晋西丘陵山区鼠类群落结构与多样性研究

目的:2011年—2016年,在吕梁市柳林县4种不同的生境地对鼠类进行捕获调查,分析其群落组成和种群多样性。方法:采用铗夜法。结果:共捕获8种鼠类,分别是社鼠、长尾仓鼠、大仓鼠、子午沙鼠、大林姬鼠、花鼠、褐家鼠、小家鼠;不同生境地鼠类多样性顺序表现为:果园农田荒山疏林地农舍;鼠类多样性总体呈现"低—高—低"的趋势。结论:鼠类多样性与生境类型密切相关,并且受人类干扰程度、植被类型、植物的生物量、降水、海拔等环境因素的影响。     

Direct Determination of Energy Band Alignments of Ni/Al2O3/GaN MOS Structures Using Internal Photoemission Spectroscopy

The energy band alignments of Ni/Al₂O₃/GaN heterostructures have been explored by internal photoemission (IPE) and capacitance–voltage (CV) measurements. By performing IPE measurements at both reverse- and forward-bias conditions, the Ni/Al₂O₃ Schottky barrier is found to be 2.9 ± 0.1 eV with the presence of a strong image force lowering effect, while the Al₂O₃/GaN conduction-band offset is determined to be 2.2 ± 0.1 eV and is insensitive to oxide electrical field. CV-based flat-band voltage analysis has further been performed on samples with different oxide thicknesses, not only confirming the IPE-measured band alignment but also revealing the presence of 3.0 × 10¹² cm^-2 net positive charge at the Al₂O₃/GaN interface.     

A Preliminary Study on Robot-Assisted Ankle Rehabilitation for the Treatment of Drop Foot

This paper involves the use of a compliant ankle rehabilitation robot (CARR) for the treatment of drop foot. The robot has a bio-inspired design by employing four Festo Fluidic muscles (FFMs) that mimic skeletal muscles actuating three rotational degrees of freedom (DOFs). A trajectory tracking controller was developed in joint task space to track the predefined trajectory of the end effector. This controller was achieved by controlling individual FFM length based on inverse kinematics. Three patients with drop foot participated in a preliminary study to evaluate the potential of the CARR for clinical applications. Ankle stretching exercises along ankle dorsiflexion and plantarflexion (DP) were delivered for treating drop foot. All patients gave positive feedback in using this ankle robot for the treatment of drop foot, although some limitations exist. The proposed controller showed satisfactory accuracy in trajectory tracking, with all root mean square deviation (RMSD) values no greater than 0.0335 rad and normalized root mean square deviation (NRMSD) values less than 6.7%. These preliminary findings support the potentials of the CARR for clinical applications. Future work will investigate the effectiveness of the robot for treating drop foot on a large sample of subjects.     

Enhanced photocatalytic properties of N–P co-doped TiO<Subscript>2</Subscript> nanosheets with {001} facets

Nitrogen (N) and phosphorus (P) co-doped anatase TiO₂ nanosheets were realized by low-temperature self-doping N–TiO₂ followed by high-temperature P doping with foreign precursor. It is found that P doping process can maintain good TiO₂ nanosheets morphology with exposed {001} facets. Chemical state of dopants indicates that N and P atoms replace O on O sites in TiO₂ lattice. Compared with pure TiO₂ and N-doped TiO₂, N–P co-doped TiO₂ nanosheets exhibits stronger optical absorption and higher degradation rate of dye molecules in visible light regime. The enhanced photocatalytic properties are attributed to two factors. On one hand, N–P co-doping can effectively reduce band gap of TiO₂ from 3.20 to 2.48 eV, leading to an enhancement of the absorption in visible light regime. On the other hand, the presence of exposed {001} facets of TiO₂ nanosheets can induce the effective separation of photogenerated electrons and holes in reaction.     

集输管道绝缘接头强度评价方法研究

绝缘接头作为阴极保护系统的关键组件,其安全性与可靠性的研究在不断深入。由于集输系统高温、高压的特点,绝缘接头必然承受由于内压和热胀等导致的弯矩,加之其结构特点,可能会引起泄漏。为此,有必要综合考虑工况条件,研究绝缘接头可承受的安全弯矩值,并形成基于强度的评价方法。根据规范要求,结合管道强度理论,推导了绝缘接头承受弯矩范围的计算公式,提出了对应的绝缘接头强度校核与设计弯矩值选取方法;研究成果为绝缘接头安全设计与强度校核提供了参考与借鉴。     

Forecasting complex group behavior via multiple plan recognition

Group behavior forecasting is an emergent research and application field in social computing. Most of the existing group behavior forecasting methods have heavily relied on structured data which is usually hard to obtain. To ease the heavy reliance on structured data, in this paper, we propose a computational approach based on the recognition of multiple plans/intentions underlying group behavior.We further conduct human experiment to empirically evaluate the effectiveness of our proposed approach.     

