1,722,210 research outputs found
FIGURES 13–14 in Seven new species of the Stenus cirrus group (Coleoptera, Staphylinidae) from Guangxi, South China
No full textFIGURES 13–14. Dorsal habitus of Stenus hechiensis sp. n. Scale bars: 1 mm.Published as part of Liu, Sheng-Nan & Tang, Liang, 2017, Seven new species of the Stenus cirrus group (Coleoptera, Staphylinidae) from Guangxi, South China, pp. 238-254 in Zootaxa 4268 (2) on page 249, DOI: 10.11646/zootaxa.4268.2.4, http://zenodo.org/record/58020
All-optical signal processing using cascaded quadratic interactions in periodically poled lithium niobate waveguides
No full textThis thesis investigates all-optical signal processing using cascaded quadratic nonlinearities in periodically poled lithium niobate (PPLN) waveguides for telecommunication applications. PPLN waveguides which possess high second-order nonlinearity are attractive due to their suitable properties with respect to high compactness, high operating speed and resistance to parasitic effects. They allow the implementation of various advanced signal processing functionalities which will be required in future ultrahigh speed fibre-optic communication systems. Several novel all-optical signal processing techniques relying on two types of cascaded quadratic processes in PPLN waveguides, namely cascaded second harmonic generation and difference frequency generation (cSHG/DFG) and cascaded sum frequency generation and difference frequency generation (cSFG/DFG), are demonstrated. These two processes are conventionally employed for wavelength conversion in the telecommunication band. To facilitate the use of these wavelength converters, a systematic study of the acceptance bandwidths of cSHG/DFG and cSFG/DFG in PPLN waveguides is presented. Following this study, an optical time- divisionmultiplexing to wavelength-division multiplexing format conversion scheme, which relies on the generation of linearly chirped pulses which are then optically switched with data pulses using cSHG/DFG in a PPLN waveguide, is demonstrated. Signal regeneration techniques exploiting cascaded quadratic nonlinearities in PPLN waveguides are also investigated. An all-optical signal retiming system for on-off keying signals relying on pulse shaping and cSHG/DFG-based switching in a PPLN waveguide is demonstrated. Subsequently, two novel configurations of PPLN-based phase sensitive amplifiers (PSA) which have the potential as regenerators for phase-shift keying signals are demonstrated. Finally, a novel method for the elimination of arbitrary frequency chirp from short optical pulses is presented. In addition, the thesis contains a study on the use of OFCGs as telecommunication sub-picosecond pulse sources. Both a theoretical and experimental study of the intensity and phase properties of the pulses generated by an OFCG is presented. Furthermore, two approaches are proposed to compensate for the intrinsic chirp of the OFCGs
Complex molecules in galactic dust cores - biologically interesting molecules and dust chemistry
Full text link"The astronomical study of molecules has been an essential research field since the development of radio astronomy. Presently nearly 120 molecules have been identified in interstellar and circumstellar environments. The complexity of molecular species, and particularly organic molecules, that can be synthesized in the interstellar medium (ISM) leads to one interesting and important subfield in interstellar molecular studies, namely, the search and study for molecules of possible biological interest.
Observationally, complex and most saturated molecules are observed exclusively toward compact hot, dense regions, often called ""hot cores"", in molecular clouds. To account for the observed amount of saturated organic molecules, interstellar dust particles play an important role. It has often been suggested that solid state reactions on grain surfaces provide an efficient way to synthesis saturated organic molecules.
The objective of this study is to obtain observational data on biologically interesting molecules and to study important complex interstellar molecules. Since hot molecular cores are inherently compact, interferometric observations are therefore an ideal approach to study these sources. All our observations were all made with the Berkeley-Illinois-MarylandAssociation (BIMA) Array"Submitted by Emily Purcell ([email protected]) on 2015-08-07T19:42:22Z
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Previous issue date: 1999-10Ope
The Stenus cirrus group (Coleoptera, Staphylinidae) in Fujian, East China
No full textLiu, Sheng-Nan, Tang, Liang, Luo, Yong-Ting (2018): The Stenus cirrus group (Coleoptera, Staphylinidae) in Fujian, East China. Zootaxa 4375 (1): 105-115, DOI: 10.11646/zootaxa.4375.1.
