Improving the Carbon Macrosegregation in High-Carbon Steel by an Electric Current Pulse

Jianhong Ma,Jie Li,Yulai Gao,Lixing Jia,Zheng Li,Qijie Zhai 대한금속·재료학회 2009 METALS AND MATERIALS International Vol.15 No.4

Thus far, the relationship between the macrosegregation and refinement of solidification structures in metals is not clearly understood. In this paper, the effect of an electric current pulse (ECP) on the refinement of the solidification structure as well as carbon macrosegregation in high-carbon steel was investigated. The experimental results revealed that if central porosity exists in the solidification structure, the carbon macrosegregation in high-carbon steel cannot be improved by applying an ECP, although increased equiaxed dendrites and a reduced primary dendritic arm in a solidification structure were obtained after an ingot was exposed to an ECP. In contrast, after central porosity was eliminated, carbon macrosegregation was improved through the refinement of the solidification structure in high-carbon steel through the use of an ECP. Thus far, the relationship between the macrosegregation and refinement of solidification structures in metals is not clearly understood. In this paper, the effect of an electric current pulse (ECP) on the refinement of the solidification structure as well as carbon macrosegregation in high-carbon steel was investigated. The experimental results revealed that if central porosity exists in the solidification structure, the carbon macrosegregation in high-carbon steel cannot be improved by applying an ECP, although increased equiaxed dendrites and a reduced primary dendritic arm in a solidification structure were obtained after an ingot was exposed to an ECP. In contrast, after central porosity was eliminated, carbon macrosegregation was improved through the refinement of the solidification structure in high-carbon steel through the use of an ECP.

