Dotted Core–Shell Nanoparticles for T1‐Weighted MRI of Tumors

Gd‐based T ₁‐weighted contrast agents have dominated the magnetic resonance imaging (MRI) contrast agent market for decades. Nevertheless, they are reported to be nephrotoxic and the U.S. Food and Drug Administration has issued a general warning concerning their use. In order to reduce the risk of nephrotoxicity, the MRI performance of the Gd‐based T ₁‐weighted contrast agents needs to be improved to allow a much lower dosage. In this study, novel dotted core–shell nanoparticles (FeGd‐HN3‐RGD2) with superhigh r ₁ value (70.0 mM^?1 s^?1) and very low r ₂/r ₁ ratio (1.98) are developed for high‐contrast T ₁‐weighted MRI of tumors. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay and histological analyses show good biocompatibility of FeGd‐HN3‐RGD2. Laser scanning confocal microscopy images and flow cytometry demonstrate active targeting to integrin α_vβ₃ positive tumors. MRI of tumors shows high tumor ΔSNR for FeGd‐HN3‐RGD2 (477 ± 44%), which is about 6‐7‐fold higher than that of Magnevist (75 ± 11%). MRI and inductively coupled plasma results further confirm that the accumulation of FeGd‐HN3‐RGD2 in tumors is higher than liver and spleen due to the RGD2 targeting and small hydrodynamic particle size (8.5 nm), and FeGd‐HN3‐RGD2 is readily cleared from the body by renal excretion.     

A Flexible Caterpillar‐Like Gold Nanoparticle Assemblies with Ultrasmall Nanogaps for Enhanced Dual‐Modal Imaging and Photothermal Therapy

Gold nanoparticle (AuNP) assemblies (GNAs) have attracted attention since enhanced coupling plasmonic resonance (CPR) emerged in the nanogap between coupling AuNPs. For one dimensional GNAs (1D‐GNAs), most CPR from the nanogaps could be easily activated by electromagnetic waves and generate drastically enhanced CPR because the nanogaps between coupling AuNPs are linearly distributed in the 1D‐GNAs. The reported studies focus on the synthesis of 1D‐GNAs and fundamental exploration of CPR. There are still problems which impede further applications in nanomedicine, such as big size (>500 nm), poor water solubility, and/or poor stability. In this study, a kind of 1D flexible caterpillar‐like GNAs (CL‐GNAs) with ultrasmall nanogaps, good water solubility, and good stability is developed. The CL‐GNAs have a flexible structure that can randomly move to change their morphology, which is rarely reported. Numerous ultrasmall nanogaps (<1 nm) are linearly distributed along the structure of CL‐GNAs and generate enhanced CPR. The toxicity assessments in vitro and vivo respectively demonstrate that CL‐GNAs have a low cytotoxicity and good biocompatibility. The CL‐GNAs can be used as an efficient photothermal agent for photothermal therapy, a probe for Raman imaging and photothermal imaging.     

热敏（温变）油墨的变色原理及其在包装领域的应用

阐述了不可逆和可逆热敏(温变)油墨的变色原理,及不可逆热敏(温变)油墨的示温功能在食品、药品等包装领域的应用,可逆热敏(温变)油墨在包装防伪领域的应用。展望了热敏(温变)油墨的发展方向,即开发出适合于胶印与凹印、成本较低、变色温度灵敏的热敏(温变)油墨。     

基于概率图模型的单信标定位算法研究

随着人类对海洋认识的逐步深入,水下目标的位置信息成为了一种不可或缺的水下信息源,传统的水下定位方法已经不能满足不同场景的应用需求。无论是在测量信息多元化时的多元信息融合定位,还是测量信息不足时的时域信息联合定位时均存在局限性。为此文章提出了基于概率图模型的单信标定位算法,在信标稀疏或者信标通信信息缺失的情况下,通过联合目标时域上其他位置时刻的所有量测信息,从而实现目标定位。此外文章还分析了模型分辨率和测距误差对定位结果的影响,并通过湖试验证概率图方法的有效性,证明其能够在传统定位方法无法使用的单信标的定位跟踪过程中,估计出每一时刻目标的位置,描述目标的运动轨迹。平均定位精度达到1.203 5 m。     

采用主分量分析方法研究随机共振

噪声能量向信号能量的转换是随机共振具有的独特优点,也是实际应用随机共振进行弱信号检测的基础。由于随机共振系统只在合适量的噪声输入时产生最大的信噪比输出(共振),过多、过少的噪声都会降低系统的性能,因此,如何有效地控制输入到随机共振系统中的噪声十分重要。本文首次提出采用主分量分析方法研究随机共振,其基本思路是分解信号和噪声能量到相互正交的主轴方向上,之后进行重构,通过控制重构主轴的数目(重构维数),获得最优量的输入噪声。实验结果证实了方法的有效性。     

以Liq:Rubrene为发光层的白色有机电致发光器件的研制

以蓝色发光材料Liq为主体,以一定的比例掺入黄光染料Rubrene,研制了新型白色有机电致发光器件.调节Rubrene的掺杂比为1.1%时得到近白光器件,色坐标为(0.308,0.347),器件的启亮电压为8V,当外加电压达到25V时,器件发光亮度达3120cd/m2.     

