Geochemical record of rapid climate change and chemical weathering in a semi-arid area, northeastern Tibetan Plateau

Wenxiang Zhang,Hucai Zhang,Jie Niu,Guoliang Lei,Fengqin Chang 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.6

Lacustrine deposits can provide insight into chemical weathering and climate change. Based on the analysis of the element concentrations and parameters of the acid-leaching residual fractions (AR) in the lacustrine deposits of the Qaidam Basin (QB), chemical weathering and paleoclimate changes in the northeastern Tibetan Plateau (NETP) have been studied. The results show that the characteristics of trace element concentrations exhibit two kinds of patterns by normalized element arbitrary units (a.u.). The rare earth element (REE) distribution patterns are moderately rich in light rare earth elements (LREEs) with slightly right-tilting and negative Eu anomalies. Triangular plots of the REEs and (La/Yb)n-ΣREE suggest that the sediments have a similar source. The geochemical records of climate proxies indicated warm-wet climate stages during 45.1–31.6 cal. ka BP., further proving that a megalake stage existed in the semi-arid area in marine isotope stage (MIS) 3. Strong evaporation resulted in a high paleolake level history in the northeastern Tibetan Plateau after the late period of MIS 3. Meanwhile, the geochemical records of the Qaidam Basin are synchronous with the global records.

한국 근해 참조기의 자원평가 및 관리방안

장창익,김수암,윤성봉 한국수산학회 1992 한국수산과학회지 Vol.25 No.4

한국근해 참조기의 지난 20여년 동안의 어획자료를 사용하여 잉여생산량 모델에 의해 추정된 MSY를 비교하여 보면, Shaefer와 Fox 모델에 의하여 추정된 값들은 각각 37,000mt와 33,450mt였고, Zhang 모델에 의하여 자원량과 순간어획사망계수를 적용시킨 MSY는 45,328mt, 자원량과 어획량 자료를 이용하는 방법에서는 40,160mt로 각각 추정되었다 이 현상은 이 모델들이 각기 독립된 다른 자료를 이용하여 MSY를 추정하였으나, 추정된 값은 거의 비슷한 결과를 보였다. 참조기자원을 가입당생산량 모델에 적용시킨 결과를 사용하여 자원관리 방안을 모색해 보면, 가능한 최대 가입당 생산량이 43g임에 비하여 현재의 t_c=0.604, F=1.11에서의 가입당생산량은 약 20g 정도에 불과하다. 여기서 t_c를 현재 상태로 고정시킨후, 가입당생산량을 높이는 방안을 생각해 보면, F를 현재의 1.11에서 0.4 정도로 낮추어야 하나, 가입당생산량의 큰 증가는 없다. 즉, 현재의 20g에서 25g밖에 증가되지 않는다. 그러나, 현재의 어획강도 (F)를 고정시키는 경우에는 t_c를 현재의 0.604세에서 3세 부근으로 조정하면 최대의 가입당생산량 (43g)을 얻을 수 있고, 이 t_c 값은 역시 F_(0.1) 방법에서 추정된 적정어획체장을 연령으로 환산한 결과와 거의 일치함을 알 수 있다. Zhang모델을 이용한 자원의 회복 방안에서 참조기 자원의 최대생산가능 자원량(B^*_MSY)를 유지시키려면 F를 약 0.5 수준으로 낮추어야 하고. 이 수준에서 약 8년 뒤에는 자원량이 적정 수준에 거의 접근하게 된다. Based on surplus production models using fishery data for the last 20 years, a stock assessment was conducted for the small yellow croaker in Korean waters. The maximum sustainable yields (MSY) from the Schaefer and Fox models were estimated to be 37,000 metric tons (mt) and 33,450 mt. Zhang's model using time-series biomass with instantaneous coefficients of fishing mortality (F) and using time-series biomass and catch yielded MSY estimates of 45,328 mt and 40,160 mt, respectively. A yield-per-recruit analysis showed that the current yield per recruit of about 20g with F=1.11 yr^(-1), where the age at first capture (t_c) is 0.604, was much lower than the maximum possible yield per recruit of 43g. Fixing t_c at the current level and reducing fishing intensity (F) from 1.11 yr^(-1) to 0.4 yr^(-1) yielded only a small increase in predicted yield per recruit, from 20 to 25g. However, estimated yield per recruit increased to 43g by increasing t_c from the current age (0.604) to age three with F fixed at the current level. This age at first capture corresponded to the optimal length which was obtained from the F_(0.1) method. According to the analysis of stock recovery strategies employing the Zhang model, the optimum equilibrium biomass (B^*_MSY) which produces the maximum yield could be achieved after approximately five years at the lower fishing intensity (F=0.5).

