1,536 research outputs found

    The research infrastructure of Chinese foundations, a database for Chinese civil society studies

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    This paper provides technical details and user guidance on the Research Infrastructure of Chinese Foundations (RICF), a database of Chinese foundations, civil society, and social development in general. The structure of the RICF is deliberately designed and normalized according to the Three Normal Forms. The database schema consists of three major themes: foundations’ basic organizational profile (i.e., basic profile, board member, supervisor, staff, and related party tables), program information (i.e., program information, major program, program relationship, and major recipient tables), and financial information (i.e., financial position, financial activities, cash flow, activity overview, and large donation tables). The RICF’s data quality can be measured by four criteria: data source reputation and credibility, completeness, accuracy, and timeliness. Data records are properly versioned, allowing verification and replication for research purposes

    Extracting energy via magnetic reconnection from Kerr-de Sitter black holes

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    It has been recently shown that magnetic reconnection can provide us a novel mechanism to extract black hole rotational energy from a Kerr black holes. In some certain values of parameters, such mechanism is found to be more efficient than the Blandford-Znajek mechanism. In this paper, we study the energy extraction from the Kerr-de Sitter black hole via this magnetic reconnection process. With the increase of the cosmological constant, a slowly spinning Kerr-de Sitter black hole can implement the energy extraction than its Kerr counterpart. Of particular interest is that although the numerical calculation shows that the maximum values of the power and efficiency decrease with the cosmological constant, Kerr-de Sitter black hole still has advantages when the black hole spin a/M>1a/M>1 and the dominant reconnection XX-point is far away from the event horizon. These results uncover the significant effects of cosmological constant on the energy extraction via the magnetic reconnection process.Comment: 16 pages, 11 figure

    Novel three-piston pump design for a slipper test rig

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    Slipper's micro motions including the squeezing motion, spinning motion, and tilting motion have a significant impact on its lubricating condition and dynamic behavior. However, few experimental studies are on these micro motions within a real axial piston pump, especially the slipper's spinning motion. The experimental investigations on the slipper in the past mainly focused on the parameters of the oil film such as pressure, thickness, and temperature. The sensors were often installed in the fixed swash plate when the cylinder block was chosen to rotate. Alternatively, the sensors were mounted in the fixed modified slipper when the swash plate rotated. The biggest challenge of the direct measurements of these micro motions is the space limitation for the sensor installation due to the compact structure of axial piston pumps as well as the slipper's macro motion. This paper presents a new three-piston pump for the slipper test rig which can provide enough installation space for the sensor. To realize the cylinder block balance, a hold-down plate is first introduced into this three-piston pump. In addition, a detailed set of relevant equations is derived to evaluate the functionality of the hold-down plate. Finally, the slipper's spinning motion was measured directly and continuously using this three-piston pump, which confirmed the capability of the slipper test rig

    Diaqua­bis­(hydrogen tartrato)cobalt(II) dihydrate

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    The title complex, [Co(C4H5O6)2(H2O)2]·2H2O, contains a CoII ion, two single deprotonated tartrate anions, two coordinated water mol­ecules and two lattice water mol­ecules. The coordination geometry of the CoII ion is a distorted octa­hedron with two O atoms from two coordinated water mol­ecules occupying cis positions in the equatorial plane and four O atoms from two hydrogen tartrate ions occupying the remaining positions. In the crystal, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network

    Mechanistic investigations of diabetic ocular surface diseases

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    With the global prevalence of diabetes mellitus over recent decades, more patients suffered from various diabetic complications, including diabetic ocular surface diseases that may seriously affect the quality of life and even vision sight. The major diabetic ocular surface diseases include diabetic keratopathy and dry eye. Diabetic keratopathy is characterized with the delayed corneal epithelial wound healing, reduced corneal nerve density, decreased corneal sensation and feeling of burning or dryness. Diabetic dry eye is manifested as the reduction of tear secretion accompanied with the ocular discomfort. The early clinical symptoms include dry eye and corneal nerve degeneration, suggesting the early diagnosis should be focused on the examination of confocal microscopy and dry eye symptoms. The pathogenesis of diabetic keratopathy involves the accumulation of advanced glycation end-products, impaired neurotrophic innervations and limbal stem cell function, and dysregulated growth factor signaling, and inflammation alterations. Diabetic dry eye may be associated with the abnormal mitochondrial metabolism of lacrimal gland caused by the overactivation of sympathetic nervous system. Considering the important roles of the dense innervations in the homeostatic maintenance of cornea and lacrimal gland, further studies on the neuroepithelial and neuroimmune interactions will reveal the predominant pathogenic mechanisms and develop the targeting intervention strategies of diabetic ocular surface complications

    Cryptanalysis of SPEEDY

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    SPEEDY is a family of ultra-lightweight block ciphers designed by Leander et al. at CHES 2021. There are three recommended variants denoted as SPEEDY-rr-192 with rr∈{5,6,7}. All of them support the 192-bit block and the 192-bit key. The main focus during its design is to ensure hardware-aware low latency, thus, whether it is designed to have enough security is worth to be studied. Recently, the full-round security of SPEEDY-7-192 is announced to be broken by Boura et al. at EUROCRYPT 2023 under the chosen-ciphertext setting, where a round-reduced attack on SPEEDY-6-192 is also proposed. However, no valid attack on SPEEDY-5-192 is given due to its more restricted security parameters. Up to now, the best key recovery attack on this variant only covers 3 rounds proposed by Rohit et al. at AFRICACRYPT 2022. In this paper, we give three full-round attacks on SPEEDY-7-192. Using the divide-and-conquer strategy and other new proposed techniques, we found a 5.5-round differential distinguisher which can be used to mount the first chosen-plaintext full-round key recovery attack. With a similar strategy, we also found a 5-round linear distinguisher which leads to the first full-round attack under the known-plaintext setting. Meanwhile, the 5.5-round differential distinguisher also helps us slightly improve the full-round attack in the chosen-ciphertext setting compared with the previous result. Besides, we also present a 4-round differential attack on SPEEDY-5-192, which is the best attack on this variant in terms of the number of rounds so far. A faster key recovery attack covering the same rounds is also given using a differential-linear distinguisher. Both attacks cannot threaten the full round security of SPEEDY-5-192

    1,4-Bis(3-pyridylmethyl­eneamino­meth­yl)benzene

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    The title compound, C20H18N4, is a flexible 3,3′-bipyridyl-type ligand with a long spacer group between the two pyridyl functions. The mol­ecule crystallizes around an inversion center, with one half-mol­ecule in the asymmetric unit and a dihedral angle of 71.85 (8)° between the pyridine ring and the central benzene ring
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