• Title/Summary/Keyword: External morphology

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A Study on Long-Term Cycling Performance by External Pressure Change for Pouch-Type Lithium Metal Batteries

  • Seong-Ju Sim;Bong-Soo Jin;Jun-Ho Park;Hyun-Soo Kim
    • Journal of Electrochemical Science and Technology
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    • v.15 no.2
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    • pp.314-320
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    • 2024
  • Lithium dendrite formation is one of the most significant problems with lithium metal batteries. The lithium dendrite reduces the lithium metal batteries' cycling life and safety. To apply consistent external pressure to a lithium metal pouch cell, we design a press jig in this study. External pressure creates dense lithium morphology by preventing lithium dendrite formation. After 300 cycles at 1 C, the cells with the external pressure perform far better than the cells without it, with a cycling retention of 97.8%. The formation of stable lithium metal is made possible by external pressure, which also enhances safety and cyclability.

Observation of the Adults and Eggs of Two Species of the Family Perlidae(Plecoptera) to Korea (강도래과(강도래목) 2 종에 대한 성충 및 란의 외부형태 관찰)

  • 나철호;백순기;조영관
    • Animal Systematics, Evolution and Diversity
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    • v.7 no.1
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    • pp.101-110
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    • 1991
  • Two species of Perlidae, Oyamia coreana and Kiotina decorata which were collected in mountain valley of the Chonnam, Chonguk and Kyongnam provinces, south Korea are reported for the first time from Korea, with description of the external morphology of their eggs by SEM.

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Monographic Study of the Endemic Plants in Korea IX. Taxonomy and interspecific relationships of the genus Melandrium (한국 고유식물의 종속지 IX. 장구채속식물의 분류와 종간유연관계)

  • 정영호
    • Journal of Plant Biology
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    • v.31 no.1
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    • pp.51-68
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    • 1988
  • To clarity the species of genus Melandrium (Caryophyllaceae) in Korea, the taxonomic characters were described and interspecific relationships were discussed to the extemal morphology with light and scanning electron microscopy. The position and size of appendages on petal, the shape and venation pattern of leaf, and the external morphology of seed and pollen were approved as the good characters to classify genus Melandrium in Korea. As the result, genus Melandrium in Korea could be arranged as 6 species, 1 variety, 1 forma. M. umbellatum was exclusively distributed in north Korea, and its taxonomic treatment was reserved.

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The external and internal morphological standard of original plants and herbal states in 2 kind of Arisaematis Rhizoma (2종 천남성(天南星)의 외부(外部) 및 내부형태(內部形態)에 대한 연구)

  • Kim, Hong-Jun;Yun, Ju-Bong;Ju, Young-Sung
    • Korean Journal of Oriental Medicine
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    • v.12 no.2 s.17
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    • pp.63-73
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    • 2006
  • In the original plant of Arisaematis Rhizomas, the features of external and internal shape of Arisaema amurense var. serratum $N_{AKAI}$ and A. amurense $_{MAXIM}$. are as follows. 1. In the external shape of original plant, Arisaema amurense var. serratum $N_{AKAI}$ has high stem, an oval-elliptic leaflet and a serrate leaf margin. But A. amurense $M_{AXIM}$ has a relatively low stem, an upside oval leaflet and no serrate leaf margin. 2. On the herbs character of original plant, Ansaema amurense var. serratum $N_{AKAI}$ is small in height and diameter, but A. amurense $M_{AXIM}$ is relatively large in height and diameter. 3. On the gathered herbs character of original plant, the section of Arisaema amurense var. serratum $N_{AKAI}$ is brightly white, easily spilt and strong scent. But the section of A. amurense $M_{AXIM}$ is thin yellowish brown, not easily spilt and weak scent. Also the grade of gathered herbs, both can be classified by diameter and external scent. 4. In the current herbs character, Korean and Sichuan Province products are irregullar shape and have no scent, Jilin Province products are regular shape. Also, Guangxi Province products are small size and concave in one side, Hebei Province products are irregular size and shape. 5. In internal shape of original plant, epidermal cell of Arisaema amurense var. serratum is very tight. With the except of micro difference in parenchyma cell of cortex, on the whole there are nearly no differences with A. amurense $M_{AXIM}$. Also, samely in the internal shape, according to collecting sites, epidermis exhibits a lot layer in curving state and secreting duct is developed and vascular bundle and exists between parenchyma cell of cortex. In the future, additional study is needed to distinguish herb and effect between same genus-degree of relatedness.

