Acetate-assisted Synthesis of Chromium(III) Terephthalate and Its Gas Adsorption Properties

Jing-jing Zhou,Kai-yu Liu,Chun-long Kong,Liang Chen 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

We report a facile synthetic approach of high-quality chromium(III) terephthalate [MIL-101(Cr)] by acetateassisted method in the absence of toxic HF. Results indicate that the morphology and surface area of the MIL- 101(Cr) can be tuned by modifying the molar ratio of acetate/Cr(NO3)3. The Brunauer-Emmett-Teller (BET) surface area of MIL-101(Cr) synthesized at the optimized condition can exceed 3300 m2/g. It is confirmed that acetate could promote the dissolution of di-carboxylic linker and accelerate the nucleation ratio. So the pure and small size of MIL-101(Cr) with clean pores can be obtained. CO2, CH4 and N2 adsorption isotherms of the samples are studied at 298 K and 313 K. Compared with the traditional method, MIL-101(Cr) synthesized by acetate-assisted method possess enhanced CO2 selective adsorption capacity. At 1.0 bar 298 K, it exhibits 47% enhanced CO2 adsorption capacity. This may be attributed to the high surface area together with clean pores of MIL-101(Cr).

Structural time-varying damage detection using synchrosqueezing wavelet transform

Jing-Liang Liu,Zuo-Cai Wang,Wei-Xin Ren,Xing-Xin Li 국제구조공학회 2015 Smart Structures and Systems, An International Jou Vol.15 No.1

This paper proposed a structural time-varying damage detection method by using synchrosqueezing wavelet transform. The instantaneous frequencies of a structure with time-varying damage are first extracted using the synchrosqueezing wavelet transform. Since the proposed synchrosqueezing wavelet transform is invertible, thus each individual component can be reconstructed and the modal participation factor ratio can be extracted based on the amplitude of the analytical signals of the reconstructed individual components. Then, the new time-varying damage index is defined based on the extracted instantaneous frequencies and modal participation factor ratio. Both free and forced vibrations of a classical Duffing nonlinear system and a simply supported beam structure with abrupt and linear time-varying damage are simulated. The proposed synchrosqueezing wavelet transform method can successfully extract the instantaneous frequencies of the damaged structures under free vibration or vibration due to earthquake excitation. The results also show that the defined time-varying damage index can effectively track structural time-varying damage.

Instantaneous frequency extraction in time-varying structures using a maximum gradient method

Jing-liang Liu,Xiaojun Wei,Ren-Hui Qiu,Jin-Yang Zheng,Yan-Jie Zhu,Irwanda Laory 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.22 No.3

A method is proposed for the identification of instantaneous frequencies (IFs) in time-varying structures. The proposed method combines a maximum gradient algorithm and a smoothing operation. The maximum gradient algorithm is designed to extract the wavelet ridges of response signals. The smoothing operation, based on a polynomial curve fitting algorithm and a threshold method, is employed to reduce the effects of random noises. To verify the effectiveness and accuracy of the proposed method, a numerical example of a signal with two frequency modulated components is investigated and an experimental test on a steel cable with time-varying tensions is also conducted. The results demonstrate that the proposed method can extract IFs from the noisy multi-component signals and practical response signals successfully. In addition, the proposed method can provide a better IF identification results than the standard synchrosqueezing wavelet transform.

Instantaneous frequency extraction in time-varying structures using a maximum gradient method

Liu, Jing-liang,Wei, Xiaojun,Qiu, Ren-Hui,Zheng, Jin-Yang,Zhu, Yan-Jie,Laory, Irwanda Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.22 No.3

A method is proposed for the identification of instantaneous frequencies (IFs) in time-varying structures. The proposed method combines a maximum gradient algorithm and a smoothing operation. The maximum gradient algorithm is designed to extract the wavelet ridges of response signals. The smoothing operation, based on a polynomial curve fitting algorithm and a threshold method, is employed to reduce the effects of random noises. To verify the effectiveness and accuracy of the proposed method, a numerical example of a signal with two frequency modulated components is investigated and an experimental test on a steel cable with time-varying tensions is also conducted. The results demonstrate that the proposed method can extract IFs from the noisy multi-component signals and practical response signals successfully. In addition, the proposed method can provide a better IF identification results than the standard synchrosqueezing wavelet transform.