隋唐士族京城化微觀探析

馬建紅(Ma-Jianhong) 경북대학교 아시아연구소 2009 아시아연구 Vol.- No.7

수당이 통일한 후 오랜 시간이 지나면서 兩京은 士族들이 이주하는 목표가 되었고, 士族의 경성화 경향이 나타나게 되었다. 구체적으로 어떤 하나의 사족에게 있어서 그 경성화는 점진적으로 완성되어가는 과정이었고, 이 과정 속에서 다양한 양상이 나타나고 있었다. 거주 공간상에서는 향촌에서 경성내로 이주하는 것이다. 사회관계상으로는, 京城人士가 위주였다. 관념상으로는 경성의 생활공간에 동화되어갔는데 구체적으로 표현하면;坊은 중당 이후 새로운 목표도시 안의 士人의 가문, 신분의 칭호로 되기시작하였으며, 家廟를 경성 안으로 옮겼으며, 묘지를 경성 부근으로 옮겼다. 경성에 들어간 士族의 거주 상태는 세 가지 특징으로 요약할 수 있는 데, 첫 번째는 “兩京雙家” 형태로, 즉 장안성과 낙양성에 따로 거처를 두는것으로, 이것은 수당이래 시행된 양경제도와 직접적인 관계가 있고, 두 京都에 거처를 두는 주요한 이유는 공무의 편리함 때문이었다.두 번째는 “城鄉雙家” 형태로, 즉 경성과 교외에 각각 거처가 있었다. 하지만 Eberhard가 저술한 '征服者與統治者'중에서 언급한 “城市鄉村雙家形態”와는 본질적 구별이 있었다. 그 저서의 내용을 보면 “城鄉雙家形態”는 하나의 가족이 향촌에서 도시로 나아가는 단계적 성격의 형태로, 당시 가족 중의 일부분이 도시로 이사한 후에도 향촌의 가족 성원과 여전히 연계를 유지하고 서로 호응하는데, 향촌이 먼저 있고 도시가 나중이다. 雙 家의 주인은 동일한 사람은 아니지만 한 집안이거나 혹은 한 가족에 속한다. 그러나 이 “城鄉雙家形態”는 사족 성원의 생활 중심이 향촌에서 경성으로 옮긴 배경이 되는 것으로 雙家의 주인이 서로 동일하니, 먼저 도시가 있고 향촌이 나중인 것이다. 양가의 주인에 대한 기능도 서로 달라서 도시의 가는 일상적인 곳이고, 향촌의 가는 자유롭고 정신적 만족을 추구하는 생활공간이었다. 이와 같은 雙家形態의 출현과 주인인 사인 신분은 직접적인 관계가 있었는데, 이것 역시 수도에 들어간 사족들의 경제적 기초에 대한 하나의 반영임은 당연하다.세 번째는 家族散居形態로, 즉 하나의 城坊내에 동거하는 범위는 부자 형제지간으로 제한되었다. 이러한 종류의 거주 형태는 하나의 일정한 대표성이 있었다. 이러한 종류의 家族散居形態는 원래 종족에서 점차 이탈한 入京士族의 가족구조를 진일보 分化하게 만들었다. 당대 京城의 裏坊制度는 다른 坊내에 거주하고 있는 성원 사이에 서로 공간적으로 봉쇄하여 거주를 제한하였기 때문에 가족 성원간의 왕래에 불리하였고, 이로 인해 경성에서 다른 坊내에서 흩어져서 거주하는 형태는 장차 성원의 가족 관념을 점차 희미하게 만들었다. 가족 구조의 분화와 가족 관념의 약화는 가족 전체의 세력을 약화시킬 수 있지만 동시에 사인들로 하여금 더욱 더 스스로에 의지하게 만들었으며 종족이나 가족을 통하지 않고 스스로 처지를 변화시키려는 관념은 중세 사회의 사족 사회가 사인 사회로 변화하는데 일정한 촉진작용을 하였다. In a long period of Sui and Tang dynasties, the two capitals, Chang’an and Louyang, were the target cities where the shizu moved, which was the trend of Shizu’s capital centralization. Particularly to a certain group of Shizu, capital centralization was a gradual process in which there were many representations in different aspects. In the living space, they moved from countryside to the capital cities; in the social relationship, they focused on the capital people; and in their conception, they recognized the capital living space. The representations included that the Fangwang became a new title to identify the origin and status of the Shizu in the city after the mid-Tang Dynasty, Jiamiao was moved into the capitals and the cemetery was moved near the city they lived. There were three type of Shizu’s living form in the capital cities. First, “two houses in both capital cities” type was formed by the double-capital system in Sui and Tang dynasties, which was convenience for the official duties. Second, “two houses in city and countryside” type was different from the type which Eberhard mentioned in his book “conquers and rulers” In his book, this type described a middle type while a family moved from countryside to the city. When some members of a family moved to the city, they still connected with the members in the countryside, therefore, the two houses did not belong to a same person but a same family. However, in this case, two houses in city and countryside were based on the movement of Shizu’s life from countryside to the city, so they had the same owner. The two houses had different function to the owner. The house in the city was the daily home but the other one was the living space of self release and spiritual demands. This type of two houses was brought by the owners’ status and reflected the economic base of the Shizu in the capital cities. Finally, ‘the family separate living’ type indicated that only the father, son or brothers lived in the same Fang and made the family structure of Shizu in the capital city distributed. Because the Li-Fang system of capital city in Tang Dynasty restricted the members of same Fang in a comparative close space and blocked the association of the family members, the separate living type could reduce the family notion of its members. Distribution of the family structure and the reduction of family notion would decrease the power of the while family, but would increase the individual consciousness to change the condition, which expedited the conversion from the Shizu society to Shiren society.

Meta-analysis of the effect of the overexpression of aquaporin family genes on the drought stress response

Ren Jianhong,Yang Xiaoxiao,Ma Chunying,Wang Yuling,Zhao Juan,Kang Le 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.2

