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A survey of photon mapping state-of-the-art research and future challenges

Chun-meng KANG,Lu WAN,Yan-ning XU,Xiang-xu MENG

《信息与电子工程前沿(英文)》 2016年 第17卷 第3期   页码 185-199 doi: 10.1631/FITEE.1500251

摘要: Global illumination is the core part of photo-realistic rendering. The photon mapping algorithm is an effective method for computing global illumination with its obvious advantage of caustic and color bleeding rendering. It is an active research field that has been developed over the past two decades. The deficiency of precise details and efficient rendering are still the main challenges of photon mapping. This report reviews recent work and classifies it into a set of categories including radiance estimation, photon relaxation, photon tracing, progressive photon mapping, and parallel methods. The goals of our report are giving readers an overall introduction to photon mapping and motivating further research to address the limitations of existing methods.

关键词: Global illumination     Photon mapping     Radiance estimation     Photon relaxation     Progressive photon mapping    

Carbon dots-based fluorescence sensor for two-photon imaging of pH in diabetic mice

《化学科学与工程前沿(英文)》 2023年 第17卷 第3期   页码 298-306 doi: 10.1007/s11705-022-2212-9

摘要: Herein, a reversible pH fluorescent sensor was developed using caffeic acid as the precursor by one-step solvothermal synthesis method. The carbon dots-based sensor (CA-CDs) exhibited pH-dependent increase in fluorescence intensity and showed linear relationship in the range of pH 6.60 and 8.00. Notably, the fluorescence sensor has a reversible response to pH change. Finally, the CA-CDs has been successfully applied for two-photon imaging of the pH in liver and kidney of diabetic mice. Imaging results showed that the pH value in kidney of diabetic mice was lower than that of the normal mice, while the pH value in liver of diabetic mice was almost the same as that of the normal mice. The present study provides a simple analytical method for pH detection suitable for in vivo.

关键词: carbon dots     two-photon imaging     pH     diabetic mice    

波粒二象性理论的若干问题

黄志洵

《中国工程科学》 2002年 第4卷 第1期   页码 54-63

摘要:

论述了光波和物质波的波粒二象性理论的发展,讨论了该理论的存留问题。认为光子的静质量和光子的内部结构仍是科学中的关键性疑点。指出,虽然波粒二象性成立的前提是波长足够小,但在现有理论中却提不出一条清晰的界线。讨论了光波和电磁波是物质还是物质属性的问题。提出了对de Broglie波超光速相速的疑问。分析表明,如何建立电磁脉冲的粒子形象的问题仍需解决。此外,探讨了当电磁脉冲以超光速传播时相对论是否受破坏。最后,讨论了消失波的粒子性和虚光子问题。

关键词: 光子     光波     物质波     波粒二象性     孤子     电磁脉冲     超光速     消失波     虚光子    

Chemical mapping of cement pastes by using confocal Raman spectroscopy

Fengjuan LIU,Zhihui SUN

《结构与土木工程前沿(英文)》 2016年 第10卷 第2期   页码 168-173 doi: 10.1007/s11709-015-0323-9

摘要: In the present study, chemical mapping on the hydration process of cement paste with water-to-cement ( / ) ratio of 0.60 was implemented by Raman spectroscopy (RS). The RS was applied to study the paste from 12 hours after mixing to 28 days. Cement ingredients and hydration products, including calcium silicates (C S and C S), calcium hydroxide (CH), and ettringite, were quantitatively studied. From the research, it is observed that calcium silicates were consumed gradually with the increased hydration age. Calcium hydroxide increased and tended to cluster in the pore vicinity during hydration. Ettringite was found to form on the surface of the unreacted particles, which was shown as a mixed zone of ettringite and calcium silicates in the maps. It is concluded from the study that chemical mapping was an effective method to assist in visualizing particle dispersion and connection on top of the quantitative analysis.

