13,457 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Raw data of Zhao et al., 2022, Geoderma
No full textRaw data associated with Zhao et al., 2022, Geoderma. Any use of the data set should be approved by the corresponding author Kai Yue at "[email protected]".</p
Nucleate Pool Boiling Heat Transfer on a Micro-Pin-Finned Surface in Short-Term Microgravity
No full textNucleate boiling heat transfer of air-dissolved FC-72 on a micro-pin-finned surface was experimentally investigated in microgravity by utilizing the drop tower facility in Beijing. The dimensions of the silicon chips were 10mm x 10mm x 0.5mm and on these, two kinds of micro-pin-fins with the dimensions of 30 x 30 x 60m(3) and 50 x 50 x 120m(3) (width x thickness x height, named PF30-60 and PF50-120) were fabricated by the dry etching technique. Nucleate pool boiling on a smooth surface was also studied under both Earth gravity and microgravity for comparison. In general, the micro-pin-fins showed better heat transfer performance when compared with a smooth surface, both under Earth gravity and microgravity. In microgravity, this is mainly due to the fact that bubbles generated on micro-pin-finned surface can depart from the heater surface continuously. For micro-pin-fins, the reduced-gravity critical heat flux was about two-thirds of that in the Earth gravity experiment, but almost three times as large as that for the smooth surface, which is larger than that in the terrestrial experiment. Under different gravity levels, PF50-120 shows a little better heat transfer than that of PF30-60, mainly due to larger heat transfer area. Besides, the fin gap of PF30-60 may generate a larger flow resistance for microconvection around the fin side walls, resulting in a lower heat transfer performance
Bubble Behavior and Heat Transfer of Nucleate Pool Boiling on Micro-Pin-Finned Surface in Microgravity
No full textNucleate pool boiling on micro-pin-finned surface structure is proposed for efficiently cooling electronic components with high heat flux in microgravity, and was verified by experiments performed utilizing the drop tower Beijing. Micro-pin-fins with the dimensions of 50 x 60 mu m(2) (thickness x height) and the space of 50 mu m were fabricated on the chip surface by the dry etching technique. FC-72 was used as the working fluid. Nucleate pool boiling of FC-72 on a smooth surface was also tested for comparison. Unlike much obvious deterioration of heat transfer of nucleate pool boiling on the smooth surface in microgravity, constant heater surface temperature of nucleate pool boiling for the micro-pin-finned surface was observed, even though a large coalesced bubble completely covered the surface under microgravity condition. The performance of high efficient heat transfer on micro-pin-finned surface is independent of the gravity, which stems from the sufficient supply of fresh liquid to the heater surface due to the capillary forces
[Zhao Yuanren zuo pin lu yin]
No full textSide A. 1. 老天爺 / 沈學詠彈 ; 2. 嗚呼三月一十八 / 沈學詠彈 -- Side B. 1. 江上撐船歌 / 趙元任唱 ; 2. 船夫 / 趙元任唱.趙元任.Title supplied by cataloguer.Live recording."Piano only"--Index for side A.Electronic reproduction from Rulan Chao Pian Audio Cassette Collection.Singer: 趙元任 ; pianist: 沈學詠.Sung in Chinese.Zhao Yuanren.Singer: Zhao Yuanren ; pianist: Shen Xueyong.Detailed contents in vernacular field only
Assessment of tomography models of Taiwan using first-arrival times from the TAIGER active-source experiment
No full textChao Yuen Ren (1892–1982)
No full textY. R. Chao is easily the most famous linguist to have come out of China. Born before the end of the last dynasty in China, he received a traditional Confucian education, but was also one of the first Chinese people to be sent to the West for training in modern Western science (under the Boxer Indemnity Fund). The remarkable breadth and scope of his studies included physics, mathematics, linguistics, musical and literary composition, and translation, and he was a pioneer in many of these fields
The Biology and Biochemistry of PhoH2 proteins
No full textPhoH2 proteins are found in a diverse range of organisms. To date little is known about these proteins and the role they play in the organisms in which they reside. PhoH2 is a PIN PhoH domain fusion, and these proteins are currently annotated as having unknown function and are described as PhoH like. PhoH domains are thought to be ATPases and all characterised PIN domain proteins are RNases. Most efforts have focussed on determining the role of PIN domain proteins that comprise the toxic component (VapC) of VapBC toxin antitoxin systems, in which the PIN domain is coexpressed as part of an operon with an inhibitor (VapB). In the remaining cases where PIN domain proteins can be found such as PIN PhoH domain fusions, these cases remain unexamined. This thesis describes the biological and biochemical characterisation of the PIN PhoH protein, PhoH2 from Mycobacterium tuberculosis and Mycobacterium smegmatis, along with a preliminary structural characterisation of a thermophilic PhoH2 protein homologue.
The phoH2 gene from both mycobacterial organisms was found to be expressed as part of a long mRNA transcript. Examination of these transcripts revealed possible alternative 5’ start sites out of frame with the phoH2 gene. For protein overexpression, and ‘normal’ growth and colony formation with conditional overexpression, phoH2 from M. tuberculosis required 152 bp of the 5’ sequence directly upstream of the annotated phoH2 gene (annotated here as phoH2alt). PhoH2 proteins: PhoH2alt MTB, PhoH2alt MSMEG and PhoH2MSMEG show ATP/Mg²⁺ dependent, sequence specific RNA unwinding and cleavage. The sequence (A C) (A/U) (A/U) (G/C) U was deduced as a substrate for PhoH2, and PhoH2alt MTB also demonstrated unwinding and cleavage activity on its upstream ~152 base RNA transcript, suggesting a potential autoregulatory mechanism. Structural analysis of a thermophilic PhoH2 protein homologue has provided preliminary crystallographic data which along with electron microscopy suggest a ring like hexameric PhoH2 oligomer
Boiling heat transfer enhancement by using micro-pin-finned surface for electronics cooling
No full textFor efficiently cooling electronic components
with high heat flux, experiments were conducted to
study the flow boiling heat transfer performance of
FC-72 over square silicon chips with the dimensions
of 10 × 10 × 0.5 mm3. Four kinds of micro-pin-fins
with the dimensions of 30 × 60, 30 × 120, 50 × 60, 50 × 120 μm2 (thickness, t × height, h) were fabricated
on the chip surfaces by the dry etching technique for
enhancing boiling heat transfer. A smooth surface was
also tested for comparison. The experiments were made
at three different fluid velocities (0.5, 1 and 2 m/s) and
three different liquid subcoolings (15, 25 and 35 K).
The results were compared with the previous published
data of pool boiling. All micro-pin-fined surfaces show
a considerable heat transfer enhancement compared
with a smooth surface. Flow boiling can remarkably
decrease wall superheat compared with pool boiling.
At the velocities lower than 1 m/s, the micro-pin-finned
surfaces show a sharp increase in heat flux with increasing
wall superheat. For all surfaces, the maximum
allowable heat flux, qmax, for the normal operation of
LSI chips increases with fluid velocity and subcooling.
For all micro-pin-finned surfaces, the wall temperature
at the critical heat flux (CHF) is less than the upper
limit for the reliable operation of LSI chips, 85◦C. The largest value of qmax can reach nearly 148 W/cm2 for
micro-pin-finned chips with the fin height of 120 μm
at the fluid velocity of 2 m/s and the liquid subcooling
of 35 K. The perspectives for the boiling heat transfer
experiment of the prospective micro-pin-finned sur-
faces, which has been planned to be made in the Drop
Tower Beijing/NMLC in the future, are also presented
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