Solar steam generation(SSG)is widely regarded as one of the most sustainable technologies for seawater desalination.However,salt fouling severely compromises the evaporation performance and lifetime of evaporators,lim... Solar steam generation(SSG)is widely regarded as one of the most sustainable technologies for seawater desalination.However,salt fouling severely compromises the evaporation performance and lifetime of evaporators,limiting their practical applications.Herein,we propose a hierarchical salt-rejection(HSR)strategy to prevent salt precipitation during long-term evaporation while maintaining a rapid evaporation rate,even in high-salinity brine.The salt diffusion process is segmented into three steps—insulation,branching diffusion,and arterial transport—that significantly enhance the salt-resistance properties of the evaporator.Moreover,the HSR strategy overcomes the tradeoff between salt resistance and evaporation rate.Consequently,a high evaporation rate of 2.84 kg m^(-2) h^(-1),stable evaporation for 7 days cyclic tests in 20 wt%NaCl solution,and continuous operation for 170 h in natural seawater under 1 sun illumination were achieved.Compared with control evaporators,the HSR evaporator exhibited a>54%enhancement in total water evaporation mass during 24 h continuous evaporation in 20 wt%salt water.Furthermore,a water collection device equipped with the HSR evaporator realized a high water purification rate(1.1 kg m^(-2) h^(-1)),highlighting its potential for agricultural applications. 展开更多
关键词 Solar water evaporation 3d printing Salt-rejection Hierarchical structures high efficiency
下载PDF
Pseudocapacitive Heteroatom-Doped Carbon Cathode for Aluminum-Ion Batteries with Ultrahigh Reversible Stability
4
作者 Jiahui Li Jehad KEl-Demellawi +9 位作者 Guan Sheng Jonas Björk Fanshuai Zeng Jie Zhou Xiaxia Liao Junwei Wu Johanna Rosen Xingjun Liu Husam N.Alshareef Shaobo Tu 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第5期150-159,共10页
Aluminum(Al)-ion batteries have emerged as a potential alternative to conventional ion batteries that rely on less abundant and costly materials like lithium.Nonetheless,given the nascent stage of advancement in Al-io... Aluminum(Al)-ion batteries have emerged as a potential alternative to conventional ion batteries that rely on less abundant and costly materials like lithium.Nonetheless,given the nascent stage of advancement in Al-ion batteries(AIBs),attaining electrode materials that can leverage both intercalation capacity and structural stability remains challenging.Herein,we demonstrate a C3N4-derived layered N,S heteroatom-doped carbon,obtained at different pyrolysis temperatures,as a cathode material for AIBs,encompassing the diffusion-controlled intercalation and surface-induced capacity with ultrahigh reversibility.The developed layered N,S-doped corbon(N,S-C)cathode,synthesized at 900℃,delivers a specific capacity of 330 mAhg^(-1)with a relatively high coulombic efficiency of~85%after 500 cycles under a current density of 0.5 A g^(-1).Owing to its reinforced adsorption capability and enlarged interlayer spacing by doping N and S heteroatoms,the N,S-C900 cathode demonstrates outstanding energy storage capacity with excellent rate performance(61 mAhg^(-1)at 20 A g^(-1))and ultrahigh reversibility(90 mAhg^(-1)at 5Ag^(-1)after 10000cycles). 展开更多