关键词: chemical mapping     Raman spectroscopy     calcium silicates     calcium hydroxide     ettringite    

Independent continuous and mapping method of structural topology optimization based on the global stress

Yunkang SUI, Jili FENG, Hongling YE, Xirong PENG,

《机械工程前沿(英文)》 2010年 第5卷 第2期   页码 130-142 doi: 10.1007/s11465-010-0011-3

摘要: There are three difficulties in topology optimization of continuum structures. 1) The topology under multiple load case is more difficult to be optimized than under single load case, because the former becomes a multiple objective based on compliance objective functions. 2) With local constraints, such as an elemental stress limit, the topology is more difficult to be solved than with global constraints, such as the displacement or frequency limits, because the sensitivity analysis of the former has very expensive computation. 3) With the phenomenon of load illness, which is similar with stiffness illness in the structural analysis, it is not easy to get the reasonable final topological structure, because it is difficult to consider different influences between the loads with small forces and big forces, and some topology paths of transferring small forces may disappear during the iteration process. To overcome difficulties above, four measures are adopted. 1) Topology optimization model is established by independent continuous mapping (ICM) method. 2) Based on the von Mises strength theory, all elements’ stress constraints are transformed into a structural energy constraint. 3) The phenomenon of load illness is divided to classify into three cases. 4) A strategy based on strain energy is proposed to adopt ICM method with stress globalization, and the problems of the above mentioned three cases of load illness are solved in terms of different complementary approaches. Several numerical examples show that the topology path of transferring forces can be obtained more easily by substituting global strain energy constraints for local stresses constraints, and the problem of load illness can be solved well by the weighting method that takes the structural energy as a weighting coefficient.

关键词: independent continuous mapping (ICM) method     global stresses constraints     topology optimization     continuum structure     load illness    

and future research directions for the phytoremediation of heavy metal-contaminated soil: A knowledge mapping

《环境科学与工程前沿(英文)》 2022年 第16卷 第6期 doi: 10.1007/s11783-021-1507-2

摘要:

• The overall global perspective of the PHMCS field was obtained.

关键词: Heavy metal-contaminated soil     Hot topics     Knowledge mapping analysis     Knowledge base     Phytoremediation    

Synthesis and characterization of 2,5-bis[4-(2-arylvinyl)phenyl]-1,3,4-oxadiazoles with two-photon fluorescence

ZHU Xiaoqin, QIAN Ying, LU Zhifeng

《化学科学与工程前沿(英文)》 2007年 第1卷 第4期   页码 381-384 doi: 10.1007/s11705-007-0069-6

摘要: Four novel 2,5-bis[4-(2-arylvinyl)phenyl]-1,3,4-oxadiazoles that exhibit strong two-photon absorption and enhanced two-photon excited fluorescence were designed and synthesized based on push-core-pull-core-push molecules built from embedding electron-transporting 1,3,4-oxadiazole in aromatic conjugated system through Wittig-Horner reaction. Their chemical structures were determined to show trans-vinylene character according to infrared (IR) and H nuclear magnetic resonance (NMR) spectra. A very effective energy transfer from the excited units to the ?-conjugated bridging unit can enhance the two-photon absorption and two-photon fluorescence.

关键词: 2-arylvinyl     trans-vinylene character     effective     fluorescence     push-core-pull-core-push    

中微子研究新进展

黄志洵

《中国工程科学》 2002年 第4卷 第10期   页码 90-93

摘要:

自从前苏联的V. Lubimov(1980年)和瑞士苏黎世大学的W. Kundig(1986年)发表了关于中微子质量的研究以来,进一步的工作已在日本等国展开;现在有一批实验室在进行中微子研究。文章论述了两个关键问题,即光子与中微子的相似性和令人感兴趣的超光速中微子理论。

关键词: 中微子     超光速     快子     光子    

Electromagnetic induction mapping at varied soil moisture reveals field-scale soil textural patterns

