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.

Investigation of channel mobility in AlGaN/GaN high-electron-mobility transistors

Chang, Sung-Jae,Kang, Hee-Sung,Lee, Jae-Hoon,Yang, Jie,Bhuiyan, Maruf,Jo, Young-Woo,Cui, Sharon,Lee, Jung-Hee,Ma, Tso-Ping Institute of Pure and Applied Physics 2016 Japanese Journal of Applied Physics Vol.55 No.4

<P>We have investigated the channel mobility in the gated region of a set of high-quality AlGaN/GaN high-electron-mobility transistors (HEMTs). The resistances in the contact, access, and gated regions were extracted from straightforward I-D(V-G) measurements on sets of HEMTs with four different gate-to-drain distances. By correcting for the effects of the contact and access resistances, much more accurate effective mobility curves in the gated region, compared to those reported in the past, have been obtained. The maximum effective mobility in that region has been found to be 1100cm(2)V(-1) s(-1) at carrier density n(s) = 7 x 10(12)cm(-2) at room temperature. We have extracted the mobility curves in a wide range of temperatures (80 to 520 K) and carrier concentrations (up to 1.3 x 10(13)cm(-2)). Our systematic measurements have revealed various dominant scattering mechanisms as the temperature and carrier concentration change. (C) 2016 The Japan Society of Applied Physics</P>

무통분만시 수막강내 Sufentanil에 첨가된 Bupivacaine의 효과

김수창,최덕환,김지애 대한마취과학회 1999 Korean Journal of Anesthesiology Vol.37 No.6

Background : The combination of a local anesthetic and an opioid has been shown to produce effective epidural labor analgesia. It was reported that the combination of intrathecal opioid and bupivacaine could produce labor analgesia with longer duration and less side effects. This study was done to evaluate the effect of intrathecal bupivacaine mixed with sufentanil for labor analgesia. Methods : Eighty women requesting labor analgesia were randomly assigned to receive intrathecal 10 mcg of sufentanil (S group, n = 40) or 2.5 mg of bupivacaine plus 10 μg of sufentanil (SB group, n = 40) diluted in a total volume of 2.2 ml with normal saline. The analgesia was performed using combined spinal-epidural technique in the lateral position. Visual analogue scales (VAS) for pain, sensory changes to cold, duration of analgesia, motor block, hypotension, fetal heart rate, pruritus, and other side effects were assessed for 30 minutes after intrathecal drug injection. Results : There were no significant differences in he VAS pain scores and sensory levels at 5 minutes after intrathecal drug injection between groups. However, VAS pain scores were significantly lower and sensory levels higher in the SB group at 15 minutes and 30 minutes after intrathecal drug injection. The duration of analgesia provided by intrathecal sufentanil (n = 31) was 103.4 41.1 min, by intrathecal sufentanil plus bupivacaine (n = 29) 113.0 32.1 min (P = 0.30). Motor block assessed by a modified Bromage scale was significantly frequent in the SB group (P< 0.001). Not only adverse effects such as hypotension, fetal bradycardia, pruritus, and nausea, but also satisfaction scores were similar in both groups. Conclusions : The addition of bupivacaine to intrathecal sufentanil produced more frequent motor block and extensive sensory block, but better analgesia. However, duration of analgesia, side effects and satisfaction score did not change. (Korean J Anesthesiol 1999; 37: 1068∼1073)

Lactobacillus casei AHU 1055 및 Lactobacillus acidophilus JAM 1043의 凍結乾燥와 生存率에 關한 硏究

金昌漢,金明浩,朴芝賢,李明燮,朴相瑨 건국대학교 동물자원연구센터 1992 動物資源硏究誌 Vol.17 No.-

In order to find the most suitable conditions of freeze-drying for the long term preservation of lacto-bacillus casei AHU 1055 and Lactobacillus acidophilus JAM 1043, the growth phase, the cryoprotection medium and inoculum size have been studied. The results obtained in this study are summerized as follows : 1. L. casei AHU 1055 and L.acidophilus JAM 1043 reached to stationary phase after incubating at 37˚C for 16hrs and 12hrs in MRS broth, respectively. 2. The highest viability of each strains was obtained in 11% skim-milk for L. casei AHU 1055 and 9% skim-milk for L. acidophilus JAM 1043 as basic cryoprotection medium. 3. The complex medium contained 11% skim milk powder, 2.5% arginine and 3% glucose was the best suspending midium for freeze-drying of L. casei AHU 1055, and the medium contained 9% skim milk powder, 7% glycerol, 9% lactose, 0.5% arginine was the best suspending medium for freeze-drying of L. acidophilus JAM 1043. 4. The strong positive correlation was found between inoculum size and the survival rate in both strains. 5. When the tested strains were cultured and freeze-dried under the best optimal conditions, the survival rates of freeze- dried L. casei AHU 1055 and L. acidophilus JAM 1043 were 85.8% and 84.0%, respectively.