关键词 2d carbon adsorption energy heteroatoms-doping high capacity long cycling life
下载PDF
Experimental and numerical study on dynamic mechanical behaviors of shale under true triaxial compression at high strain rate
5
作者 Xiaoping Zhou Linyuan Han +1 位作者 Jing Bi Yundong Shou 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第2期149-165,共17页
High-energy gas fracturing of shale is a novel,high efficacy and eco-friendly mining technique,which is a typical dynamic perturbing behavior.To effectively extract shale gas,it is important to understand the dynamic ... High-energy gas fracturing of shale is a novel,high efficacy and eco-friendly mining technique,which is a typical dynamic perturbing behavior.To effectively extract shale gas,it is important to understand the dynamic mechanical properties of shale.Dynamic experiments on shale subjected to true triaxial compression at different strain rates are first conducted in this research.The dynamic stress-strain curves,peak strain,peak stress and failure modes of shale are investigated.The results of the study indicate that the intermediate principal stress and the minor principal stress have the significant influence on the dynamic mechanical behaviors,although this effect decreases as the strain rate increases.The characteristics of compression-shear failure primarily occur in shale subjected to triaxial compression at high strain rates,which distinguishes it from the fragmentation characteristics observed in shale under dynamic uniaxial compression.Additionally,a numerical three-dimensional Split Hopkinson Pressure Bar(3D-SHPB),which is established by coupling PFC3D and FLAC3D methods,is validated to replicate the laboratory characteristics of shale.The dynamic mechanical characteristics of shale subjected to different confining stresses are systematically investigated by the coupling PFC3D and FLAC3D method.The numerical results are in good agreement with the experimental data. 展开更多
关键词 dynamic behaviors True triaxial compression high strain rates dynamic failure mechanism PFC3d-FLAC3d coupled method
下载PDF
高光纯D-乳酸生产菌株假肠膜明串珠菌HL64-1的分离鉴定及其发酵特性
6
作者 黄筱萍 王通 +1 位作者 李鹏 刘兰 《食品工业科技》 CAS 北大核心 2024年第11期133-141,共9页
从自然界中筛选分离产酸菌是获得高光学纯度乳酸生产菌株有效的途径之一。从腐烂果实中分离获得一株产高光学纯度D-乳酸菌株HL64-1,经形态学、16S rDNA序列分析、序列相似性Blast比对分析鉴定为假肠膜明串珠菌(Leuconostoc pseudomesent... 从自然界中筛选分离产酸菌是获得高光学纯度乳酸生产菌株有效的途径之一。从腐烂果实中分离获得一株产高光学纯度D-乳酸菌株HL64-1,经形态学、16S rDNA序列分析、序列相似性Blast比对分析鉴定为假肠膜明串珠菌(Leuconostoc pseudomesenteroides)。在基础发酵培养基中摇瓶发酵24 h,产D-乳酸的量达到62.18 g/L,产酸速率达2.59 g/(L·h),光学纯度达99.90%(ee);在5 L发酵罐中放大培养,通过补加碳源,发酵72 h,D-乳酸产量达到78.74 g/L,平均产酸速率达1.09 g/(L·h)。该菌株可以有效利用农业副产物花生饼粉和棉籽粉作为替代氮源以降低发酵原料成本。该菌还可利用木糖产生D-乳酸,且葡萄糖能显著提高木糖的利用效率,极具工业应用前景。 展开更多
关键词 d-乳酸生产菌 分离 高光学纯度 发酵 木糖
下载PDF
基于多水准的高强钢框架-D形偏心支撑结构层剪力分布研究
7
作者 李慎 丁世豪 +1 位作者 李晓蕾 穆林 《计算力学学报》 CAS CSCD 北大核心 2024年第4期734-741,共8页
