基于时频分帧能量熵的陶瓷制品敲击声波信号特征识别

针对现有陶瓷制品敲击声波信号特征提取方法中提取的特征代表性降低的问题,该文提出结合最大重叠离散小波包变换(MODWPT)和时频分帧能量熵的特征提取方法。首先采用MODWPT将信号分解为4层,再对每个节点的子信号分帧后计算各个节点的时频分帧能量熵,然后根据能量分布特征选择了前6个节点的时频分帧能量熵特征,最后构建随机森林分类器完成识别。将该方法和MODWPT时频分段能量熵、MODWPT归一化能量特征两种方法进行比较。实验结果表明,相比MODWPT时频分段能量熵、MODWPT归一化能量两种特征提取方法,MODWPT时频分帧能量熵能提升特征的代表性,具有更优的陶瓷制品敲击声波信号特征识别性能,其识别的F₁值达到了98.46%,相比上述两种方法分别提升F₁值3.22%、1.86%。     

Evaluation of simulated reservoirs by using the oblique-incidence reflectivity difference technique

正Dear Editors,The evaluation of the oil-gas resources’potential depends on the characterization of reservoirs.The geometry of the pore-crack structures and the compositions of the pore walls have influence on hydrocarbon production about capillarity and permeability[1].Besides,it has been known that the adsorption phenomenon in micro-structure plays a significant role in oil-gas reservoirs.Some techniques have been applied to characterize conventional and unconventional reservoirs,     

含吡啶基团的双极主体材料的合成、性能与蓝光电致磷光器件研究

吡啶类衍生物具有较好的电子传输性能和较高的三线态能级,在有机电致发光中一般用来构建电子传输材料或主体材料中的电子传输单元.本文通过将吡啶的2,6位与三苯胺或N-苯基-咔唑的邻位连接设计合成了两个基于吡啶的双极主体材料DTPAPPy和DCzPPy.它们的三线态能级分别为2.64和2.70eV.以它们作为主体材料制备的基于Firpic的蓝光磷光器件最大电流效率分别为15.4和25.3cd/A.     

Geometry of 2×2 Hermitian matrices over any division ring

Let D be a division ring with an involution-,H2(D) be the set of 2 × 2 Hermitian matrices over D. Let ad(A,B) = rank(A-B) be the arithmetic distance between A,B ∈ H2(D) . In this paper,the fundamental theorem of the geometry of 2 × 2 Hermitian matrices over D(char(D) = 2) is proved:if  :H2(D) → H2(D) is the adjacency preserving bijective map,then  is of the form (X) = tP XσP +(0) ,where P ∈ GL2(D) ,σ is a quasi-automorphism of D. The quasi-automorphism of D is studied,and further results are obtained.     

Parallel detection and quantitative analysis of specific binding of proteins by oblique-incidence reflectivity difference technique in label-free format

In this work, we parallelly detected the specific binding between microarray targets including 12 different kinds of proteins and the probe solution containing five corresponding antibodies and quantitatively analyzed the interactions between CDH13 and solution phase anti-CDH13 at six different probe concentrations by oblique-incidence reflectivity difference (OIRD) method in label-free format. The detection sensitivity reached 10 ng/mL. The experimental results indicate that the OIRD method is a promising and competing technique not only in research work but also in clinic.     

一种新型设计肽作为药物载体的潜在应用研究

目前有大量关于全程电荷匹配设计肽的应用的研究,但是关于半程电荷匹配设计肽作为药物的应用研究却未见报道.本文对新型设计的半程电荷匹配肽P9（AC-Pro-Ser-Phe-Asn-Phe-Lys-Phe-Glu-Pro-NH2）的研究发现,P9可以成功地将作为疏水药物模型的芘稳定悬浮于水溶液中.大豆卵磷脂微囊被用以模拟细胞膜.荧光数据显示芘可以借助P9的包埋作用以晶体状态存在于水溶液中.并且当包埋体加入到脂质体微囊体系中时,芘可以从P9的包埋体系中以分子形态释放到膜的脂质层内.实验发现当包埋于芘上的P9较多,包埋壁较厚,芘的释放速度相对变缓.我们可以利用这一特性,通过调节加入的P9的浓度来控制包埋于芘上P9的厚度,从而控制芘的释放速率.研究表明,具有半程电荷匹配性质的P9肽可以作为运载疏水药物的载体.     

Label-free high-throughput and real-time detections of protein interactions by oblique-incidence reflectivity difference method

Selected Mouse IgG of 1 mg/mL as target was fabricated on microarray for 500 sample dots.Label-free and real-time reaction dynamic processes were detected between the microarrays with Goat Anti-mouse IgG of 0.02 mg/mL using the obliqueincidence reflectivity difference(OIRD)method.We obtained the reaction results and the reaction dynamic curves of 500 protein dots.In addition,we also used label-free detection of protein microarrays of 10080 sample dots,including BSA and different concentrations of Mouse IgG and Rabbit IgG,by OIRD.The obtained reaction results between the protein microarray with 1 mg/mL Goat Anti-mouse IgG and 1 mg/mL Goat Anti-rabbit IgG are reported herein.Experimental results show that OIRD can be not only label-free high-throughput detection method for biological microarrays but also label-free real-time detection in the interaction processes of biomolecules.     

A novel and efficient synthesis of Entecavir

A practical synthesis of Entecavir (1) has been accomplished in 10 steps with 21% overall yield. The key steps to construct the five-membered carbocyclic framework 2 are a ring-closing metathesis and a diethyl-aluminum 2,2,6,6-tetramethyl piperidide (DA-TMS) mediated epoxide isomerization. Furthermore, the guanine was introduced by modified Mitsunobu reaction.     

Crystal formation and growth mechanism of inorganic nanomaterials in sonochemical syntheses

A clear understanding of the nucleation, growth, coarsening, and aggregation processes of nanomaterials is necessary to enable the preparation of highly controlled nanostructures. Among wet chemical synthetic methods, ultrasound-assisted preparation has become an important tool in material science. The formation and crystal growth mechanism under ultrasound is special compared with other wet chemical synthetic routes. In this review, we discussed the chemical and physical effect of ultrasound and summarized the ultrasonic effect on crystallization. The sonolysis of water and the cavitation-induced microjet impact and shockwave are the two key factors in the sonochemical formation of inorganic nanomaterials. The ultrasonic-assisted Ostwald ripening and oriented attachment processes have been reviewed for the possible crystal growth mechanisms in the fabrication of inorganic nanostructures.     

Improvement of the physical properties of poly(methyl methacrylate) by copolymerization with N-pentafluorophenyl maleimide; zero-orientational and photoelastic birefringence polymers with high glass transition temperatures

Copolymers of N-pentafluorophenyl maleimide (PFPMI) with methyl methacrylate (MMA) were synthesized by a free radical initiator, such as AIBN. The refractive indexes of the copolymers remained nearly constant (1.4970 at 532 nm) regardless of the polymer composition. These copolymers also showed high thermal stability. The orientational and photoelastic birefringence of the copolymers obtained were measured. Since both of the orientational and photoelastic birefringences of PMMA are negative whereas poly(PFPMI) exhibits positive, thus we have obtained nearly zero orientational and photoelastic birefringence polymers when the ratios of MMA/PFPMI were 91.8/8.2 and 97.0/3.0 mol%, respectively. Based on the experimental data, the ratios of MMA/PFPMI for zero birefringence were determined to be 88.9/11.1 and 93.8/6.2 mol% for orientational and photoelastic birefringence, respectively. The Tgs of corresponding copolymers were estimated to be 128 and 122 ℃.