An improved algorithm for pile damage localization based on complex continuous wavelet transform

Jing-Liang Liu,Cheng-Xu Lin,Xi-Jun Ye,Wen-Ting Zheng,Yong-Peng Luo 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.27 No.3

Since the complex continuous wavelet transform (CCWT) based pile damage detection method is empirical and subjective, an improved algorithm for pile damage localization based on CCWT is proposed by introducing K-means clustering and fast Fourier transform (FFT). In this method, the K-means clustering algorithm is used to accurately calculate the time coordinates of two energy concentrating points caused by the incident and reflected waves, respectively. Meanwhile, FFT is employed to estimate the concerned frequency band of the response signal. Therefore, a specific region in the time frequency plane is defined objectively and it can be used to search the phase angle turning points and localize pile damage. The proposed method is verified by numerical examples of piles with single and multiple damage positions. A parameter analysis is also conducted to investigate how damage depth and damage degree in piles affect the accuracy and effectiveness of the proposed method. The results demonstrate that the proposed method is able to localize a pile with a damage at least 2.5 m away from the pile head when the damage degree is as less as 5%. After that, dynamic tests of an actual square reinforced concrete pile and an actual circular reinforced concrete pile are investigated to verify the application of the proposed method on practical engineering. Although the proposed method is capable of localizing actual piles more accurately than the CCWT method, the problem of interference points needs to be addressed by mutual verification with other pile damage localization methods.

Fenofibrate Increases Radiosensitivity in Head and Neck Squamous Cell Carcinoma via Inducing G2/M Arrest and Apoptosis

Liu, Jia,Ge, Yang-Yang,Zhu, Hong-Cheng,Yang, Xi,Cai, Jing,Zhang, Chi,Lu, Jing,Zhan, Liang-Liang,Qin, Qin,Yang, Yan,Yang, Yue-Hua,Zhang, Hao,Chen, Xiao-Chen,Liu, Zhe-Ming,Ma, Jian-Xin,Cheng, Hong-Yan,S Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Radiation therapy is an important treatment for head and neck squamous cell carcinoma (HNSCC). However, how to promote radiation sensitivity in HNSCC remains a challenge. This study aimed to investigate the radiosensitizing effects of fenofibrate on HNSCC and explore the underlying mechanisms. HNSCC cell lines CNE-2 and KB were subjected to ionizing radiation (IR), in the presence or absence of fenofibrate treatment. Cell growth and survival, apoptosis and cell cycle were evaluated. In addition, CNE-2 cells were xenografted into nude mice and subjected to IR and/or fenofibrate treatment. The expression of cyclinB and CDK1 was detected by Western blotting. Our results showed that fenofibrate efficiently radiosensitized HNSCC cells and xenografts in mice, and induced apoptosis and G2/M arrest via reducing the activity of the CDK1/cyclinB1 kinase complex. These data suggest that fenofibrate could be a promising radiosensitizer for HNSCC radiotherapy.

Structural time-varying damage detection using synchrosqueezing wavelet transform

Liu, Jing-Liang,Wang, Zuo-Cai,Ren, Wei-Xin,Li, Xing-Xin Techno-Press 2015 Smart Structures and Systems, An International Jou Vol.15 No.1

This paper proposed a structural time-varying damage detection method by using synchrosqueezing wavelet transform. The instantaneous frequencies of a structure with time-varying damage are first extracted using the synchrosqueezing wavelet transform. Since the proposed synchrosqueezing wavelet transform is invertible, thus each individual component can be reconstructed and the modal participation factor ratio can be extracted based on the amplitude of the analytical signals of the reconstructed individual components. Then, the new time-varying damage index is defined based on the extracted instantaneous frequencies and modal participation factor ratio. Both free and forced vibrations of a classical Duffing nonlinear system and a simply supported beam structure with abrupt and linear time-varying damage are simulated. The proposed synchrosqueezing wavelet transform method can successfully extract the instantaneous frequencies of the damaged structures under free vibration or vibration due to earthquake excitation. The results also show that the defined time-varying damage index can effectively track structural time-varying damage.