인삼 투여가 정신지체아의 GPX와 MDA에 미치는 영향

이소영,장석암,김창환,권광선 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.4

The purpose of this study is to investigate the change of antioxidant enzyme(GPX) and lipid peroxide (MDA) by ginseng supplementation for nine weeks. Choosing as objects of test women mental retardation, this study analyzed the blood obtained from the objects who were in a rest, immediately and 30 minutes after maximal exercise. The comclusions obtained from this study were as follow. 1. In the tendency of whole activation of GPX, ginseng supplemintation group showed more GPX activation than placebo group. 2. In the change of GPX activation according to the passage of exercise time, there was no difference between each group before and after supplementation for nine weeks. 3. In the change of GPX activation according to (before and after) supplementation, there was no significant difference between each group at a rest, immediately and 30 minutes after maximal exercise. 4. In the change of MDA concentration according to the passage of exercise time, there was no difference between each group before and after supplemintation for nine weeks. 5. In the change of MDA concentration according to (before and after) supplementation there was o significant difference between each group at a rest, immediately and 30 minutes after maximal exercise.

Evaluation of the susceptibility of coal to spontaneous combustion by a TG profile subtraction method

Yulong Zhang,Sheng Xue,Junfeng Wang,Yue Wu,Zhengfeng Li,Liping Chang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.3

−It is imperative to have an in-depth understanding of the intrinsic reaction between coal and oxygen during low-temperature oxidation, as the reaction is the main source responsible for the self-heating and spontaneous combustion of coal. As low-temperature oxidation of coal involves a series of physical and chemical process and many parallel reactions, it is difficult to directly investigate the intrinsic reaction between coal and oxygen by conventional analytical method. Thermogravimetric analysis (TGA) was used to investigate the intrinsic reaction between coal and oxygen based on the mass change. By means of the subtraction analysis method of TGA, the TG-subtraction curves were obtained by subtracting the TG-N2 curves from the TG-air curves. The results indicate that a TG-subtraction curve can better reflect the intrinsic reaction of coal oxidation than a TG-air curve by eliminating the influence of evaporation of water and thermal decomposition of inherent oxygen-containing groups. In terms of the rate of mass increase, the intrinsic reactions can be divided into three stages: slow oxidation stage, advanced oxidation stage and rapid oxidation stage. The activation energy at each of the stages, obtained by Coats and Redfern’s model, can be used to as a technical parameter to evaluate the proneness of coal spontaneous combustion. The optimum experiment conditions were also developed to study low-temperature coal oxidation with the subtraction method of TGA.

중국 디지털 음악 산업의 발전전략에 관한 연구

장일주(Zhang, Yizhou),이규창(Lee, Gyu-Chang),배기형(Bae, Ki-Hyung) 한국문화산업학회 2020 문화산업연구 Vol.20 No.3

본 논문은 문헌 조사 연구방법을 통하여 정책 측면, 시장 측면, 음반 회사 측면, 디지털 음악 플랫폼 측면과 소비 측면을 나누어 중국 디지털 음악 산업의 발전 현황을 고찰하였다. 이 토대로 중국 디지털 음악 산업의 문제점을 발견하였다. 첫째, 플랫폼 측면에 높은 저작권 비용, 혁신 동력 부족, 인디뮤지션의 수입 부족 세 기가지 문제점이 있다. 둘째, 소비자 측면에 낮은 요금 지급률을 하고 소비자 선호의 변화 두 개 문제점이 존재하고 있다. 셋째, 정부 측면에 보호 정책 부족한 문제점도 있다. 이상 문제점을 해결하기 위하여 본 연구는 기업 측면, 정부 측면, 민간 측면을 나누어 발전전략을 제시하였다. 먼저 기업 측면에 자작권의 가치를 발굴해야 하고, 효율적인 이익 모델을 형성시켜야 한다. 또한, 소비자의 요금 지급 습관도 육성시켜야 한다. 둘째, 정부 측면에 감독 체계 개선하는 동시에 인디뮤지션의 육성에 대한 지원을 체공해야 하고 음악 인재도 활용해야 한다. 마지막으로 민간 측면에 산학협력을 활용하고 음악 예능 프로그램 개선하는 동시에 프로그램의 혁신도 요구된다. The paper divided into policy, marketing, record company, digital music and consumption aspects for studying present situation of China’s digital music industry by literature research. Based on this, the study found some problems of China’s digital music industry. Firstly, in platform aspect, there are three problems including high cost for paying for copyright, lack of innovation and low income in independent musicians. Secondly, there are two problems in consumer aspect including low rate of paying for music and consumer’s preference is changing. Thirdly, in government aspect, protecting policy for digital music is inadequate. To solve these problems, the essay put forward development strategies in three aspects. First, in corporation aspect, it is suggested that extract copyright’s value and form efficient profit model. Second, it is advised that improve system’s supervision, support cultivating independent musician and use music talents in government aspect. Finally, in public respect, it is suggested that ally industry with academic and improve music program, at the same time, it is need to innovate program’s form.

