11 results on '"Tang, Jun"'
Search Results
2. Recent Advances of Polymer‐Based Pure Organic Room Temperature Phosphorescent Materials.
- Author
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Wang, Jun, Lou, Xin‐Yue, Wang, Yan, Tang, Jun, and Yang, Ying‐Wei
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STOKES shift ,PHOSPHORESCENCE ,TEMPERATURE ,PHOSPHORS ,LINCRNA - Abstract
Room temperature phosphorescence (RTP) has attracted broad attention due to their long lifetimes, large Stokes shift, and widespread applications. Achieving RTP emission has long been a challenging task under common conditions, for the necessary requirements of promoting intersystem crossing processes and suppressing nonradiative transitions are always tough to meet. Over the past decade, RTP has been obtained through several specific strategies, among which an important method lies in immobilizing phosphors into polymer matrices. Via the effect of steric overcrowding exerted by the polymeric structures, the phosphorescence of the initial phosphors can be promoted significantly. Hence, polymer‐based pure organic materials have proved to be one newly emerging subject in the field of RTP materials. In this review article, the progresses of polymer‐based pure organic room temperature phosphorescent materials are elaborated from four main approaches, including doped polymer systems, copolymer systems, homopolymer systems, and host–guest complexation systems, whereby the design principles, synthesis methods, possible mechanisms, and applications are summarized and discussed in detail. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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3. Simultaneous imaging of magnetic field and temperature using a wide-field quantum diamond microscope.
- Author
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Chen, Yulei, Li, Zhonghao, Guo, Hao, Wu, Dajin, and Tang, Jun
- Subjects
MAGNETIC fields ,MICROSCOPES ,DIAMONDS ,MAGNETICS ,TEMPERATURE - Abstract
Quantum sensing based on nitrogen-vacancy centers in diamond has shown excellent properties. Combined with the imaging technique, it shows exciting practicability. Here, we demonstrate the simultaneously imaging technique of magnetic field and temperature using a wide-field quantum diamond microscope. We describe the operating principles of the diamond microscope and report its sensitivity (magnetic field ∼ 1.8 μ T/Hz 1 / 2 and temperature ∼ 0.4 K/Hz 1 / 2 ), spatial resolution (1.3 μm), and field of view (400 × 300 μ m 2 ). Finally, we use the microscope to obtain images of an integrated cell heater and a PCB, demonstrating its ability in the application of magnetic field and temperature simultaneously imaging at wide-field. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
4. Functional sustainability of nutrient accumulation by periphytic biofilm under temperature fluctuations.
- Author
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Sun, Rui, Xu, Ying, Wu, Yonghong, Tang, Jun, Esquivel-Elizondo, Sofia, Kerr, Philip G., Staddon, Philip L., and Liu, Junzhuo
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BIOFILMS ,NUTRIENT cycles ,SPECIES diversity ,TEMPERATURE ,MICROBIAL communities ,SUSTAINABILITY - Abstract
Temperature can fluctuate widely between different seasons, and this may greatly impact many biological processes. However, little is known about its influence on the functioning of benthic microbial communities. Here we investigated the nutrient accumulation capability of periphytic biofilm under temperature fluctuations (17–35°C). Periphytic biofilm maintained the same nutrient accumulation capacity after experiencing the 'warming-hot-cooling' temperature fluctuation under both lab and outdoor conditions as those without temperature disturbance. In response to temperature increase, both community composition and species richness changed greatly and the increase in biodiversity was identified as being the underlying mechanism boosting the sustainable function in nutrient accumulation, indicating zero net effects of community changes. These findings provide insights into the underlying mechanisms of how benthic microbial communities adapt to temperature fluctuations to maintain nutrient accumulation capacity and elucidate that periphytic biofilm plays important roles in influencing nutrient cycling in aquatic ecosystems under temperature changes such as seasonal fluctuations. [ABSTRACT FROM AUTHOR]