Effect of In-Situ Ti2N on Microstructure and Properties of SAF2906 Duplex Stainless Steel Fabricated by Laser Melting Deposition

Jing Liang,Sheng Yang,Ye Liu,Xiuyuan Yin,Suiyuan Chen,Changsheng Liu 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.7

SAF2906 Duplex Stainless Steel (DSS) was fabricated by powder prepasted Laser Melting Deposition(LMD). The formationof ferrite was promoted by increasing the molybdenum content. The volume ratio of ferrite and austenite of LMDed SAF2906DSS with 3 wt% molybdenum content reached 4:6. The effects of 2 wt% and 4 wt% nano TiN addition on the microstructureand comprehensive properties of LMDed SAF2906 DSS were investigated in detail. The results showed that in-situ generatednano (10 nm ~ 100 nm) and submicron (100 nm ~ 1 μm) Ti2Nparticles were uniformly distributed in the LMDed SAF2906DSS matrix, and some nano Ti2Nparticles preferred to be distributed among grain boundaries. The primary and secondarydendrite spacing of austenite of LMDed SAF2906 with 4wt% TiN addition decreased by 48% and 62%, respectively, whilethe austenite content increased by 15%. The wear resistance, strength, elongation and corrosion resistance of the LMDedSAF2906 were gradually improved with the increase of nano TiN addition from 0 to 4 wt%. The average microhardnessfor the sample with 4 wt% nano TiN addition (381 HV0.2)was 1.2 times that of the sample without TiN (326 HV0.2),whilethe wear rate (9.12 × 10–13 m3/Nm) was only 71% that of the sample without TiN (1.28 × 10–12 m3/Nm). The yield strength,tensile strength and elongation of the LMDed SAF2906 with 4wt% TiN addition increased to 801 MPa, 1028 MPa and31.8%, respectively. The self-corrosion potential increased to 0.0216 V, and the self-corrosion current density also reached4.57 × 10–7 A·cm−2 for LMDed SAF2906 with 4wt% TiN addition.

A generalized adaptive variational mode decomposition method for nonstationary signals with mode overlapped components

Jing-Liang Liu,Fu-Lian Qiu,Zhi-Ping Lin,Yu-Zu Li,Fei-Yu Liao 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.30 No.1

Engineering structures in operation essentially belong to time-varying or nonlinear structures and the resultant response signals are usually non-stationary. For such time-varying structures, it is of great importance to extract time-dependent dynamic parameters from non-stationary response signals, which benefits structural health monitoring, safety assessment and vibration control. However, various traditional signal processing methods are unable to extract the embedded meaningful information. As a newly developed technique, variational mode decomposition (VMD) shows its superiority on signal decomposition, however, it still suffers two main problems. The foremost problem is that the number of modal components is required to be defined in advance. Another problem needs to be addressed is that VMD cannot effectively separate nonstationary signals composed of closely spaced or overlapped modes. As such, a new method named generalized adaptive variational modal decomposition (GAVMD) is proposed. In this new method, the number of component signals is adaptively estimated by an index of mean frequency, while the generalized demodulation algorithm is introduced to yield a generalized VMD that can decompose mode overlapped signals successfully. After that, synchrosqueezing wavelet transform (SWT) is applied to extract instantaneous frequencies (IFs) of the decomposed mono-component signals. To verify the validity and accuracy of the proposed method, three numerical examples and a steel cable with time-varying tension force are investigated. The results demonstrate that the proposed GAVMD method can decompose the multi-component signal with overlapped modes well and its combination with SWT enables a successful IF extraction of each individual component.

Preparation and Evaluation of Pectin-based Colon-specific Pulsatile Capsule In Vitro and In Vivo

Jing Liu,Liang-ke Zhang,Yuntao Jia,Wenjing Hu,Jing-qing Zhang,Huiming Jiang 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.11

The purpose of this study was to develop and evaluate a colon-specific, pulsatile drug delivery system, which consists of an impermeable capsule body filled with a 5-aminosalicylic acid rapid-disintegrating tablet and a pectin-based erodible plug placed in the opening of the capsule body. To obtain an appropriate gel-forming ability and suitable lag time for the colon-specific drug delivery, high-methoxy pectin (HM-pectin) was formulated with lactose and lowmethoxy pectin (LM-pectin) with HPMC to prepare the plug tablet. In order to evaluate the lag time, prior to the rapid drug release, both the formulation of the plug tablet and in vitro release medium were studied. The lag time prior to the rapid drug release was mainly determined by the HM-pectin/lactose or LM-pectin/HPMC ratio. The addition of pectinase or rat cecal content into the release medium shortened the lag time significantly, which predicted the probable enzyme sensitivity of pectin plug tablet. In vivo studies showed that the plasma concentration of drug can only be detected 6 h after oral administration of the pulsatile capsule, which indirectly proved the colon-specific characteristics. These results show that the pulsatile capsule may have the therapeutic action for colon-specific drug delivery.