Hiruy ABDU, David A. ROBINSON, Janis BOETTINGER, Scott B. JONES

《农业科学与工程前沿(英文)》 2017年 第4卷 第2期   页码 135-145 doi: 10.15302/J-FASE-2017143

摘要: Knowledge of the spatial distribution of soil textural properties is important for determining soil moisture storage and soil hydraulic transport properties. Capturing field heterogeneity without exhaustive sampling and costly sample analysis is difficult. Our objective was to employ electromagnetic induction (EMI) mapping in low apparent electrical conductivity (EC ) soils at varying soil water contents to capture time invariant properties such as soil texture. Georeferenced EC measurements were taken using a ground conductivity meter on six different days where volumetric water content ( ) varied from 0.11 to 0.23. The 50 m × 50 m field included a subsurface gravelly patch in an otherwise homogeneous silt-loam alluvial soil. Ordinary block kriging predicted EC at unsampled areas to produce 1-m resolution maps. Temporal stability analysis was used to divide the field into three distinct EC regions. Subsequent ground-truthing confirmed the lowest conductivity region correlated with coarse textured soil parent materials associated with a former high-energy alluvial depositional area. Combining maps using temporal stability analysis gives the clearest image of the textural difference. These maps could be informative for modeling, experimental design, sensor placement and targeted zone management strategies in soil science, ecology, hydrology, and agricultural applications.

关键词: soil electrical conductivity     soil texture mapping     temporal stability analysis    

Quantifying and mapping spatial variability of Shanghai household carbon footprints

Shangguang YANG,Chunlan WANG,Kevin LO,Mark WANG,Lin LIU

《能源前沿(英文)》 2015年 第9卷 第1期   页码 115-124 doi: 10.1007/s11708-015-0348-8

摘要: Understanding the spatial variability of household carbon emissions is necessary for formulating sustainable and low-carbon energy policy. However, data on household carbon emissions is limited in China, the world’s largest greenhouse gases emitter. This study quantifies and maps household carbon emissions in Shanghai using a city-wide household survey. The findings reveal substantial spatial variability in household carbon emissions, especially in transport-related emissions. Low emission clusters are founded in Hongkou, Xuhui, Luwan, Jinshan, and Fengxian. High emission clusters are located in Jiading and Pudong. Overall, the spatial pattern of household carbon emissions in Shanghai is donut-shaped: lowest in the urban core, increasing in the surrounding suburban areas, and declining again in the urban fringe and rural regions. The household emissions are correlated with a number of housing and socioeconomic factors, including car ownership, type of dwelling, size of dwelling, age of dwelling, and income. The findings underscore the importance of a localized approach to low-carbon policy-making and implementation.

关键词: household carbon emissions     spatial variability     energy policy     Shanghai     China    

Mapping the structure-activity relationship of

Worawan PANPIPAT, Hasene KESKIN, Zheng GUO

《化学科学与工程前沿(英文)》 2015年 第9卷 第1期   页码 105-113 doi: 10.1007/s11705-015-1502-x

摘要: The phase behavior of twelve synthesized -sitosteryl fatty acid esters with acyl moieties with different chain lengths (C2:0-C18:0) and different degrees of unsaturation (C18:1-C18:3) were investigated in pure and mixed Langmuir monolayers with phospholipids. The surface-pressure isotherms showed that short chain -sitosteryl fatty acid esters gave smaller mean molecular areas and had decreased monolayer stability and the long chain steryl esters did not produce collapsed plateaus. All the steryl esters displayed strong condensing effects, but there was a pronounced structural dependency: medium chain esters (C8 and C10) were less efficient than short and long chain esters. Atomic force microscopy imaging demonstrated that monolayers mixed with dipalmitoyl phosphatidylcholine (DPPC) displayed both DPPC-rich and steryl lipid-rich domains. However, the height and area differences between the two phases and the roughness and morphologic patterns were very dependent on the steryl lipid concentrations as well as the length, the degree of unsaturation and the molecular conformations of the acyl segments. These findings not only provide a better understanding of the interactions between phytosteryl hydrophobic derivatives and biomembranes, but also may be of general use for the design and engineering of phytosterol structural derivations for specific food and pharmaceutical applications.