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A Study on Internal-External Morphology and Pattern Analysis in Angelicae Pubescentis Radix (독활(獨活)의 외부(外部) 및 내부형태(內部形態)와 이화학패턴연구)

  • Kim, Hong-Jun;Kim, Ja-Young;Choi, Go-Ya;Jeong, Seung-Il;Ju, Young-Sung
    • Korean Journal of Oriental Medicine
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    • v.12 no.3 s.18
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    • pp.101-115
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    • 2006
  • The purpose of this study was to introduce the differential standard of the types of Angelicae Pubescentis Radix. We established the classificatory standard according to the external and internal morphology and the physicochemistrical pattern for the four types of Aucklandiae Radix. The results follow: 1. At the external shape, Angelica pubescens f. biserrata has rising lenticel and dark brown surface, Its section is light gray and its xylem is yellow gray. Aralia continentalis has big stem mark in upper portion, its section has no dense tissue with yellow gray. Heracleum hemsleyanum has dark brown surface and little lenticel, its cortical layer is white yellow and xylem is isabella and powdered. 2. At the internal shape, Angelica pubescens f. biserrata has phloem with half of the root and rare vessel. Aralia continentalis has phloem with two-thirds of the root and it has broad cutting and putting vessel that formed 1-2 row. Heracleum hemsleyanum also has phloem with half of the root and wide scattered latex tube and many large vessel. 3. At the TLC pattern, Heracleum hemsleyanum has remarkable dark spot at $R_{f}$ 0.23 on the sulphuric acid color pattern test, but others have faint. 4. At the HPLC pattern, all samples have generally patterns. But Angelica pubescens f. biserrata shows diminutive continentalic acid content and the peak at Rt 20.278min comes out on Heracleum hemsleyanum, but do not come out on Aralia continentalis and Angelica pubescens f. biserrata. Heracleum hemsleyanum has remarkable peak at Rt 20.278min, but shows no peak at Rt 29.023min unlike Aralia continentalis or Angelica pubescens f. biserrata. Also Aralia continentalis and Angelica pubescens f. biserrata show one remarkable peak at Rt 29.023, but Heracleum hemsleyanum do not show. Consequently, Aralia continentalis and Angelica pubescens f. biserrata are comparable whit continentalic acid content and Heracleum hemsleyanum is comparable with the peak at Rt 20.273 and Rt 29.023. So it is thought that content of continentalic acid and the peaks at Rt 20.278 and Rt 29.023 can apply to differentiate a species from other. It is considered the results of this study will be furnished the basis to succeeding studies and it is needed to extensive comparative study for the same genus-degree of relatedness.

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담죽엽(淡竹葉)과 죽엽(竹葉)의 기원(起源)에 관한 문헌적(文獻的) 고찰(考察)

  • Kim, Jae-Hwan;Ju, Yeong-Seung
    • The Journal of Korean Medicine
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    • v.17 no.2 s.32
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    • pp.5-16
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    • 1996
  • For distinguish between Lophatherum gracile and Phyllostachys nigra var. henonis based on natural shape and external-internal morphology of medicinal shape, general contents of oriental medicine were rearranged through bibliography. As a result, two medicinal stuffs indicated the difference in shape and structure(external-internal and powder)of origin plant bibiliographically. After this, this contents were utilized to give proof of many effective difference between two medicinal stuff.

