A facile and efficient gas phase process for purifying single-walled carbon nanotubes

Haiqin Rong,Zhenyu Liu,Qilin Wu,이영희 한국물리학회 2010 Current Applied Physics Vol.10 No.4

Reproducible, low loss and high-yield purification process for single-walled carbon nanotubes (SWNTs)was developed by coupling of oxidation in wet air and treatment with gas phase nitric acid. Oxidation in wet air can burn out the carbonaceous particles and gas phase nitric acid treatment can etch away the catalytic metals. The as-synthesized SWNTs and the purified SWNTs were characterized by field emission scanning electron microscopy, high resolution transmission electron microscopy, Raman spectrophotometer and thermal gravimetric analysis. It was shown that such a facile and controllable gas phase process for purifying SWNTs can lead to the minimal losses and minimal destruction of SWNTs,thus highly purified SWNTs without amorphous carbon and with very low metal content were obtained.

A New Prediction Model Based on Web Access Behavior

Haiqin Ye,Huan Li,Ailing Zhang 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.12

In order to predict network users’ access behavior accurately, this paper proposes a new prediction model based on Web access behavior. To improve prediction performance and reduce the state-space complexity, the model uses hybrid-order Markov chain structure and stores the sequences which share the same prefix. The problems that lower-order models have poor prediction performance and higher-order models result in high state-space complexity are solved in this paper. Simulation results have shown that the prediction model based on Web access behavior can improve the precision and recall to some extent.

Research on Chinese Microblog Sentiment Classification Based on TextCNN-BiLSTM Model

Haiqin Tang,Ruirui Zhang 한국정보처리학회 2023 Journal of information processing systems Vol.19 No.6

Currently, most sentiment classification models on microblogging platforms analyze sentence parts of speechand emoticons without comprehending users’ emotional inclinations and grasping moral nuances. This studyproposes a hybrid sentiment analysis model. Given the distinct nature of microblog comments, the modelemploys a combined stop-word list and word2vec for word vectorization. To mitigate local information loss,the TextCNN model, devoid of pooling layers, is employed for local feature extraction, while BiLSTM isutilized for contextual feature extraction in deep learning. Subsequently, microblog comment sentiments arecategorized using a classification layer. Given the binary classification task at the output layer and the numeroushidden layers within BiLSTM, the Tanh activation function is adopted in this model. Experimental findingsdemonstrate that the enhanced TextCNN-BiLSTM model attains a precision of 94.75%. This represents a1.21%, 1.25%, and 1.25% enhancement in precision, recall, and F1 values, respectively, in comparison to theindividual deep learning models TextCNN. Furthermore, it outperforms BiLSTM by 0.78%, 0.9%, and 0.9%in precision, recall, and F1 values.

A high-resolution ocean-atmosphere coupled downscaling of the present climate over California

Li, Haiqin,Kanamitsu, Masao,Hong, Song-You,Yoshimura, Kei,Cayan, Daniel R.,Misra, Vasubandhu Springer-Verlag 2014 Climate dynamics Vol.42 No.3

Maternal Separation Induced Visceral Hypersensitivity from Childhood to Adulthood

( Lisha Yi ),( Haiqin Zhang ),( Huihui Sun ),( Lu Zhou ),( Ying Chen ),( Liqian Xuan ),( Yuanxi Jiang ),( Shuchang Xu ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2017 Journal of Neurogastroenterology and Motility (JNM Vol.23 No.2

Background/Aims Early adverse life events (EALs) are relevant to irritable bowel syndrome in adulthood. Maternal separation (MS), as one of the EALs, has proved to induce visceral hypersensitivity in adult rats. However, the effect of MS on visceral hypersensitvity from the post-weaning period to adulthood remains unknown. Methods One hundred and ten neonatal Sprague-Dawley rats were randomly divided into 2 groups: rats in the MS group were exposed to 3 hours daily MS on postnatal day (PND) 2-14; the normal control (NC) group remained undisturbed. Visceral sensitivity was determined by measuring the visceromotor response to colorectal distention on PND21, 35, and 56. Anxiety-like behaviors were measured by the open field test. Results Compared with NC rats, MS rats showed significant visceral hypersensitivity from the post-weaning period to adult. The proportion of visceral hypersensitive rats decreased with age from 87.5% to 70.0% in the female MS group and from 90.0% to 66.7% in the male MS group. The relative VMR ratio of MS and NC on PND21 was higher than PND35 and PND56. MS rats showed decreased ability of movement and exploration to the novel environment in the post-weaning period, obesity in the prepubertal period, and more anxietylike behaviors in adulthood. Conclusions MS can significantly affect visceral sensitivity and behaviors of rats in different age stages, especially in the post-weaning period. Visceral hypersensitivity of MS rats is more pronounced in the post-weaning period and slightly restored in adults. Thus, visceral hypersensitivity in the post-weaning period might play a more meaningful pathophysiologic role in the formation of adult irritable bowel syndrome. (J Neurogastroenterol Motil 2017;23:306-315)

Catalina Eddy as Revealed by the Historical Downscaling of Reanalysis

Masao Kanamitsu,Elena Yulaeva,Haiqin Li,홍성유 한국기상학회 2013 Asia-Pacific Journal of Atmospheric Sciences Vol.49 No.4