PICC에서 사정변경의 원칙에 관한 사례 연구

윤걸 ( Yin Jie ),허재창 ( Huh Jae-chang ) 경남대학교 산업경영연구소 2023 지역산업연구 Vol.46 No.2

본 연구는 국제무역계약의 사정변경원칙의 실무적용에서 유의점을 분석하는 것을 목적으로 한다. 사정변경이란 계약체결 당시 계약의 기초가 되었던 제반 사정이 계약이 성립된 이후 크게 변경되는 것을 말한다. 국제무역계약을 이행하는 과정에서 당사자의 책임이 아닌 우발적인 사태가 발생하여 당사자의 이익이 심각하게 훼손되는 경우 가장 일반적으로 선호되는 것은 사정변경원칙을 행사하는 구제조치이다. 이러한 경우 신의성실 및 당사자 간의 권리의무의 균형을 실현하기 위해 당사자는 면책상태에서 원래 계약의 변경 또는 해제를 허용한다. 그러나 관련한 사례를 분석해 본 결과 사정변경의 원칙을 실무적으로 적용할 때 분쟁이 자주 발생하는 것으로 나타났다. 따라서 본 연구에서는 PICC를 주요 연구대상으로 하여 주로 제6.2.1조, 제6.2.2조, 제6.2.3조를 고찰하며, PICC상 사정변경원칙에 관한 이론적 내용을 해석하여 적용범위, 구성요건 및 법적효력 등에 관한 규정을 살펴보았다. 그리고 PICC의 사정변경 관련 사례를 시장환경의 변화, 불가항력의 발생, 계약의 성실한 이행, 기타의 4가지 범주로 분류하고, 각 측면에 대한 실무적 차원에서 당사자의 유의점을 제시하였다. This study aims to analyze the points of consideration in the practical application of the principle of change of circumstances in international trade contracts. The change of circumstances refers to the fact that the various circumstances that were the basis of the contract when the contract was signed changed dramatically after the contract was established. In this case, in order to achieve the good faith of the contract and the balance of rights and obligations between the parties, the parties are allowed to change or cancel the original contract under the exemption status. However, the results of the analysis of relevant cases showed that disputes often occur when the principle of change of circumstances was applied in practice. Therefore, this study takes PICC as the main research object, mainly examines Articles 6.2.1, 6.2.2, and 6.2.3, analyzes the theoretical content of the principle of change of circumstances in PICC and examines its application scope, constituent elements, legal effect, and other relevant provisions. At the same time, the relevant cases involving PICC changes are divided into four categories: changes in the market environment, the occurrence of force majeure, the honest performance of contracts, and others, and put forward the points of consideration from various practical perspectives.

Oxidation behavior of YAG-ZrB2 ceramics prepared by spark plasma sintering

Jie-Guang Song,Da-Ming Du,Yin-Yan Ju,Yang-Liang Li,Shi-Bin Li,Gang-Chang Ji 한양대학교 세라믹연구소 2010 Journal of Ceramic Processing Research Vol.11 No.4

ZrB2 and YAG are widely applied because of some excellent properties, but ZrB2 is easily oxidized in high-temperature air. To make ZrB2 ceramics have better oxidation resistance, high-density YAG-ZrB2 ceramics were prepared. The oxidation behavior of YAG-ZrB2 ceramics is investigated at different temperatures. The results indicate that the enhanced weight change differs according to the temperature range, slightly in the temperature 900-1000oC, sharply from 1100-1300 and smoothly above 1300oC. The weight change rate of YAG-ZrB2 ceramics is increased by prolonging the oxidation time, but the weight change rate of YAG-ZrB2 ceramics is gradually reduced. The oxidation layer is porous as compared to the YAG-ZrB2 ceramics layer.