高强钢框架GD形偏心支撑结构中耗能梁段采用Q355钢,非耗能构件(即框架梁和柱)采用高强度钢材,形成一种新型结构体系.耗能梁段在结构遭遇罕遇地震时充分发挥塑性变形耗能,保护高强钢框架处于弹性受力状态,高强钢框架GD形偏心支撑结构由... 高强钢框架GD形偏心支撑结构中耗能梁段采用Q355钢,非耗能构件(即框架梁和柱)采用高强度钢材,形成一种新型结构体系.耗能梁段在结构遭遇罕遇地震时充分发挥塑性变形耗能,保护高强钢框架处于弹性受力状态,高强钢框架GD形偏心支撑结构由于在塑性状态下结构刚度发生改变,其层剪力分布模式不再符合基于强度的设计理论,因此,本文研究了高强钢框架GD形偏心支撑结构在多水准地震动状态下的层剪力分布模式.本文设计了四种不同层数(4层,8层,12层和16层)和三种不同耗能梁段长度(900mm,1000mm和1100mm)的高强钢框架GD形偏心支撑结构,输入40条近场脉冲地震和40条远场地震记录,得到结构在多遇地震、设防地震、罕遇地震以及极罕遇地震下的层剪力分布模式,并对罕遇地震下的层剪力分布模式进行参数标定,获取塑性状态下结构的弹塑性侧向力分布状态. 展开更多
关键词 d形偏心支撑 层剪力分布模式 近场脉冲地震 高强钢框架
下载PDF
妊娠期高血压患者肠道菌群分布及其与血清HtrA3、25(OH)D水平的关系
8
作者 李文辉 崔丽茹 +1 位作者 张慧然 田莹珺 《中国妇幼健康研究》 2024年第4期84-89,共6页
目的 探讨妊娠期高血压患者肠道菌群分布特征及其与血清丝氨酸蛋白酶A3(HtrA3)、25羟基维生素D[25(OH)D]水平的相关性。方法 选取2021年5月至2023年5月期间在本院就诊的106例妊娠期高血压患者作为研究组,选取同期体检健康的妊娠孕妇98... 目的 探讨妊娠期高血压患者肠道菌群分布特征及其与血清丝氨酸蛋白酶A3(HtrA3)、25羟基维生素D[25(OH)D]水平的相关性。方法 选取2021年5月至2023年5月期间在本院就诊的106例妊娠期高血压患者作为研究组,选取同期体检健康的妊娠孕妇98例作为对照组;同时收集整理其临床特征资料。采用16s rDNA测序技术检测两组肠道菌群,并比较两组肠道菌群多样性及其相对丰度;采用ELISA法检测两组血清HtrA3、25(OH)D水平;采用Pearson法分析妊娠期高血压患者肠道菌群与血清HtrA3、25(OH)D水平的相关性。结果 与对照组相比,研究组Chao1指数、Ace指数、Shannon指数明显降低,Simpson指数明显升高(Z值介于2.462~5.163之间,均P<0.05)。门水平上,与对照组相比,研究组厚壁菌门、拟杆菌门、放线菌门菌群相对丰度明显降低(t值介于2.976~10.722之间),变形菌门相对丰度明显升高(t=2.569);属水平上,乳杆菌属、双歧杆菌属、毛螺菌属、Rikenellaceae属、真杆菌属相对丰度明显降低(t值介于2.344~11.277之间),肠球菌属相对丰度明显升高(t=4.220)(均P<0.05)。与对照组相比,研究组血清HtrA3水平明显升高,25(OH)D水平明显降低(t=8.425、8.308,P<0.05)。Pearson相关性分析结果显示,乳杆菌属、双歧杆菌属、真杆菌属、毛螺菌属、Rikenellaceae属与血清HtrA3水平呈负相关(r值介于-0.581~-0.478之间),与25(OH)D水平呈正相关(r值介于0.470~0.638之间);肠球菌属与血清HtrA3水平呈正相关(r=0.527),与25(OH)D水平呈负相关(r=-0.479)(均P<0.05)。结论 妊娠期高血压患者肠道菌群与血清HtrA3、25(OH)D之间有明显相关性,临床上检测二者相关性对治疗妊娠期高血压具有重要意义。 展开更多
关键词 妊娠期高血压 肠道菌群 血清丝氨酸蛋白酶A3 25羟基维生素d
下载PDF
一种高速A/D转换器时域重构技术研究
9
作者 崔庆林 杨松 《微电子学》 CAS 北大核心 2024年第2期317-322,共6页
A/D转换器在航空航天系统中的重要元器件,随着器件转换时钟频率不断提高而其工作环境不断恶化,如何准确测试其时间参数对于全面评价A/D转换器性能特别重要。目前对于高速A/D转换器时间参数测试,主流方法是通过示波器直接测试其输出,该... A/D转换器在航空航天系统中的重要元器件,随着器件转换时钟频率不断提高而其工作环境不断恶化,如何准确测试其时间参数对于全面评价A/D转换器性能特别重要。目前对于高速A/D转换器时间参数测试,主流方法是通过示波器直接测试其输出,该方法对于示波器采样速度要求比较高。文章提出一种高速A/D转换器时域重构技术,可以通过计算机数字信号处理方法来实现高速A/D转换器时间参数测试,同时避免对示波器采样速度的依赖。同时,在研究高速A/D转换器时域重构技术方法及其应用的基础上,通过了相关试验验证。 展开更多
关键词 高速a/d转换器 时域重构 瞬态响应 过压恢复 缺陷分析 单粒子闭锁和翻转
原文传递
Effects of endogenous dopamine induced by low concentration atropine eye drops on choroidal neovascularization in high myopia mice 被引量:3
10
作者 Yan-Yan Ji Shi-Xi Zhang +1 位作者 Ye Kang Song Chen 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第7期1034-1040,共7页
AIM:To evaluate effects of endogenous dopamine induced by low concentration atropine eye drops on choroidal neovascularization(CNV)in high myopia mice.METHODS:The C57BL/6J mice were deprived of the right eye for 4wk,a... AIM:To evaluate effects of endogenous dopamine induced by low concentration atropine eye drops on choroidal neovascularization(CNV)in high myopia mice.METHODS:The C57BL/6J mice were deprived of the right eye for 4wk,and the high myopia was diagnosed by optometry,the diopter was less than-6.00 D,and CNV was induced by 532 nm laser.The changes of dopamine D1 receptor(DRD1),dopamine D2 receptor(DRD2),and vascular endothelial growth factor A(VEGFA)were detected by Western blot technology at 0.5,1,2h,and 7d after 0.01%,0.05%,and 0.1%atropine eye drops,respectively,the area of CNV was measured.RESULTS:Significant increases were observed on the expression of DRD2 in mouse high myopia model at 