四川盆地芭蕉场石炭系储层特征研究

芭蕉场气田是川东地区的小型气田。唯一的芭蕉1井，仅钻获石炭系气层与区域特征相似。石炭系为主要由石灰岩、白云岩与少量石膏构成的岩性组合。由于沉积和剥蚀的原因，仅残存上石炭统黄龙组。储集岩包括细粉晶云岩、泥-细粉晶云岩、细-粗粉晶云岩、针孔云岩、残余生屑灰质云岩及细-粗粉晶灰岩、泥晶、细-粗粉晶灰岩。储集空间主要为各种孔隙，辅以洞穴和裂缝；孔隙分为溶蚀孔隙及原生孔隙，溶蚀孔隙包括粒间、粒内溶孔、砾内溶孔、铸模孔、体腔孔及粒裂孔等。原生孔隙中包括粒间晶间孔、生物遮蔽孔，裂缝为主要的渗流通道；有利储层发育的成岩作用主要有白云化作用和溶蚀作用。综合评价，芭蕉场石炭系储层为为低孔、低渗、高含气饱和度储层。     

110ksi级钛合金油管耐蚀性能研究

针对钛合金在油气井环境下面临的腐蚀问题,通过开展模拟油田腐蚀工况下应力腐蚀及不同温度条件下酸化液中失重试验,同时开展与镍基合金管材的缝隙腐蚀和电偶腐蚀等系列试验,采用扫描电子显微镜、XRD等方法观察试样形貌和腐蚀产物,评价钛合金油管的耐腐蚀性能。结果表明,在苛刻腐蚀工况(溶液介质：5 MPa H₂S+11 MPa CO₂+10%Cl^-)及NACE TM 0177标准A溶液下,采用四点弯曲的试验方法,加载应力为758 MPa,经720 h后试样未发生断裂且无应力腐蚀裂纹,表明该钛合金管材应力腐蚀敏感性较低。在两种浓度为0.1 mol/L的酸化液中,随着试验温度从室温升至160℃,钛合金管材腐蚀速率均逐渐增大,且腐蚀速率在胶凝酸中低于在转向酸中;与镍基合金管材对比,钛合金管材具有更优异的抗点蚀和抗缝隙腐蚀;在模拟苛刻腐蚀工况下,钛合金管材分别与625和825镍基合金偶接后均未出现明显的电偶腐蚀效应导致加速腐蚀现象。     

集肤效应电伴热系统的建模与控制策略

鉴于海底输油管道集肤效应电伴热系统在加热降凝时的重要性,以集肤效应电伴热系统的机理为基础,分析集肤效应伴热系统的磁场分布,进而获得集肤效应电伴热系统的等效电路模型,并引入加热功率作为中间变量,从而建立电源频率与集肤效应伴热温度之间的关系。针对集肤效应电伴热系统,从整体上提出一种基于Hammestein模型的非线性 预测控制方法,首先采用辅助模型运用标准粒子群算法对Hammerstein模型的参数进行辨识及优化,然后对线性环节设计广义预测控制器,利用所需伴热温度求解出中间变量加热功率,再对非线性环节求逆反解出所需的电源频率,从而达到高效伴热的目的,并通过仿真研究验证了该控制策略的可行性和有效性。     

Analysis of the p+/p window layer of thin film solar cells by simulation

正The application of a p~+/p configuration in the window layer of hydrogenated amorphous silicon thin film solar cells is simulated and analyzed utilizing an AMPS-ID program.The differences between p~+-p-i-n configuration solar cells and p-i-n configuration solar cells are pointed out.The effects of dopant concentration, thickness of p~+-layer,contact barrier height and defect density on solar cells are analyzed.Our results indicate that solar cells with a p~+-p-i-n configuration have a better performance.The open circuit voltage and short circuit current were improved by increasing the dopant concentration of the p~+ layer and lowering the front contact barrier height.The defect density at the p/i interface which exceeds two orders of magnitude in the intrinsic layer will deteriorate the cell property.