Aquaporin (AQP) plays an essential role in water uptake and transport in plants, especially in the response to drought stress, which suggests the use of AQP expression to regulate plant water-use efciency. The overexpression of various AQP genes in a variety of plants has been reported, but inconsistencies in the experimental variables (such as stress type, gene donor, and recipient genus) and physiological parameters used to evaluate transgenic plants have made it difcult to elucidate the complex mechanisms by which AQPs afect drought tolerance. In this study, we performed a meta-analysis to categorize the responses of physiological parameters involved in drought tolerance in AQP-overexpressing plants and to evaluate the experimental variables that afect transgenic plant performance. The results of various studies indicated that two primary physiological processes (osmotic adjustment and alleviation of oxidative damage) were signifcantly afected by AQP overexpression. Among the examined experimental variables, treatment media (soil), stress type (no watering), stress duration (long-term), recipient genus (Nicotiana), donor species (Musaceae), and gene family (PIP2) had positive impacts on drought tolerance in transgenic plants. These fndings may help to guide future studies investigating the function of AQPs in the response of plants to water defcit stress.

Study on the Black Phenotype Mutants of Adult and Pupa of Helicoverpa armigera

Mo Wang,Jianhong Li,Weihua Ma,Lizhen Chen 한국응용곤충학회 2005 한국응용곤충학회 학술대회논문집 Vol.2005 No.05

Development and Validation of a Nomogram Prediction Model for Endometrial Malignancy in Patients with Abnormal Uterine Bleeding

Hengchao Ruan,Suhan Chen,Jingyi Li,Linjuan Ma,Jie Luo,Yizhou Huang,Qian Ying,Jianhong Zhou 연세대학교의과대학 2023 Yonsei medical journal Vol.64 No.3

Purpose: This study aimed to identify the risk factors and sonographic variables that could be integrated into a predictive model for endometrial cancer (EC) and atypical endometrial hyperplasia (AEH) in women with abnormal uterine bleeding (AUB). Materials and Methods: This retrospective study included 1837 patients who presented with AUB and underwent endometrial sampling. Multivariable logistic regression was developed based on clinical and sonographic covariates [endometrial thickness (ET), resistance index (RI) of the endometrial vasculature] assessed for their association with EC/AEH in the development group (n=1369), and a predictive nomogram was proposed. The model was validated in 468 patients. Results: Histological examination revealed 167 patients (12.2%) with EC or AEH in the development group. Using multivariable logistic regression, the following variables were incorporated in the prediction of endometrial malignancy: metabolic diseases [odds ratio (OR)=7.764, 95% confidence intervals (CI) 5.042–11.955], family history (OR=3.555, 95% CI 1.055–11.971), age ≥40 years (OR=3.195, 95% CI 1.878–5.435), RI ≤0.5 (OR=8.733, 95% CI 4.311–17.692), and ET ≥10 mm (OR=8.479, 95% CI 5.440–13.216). A nomogram was created using these five variables with an area under the curve of 0.837 (95% CI 0.800–0.874). The calibration curve showed good agreement between the observed and predicted occurrences. For the validation group, the model provided acceptable discrimination and calibration. Conclusion: The proposed nomogram model showed moderate prediction accuracy in the differentiation between benign and malignant endometrial lesions among women with AUB.

Hyphae and organic acids of Aspergillus Niger promote uranium recovery by destroying the ore surface and increasing the porosity and permeability of ores

Wang Yongdong,Wang Jinhua,Ding Dexin,Li Guangyue,Sun Jing,Hu Nan,Li Feng,Ma Jianhong,Zhang Hui,Ding Yang,Dai Zhongran 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.5

To elucidate the mechanism of damage caused by hyphae and organic acids produced by Aspergillus Niger on the surface and internal structure of uranium ore, direct uranium leaching, indirect uranium leaching and semidirect uranium leaching were conducted, and the surface morphology, strength, mineral crystallinity, porosity, and permeability of the ore were analyzed. The results demonstrated that the combination of biomechanical forces exerted by hyphae and the complexation effects of organic acids led to the dissolution of SiO2 and other substances on the surface of ore, resulting in exfoliation from the exterior to the interior, thereby promoting uranium recovery. Furthermore, the proton exchange involving H+ and the complexation of organic acids resulted in the dissolution of cations within the ore, causing destruction to the crystal lattice structure of minerals and increasing the porosity and permeability inside the ore. The dominant factor contributing to ore damage during recovery was organic acids.