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- 2021
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- View/download PDF
5. Association between ambient temperature and hypertensive disorders in pregnancy in China.
- Author
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Xiong, Tao, Chen, Peiran, Mu, Yi, Li, Xiaohong, Di, Baofeng, Li, Jierui, Qu, Yi, Tang, Jun, Liang, Juan, and Mu, Dezhi
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PREECLAMPSIA ,PREGNANCY ,PREGNANT women ,HYPERTENSION ,TEMPERATURE ,DISEASES - Abstract
Hypertensive disorders in pregnancy (HDPs) are leading perinatal diseases. Using a national cohort of 2,043,182 pregnant women in China, we evaluated the association between ambient temperatures and HDP subgroups, including preeclampsia or eclampsia, gestational hypertension, and superimposed preeclampsia. Under extreme temperatures, very cold exposure during preconception (12 weeks) increases odds of preeclampsia or eclampsia and gestational hypertension. Compared to preconception, in the first half of pregnancy, the impact of temperature on preeclampsia or eclampsia and gestational hypertension is opposite. Cold exposure decreases the odds, whereas hot exposure increases the odds. Under average temperatures, a temperature increase during preconception decreases the risk of preeclampsia or eclampsia and gestational hypertension. However, in the first half of pregnancy, temperature is positively associated with a higher risk. No significant association is observed between temperature and superimposed preeclampsia. Here we report a close relationship exists between ambient temperature and preeclampsia or eclampsia and gestational hypertension. Hypertensive disorders in pregnancy are prevalent perinatal diseases. Here the authors report an association between ambient temperature before or after conception and risk of preeclampsia or eclampsia and gestational hypertension. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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6. Pole-Zero Temperature Compensation Circuit Design and Experiment for Dual-Mass MEMS Gyroscope Bandwidth Expansion.
- Author
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Cao, Huiliang, Zhang, Yingjie, Han, Ziqi, Shao, Xingling, Gao, Jinyang, Huang, Kun, Shi, Yunbo, Tang, Jun, Shen, Chong, and Liu, Jun
- Abstract
This paper presents a bandwidth expansion method for dual-mass microelectromechanical system (MEMS) gyroscopes based on the pole–zero temperature compensation method. When the sense loop operates under open conditions, the mechanical sensitivity of the gyroscope structure conflicts with the bandwidth and is governed by the frequency difference between the drive and the sense modes (min {Δω1, Δω2}), which is proven to change with temperature during the experiment. The pole–zero temperature compensation proportional controller (PZTCPC) is proposed to expand the bandwidth under different temperatures based on the pole–zero compensation method. The force rebalancing combs stimulation method (FRCSM) is used to achieve accurate gyroscope bandwidth characteristics. The mechanical bandwidth of the gyroscope is proven to be approximately 13 Hz when the sense-mode loop is open, and the simulation results show that the PZTCPC method expands the bandwidth to greater than 91.7 Hz after the sense-mode loop is closed. The FRCSM experiments indicate that gyroscope bandwidth is expanded to 95 Hz at –40 °C, 94 Hz at 20 °C and 92 Hz at 60 °C, while the bandwidths at –40, 20, and 60 °C are all 93 Hz with the turntable method. The experimental curves match the simulation curves well and verify the simulation results. The new limiting condition of the closed-loop bandwidth is the trough generated by conjugate zeros, formed by superposition of in-phase and anti-phase sense modes. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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7. Novel organic base-immobilized magneto-polymeric nanospheres as efficient Pickering interfacial catalyst for transesterification.