Climatological properties, dynamical and thermodynamical characteristics of the Catalina Eddy are examined from the 61 years NCEP/NCAR Reanalysis downscaled to hourly 10 km resolution. The eddy is identified as a mesoscale cyclonic circulation confined to the Southern California Bight. Pattern correlation of wind direction against the canonical Catalina Eddy is used to extract cases from the downscaled analysis. Validation against published cases and various observations confirmed that the downscaled analysis accurately reproduces Catalina Eddy events. A composite analysis of the initiation phase of the eddy indicates that no apparent large-scale cyclonic/anti-cyclonic large-scale forcing is associated with the eddy formation or decay. The source of the vorticity is located at the coast of the Santa Barbara Channel. It is generated by the convergence of the wind system crossing over the San Rafael Mountains and the large-scale northwesterly flow associated with the subtropical high. This vorticity is advected towards the southeast by the northwesterly flow, which contributes to the formation of the streak of positive vorticity. At 6 hours prior to the mature stage, there is an explosive generation of positive vorticity along the coast, coincident with the phase change of the sea breeze circulation (wind turning from onshore to offshore), resulting in the convergence all along the California coast. The generation of vorticity due to convergence along the coast together with the advection of vorticity from the north resulted in the formation of southerly flow along the coast, forming the Catalina Eddy. The importance of diurnal variation and the lack of large-scale forcing are new findings, which are in sharp contrast to prior studies. These differences are due to the inclusion of many short-lived eddy events detected in our study which have not been included in other studies.

The Global/Regional Integrated Model System (GRIMs)

홍성유,박훈,정형빈,김정은,구명서,장지현,함수륜,황승오,박병권,장은철,Haiqin Li 한국기상학회 2013 Asia-Pacific Journal of Atmospheric Sciences Vol.49 No.2

A multiscale atmospheric/oceanic model system with unified physics, the Global/Regional Integrated Model system (GRIMs) has been created for use in numerical weather prediction, seasonal simulations,and climate research projects, from global to regional scales. It includes not only the model code, but also the test cases and scripts. The model system is developed and practiced by taking advantage of both operational and research applications. This article outlines the history of GRIMs, its current applications, and plans for future development,providing a summary useful to present and future users.

Research on Drug Retail Surveillance and Management System Concerned with Adverse Drug Reaction

Zhang Qinghua,Zhao Shanshan,Wang Zhuan,Cheng Guoquan,Wei Jun,Hu Haiqin 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

Drug security is very important to people. The adverse drug reaction events happened several times these years. The drug retail record should be monitored to prevent drug security event occur. There should be a system to monitor the drug stores to find out which one is selling the outdated drugs, or selling the drugs that have no license agreement. When drug security event occurred, the retail information can be used to find out the customer who bought the drug, where and how much the drug left in the drug stores. The solution and measures such as drug recycle or going to hospital should be carried out according to the retail information from the terminal market. This paper brings out a drug retail tracking and tracing solution system. With this system, drug retail information can be real-time obtained. The information supports the decision to solve the adverse drug reaction events.

Monitoring polarization and dielectric relaxation behaviors of BaTiO3/ PC composite films via transmittance measurement

Haifa Zhai,Jinfeng Wang,Tiantian Zhang,Min Su Cho,Hongying Luo,Haiqin Li,In Man Kang,Hairui Liu,Jian Su 한국물리학회 2016 Current Applied Physics Vol.16 No.7

BaTiO3/polycarbonate (BT/PC) composite films with different concentration of BaTiO3 ferroelectric nanocrystals are prepared by a spin coating method. The polarization and dielectric relaxation behaviors of BT/PC composite films are characterized by the introduction of orientational order parameter (f) through in-situ transmission spectrum measurement. It's found that 15%BT/PC composite film has the largest orientation change with the f value of 10.5% and slow dielectric relaxation, almost 10% decay of f after 24 h. The optical band-gap of 15%BT/PC composite film decreases after poling indicates that the orientation of BaTiO3 ferroelectric nanocrystals aligns due to the effect of polarization, from 3.8 eV to 3.67 eV. From the XRD results, we consider that the preferential alignment orientation of BaTiO3 ferroelectric nanocrystals after poling is [001]. This suggests that in-situ transmittance measurement is a simple and effective way to evaluate the polarization and dielectric relaxation behaviors of ferroelectric nanocrystals/polymer systems.

Synthesis and Photo-Response of CuS Thin Films by an In Situ Multi-Deposition Process at Room Temperature: A Facile and Eco-Friendly Approach

Weiyan Liu,Huiming Ji,Jian Wang,Xuerong Zheng,Junyun Lai,Junna Ji,Tongfei Li,Yuanliang Ma,Haiqin Li,Suqin Zhao,Zhengguo Jin 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.3

"Uniform hexagonal covellite CuS thin films were deposited at room temperature by an in situ solution chemical reaction using copper precursor solid films as cationic source and ammonium sulfide ethanol solution as anionic reaction medium. We investigated the influence of both ethanolamine and butanol contents used in copper nitrate/ethylene glycol monomethylether (EGME) cationic solution for the preparation of copper precursor solid films, deposition cycle numbers and annealing treatment of the as-grown thin films by X-ray diffraction (XRD), FESEM, energy dispersive X-ray fluorescence EDX, transmission electron microscopy–Selected area electronic diffraction (TEM–SAED), atomic force microscopy (AFM) and ultraviolet-visible-near-infrared (UV-Vis–NIR) measurements. Photo-response of the CuS thin films was characterized by linear sweep voltammetry. The deposited CuS thin films were used to sensitize TiO2 anodes for solar cell application. The results showed that the CuS films had two-dimension oriented, half-sheet shaped growing morphology standing disorderly but vertically to substrates, and the calculated texture coefficient TC(102) verified that the half-sheet shaped crystallites had (102) plane orientation. This in situ multi-deposition process had an average deposited rate of 9 nm per cycle, and a selfperfect function to grow smooth, uniform and 2D oriented morphology with increase in the dip-cycle numbers. The photocurrent density was 14.5 Ma/cm2 at 1 V versus Ag/AgCl electrode for the annealed CuS thin films. CuS-sensitized TiO2 solar cells had a maximum conversion efficiency of 0.224%."