从有损到无损的音频编解码框架

无损音频编码技术是用于数字音频数据存档,高质量音频编码的一种重要技术,提出了一种兼容有损编解码器的无损音频编解码系统设计。包括通过有损编码残差进行无损扩展和独立的无损编解码两部分。系统采用了声道去相关、整型提升小波、线性预测、残差处理和算术熵编码等技术。在相当复杂度条件下,达到与国际主流无损音频编码技术相当的压缩性能。     

Linking science to technology: Using bibliographic references in patents to build linkage schemes

In this paper, we develop and discuss a method to design a linkage scheme that links the systems of science and technology through the use of patent citation data. After conceptually embedding the linkage scheme in the current literature on science-technology interactions and associations, the methodology and algorithms used to develop the linkage scheme are discussed in detail. The method is subsequently tested on and applied to subsets of USPTO patents. The results point to highly skewed citation distributions, enabling us to discern between those fields of technology that are highly science-interactive and those fields where technology development is highly independent from the scientific literature base. This revised version was published online in August 2006 with corrections to the Cover Date.     

基于立体视觉的人脸三维空间位置定位方法*

针对基于姿势的自然人机交互接口设计中头部定位问题,提出了一种快速的人脸三维空间位置定位算法。首先采用级联肤色分类器与类Haar特征分类器的人脸检测器对左右路输入的图像进行快速的人脸区域定位;然后利用仿射模型匹配局部收敛性好、速度快的特点实现了左右路图像的人脸区域对齐;最后通过立体视觉原理恢复人脸的三维空间坐标。实验结果证明,提出的人脸三维空间位置定位方法速度快、定位精度较高。     

Optimization of material removal strategy in milling of thin-walled parts

The optimal material removal strategy can improve a geometric accuracy and surface quality of thin-walled parts such as turbine blades and blisks in high-speed ball end milling.The dominant conception in the material removal represents the persistence of the workpiece cutting stiffness in operation to advance the machining accuracy and machining efficiency.On the basis of theoretical models of cutting stiffness and deformation,finite element method (FEM) is applied to calculate the virtual displacements of the thin-walled part under given virtual loads at the nodes of the discrete surface.With the reference of deformation distribution of the thin-walled part,the milling material removal strategy is optimized to make the best of bracing ability of still uncut material.This material removal method is summarized as the lower stiffness region removed firstly and the higher stiffness region removed next.Analytical and experimental results show the availability,which has been verified by the blade machining test in this work,for thin-walled parts to reduce cutting deformation and meliorate machining quality.     

Zinc and vitamin A supplementation fails to reduce sputum conversion time in severely malnourished pulmonary tuberculosis patients in Indonesia

Background  

A previous study showed that combination of zinc and vitamin A reduced sputum conversion time in pulmonary tuberculosis (TB) patients.     

对称复合板冷轧变形模式的上限分析

应用上限法建立了对称复合板冷轧变形模式的数学模型,在此基础上对软复层复合板在不同条件下冷轧时的变形模式进行了计算,给出了相关计算曲线。计算结果表明,依过程参数的不同,软复层复合板冷轧时存在比例变形、界面撕开及不稳定变形三种可能的变形模式。加工率越大、界面结合强度越高、基体材料的相对强度和复合板轧后的相对厚度越小,则均匀变形区越大,界面撕开区越小。不稳定变形区仅在基体材料的相对厚度和相对强度足够大时才存在。      

Three-dimensional films of photoluminescent polyoxometalates fabricated by a colloidal crystal template

Three-dimensional ordered thin films based on 12-phosphotungstic acid (PW₁₂O₄₀/SiO₂) and lanthanide-substituted phosphotungstate (Eu(PW₁₁O₃₉)₂/SiO₂, Gd(PW₁₁O₃₉)₂/SiO₂ and Eu(P₂W₁₇O₆₁)₂/SiO₂) were constructed by an inverse opal method, using polystyrene colloidal crystal as a template. The samples were characterized by elemental analysis, XRD, IR spectra, UV–vis diffuse reflectance spectra (DR-UV–Vis) and SEM techniques. These thin films show well-defined lamellar array with inverse opal structure, and lanthanide polyoxometalate thin films exhibit photoluminescent properties.     

HY分子筛催化剂作用时机对毛竹热解的影响(英文)

A laboratory reactor was designed to test the effect of the interference instant of HY on the pyrolysis of pubescens. The time instant for intermediate species from pyrolysis to contact HY was controlled by varying the position of the catalyst bed relative to the pyrolytic cell. It was found that the effect of the interference instant was significant on the variation of different intermediate species, and the yield and quality of the products. The results also showed that, with the increase in the distance between the pyrolytic cell and the catalyst bed, the yield of liquid and relative content of the organics such as aldehyde, phenols, etc., decreased, while the yield of residue and relative content of acetic acid increased. The deoxygenation of the intermediate species was favored when the catalyst exerted its performance on them immediately after their formation.     

Aggregation-Induced Emission Photosensitizer-Armored Magnetic Nanoparticles for Sepsis Treatment: Combating Multidrug-Resistant Bacteria and Alleviating Inflammation

Sepsis, a life-threatening condition stemming from an uncontrolled host immune response to bacterial infections, continues to impose a significant global burden with high morbidity and mortality. Addressing the challenges posed by antimicrobial resistance and uncontrollable inflammation remains a challenge in sepsis treatment. Moreover, traditional antibacterial materials have low bacterial trapping efficiency and inevitable prolonged circulation within the bloodstream, resulting in suboptimal antibacterial effects, metabolic complications, and undesirable side effects. In this study, an innovative solution is introduced through the development of Fe₃O₄@SH@TBTCP-PMB, an aggregation-induced emission (AIE) photosensitizer (PS)-armored magnetic nanoparticles (NPs). It has high reactive oxygen species (ROS) generation efficiency and an exceptional ability to capture Gram-positive bacteria with over 80% enrichment efficiency within just 1 h, even at low bacterial concentrations. Under white light illumination, 100 µg mL⁻¹ of Fe₃O₄@SH@TBTCP-PMB effectively eliminated more than 99.9% of methicillin-resistant Staphylococcus aureus (MRSA). Furthermore, its magnetic separation properties efficiently prevent systemic blood circulation and associated side effects. Most importantly, Fe₃O₄@SH@TBTCP-PMB demonstrates superior anti-inflammatory effects by regulating cytokines, reducing adhesion molecule expression, and managing oxidative stress levels. This multifunctional approach significantly enhances sepsis survival rates, offering a promising strategy for combating multidrug-resistant (MDR) bacterial infections in sepsis patients while addressing inflammation-related complications.