0.5,1,2h,7d with 0.05%and 0.1%atropine eye drops(P<0.05).Significant decreases were observed on the expression of DRD1 and VEGFA in mouse high myopia model at 0.5,1,2h,7d with 0.05%and 0.1%atropine eye drops(P<0.05).The area of CNV induced by laser in the drug-treated group was significantly smaller than that in the control group,and the higher the concentration,the more significant the inhibitory effect(P<0.05).CONCLUSION:The 0.01%,0.05%,0.1%atropine eye drops can decrease the level of VEGFA and inhibit high myopia CNV indirectly by up-regulating the level of DRD2 and down-regulating the level of DRD1,and the effect of 0.05%and 0.1%atropine eye drops is more significant. 展开更多
关键词 high myopia choroidal neovascularization low concentration atropine eye drops dopamine d1 receptor dopamine d2 receptor
原文传递
基于GaAs E/D PHEMT工艺的Ku波段双通道幅相控制多功能芯片
11
作者 徐伟 赵子润 +1 位作者 刘会东 李远鹏 《半导体技术》 CAS 北大核心 2024年第6期575-579,588,共6页
基于GaAs增强/耗尽型赝配高电子迁移率晶体管(E/D PHEMT)工艺设计了一款14~18 GHz的双通道多功能芯片。芯片集成了单刀双掷(SPDT)开关、6 bit数控移相器、4 bit数控衰减器和增益补偿放大器。采用正压控制开关以减小控制位数;优化移相、... 基于GaAs增强/耗尽型赝配高电子迁移率晶体管(E/D PHEMT)工艺设计了一款14~18 GHz的双通道多功能芯片。芯片集成了单刀双掷(SPDT)开关、6 bit数控移相器、4 bit数控衰减器和增益补偿放大器。采用正压控制开关以减小控制位数;优化移相、衰减和放大等电路拓扑结构,以获得良好的幅相特性;采用紧凑布局、双通道对称的版图设计,以实现小尺寸和高性能。测试结果表明,+5 V电压下,接收通道增益大于3 dB,1 dB压缩点输出功率大于8 dBm;发射通道增益大于1 dB,1 dB压缩点输出功率大于2 dBm;64态移相均方根误差小于2.5°,16态衰减均方根误差小于0.3 dB,芯片尺寸为3.90 mm×2.25 mm。该多功能芯片可实现对射频信号幅度和相位的高精度控制,可广泛应用于微波收发模块。 展开更多
关键词 双通道 多功能芯片 增强/耗尽型赝配高电子迁移率晶体管(E/d PHEMT) 单刀双掷(SPdT)开关 数控移相器 数控衰减器
原文传递
Novel ternary metals-based telluride electrocatalyst with synergistic effects of high valence non-3d metal and oxophilic Te for pH-universal hydrogen evolution reaction 被引量:2
12
作者 Seunghwan Jo Wenxiang Liu +5 位作者 Yanan Yue Ki Hoon Shin Keon Beom Lee Hyeonggeun Choi Bo Hou Jung Inn Sohn 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第5期736-743,I0015,共9页
Electrocatalyst designs based on oxophilic foreign atoms are considered a promising approach for developing efficient pH-universal hydrogen evolution reaction(HER)electrocatalysts by overcoming the sluggish alkaline H... Electrocatalyst designs based on oxophilic foreign atoms are considered a promising approach for developing efficient pH-universal hydrogen evolution reaction(HER)electrocatalysts by overcoming the sluggish alkaline HER kinetics.Here,we design ternary transition metals-based nickel telluride(Mo WNi Te)catalysts consisting of high valence non-3d Mo and W metals and oxophilic Te as a first demonstration of non-precious heterogeneous electrocatalysts following the bifunctional mechanism.The Mo WNi Te showed excellent HER catalytic performance with overpotentials of 72,125,and 182 mV to reach the current densities of 10,100,and 1000 mA cm^(-2),respectively,and the corresponding Tafel slope of 47,52,and 58 mV dec-1in alkaline media,which is much superior to commercial Pt/C.Additionally,the HER performance of Mo WNi Te is well maintained up to 3000 h at the current density of 100 mA cm^(-2).It is further demonstrated that the Mo WNi Te exhibits remarkable HER activities with an overpotential of 45 mV(31 mV)and Tafel slope of 60 mV dec-1(34 mV dec-1)at 10 mA cm^(-2)in neutral(acid)media.The