关键词: β-sitosteryl fatty acid esters     dipalmitoyl phosphatidylcholine     Langmuir monolayer     condensing effect     structure-activity relationship    

Mapping the trends and prospects of battery cathode materials based on patent landscape

《能源前沿(英文)》   页码 822-832 doi: 10.1007/s11708-023-0900-x

摘要: Advancing portable electronics and electric vehicles is heavily dependent on the cutting-edge lithium-ion (Li-ion) battery technology, which is closely linked to the properties of cathode materials. Identifying trends and prospects of cathode materials based on patent analysis is considered a kernel to optimize and refine battery related markets. In this paper, a patent analysis is performed on 6 popular cathode materials by comprehensively considering performance comparison, development trend, annual installed capacity, technology life cycle, and distribution among regions and patent assignees. In the technology life cycle, the cathode materials majorly used in electric vehicle have entered maturity stage, while the lithium cobalt oxide (LCO) cathode that is widely used in portable electronics is still in the growth stage. In global patent distributions, China holds more than 50% of total patents. In the top 10 patent assignees of 6 cathode materials, 2 institutes are from China with the rest being Japan (6) and Republic of Korea (2), indicating that the technology of cathode materials in China is relatively scattered while cathode research is highly concentrated in Japan and Republic of Korea. Moreover, the patent distribution has to consider practical issues as well as the impacts of core patents. For example, the high cost discourages the intention of applying international patents. This paper is expected to stimulate battery research, understand technical layout of various countries, and probably forecast innovative technology breakthroughs.

关键词: patent analysis     cathode     batteries     technology life cycle    

血浆代谢组学结合超微弱发光表征早期2型糖尿病的中医证型 Article

何敏, 孙濛濛, Slavik Koval, Roeland Van Wijk, Thomas Hankemeier, Jan Van der Greef, Eduard P.A. Van Wijk, 王梅

《工程(英文)》 2019年 第5卷 第5期   页码 916-923 doi: 10.1016/j.eng.2019.03.011

摘要:

2型糖尿病(T2DM)的患病率在全球范围内呈迅速上升趋势。因通用干预措施收效甚微,所以疾病研究的重点已经转向个性化策略,特别是疾病的早期阶段的个性化策略。中医基于系统观建立并结合了个性化策略,提高了我们对个性化诊断的认识。从系统生物学的角度,例如将代谢组学与其他系统性诊断方法(如超微弱发光)相结合,可提高对个性化诊断的理解,同时为此类个性化诊疗策略提供生化相关物质基础。在本研究中,我们研究了44名处于2型糖尿病前期的受试者的血浆代谢组学,探讨了基于以下中医亚型进行疾病早期分型的可行性:气阴两虚、气阴两虚挟痰湿、气阴两虚挟血瘀。此外,通过血浆代谢组学和超微弱发光在中医亚分型方面的关系,获得体内生化参数与体外表征参数的关联性信息,从而尝试对疾病亚型分类及判断有更深一步的阐释。结果表明,血浆代谢物的主成分分析揭示了从中医角度划分的2型糖尿病前期不同亚型之间的差异性。对于3种2型糖尿病前期亚型,相对含量较高的脂质(如胆固醇酯和甘油三酯)是鉴别其中之二的重要元素,并且可能与较高的心血管疾病风险相关。血浆代谢组学数据表明,血脂谱是超微弱发光在2型糖尿病亚型分型中收集的重要组成部分。结果表明,2型糖尿病前期的不同中医亚型之间存在代谢差异,可通过血浆代谢物分析来区分这些亚型,血浆代谢组学为系统性超微弱发光体表测量提供了生化参数相关依据。

关键词: 2型糖尿病     血浆代谢物     疾病亚型     超微弱发光     相关性网络    

人类遗传病的家系收集疾病基因定位克隆与疾病基因功能的研究

夏家辉

《中国工程科学》 2000年 第2卷 第11期   页码 1-11

摘要:

