Wyniki wyszukiwania - Biblioteka Nauki

1

Quartz enhanced photoacoustic spectroscopy based on an external cavity quantum cascade laser

100%

Xu L. , Zhou S. , He T. , Li J.

Optica Applicata

|

2018

|

tom Vol. 48, nr 4

687--695

EN

Mid-infrared laser spectroscopy is a powerful analytical tool for trace gases detection. In this study, a spectroscopic system based on an external cavity quantum cascade laser (ECQCL) and quartz enhanced photoacoustic spectroscopy (QEPAS) was developed for volatile organic compounds (VOCs) measurements. Primary laboratory test on ethanol spectroscopy was investigated and compared with traditional direct absorption spectroscopy (DAS). Experimental results show that the proposed QEPAS is more sensitive than the conventional DAS method. In addition, the significant linear dependence of photoacoustic signal on sample pressures and laser operating parameters was observed.

2

Construct DNA Symmetric Encryption Based on the Problem of Fragment stitching

100%

Zhang Y. , Zhang X. , Fu B. , He T.

Przegląd Elektrotechniczny

|

2013

|

tom R. 89, nr 3b

4--6

EN

DNA cryptography is a new born information security field and have been the international frontier of cryptography emerged with the constantly invasion of traditional cryptography and improvement of research on DNA computing and bio-technology. The security of DNA cryptography is based on difficult biological problems which are unrelated with computing power and thus it is immune to current computer and even future quantum computers. In this paper, we study the difficult biological problem which is the key and basic part in designing of DNA encryption. After analysis of encoding of DNA and mechanism of symmetric encryption, we design a symmetric system using the technology of DNA digital coding and DNA fragment assembly. By implanting DNA secret fragment into the numerous plaintext ones, we destroy the key overlap phase of DNA fragment assembly, thus the normal assembly process cannot be accomplished. In this way, the safety of the encryption scheme is achieved.

PL

W artykule omówiono zagadnienie kodowania DNA i związanych z tym skomplikowanych procesów biologicznych, w odniesieniu do komercyjnych zastosowań. Z uwagi na duży postęp w badaniach nad DNA oraz rozwój klasycznej kryptografii, kodowanie DNA stało się nową, dostępną kategorią. Zaproponowana metoda implementacji tworzy bezpieczny schemat kodowania.

3

Determition of gentiopicroside contents during somatic embryogenesis in Gentiana straminea Maxim

100%

Yang L. , Wang H. , He T.

Acta Physiologiae Plantarum

|

2014

|

tom 36

|

nr 07

EN

A protocol for regeneration of Gentiana straminea Maxim recently established in our laboratory, somatic embryogenesis was obtained from its leaf derived calli. The gentiopicroside contents of embryogenic calli, globular-, heart-, torpedo-, and cotyledon-shaped embryoids as well as regenerated plantlets were determined by high-performance liquid chromatography. Gentiopicroside was detectable in all materials tested. Embryogenic calli showed the lowest gentiopicroside content. The changes of gentiopicroside contents were not significant (P<0.05) with the development of somatic embryos. The highest gentiopicroside content (30.7 mg g⁻¹ dry weight) was achieved in regenerated plantlets. The contents of gentiopicroside were not significant (P<0.05) differences between control plants and embryogenic calli, different stages of somatic embryos and regenerated plantlets. This protocol could be employed for producing gentiopicroside or other medicinal compounds.

4

Preparation and properties of UV-curable acrylate compositions containing silicon

88%

Liu H. , Chen M. , Zhang X. , He T. , Wang Z.

Polimery

|

2004

|

tom T. 49, nr 3

168-172

EN

Some di- and triacrylates were subjected to Michael addition reaction with N-cyclohexyl-gamma-aminopropylmethyldimethoxysilane (CAMS). FT-IR method has been used to follow the course of the reaction of -NH group in CAMS with double bond in an acrylate. Post-reaction mixtures obtained underwent UV-curing in the presence of a photoinitiator (2-hydroxy-2,2-dimethyl-1-phenylethane-1-one, trade name "Darocur 1173") and formed thin films on the glass or plastic substrate. Dependence of the thermal stability of cured material on its initial composition was characterized using thermogravimetric method. There were determined the effects of non-reacted acrylic groups' part in the post-reaction mixture as well as of irradiation time (crosslinking degree) on hardness and brittleness of the coatings cured. Silicon atoms presence in the compositions improves their elasticity but deteriorates thermal stability.

PL

Szereg di- i triakrylanów poddano reakcji typu addycji Michaela z N-cykloheksylo-gamma-aminopropylometylodimetoksysilanem (CAMS) (tabela 1). Przebieg reakcji grup -NH w CAMS z podwójnym wiązaniem w akrylanach śledzono metodą FT-IR (rys. 1 i 2). Uzyskane mieszaniny poreakcyjne ulegały wobec fotoinicjatora (2-hydroksy-2,2-dimetylo-1-fenyloetan-1-onu o nazwie handlowej "Darocur 1173") utwardzeniu pod wpływem promieniowania UV tworząc cienkie błony na podłożu szklanym lub tworzywowym. Metodą termograwimetryczną scharakteryzowano zależność termostabilności utwardzonych kompozycji od ich wyjściowego składu (rys. 3, tabela 2). Określono wpływ udziału nieprzereagowanych grup akrylanowych w mieszaninie poreakcyjnej i czasu napromieniania (stopnia usieciowania) na twardość oraz kruchość utwardzonych powłok (tabela 1). Obecność atomów krzemu w kompozycjach polepsza ich elastyczność, lecz pogarsza termostabilność.