The geochemistry of trace elements in marine oil shales and their combustion residues: Occurrence and environmental aspects

With the aim of better understanding geochemistry of trace elements in marine oil shale and its combustion residues, 23 raw samples, 17 oil shale combustion residues, and 18 selected minerals from Bilong Co oil shale are studied. Potentially hazardous trace elements in raw samples include As, B, Cd, Mo, and Se, while Se, Mo, Cd, As, Bi, and U are potentially hazardous trace elements in combustion residues. As is controlled mainly by Fe-bearing minerals. B occurs mainly in clay minerals. Cd is enriched mainly in calcite. Mo is controlled mainly by organic matter. Se is mainly controlled by P-bearing minerals.     

制备工艺对钯粉粒径的影响

探讨了利用液相还原法,以水合肼为还原剂,制备大颗粒钯粉,应用单变量对比试验的方法讨论了Pd2+浓度、温度、pH值对钯颗粒形核和生长过程的影响,这些因素的影响决定了钯颗粒粒度大小和服役性能。经分析和讨论,得出参数Pd2+浓度为0.1 mol·L-1,pH值为12,温度为50℃是最佳工艺参数的结论,并在此参数下制备出较大粒径的钯粉,且利用SEM,XRD,马尔文激光粒度仪、氮吸附等对其进行表面微观形貌、成分、粒度分布和比表面积等性能进行了分析,较有力地说明这种钯粉具有纯度高、比表面积大等优点,能够满足现排代服役条件的要求,对实际工业生产具有一定的指导意义。     

A Multiplex PCR Assay for the Rapid and Sensitive Detection of Methicillin‐Resistant Staphylococcus aureus and Simultaneous Discrimination of Staphylococcus aureus from Coagulase‐Negative Staphylococci

Abstract: Methicillin‐resistant Staphylococcus aureus (MRSA) is a global health concern, which had been detected in food and food production animals. Conventional testing for detection of MRSA takes 3 to 5 d to yield complete information of the organism and its antibiotic sensitivity pattern. So, a rapid method is needed to diagnose and treat the MRSA infections. The present study focused on the development of a multiplex PCR assay for the rapid and sensitive detection of MRSA. The assay simultaneously detected 4 genes, namely, 16S rRNA of the Staphylococcus genus, femA of S. aureus, mecA that encodes methicillin resistance, and one internal control. It was rapid and yielded results within 4 h. The analytical sensitivity and specificity of the multiplex PCR assay was evaluated by comparing it with the conventional method. The analytical sensitivity of the multiplex PCR assay at the DNA level was 10 ng DNA. The analytical specificity was evaluated with 10 reference staphylococci strains and was 100%. The diagnostic evaluation of MRSA was carried out using 360 foodborne staphylococci isolates, and showed 99.1% of specificity, 96.4% of sensitivity, 97.5% of positive predictive value, and 97.3% of negative predictive value compared to the conventional method. The inclusion of an internal control in the multiplex PCR assay is important to exclude false‐negative cases. This test can be used as an effective diagnostic and surveillance tool to investigate the spread and emergence of MRSA.     

Electric field analysis of spinneret design for multihole electrospinning system

Electric field plays a key role in producing required nanofibers in electrospinning. This study aims to improve the electric field distribution of the multijet spinning system by designing the spinneret configuration. A novel 19-hole multistep electrospinning configuration is presented. The simulation results show that the electric field strength at the central position is intensified due to the protuberant step on the spinneret, and therefore more uniform electric field is obtained compared with the 19-hole flat spinneret. We demonstrate that the multistep spinneret configuration produces finer fibers and more continuous fiber mats compared with the flat spinneret configuration because of the improved electric field distribution. Jet repulsion in the multijet electrospinning process is studied. It is found that the electric field line distribution, which is determined by the spinneret configuration, plays a dominant role in influencing jet repulsion. Applied voltage is the main factor responsible for jet repulsion for a given spinneret configuration.