superior HER performance of Mo WNi Te is attributed to the electronic structure modulation,inducing highly active low valence states by the incorporation of high valence non-3d transition metals.It is also attributed to the oxophilic effect of Te,accelerating water dissociation kinetics through a bifunctional catalytic mechanism in alkaline media.Density functional theory calculations further reveal that such synergistic effects lead to reduced free energy for an efficient water dissociation process,resulting in remarkable HER catalytic performances within universal pH environments. 展开更多
关键词 Telluride catalyst Oxophilic effect high valence non-3d metal Bifunctional mechanism pH-universal hydrogen evolution reaction
下载PDF
Application of tensor CSAMT with high-power orthogonal signal sources in Jiama porphyry copper deposit,South Tibet 被引量:2
13
作者 Peng-liang Yu Ting Qu +3 位作者 Ri-zheng He Jian-li Liu Su-fen Wang Xiao-long Chen 《China Geology》 CAS CSCD 2023年第1期37-49,共13页
The Jiama porphyry copper deposit in Tibet is one of the proven supergiant copper deposits in the Qinghai-Tibet Plateau at present,with the reserves of geological resources equivalent to nearly 20×10^(6) t.Howeve... The Jiama porphyry copper deposit in Tibet is one of the proven supergiant copper deposits in the Qinghai-Tibet Plateau at present,with the reserves of geological resources equivalent to nearly 20×10^(6) t.However,it features wavy and steep terrain,leading to extremely difficult field operation and heavy interference.This study attempts to determine the effects of the tensor controlled-source audiomagnetotellurics(CSAMT)with high-power orthogonal signal sources(also referred to as the high-power tensor CSAMT)when it is applied to the deep geophysical exploration in plateaus with complex terrain and mining areas with strong interference.The test results show that the high current provided by the highpower tensor CSAMT not only greatly improved the signal-to-noise ratio but also guaranteed that effective signals were received in the case of a long transmitter-receiver distance.Meanwhile,the tensor data better described the anisotropy of deep geologic bodies.In addition,the tests also show that when the transmitting current reaches 60 A,it is still guaranteed that strong enough signals can be received in the case of the transmitter-receiver distance of about 25 km,sounding curves show no near field effect,and effective exploration depth can reach 3 km.The 2D inversion results are roughly consistent with drilling results,indicating that the high-power tensor CSAMT can be used to achieve nearly actual characteristics of underground electrical structures.Therefore,this method has great potential for application in deep geophysical exploration in plateaus and mining areas with complex terrain and strong interference,respectively.This study not only serves as important guidance on the prospecting in the Qinghai-Tibet Plateau but also can be used as positive references for deep mineral exploration in other areas. 展开更多
关键词 Jiama porphyry copper deposit Supergiant copper polymetallic deposit Tensor CSAMT of 150 kw high power 2d inversion deep prospecting Mineral exploration engineering Xizang(Tibet)