5

Dynamic characteristics of magnetic coupling in horizontal axis wave energy device

88%

Zhang J. , Liu Y. , Liu J. , He T. , Xie Y.

Polish Maritime Research

|

2017

|

tom 24

|

nr Special Issue S3

EN

To solve the dynamic response problems of magnetic coupling in the horizontal axis wave energy device, this has researched the dynamic characteristicsof magnetic coupling. The fitting formula about torque and angle of the magnetic coupling is obtained through experiments. The mathematical models of the magnetic coupling torque transmission are established. The steady state error of the magnetic coupling and the transfer function of the output angle are obtained. The analytical solution of the step response of the output angle in time domain is derived. The influence of the torsional rigidity, the damping coefficient and the driven rotor’s rotational inertia on dynamic characteristics of the magnetic coupling isanalyzed. According to the analysis results, the design rules of magnetic coupling are proposed

6

Dynamic characteristics of magnetic coupling in horizontal axis wave energy device

88%

Zhang J. , Liu Y. , Liu J. , He T. , Xie Y.

Polish Maritime Research

|

2017

|

tom S 3

165--170

EN

To solve the dynamic response problems of magnetic coupling in the horizontal axis wave energy device, this has researched the dynamic characteristicsof magnetic coupling. The fitting formula about torque and angle of the magnetic coupling is obtained through experiments. The mathematical models of the magnetic coupling torque transmission are established. The steady state error of the magnetic coupling and the transfer function of the output angle are obtained. The analytical solution of the step response of the output angle in time domain is derived. The influence of the torsional rigidity, the damping coefficient and the driven rotor’s rotational inertia on dynamic characteristics of the magnetic coupling isanalyzed. According to the analysis results, the design rules of magnetic coupling are proposed.

7

The effects of bridge abutments on the benthic macroinvertebrate community

75%

Yu Z. , Wang H. , Wang R. , He T. , Cao Q. , Wang Y. , Liu J.

Polish Journal of Environmental Studies

|

2016

|

tom 25

|

nr 3

EN

A river ecosystem is a treasure that is home to a wide variety of wetland species. The construction of bridges might have a deep impact on diversity of such an ecosystem. The ecological consequence of bridge abutments was studied by monitoring the benthic macroinvertebrate community at six main bridges on the Tuhai and Majia rivers in eastern China. We collected samples of macroinvertebrates from upstream to downstream during the summer hight-water period, and we monitored water quality at each site. The macroinvertebrate community of under-bridge sites was signifi cantly correlated with that of reference sites in abundance, biomass, and richness. The benthic macroinvertebrate communities were not significantly different between under-bridge sites and reference sites in terms of abundance and biomass, while they were significantly different in terms of richness and the Shannon-Wiener index. This pattern outlined a major impact of bridge abutments on benthic macroinvertebrate communities for the first time, indicating the importance of habitat restoration after river construction was finished. Suitable measures should be taken to minimize the impact of bridge abutments.

8

Expression profiles uncover the relationship between erythropoietin and cell proliferation in rat hepatocytes after a partial hepatectomy

75%

Zhang J. , Yang Y. , He T. , Liu Y. , Zhou Y. , Chen Y. , Xu C.

Cellular and Molecular Biology Letters

|

2014

|

tom 19

|

nr 3

EN

Erythropoietin (EPO) has a beneficial effect on hepatic cell proliferation during liver regeneration. However, the underlying mechanism has not yet been elucidated. To uncover the proliferation response of EPO in rat liver regeneration after partial hepatectomy (PH) at the cellular level, hepatocytes (HCs) were isolated using Percoll density gradient centrifugation. The genes of the EPO-mediated signaling pathway and the target genes of the transcription factor (TF) in the pathway were identified in a pathway and TF database search. Their expression profiles were then detected using Rat Genome 230 2.0 Microarray. The results indicated that the EPO-mediated signaling pathway is involved in 19 paths and that 124 genes participate, of which 32 showed significant changes and could be identified as liver regeneration-related genes. In addition, 443 targets regulated by the TFs of the pathway and 60 genes associated with cell proliferation were contained in the array. Subsequently, the synergetic effect of these genes in liver regeneration was analyzed using the E(t) mathematical model based on their expression profiles. The results demonstrated that the E(t) values of paths 3, 8, 12 and 14–17 were significantly strengthened in the progressing phase of liver regeneration through the RAS/MEK/ERK or PI3K/AκT pathways. The synergetic effect of the target genes, in parallel with target-related cell proliferation, was also enhanced 12–72 h after PH, suggesting a potential positive effect of EPO on HC proliferation during rat liver regeneration. These data imply that the EPO receptor may allow EPO to promote HC proliferation through paths 3, 8, 12 and 14–17, mediating the RAS/MEK/ERK and PI3K/AκT pathways in rat liver regeneration after PH.

9

Fiber-optic accelerometer based on a modal interferometer using a thin-core fiber

75%

Wang X. , Wu X. , Li S. , Ge Q. , He T. , Yu B.

Optica Applicata

|

2015

|

tom Vol. 45, nr 3

317--325

EN

A compact fiber-optic accelerometer based on a modal interferometer, which is fabricated by misaligned splicing of a short section of a thin-core fiber between two sections of a standard single-mode fiber, is demonstrated experimentally. A spectrum analysis method is used to detect an acceleration signal rapidly. The experimental results show that the thin-core fiber-based fiber-optic accelerometer has a minimum detectable acceleration of 3.3×10–3g (g – gravitational acceleration), and a wide frequency response range from 10 to 1200 Hz. Moreover, the proposed accelerometer exhibits the advantages of low cost, simple structure and easy fabrication.