- Author
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Tang, Jun, Zhang, Qi, Hu, Kecheng, Cao, Shixiong, Zhang, Shouhao, and Wang, Jianli
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CATALYSTS , *TRANSESTERIFICATION , *CATALYSIS , *TEMPERATURE , *NANOPARTICLES - Abstract
Graphical abstract Highlights • Fe 3 O 4 @PS-TMG was synthesized by immobilizing TMG onto the shell of nanohybrids. • The loading of TMG as well as surface property of catalyst can be well regulated. • The MPIC can stabilize soybean oil-in-methanol Pickering emulsion. • The MPIC exhibited higher catalytic activity for transesterification. Abstract A novel magnetic Pickering interfacial catalyst (MPIC) was developed and used for highly effective and clean production of biodiesel. The catalyst was synthesized by immobilization of 1,1,3,3-tetramethylguanidine (TMG) onto the shell of Fe 3 O 4 @Chloromethyl PS nanohybrids. The resultant Fe 3 O 4 @PS-TMG was measured by transmission electron microscope (TEM), dynamic lighting scattering (DLS), Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA), thermogravimetric analysis (TG), contact angles (CA). The results showed that surface property and TMG loading of catalyst can be finely regulated via adjusting the feeding of TMG. Fe 3 O 4 @PS-TMG with amphiphilic surface can stabilize soybean oil-in-methanol Pickering emulsion, which would offer large interfacial area and surface enrichment of reactants, leading to a significant enhancement of such liquid-liquid (L-L) biphasic reaction with high mass transfer resistance. Furthermore, the MPIC can be facile separated from the mixture of reaction by magnet, and showed excellent stability over 5 recycles. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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8. Theoretical and experimental studies on non-reciprocity error induced by varying temperatures in polarization-maintaining fiber optical gyro with orthogonal-polarization states.
- Author
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Li, Jing, Zhou, Yanru, Xue, Luyao, Liu, Wenyao, Xing, Enbo, Tang, Jun, and Liu, Jun
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OPTICAL fibers ,OPTICAL gyroscopes ,OPTICAL devices ,REFRACTIVE index ,TEMPERATURE - Abstract
In this study, a polarization-maintaining fiber optical gyro (PMFOG) with orthogonal-polarization states is constructed, and the non-reciprocity error induced by varying temperatures has been studied. Compared with the traditional optical gyro system based on single-polarization, theory and experiments have shown that the non-reciprocity error induced by varying temperatures is more evident in the PMFOG with orthogonal-polarization states. It is approximately five times larger than that of the traditional PMFOG. To decrease the non-reciprocity error induced by varying temperatures, we proposed an innovative structure in this study, which enhances the symmetry of the light path without the addition of redundant optical devices. The clockwise and counterclockwise light beams experience the same change of refractive index along the fast and slow axes of the fiber, and the non-reciprocity error induced by varying temperatures can be reduced to zero when the whole gyro is heated up nearly uniformly. This research, which overcomes a design limitation in PMFOGs with orthogonal-polarization states, is significant for the miniaturization and optimization of the environmental adaptability of fiber optic gyroscopes. [ABSTRACT FROM AUTHOR]
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- 2022
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9. Multi-scale parallel temperature error processing for dual-mass MEMS gyroscope.
- Author
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Shen, Chong, Li, Jie, Zhang, Xiaoming, Tang, Jun, Cao, Huiliang, and Liu, Jun
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MICROELECTROMECHANICAL systems , *GYROSCOPES , *TEMPERATURE , *ENTROPY , *ARTIFICIAL neural networks - Abstract
A temperature error processing method for a dual-mass micro-electromechanical system (MEMS) gyroscope based on multi-scale parallel model is proposed. At first, a sample entropy based bounded ensemble empirical mode decomposition (SE-BEEMD) is proposed to decompose the original signal into different scales, include noise-only scale, mixed scale and drift scale; then forward linear prediction (FLP) is employed to eliminate the noise at mixed scale and extreme learning machine (ELM) based model is employed to compensate the drift at drift scale, the two steps are carried out paralleled; at last the final results can be obtained after reconstruction. Experimental results show that: (1) compared to tradition serial model, the proposed parallel model can eliminate the temperature errors more effectively, and each parameter of Allan analysis is improved. Specially, the quantification noise reduced from 0.035 μrad to 9.93e4 μrad, angle random walk reduced from 2.13e-5/s 1/2 to 7.94e-6/s 1/2 , bias instability reduced from 5.28e-4/s to 4.79e-4/s, rate random walk from 0.012/s 3/2 to 0.092/s 3/2 and angular rate ramp reduced from 0.013/s 2 to 0.011/s 2 ; (2) compared to traditional time consuming neural networks, the ELM has the best modeling accurate and shortest training time, which would be valuable for online temperature drift modeling and compensation. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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10. An improved interface and noise analysis of a turning fork microgyroscope structure.
