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1. chinaXiv:201711.00123 [pdf]

Structural Features and Biological Activities of Bioactive Compounds from Fortunella margarita (Lour.) Swingle: A Review

ZENG Hong-Liang; CHEN Pei-Lin; HUANG Can-Can; SHEN Jin-Ye; CHANG Qing; ZHENG Bao-Dong; ZHANG Yi
Subjects: Chemistry >> Physical Chemistry

Fortunella margarita (Lour.) Swingle, commonly known as kumquat, is the smallest citrus fruit. It thrives in southeastern China and is widely cultivated and consumed in the world due to its multiple health benefits. It has been used as an important herbal medicine in traditional Chinese medicine and also as one of the most popular fruits. There are various kinds of bioactive compounds in F. margarita, such as polysaccharides, limonoids, essential oils, flavonoids, phenolic acids, vitamins, dietary fiber, etc. In addition, many studies have reported that these bioactive compounds can be used as antioxidant, antimicrobial, hypolipidemic, drosophila lure components in functional foods, pharmaceuticals and daily chemical products due to their biological activities. This review focuses on the structural features and biological activities of polysaccharides, limonoids, essential oils and flavonoids and other bioactive substances from F. margarita and their potential applications in food, daily chemical and pharmaceutical industries.

submitted time 2017-11-05 From cooperative journals:《结构化学》 Hits3689Downloads1733 Comment 0

2. chinaXiv:201605.01572 [pdf]

THE ROLE OF LARGE AMPLITUDE UPSTREAM LOW-FREQUENCY WAVES IN THE GENERATION OF SUPERTHERMAL IONS AT A QUASI-PARALLEL COLLISIONLESS SHOCK: CLUSTER OBSERVATIONS

Wu, Mingyu; Hao, Yufei; Lu, Quanming; Huang, Can; Guo, Fan; Wang, Shui
Subjects: Geosciences >> Space Physics

The superthermal ions at a quasi-parallel collisionless shock are considered to be generated during the reformation of the shock. Recently, hybrid simulations of a quasi-parallel shock have shown that during the reformation of a quasi-parallel shock the large-amplitude upstream low-frequency waves can trap the reflected ions at the shock front when they try to move upstream, and then these reflected ions can be accelerated several times to become superthermal ions. In this paper, with the Cluster observations of a quasi-parallel shock event, the relevance between the large-amplitude upstream low-frequency waves and the superthermal ions (about several keV) have been studied. The observations clearly show that the differential energy flux of superthermal ions in the upstream region is modulated by the upstream low-frequency waves, and the maxima of the differential energy flux are usually located between the peaks of these waves (including the shock front and the peak of the upstream wave just in front of the shock front). These superthermal ions are considered to originate from the reflected ions at the shock front, and the modulation is caused due to the trapping of the reflected ions between the upstream waves or the upstream waves and the shock front when these reflected ions try to travel upstream. It verifies the results from hybrid simulations, where the upstream waves play an important role in the generation of superthermal ions in a quasi-parallel shock.

submitted time 2016-05-12 Hits856Downloads535 Comment 0

3. chinaXiv:201605.01562 [pdf]

IMPACT OF PICKUP IONS ON THE SHOCK FRONT NONSTATIONARITY AND ENERGY DISSIPATION OF THE HELIOSPHERIC TERMINATION SHOCK: TWO-DIMENSIONAL FULL PARTICLE SIMULATIONS AND COMPARISON WITH VOYAGER 2 OBSERVATIONS

Yang, Zhongwei; Liu, Ying D.; Richardson, John D.; Lu, Quanming; Huang, Can; Wang, Rui
Subjects: Geosciences >> Space Physics

Voyager 2 (V2) observed multiple crossings of the heliospheric termination shock (TS) on 2007 August 31-September 1 at a distance of 84 AU from the Sun. Here, for the first time, we present two-dimensional particle-incell (PIC) simulations of the TS self-consistently including pickup ions (PUIs), and compare the simulation results with V2 observations. We find that (1) PUIs play a key role in the energy dissipation of the TS, and most of the incident ion kinetic energy is transferred to the thermal energy of PUIs. The PIC simulation indicates that, for the upstream parameters chosen for V2 conditions, the density of PUIs is about 25% and the PUIs gain the largest fraction (approximately 86.6%) of downstream thermal pressure. (2) The simulated heliosheath ion distribution function is a superposition of a cold core formed by transmitted solar wind ions (SWIs), with the shoulders contributed by the hot reflected SWIs and directly transmitted PUIs, and the wings of the distribution dominated by the very hot reflected PUIs. The V2 Faraday cups observed the cool core of the distribution, and so they only saw the tip of the iceberg. (3) The nonstationarity of the shock front is mainly caused by ripples along the shock front which form even if the percentage of PUIs is high. These simulation results agree reasonably well with the V2 experimental data. The relevance of the shock front ripples to the multiple TS crossings observed by V2 is also discussed in this paper.

submitted time 2016-05-12 Hits1451Downloads706 Comment 0

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