介绍了中国医学遗传学国家重点实验室在遗传病家系收集、疾病基因定位、疾病基因克隆和疾病基因功能研究方面的研究工作。用细胞遗传学G显带技术于1975年发现了一条与鼻咽癌相关的标记染色体t(1;3)(q44;p11);1981年将睾丸决定基因(TDF)定位于Yp11.32带;1991年以来收集遗传病家系345种共590个;1996年用显微切割、PCR、微克隆技术克隆了EXT2基因;1998年用基因家族-候选疾病基因克隆方法克隆了遗传性神经性耳聋基因GJB3;1999年用连锁分析和全基因组扫描将一种遗传性弥漫性浅表性光敏性汗孔角化症定位于12q23.2带,并在基因功能研究中发现了一个新的细胞内转运蛋白。

关键词: 遗传病家系     基因定位和克隆     基因家族-候选疾病基因克隆     基因组扫描     基因功能研究    

光的本性

范良藻,冯劲松

《中国工程科学》 2007年 第9卷 第2期   页码 58-67

摘要:

文献[1]提出每一个光量子hf都由个数不同的N(λ)个单光子组成的假设,并在已公布的氢光谱的数 据中找出和不同hf的光量子相对应的N(λ)值和单光子的质量。文章报告了进一步发现光量子hf的波长与N(λ) 的乘积在某些特定条件下是一个不变量ζ=N(λ)λ[2]这一特征现象,从而破解了波粒二象性近百年之迷端:所 谓光量子的波长不过是相邻两个单光子的间距,而频率f则是在单位时间内通过空间坐标某处单光子的个数, 并用单光子的数形结构导出所有惯性系中光速c=λf都是不变的结论。狭义相对论的光速不变原理,不再是一 个

关键词: 光量子     波粒二象性     原子光谱     狭义相对论    

标题 作者 时间 类型 操作

A survey of photon mapping state-of-the-art research and future challenges

Chun-meng KANG,Lu WAN,Yan-ning XU,Xiang-xu MENG

期刊论文

Carbon dots-based fluorescence sensor for two-photon imaging of pH in diabetic mice

期刊论文

波粒二象性理论的若干问题

黄志洵

期刊论文

Chemical mapping of cement pastes by using confocal Raman spectroscopy

Fengjuan LIU,Zhihui SUN

期刊论文

Independent continuous and mapping method of structural topology optimization based on the global stress

Yunkang SUI, Jili FENG, Hongling YE, Xirong PENG,

期刊论文

and future research directions for the phytoremediation of heavy metal-contaminated soil: A knowledge mapping

期刊论文

Synthesis and characterization of 2,5-bis[4-(2-arylvinyl)phenyl]-1,3,4-oxadiazoles with two-photon fluorescence

ZHU Xiaoqin, QIAN Ying, LU Zhifeng

期刊论文

中微子研究新进展

黄志洵

期刊论文

Electromagnetic induction mapping at varied soil moisture reveals field-scale soil textural patterns

Hiruy ABDU, David A. ROBINSON, Janis BOETTINGER, Scott B. JONES

期刊论文

Quantifying and mapping spatial variability of Shanghai household carbon footprints

Shangguang YANG,Chunlan WANG,Kevin LO,Mark WANG,Lin LIU

期刊论文

Mapping the structure-activity relationship of

Worawan PANPIPAT, Hasene KESKIN, Zheng GUO

期刊论文

Mapping the trends and prospects of battery cathode materials based on patent landscape

期刊论文

血浆代谢组学结合超微弱发光表征早期2型糖尿病的中医证型

何敏, 孙濛濛, Slavik Koval, Roeland Van Wijk, Thomas Hankemeier, Jan Van der Greef, Eduard P.A. Van Wijk, 王梅

期刊论文

人类遗传病的家系收集疾病基因定位克隆与疾病基因功能的研究

夏家辉

期刊论文

光的本性

范良藻,冯劲松

期刊论文