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Micromorphology of Benthic Diatom Species Achnanthes alteragracillima Lange-Bert

  • Lee, Jung Ho
    • Journal of Plant Biology
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    • v.37 no.4
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    • pp.417-420
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    • 1994
  • Morphology of Achnanthes alteragracillima Lange-Bert. was studied with scanning electron microscopy in epilithic samples from the Kwang River (Kwangchun), Kyungsangbuk-Do, Korea. The species was characterized by the external raphe terminal fissure deflecting up to valve margin, the internal raphe proximal endings slightly deflecting to the opposite direction each other and biased hyaline area at the valve pole. It could be distinguished from A. minutissima K tz., closely related species, in having not straight external raphe terminal fissures, and from A. convergens H.Kob. in having a biased hyaline area at the valve pole and not a convergent striae arrangement at the pole of the raphe valve.

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A taxonomic study of the Ophezia(Gentianaceae) in Korea 1. External morphology and distribution (한국산 용담과 쓴풀속(Ophelia) 식물의 분류 1. 외부형태 및 분포)

    • Korean Journal of Plant Resources
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    • v.12 no.4
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    • pp.324-339
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    • 1999
  • Morphological reinvestigation, external characters and discriminant functional analysis(44 qualitative characters) were examined on 6 taxa of Korean Ophelia, including 5 taxa distributed in south Korea, and one taxon considered to be the variation type of Ophelia wilfordi in order to clarify the limit of intersection and interspecies. And to establish the taxonomic position. One taxon distributed in north Korea was included in the description of species by observation of herbarium specimen of the University of Tokyo in Japan. The two sections were successfully distinguished by internal structure of ovary, morphology of nectary, number of corolla lobe and calyx lobe, and species were also distinguished by morphology of cauline leaf, and color and spot of corolla, respectively. The variation type of Ophelia wilfordi was not distinguished with other species except for absent or present of purple spot in corolla lobe. The results of the discriminal functional analysis indicated that characters of corolla were the most important qualitative characters to distinguish the Ophelia taxa, and morphology of seed and seed coat was useful characters to distinguish taxa higher than species. Therefore the difficult problems of identification of species were successfully solved, and the taxonomic position in intrageneric level was clarified on Korean Ophelia.

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Gnaphalium tranzschelii Kirp. (Asteraceae): An unrecorded species from Korea

  • Lee, Dong Hyuk;Byeon, Jun Gi;Heo, Tae Im;Park, Byeong Joo;Lee, Jun Woo;Kim, Ji Dong;Choi, Byoung Hee
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.04a
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    • pp.78-78
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    • 2019
  • Gnaphalium L. is a small herbaceous genus comprising up to 80 species in worldwide (Asia, North to South America, Africa, and Oceania). This genus is highly polymorphic which embrace uncommon broad morphological boundary, and thus further studies were needed to proper taxonomic delimitations for the genus and its relatives. Gnaphalium uliginosum L. was usually found in moist sites such as margins of lake, pond, reservoir, stream banks and paddy field. This squat plant is solely known species in Korean Gnaphalium. During the revisionary study of the tribe Gnaphalieae (Asteraceae) in Korea, however, we found several materials in domestic herbaria (e.g., SNU, KWNU) that identified as G. uliginosum or Gamochaeta pensylvanica (Willd.) Cabrera collected from central to northern Korea, but clearly differ to the morphology of G. uliginosum. The external morphology of the materials is seemingly the only feature at odds with G. uliginosum. However, its morphological characters such as tall erected stems (ca. 30cm), hairs on seeds and whitish tomentose hairs on the whole plants are easily distinguished from G. uliginosum, and rather it looks like G. tranzschelii Kirp. Although the name G. tranzschelii have been treated as synonym of G. uliginosum by several authors, its distinct morphology might be sufficient to separate to two independent taxa. Generally, the morphological polymorphisms and hybridization of G. uliginosum complicate the taxonomy of the species, and thus further investigation for their habitat, distribution and morphology were needed to their taxonomic entity.

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