下载PDF
一种基于MIPI D-PHY物理层的高速比较器 被引量:1
14
作者 张欣瑶 黄尊恺 +3 位作者 汪辉 田犁 汪宁 封松林 《合肥工业大学学报(自然科学版)》 CAS 北大核心 2024年第3期360-366,共7页
基于MIPI D-PHY物理层传输协议,文章设计一种高速低功耗的自偏置比较器电路,并对电路进行理论分析和仿真验证。该高速比较器总体结构由二级运放构成:共栅极和共源极以及工作在线性区的NMOS管组成第1级放大结构;电流源作负载的四管运放... 基于MIPI D-PHY物理层传输协议,文章设计一种高速低功耗的自偏置比较器电路,并对电路进行理论分析和仿真验证。该高速比较器总体结构由二级运放构成:共栅极和共源极以及工作在线性区的NMOS管组成第1级放大结构;电流源作负载的四管运放组成第2级放大结构。差分信号通过NMOS源极进行输入,提升信号的共模电压接收范围。电路结构中无额外电流源偏置,提高数据传输速率的同时减小了功耗。基于SMIC 0.18μm CMOS工艺设计,采用1.8 V电压供电,仿真结果表明:高速比较器能准确接收低共模电平的差分信号,直流增益为37.4 dB,传输速率达到2.5 Gb/s,功耗达到326μW/(Gb/s),可以接收到差分信号的共模电平范围为30~330 mV。 展开更多
关键词 移动产业处理器接口(MIPI) 高速接收电路 MIPI d-PHY物理层 CMOS图像传感器 高速比较器
下载PDF
高压热杀菌处理时D-果糖对枯草芽孢杆菌芽孢灭活的抑制机制 被引量:1
15
作者 李青桓 辛伟山 +3 位作者 李佳佳 刘永霞 刘燚畅 章中 《食品科学技术学报》 EI CAS CSCD 北大核心 2024年第4期145-155,共11页
研究高压热杀菌(high-pressure thermal sterilization,HPTS)处理时D-果糖对枯草芽孢杆菌芽孢灭活的抑制作用。HPTS处理压力为200、600 MPa,处理温度为25、65、75℃,处理时间为20 min,D-果糖质量分数为0、15%、30%、60%。使用流式细胞... 研究高压热杀菌(high-pressure thermal sterilization,HPTS)处理时D-果糖对枯草芽孢杆菌芽孢灭活的抑制作用。HPTS处理压力为200、600 MPa,处理温度为25、65、75℃,处理时间为20 min,D-果糖质量分数为0、15%、30%、60%。使用流式细胞术检测处理前后芽孢内膜的损伤情况,采用傅里叶红外光谱对处理前后芽孢蛋白质和内膜脂质进行分析,以揭示蛋白质结构与内膜脂质相态的变化。HPTS处理后芽孢内膜通透性增大,内膜完整性受损,然而随着添加的D-果糖质量分数的升高,芽孢内膜脂质的相态由液晶态逐渐转变为凝胶态,内膜稳定性增加、通透性降低、完整性提高,且芽孢蛋白质的有序二级结构的含量增加。不添加D-果糖时,600 MPa、75℃处理20 min后,芽孢死亡了5.31 lg(CFU/mL),芽孢悬浮液OD_(600)下降到0.41,2,6-吡啶二羧酸(2,6-pyridinedicarboxylic acid,DPA)泄漏率达93.56%,内膜受损的芽孢比率达到80.95%,芽孢蛋白质的α-螺旋和β-折叠结构含量分别下降到16%和17%;而当添加的D-果糖质量分数提升到60%时,相同条件的HPTS处理后,芽孢存活数量上升了1.69 lg(CFU/mL),芽孢悬浮液OD_(600)上升了0.09,内膜受损的芽孢比率减少了20.74个百分点,芽孢蛋白质的α-螺旋和β-折叠结构含量分别回升到25%和28%。D-果糖抑制了HPTS处理对芽孢结构的破坏和孢内关键物质的泄漏,且这种作用与D-果糖质量分数呈正相关。 展开更多
关键词 高压热杀菌 d-果糖 枯草芽孢杆菌 芽孢 灭活 抑制机制 内膜
下载PDF
An adaptive physics-informed deep learning method for pore pressure prediction using seismic data 被引量:2
16
作者 Xin Zhang Yun-Hu Lu +2 位作者 Yan Jin Mian Chen Bo Zhou 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期885-902,共18页
Accurate prediction of formation pore pressure is essential to predict fluid flow and manage hydrocarbon production in petroleum engineering.Recent deep learning technique has been receiving more interest due to the g... Accurate prediction of formation pore pressure is essential to predict fluid flow and manage hydrocarbon production in petroleum engineering.Recent deep learning technique has been receiving more interest due to the great potential to deal with pore pressure prediction.However,most of the traditional deep learning models are less efficient to address generalization problems.To fill this technical gap,in this work,we developed a new adaptive physics-informed deep learning model with high generalization capability to predict pore pressure values directly from seismic data.Specifically,the new model,named CGP-NN,consists of a novel parametric features extraction approach(1DCPP),a stacked multilayer gated recurrent model(multilayer GRU),and an adaptive physics-informed loss function.Through machine training,the developed model can automatically select the optimal physical model to constrain the results for each pore pressure prediction.The CGP-NN model has the best generalization when the