- Author
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Cao, Huiliang, Li, Hongsheng, Liu, Jun, Shi, Yunbo, Tang, Jun, and Shen, Chong
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GYROSCOPES , *MECHANICAL engineering , *THERMAL noise , *SIGNAL detection , *INTERFACES (Physical sciences) , *MICROELECTROMECHANICAL systems - Abstract
This paper analyzes different noise components in MEMS gyroscope silicon structure, including mechanical–thermal noise (MTN), electronic-thermal noise (ETN), flicker noise (FN) and Coriolis signal in-phase noise (IPN). The structure equivalent electronic model is established, and the improved differential interface is proposed based on weak signal detection technology, after that, the noise components in silicon structure are introduced and analyzed in sense open loop. The quadrature error (QE) signal automatically cancellation loop is proposed, and the results of the experiment indicate that the equivalent angular rates of QE and IPN are 46°/s and 4.55°/s respectively. The interfaces contrast experiments show that the DC noise and the useful signal amplitudes of differential and single-side detection interfaces are −49.8 dBmV, −16.8 dBmV and −39.8 dBmV (−42.1 dBmV), −22.1 dBmV (−22.2 dBmV), which confirms the differential interface has better SNR. The carrier experiments also illustrate that higher carrier frequency (from 500 kHz to 10 MHz) can restrain DC noise (from −19.8 dBmV to −54.2 dBmV) better, which demonstrate the FN is the dominant noise component of the silicon structure under normal temperature. The temperature experiments show the DC noise enhances from −48.5 dBmV to −14.6 dBmV over the range 20 °C to 60°C while the useful signal amplitude remains around -16.6dBmV, and this phenomenon indicates the MTN and ETN become the dominant structure noise components gradually with temperature rising. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
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11. Error analysis of dual-polarization fiber optic gyroscope under the magnetic field-variable temperature field.
- Author
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Xue, Luyao, Zhou, Yanru, Li, Jing, Liu, Wenyao, Xing, Enbo, Chen, Jianjun, Tang, Jun, and Liu, Jun
- Subjects
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OPTICAL gyroscopes , *GYROSCOPES , *MAGNETIC fields , *TEMPERATURE - Abstract
• The mechanism of nonreciprocal errors under the magnetic field-variable temperature field is proposed. • Based on dual-polarization interferometric fiber optic gyroscope (IFOG). • The nonreciprocal errors under the magnetic field, variable temperature field and magnetic field-variable temperature field are compared. A dual-polarization fiber optic gyroscope system is built to systematically analyze the nonreciprocal errors of the system under the magnetic field-variable temperature field. Under the magnetic field-variable temperature field, the nonreciprocal errors are caused by magnetic-thermal coupling birefringence nonreciprocal error, linear birefringence nonreciprocal error and Shupe effect error. The nonreciprocal errors of dual-polarization fiber optic gyroscope system are related to temperature and temperature gradient. In X and Y polarization states, the signs of magnetic-thermal coupling birefringence nonreciprocal error and linear birefringence nonreciprocal error are opposite, and these two errors can be suppressed in the dual-polarization system. But the Shupe effect errors are the same in X and Y polarization states, which can not be suppressed in the dual-polarization system. The experimental results are consistent with the theoretical analysis, which verifies the correctness of the nonreciprocal error model under the magnetic field-variable temperature field. The research results provide a theoretical and experimental basis for the study of the environmental adaptability of the fiber optic gyroscope and other common-path fiber sensing systems based on dual-polarization. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
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