Synthesis and Experimental Implementation of DSP Based Backstepping Control of Positioning Systems

Jie Chang,Yaolong Tan 전력전자학회 2007 JOURNAL OF POWER ELECTRONICS Vol.7 No.1

Novel nonlinear backstepping control with integrated adaptive control function is developed for high-performance positioning control systems. The proposed schemes are synthesized by a systematic approach and implemented based on a modern low-cost DSP controller, TMS320C32. A baseline backstepping control scheme is derived first, and is then extended to include a nonlinear adaptive control against the system parameter changes and load variations. The backstepping control utilizes Lyapunov function to guarantee the convergence of the position tracking error. The final control algorithm is a convenient in the implementation of a practical 32-bit DSP controller. The new control system can achieve superior performance over the conventional nested PI controllers, with improved position tracking, control bandwidth, and robustness against external disturbances, which is demonstrated by experimental results.

Immobilization of β-Glucosidase from Exiguobacterium sp. DAU5 on Chitosan Bead for Improved Enzymatic Properties

Jie Chang(창지에),In Hye Park(박인혜),Yong Seok Lee(이용석),Soo Yeol Chung(정수열),Shu Jun Fang(방숙군),M Subhosh Chandra(슈보쉬 찬드라),Yong Lark Choi(최용락) 한국생명과학회 2010 생명과학회지 Vol.20 No.11

Exiguobacterium sp. 유래의 β-glucosidase 고정을 위하여 글루타르알데하이드를 사용한 키토산 비드를 조제하였다. 키토산 비드의 교차결합 및 고정화의 조건을 최적화하였다. β-glucosidase 고정화의 최적생산 조건에서 20%의 수율과 5.22 U/g의 효소활성을 나타냈다. 최적 pH 와 온도는 9.0과 55°C를 나타냈다. 고정된 효소의 안정성은 pH 7.0-10.0에서는 80%, 40°C 2시간 반응에서는 80% 및 50°C 1시간 반응에서는 48%의 활성을 보유하였다. 이러한 결과는 높은 pH와 고온에서 비고정 효소보다 안정성을 보여주었다. 고정된 효소를 가지고 대두 이소플라 본 배당체의 높은 가수분해능을 확인하였다. 이상의 결과는 고정화 효소의 다양한 이용 가능성을 시사하였다. Glutaraldehyde was used to cross-link chitosan beads to immobilize the crude enzyme β-glucosidase from Exiguobacterium sp. DAU5. The conditions for preparing cross-linking chitosan beads and immobilization such as concentration of glutaradehyde, cross-linking time, immobilization pH and time were optimized. The chitosan beads were cross-linked with 1.5% glutaraldehyde for 1.5 hr. The immobilized β-glucosidase had an overall yield of 20% and specific activity of 5.22 U/g. The optimized pH and temperature were 9.0 and 55°C, respectively. More than 80% of its activity at pH 7.0-10.0, 80% at 40°C for 2 hr and 48% at 50°C for 1 hr, were retained. However, the immobilization product showed higher pH and thermal stabilities than free enzymes. It also showed high hydrolyzing activity on soybean isoflavone glycoside linkage. These results suggest the broad application prospects of immobilization enzymes.

Detection of rare point mutation via allele-specific amplification in emulsion PCR

Chang Ming Cheng,Yin Zhou,Chao Yang,Juan Chen,Jie Wang,Jie Zhang,Guo Ping Zhao 생화학분자생물학회(구 한국생화학분자생물학회) 2013 BMB Reports Vol.46 No.5

Synthesis and Experimental Implementation of DSP Based Backstepping Control of Positioning Systems

Chang, Jie,Tan, Yaolong The Korean Institute of Power Electronics 2007 JOURNAL OF POWER ELECTRONICS Vol.7 No.1

Novel nonlinear backstepping control with integrated adaptive control function is developed for high-performance positioning control systems. The proposed schemes are synthesized by a systematic approach and implemented based on a modern low-cost DSP controller, TMS320C32. A baseline backstepping control scheme is derived first, and is then extended to include a nonlinear adaptive control against the system parameter changes and load variations. The backstepping control utilizes Lyapunov function to guarantee the convergence of the position tracking error. The final control algorithm is a convenient in the implementation of a practical 32-bit DSP controller. The new control system can achieve superior performance over the conventional nested PI controllers, with improved position tracking, control bandwidth, and robustness against external disturbances, which is demonstrated by experimental results.