physicsrelated metricλ=0.5.A hybrid approach combining Eaton and Bowers methods is also proposed to build machine-learnable labels for solving the problem of few labels.To validate the developed model and methodology,a case study on a complex reservoir in Tarim Basin was further performed to demonstrate the high accuracy on the pore pressure prediction of new wells along with the strong generalization ability.The adaptive physics-informed deep learning approach presented here has potential application in the prediction of pore pressures coupled with multiple genesis mechanisms using seismic data. 展开更多
关键词 Pore pressure prediction Seismic data 1d convolution pyramid pooling Adaptive physics-informed loss function high generalization capability
下载PDF
高稳定液态D-阿洛酮糖3-差向异构酶制剂研究 被引量:1
17
作者 韩亚宏 郭元亨 +4 位作者 王小艳 丁长河 周浩 冉小力 田芳 《当代化工》 CAS 2024年第3期712-716,721,共6页
为解决D-阿洛酮糖3-差向异构酶(DAE)衰减过快、贮运成本高的问题,拟开发一款具有良好存贮稳定性的DEA液态酶制剂。以半衰期为评价依据,通过单因素试验筛选出对半衰期影响显著的4个因素,并进一步利用响应曲面法对酶制剂的配方进行优化。... 为解决D-阿洛酮糖3-差向异构酶(DAE)衰减过快、贮运成本高的问题,拟开发一款具有良好存贮稳定性的DEA液态酶制剂。以半衰期为评价依据,通过单因素试验筛选出对半衰期影响显著的4个因素,并进一步利用响应曲面法对酶制剂的配方进行优化。结果表明:稳定DAE酶制剂的最佳配比为0.1mol·L^(-1)CaCl_(2)、3.96%海藻糖、41.68%葡萄糖、29.32%PEG-400。在此条件下,半衰期为292天,与模拟理论值的相对误差仅为0.17%。通过工艺优化,将DAE的储存时间大幅延长,提高了酶制剂的贮运性能。 展开更多
关键词 d-阿洛酮糖3-差向异构酶 高稳定性 液态酶制剂
下载PDF
重组大肠杆菌发酵条件优化提高D-阿洛酮糖3-差向异构酶活性的研究 被引量:1
18
作者 刘微微 常楚婷 +4 位作者 冯敬杰 张家赫 李飞胜 丁文涛 王昌禄 《食品与发酵工业》 CAS CSCD 北大核心 2024年第4期253-259,共7页
功能性稀有糖D-阿洛酮糖主要由基因工程菌株表达D-阿洛酮糖3-差向异构酶(D-allulose 3-epimerase,DAE)催化果糖生产。该研究以表达DAE的重组大肠杆菌为研究对象,利用单因素试验对发酵培养基的碳源、氮源、金属离子等成分进行优化,获得... 功能性稀有糖D-阿洛酮糖主要由基因工程菌株表达D-阿洛酮糖3-差向异构酶(D-allulose 3-epimerase,DAE)催化果糖生产。该研究以表达DAE的重组大肠杆菌为研究对象,利用单因素试验对发酵培养基的碳源、氮源、金属离子等成分进行优化,获得了最佳的培养基组合:蔗糖10 g/L、大豆蛋白胨15 g/L、(NH4)2SO_(4)3 g/L、KH2PO_(4)3 g/L、MgSO_(4)0.5 g/L、MnSO_(4)0.025 mmol/L。在此基础上,利用单因素试验对培养条件进行研究,确定了最佳发酵诱导时间(10 h)、接种量(3%,摇瓶)、装液量(30%)以及异丙基-β-D-硫代半乳糖苷(isopropyl-beta-D-thiogalactopyranoside,IPTG)添加浓度(1 mmol/L),使OD_(600)增加了1.46倍,酶活提高了2.57倍。在此基础上,利用5 L发酵罐进行放大发酵实验,确定了最佳诱导时间。在最佳条件下,经过18 h的诱导发酵,菌体OD_(600)最高值达51.8,干重达到21.5 g/L,酶活达到103.8 U/mL。当细胞添加量为0.014 g DCW/L时,以500 g/L D-果糖为底物,pH为7,50℃,1 h转化率达28.76%,D-阿洛酮糖最高生成量可达149.74 g/L。该研究对D-阿洛酮糖3-差向异构酶的发酵生产具有参考价值。 展开更多
关键词 d-阿洛酮糖-3-差向异构酶 重组大肠杆菌 高密度发酵 发酵优化 重组蛋白
下载PDF
Design of a High Precision Multichannel 3D Bioprinter
19
作者 Jintao Li Bin Zhang +1 位作者 Yichen Luo Huayong Yang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第6期127-146,共20页
Three-dimensional(3D)printing technology is expected to solve the organ shortage problem.However,owing to the accuracy limitations,it is difficult for the current bioprinting technology to achieve an accurate control ... Three-dimensional(3D)printing technology is expected to solve the organ shortage problem.However,owing to the accuracy limitations,it is difficult for the current bioprinting technology to achieve an accurate control of the spatial position and distribution of a single cell or single component droplet.In this study,to accurately achieve the directional deposition of different cells and biological materials in the spatial position for the construction of large transplantable tissues and organs,a high-precision multichannel 3D bioprinter with submicron-level