한국인에서 Quadruplex PCR을 이용한 8종류 상염색체 STR 유전좌의 다형성 분석

장영길,김기범,신창호,이숭덕,이윤성,이정빈 大韓法醫學會 2001 대한법의학회지 Vol.25 No.1

Two quadruplex PCR reactions were designed for 7 tetrameric (D3S2406, D4S2368, D5S818, D7S821, D9S925, D13S317, D19S253) and one trimeric (D6S1043) short tandem repeats loci to study the allele frequency and the applicability of genetic variation in these loci in forensic case works. For 310 unrelated Koreans DNA was isolated from peripheral blood using phenol/chloroform method. Quadruplex I was consisted of D4S2368, D6S1043, D7S821, D9S925 and quadruplex II D3S2406, D5S818, D13S317, D19S253. The amplified products were analyzed by 5% polyacrylamide gel electrophoresis followed by silver staining. The heterozygosity in each loci ranged 92.91-66.13%, and PD(Power of Discrimination) was above 085 in each loci. Every loci except D6S1043 followed hardy-Weinberg expectation. The cumulative PI was low as 1.65×10-10. Two mutations were noted, one in D19S253 and the other in D9S925 among 234 gametes. With these results above eight STR loci studied here preyed to be highly polymorphic enough to be used in forensic field. This study provides valuable population data in these loci for Korean.

바다목장의 생태계 기반 자원관리방안

장창익,이성일,김종만 한국수산자원학회 2003 한국수산자원학회지 Vol.6 No.-

An ecosystem-based approach is introduced to manage fisheries resources in marine ranching areas by considering ecological interactions of organisms in the ecosystem. The ecosystem structure model (ESM) analyses ecotrophic levels among functional groups in the ecosystem and the ecosystem dynamic model (EDM) conducts dynamic simulation of the ecosystem according to the fishing mortality intensity or environmental changes. Here, we developed two models : the fishery stock enhancement model which estimates parameters to enhance required fishery stocks by artificial releasing and the ABC(acceptable biological catch) estimation model for an effective fishery resource management. In addition, methods for estimating parameters required for the ecosystem models and population models were also investigated. Finally, a necessity for studying the ecosystem-based approach for the management of fisheries resources was stressed.

Changes in Fisheries Resources and Future Research Need for the Yellow Sea Ecosystem

장창익,유신재,손명호 제주대학교 해양연구소 1993 해양자원연구소연구보고 Vol.17 No.-

음향방출법에 의한 SM 490A 강의 복합용접성 평가(2)

이장규,우창기,김봉각,윤종희,인승현 한국공작기계학회 2003 한국공작기계학회 춘계학술대회논문집 Vol.2003 No.-

The object of this study is to investigate the effect of compounded welding by using an acoustic emission (AE) signals and doing a source location for weld heat affected zone (HAZ) through tensile testing. This study was carried out a SM 490A high tension steel for electronic shielded metal arc welding (SMAW), CO₂ gas arc welding and TIG welding. Data displays are based on the measured parameters of the AE signals, along with environmental variables such as time and load. These history plots are displays showing the chronological course of the test. Also, source location gives the X- and Y-coordinates of the AE source.

인공신경회로망을 이용한 원공결함을 갖는 유한 폭 판재의 음향방출 음원특성과 파괴거동에 관한 연구

이장규,우창기 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

The objective of this study is to evaluate an acoustic emission (AE) source characterization and fracture behavior of the SM45C steel by using back-propagation neural network (BPN). In previous research Ref. [8] about k-nearest neighbor classifier (k-NNC) continuously, we used K-means clustering method as an unsupervised learning method for obtained multi-variate AE main data sets, such as AE counts, energy, amplitude, risetime, duration and counts to peak. Similarly, we applied k-NNC and BPN as a supervised learning method for obtained multi-variate AE working data sets. According to the error of convergence for determinant criterion Wilk's λ, heuristic criteria D&B(Rij) and Tou values are discussed. As the results show that BPN produced some empty classes before or at the same time k-NNC detect fracture signals. And confirmed that could save trouble to AE signal processing if suitable error of convergence or acceptable encoding error gives to BPN.