FIGURES 11–14. Stenus mangdangshanus. 11 male sternite VIII, 12 male sternite IX, 13, 14 in The Stenus cirrus group (Coleoptera, Staphylinidae) in Fujian, East China
No full textFIGURES 11–14. Stenus mangdangshanus. 11 male sternite VIII, 12 male sternite IX, 13, 14 aedeagus. Scale bars: 0.25 mm.Published as part of Liu, Sheng-Nan, Tang, Liang & Luo, Yong-Ting, 2018, The Stenus cirrus group (Coleoptera, Staphylinidae) in Fujian, East China, pp. 105-115 in Zootaxa 4375 (1) on page 112, DOI: 10.11646/zootaxa.4375.1.5, http://zenodo.org/record/115818
FIGURE 7 in Notes on the genus Neopseustis Meyrick with description of a new species from China (Lepidoptera: Neopseustidae)
No full textFIGURE 7. Distribution map of all Neopseustis species in southeastern Asia.Published as part of Liao, Cheng-Qing, Chen, Liu-Sheng & Huang, Guo-Hua, 2021, Notes on the genus Neopseustis Meyrick with description of a new species from China (Lepidoptera: Neopseustidae), pp. 340-352 in Zootaxa 4970 (2) on page 349, DOI: 10.11646/zootaxa.4970.2.7, http://zenodo.org/record/476182
FIGURES 3–4 in The Stenus cirrus group (Coleoptera, Staphylinidae) in Fujian, East China
No full textFIGURES 3–4. Habitus of S. fujianensis. Scale bars: 1mm.Published as part of Liu, Sheng-Nan, Tang, Liang & Luo, Yong-Ting, 2018, The Stenus cirrus group (Coleoptera, Staphylinidae) in Fujian, East China, pp. 105-115 in Zootaxa 4375 (1) on page 108, DOI: 10.11646/zootaxa.4375.1.5, http://zenodo.org/record/115818
Seven new species of the Stenus cirrus group (Coleoptera, Staphylinidae) from Sichuan, Southwest China
No full textTang, Liang, Liu, Sheng-Nan, Dong, Xin-Yu (2018): Seven new species of the Stenus cirrus group (Coleoptera, Staphylinidae) from Sichuan, Southwest China. Zootaxa 4425 (3): 527-540, DOI: 10.11646/zootaxa.4425.3.
Optimal data allocation in a bus computer network
No full textA study is made of the partitioning of a global database and the allocation of the partitions in a bus computer system. The authors deal with systems where database partitioning and the allocation of the partitions to processing nodes can be solved simultaneously. The combined decision is referred to as data allocation. The objective is to allocate data so that the mean transaction response time is minimized. A queuing optimization model for solving the problem is formulated as a nonlinear programming problem. The uniqueness of the optimal policy is proved and an optimization procedure is developed. The model is illustrated with a sample system
3D interconnect technology based on low temperature copper nanoparticle sintering
No full textWe explore a methodology for patterned copper nanoparticle paste for 3D interconnect applications in wafer to wafer (W2W) bonding. A novel fine pitch thermal compression bonding process (sintering) with coated copper nanoparticle paste was developed. Most of the particle size is between 10-30 nm. Lithographically defined stencil printing using photoresist and lift-off was used to apply and pattern the paste. Variations in sintering process parameters, such as: pressure, geometry and ambient atmosphere, were studied. Compared to Sn-Ag-Cu (SAC) microsolder bumps, we achieved better interconnect resistivity after sintering at 260 °C for 10 min, in a 700 mBar hydrogen forming gas (H2/N2) environment. The electrical resistivity was 7.84 ± 1.45 μΩ·cm, which is about 4.6 times that of bulk copper. In addition, metallic nanoparticle interconnect porosity can influence the electrical properties of the interconnect. Consequently, we investigated the porosity effect on conductivity using finite element simulation. A linear relationship between the equivalent conductivity and particle overlapping ratio was found.Accepted Author ManuscriptElectronic Components, Technology and MaterialsEKL Processin
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