motion accuracy is designed,and concurrent and synergistic printing methods are proposed.Based on the high-precision motion characteristics of the gantry structure and the requirements of concurrent and synergistic printing,a 3D bioprint-ing system with a set of 6 channels is designed to achieve six-in-one printing.Based on the Visual C++environ-ment,a control system software that integrates the programmable multi-axis controller(PMAC)motion,pneumatic,and temperature control subsystems was developed and designed.Finally,based on measurements and experiments,the 3D bioprinter and its control system was verified to fulfil the requirements of multichannel,concurrent,and syn-ergistic printing with submicron-level motion accuracy,significantly shortening the printing time and improving the printing efficiency.This study not only provides an equipment basis for printing complex heterogeneous tissue structures,but also improves the flexibility and functionality of bioprinting,and ultimately makes the construction of complex multicellular tissues or organs possible. 展开更多
关键词 3d bioprinting high precision Concurrent and synergistic printing MULTICHANNEL Control system Six-in-one printing
下载PDF
Study on Asymmetric Deformation Law and Surrounding Rock Control Technology of High Stress Soft Rock Crossing Roadway
20
作者 Linhao Zhang 《World Journal of Engineering and Technology》 2023年第2期353-369,共17页
In order to solve the problem of asymmetric large deformation of high-stress soft rock crossing roadway under complex geological conditions in deep mines, taking the 2# total return airway of 76.2# section of Wuyang C... In order to solve the problem of asymmetric large deformation of high-stress soft rock crossing roadway under complex geological conditions in deep mines, taking the 2# total return airway of 76.2# section of Wuyang Coal Mine as the engineering background, the causes of asymmetric deformation and failure of soft rock crossing roadway in deep mines were summarized and analyzed by means of field investigation, theoretical analysis and numerical simulation, and the asymmetric high-efficiency support technology with large row spacing was studied. The results show that the lithology of roadway strata is the main cause of asymmetric deformation and failure of roadway. The shape change of roadway is not the main influencing factor of asymmetric deformation of roadway, but for the control of roadway surrounding rock, the straight wall semi-circular arch roadway is better than the rectangular roadway. The field industrial test shows that after adopting the new support design scheme, the displacement of the roof and floor of the roadway is reduced by 86.39% compared with the original support design scheme, and the displacement of the two sides of the roadway is reduced by 86.05% compared with the original support design scheme, which can ensure the normal and safe production of the roadway during the service period, and provide reference for the support design of other similar geological conditions. 展开更多
关键词 deep high Stress Soft Rock Penetration Asymmetric deformation Support FLAC3d
下载PDF
上一页 1 2 121 下一页 到第
使用帮助 返回顶部