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Search Results: 1 - 10 of 23245 matches for " He Guotian "
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Sinusoidal phase modulating interferometer for real-time surface profile measurement
He Guotian,Jiang Helun,Tan Xingwen
Optica Applicata , 2008,
Abstract: The optical interferometry for the surface profile measurement is high accuracy, non-contact, and has a wide application in industry and scientific research. In this paper, a sinusoidal phase modulating (SPM) interferometer to realize real-time surface profile measurement is proposed, and its measuring principle is analyzed theoretically. In the SPM interferometer, the interference signal is detected by a high speed image sensor based on a low-speed CCD and a signal processing circuit is used to obtain the phase of each point on the surface. Therefore, the surface profile can be measured real time. The experiments measuring the surface profile of a wedge-shaped optical flat show that the measurement time of the SPM interferometer is less than 10 ms, the repetitive measurement accuracy is 5.2 nm. The experimental results confirm the validity of the SPM interferometer, and the merits of the interferometer is simple structure, high measurement accuracy.
The application of the self-adaptive tracking method to the sinusoidal phase modulating interferometry
Guotian He,Yuangang Lu,Changrong Liao,Zhi Zeng
Optica Applicata , 2009,
Abstract: In this paper, we analyze theoretically the accuracy of the surface profile measurement in a sinusoidal phase modulating interferometer, derive the relative error formula, and investigate the influence of spectral leakage on the measurement accuracy. The theoretical results show that when the offset of sampling frequency from its theoretical ideal is outside the range of – 0.188% to +0.075%, the spectrum leakage results in an relative error greater than λ/320 nm, and thus the spectral leakage is not negligible. In order to eliminate the influence of the spectral leakage, a self-adaptive tracking method is proposed. The tracking method can adjust automatically the sampling signal frequency in such a way that the sampling signal frequency is an integer multiple of the modulating signal frequency. The simulation and experimental results show that the problem of the spectrum leakage can be solved with the proposed technique, and therefore the measurement accuracy and reliability of the SPM interferometer are enhanced.
MicroRNA and Its Role in Cardiovascular Disease  [PDF]
Suvash Pokhrel, Yin Guotian
World Journal of Cardiovascular Diseases (WJCD) , 2017, DOI: 10.4236/wjcd.2017.710032
Abstract: MicroRNAs play a key role in regulation of gene expression during cardiac development and cardiac remodeling. MicroRNAs that present in bodily fluids may?be?useful for screening, diagnosis or therapeutic implication as a treatment. MicroRNAs are relatively new approach targets for researchers and clinicians in today world.MicroRNAs are small noncoding RNA (ncRNA) having approximately 21 to 25 nucleotides in length, and they mainly act as a transcriptional regulators of gene expression in diverse biological processes such as cellular proliferation, differentiation, tumorigenesis to death and so on. There is no doubt that lethiferous cardiac disease is one of the most common causes of deaths worldwide.MicroRNAs may regulate in several cardiovascular pathologies, not only limited to hypertrophy, heart failure, arrhythmias, hypertension, myocardial infarction, dyslipidemias and congenital heart diseases, but in circulation and bodily fluids are potential novel biomarkers for above mentioned cardiac pathologies. Knowing abnormalities in genetic level, early and accurate detection, effective treatment and prevention is the ideal management of cardiovascular diseases in today’s world.However, every detail of an individual microRNA and their system is huge and beyond the scope of this article. Therefore, in this review we try to cover the overall major aspects of the microRNAs and its role in cardiovascular system.
Characteristics of N and P Loss in the Soil of Purple Sloping Farmland at Different Fertilization Levels
重庆师范大学学报(自然科学版) , 2012, DOI: 10.11721/cqnuj20120325
Abstract: Usingthe"WinterWheat-SummerMaize"modelandtheplotrunoffmonitoringmethod,westudiedthecharacteristicsofnitrogenandphosphoruslossinthesoilsedimentofpurpleslopingfarmlandunderfiveconditions,includingcontrol,combinedmanure/fertilizerapplication,chemicalfertilizer,highintensitychemicalfertilizer,andcrossridgefarming.Theresultsshowedthatthenutrientcontentofthesurfacesoilincreased,tosomeextent.Furthermore,thenutrientswereenrichedinthesedimentforallgroups.Thedegreeofsedimentnutrientenrichmentofcrossridgefarmingwaslessgreatcomparedtolongitudinalfarming.Forthecombinedmanure/fertilizerapplication,theratioofeffectivenutrientswaslargerthanthatoftotalnutrients;whereas,forthechemicalfertilizergroup,theratioofeffectivenutrientswassignificantlysmaller.Atallfertilizationlevels,sedimentlossonlyaccountedfor0.34%~6.21%.78.80%~84.83%ofthetotalphosphoruslossoccurredinthesediment,andthephosphoruslosswaslargelyinthesediment.Therelativelossfactorofnitrogenwasthelargestforthechemicalfertilizergroup,followedbythecrossridgefarminggroup,thehighintensitychemicalfertilizergroup,andthecombinedmanure/fertilizerapplicationgroup.Therelativelossfactorofphosphoruswasthelargestforthehighintensitychemicalfertilizergroup,followedbythecrossridgefarminggroup,thechemicalfertilizergroup,andthecombinedmanure/fertilizerapplicationgroup.
Progress in China’s Energy Security Research

CAI Guotian,ZHANG Lei,
,张 雷

地理科学进展 , 2005,
Abstract: As one of the largest energy consumers and producers in the world, China has faced great challenges of energy security on the way of modernizing itself. Energy security mainly concludes reliable energy provision and safe energy use. The paper reviews the progress in China's energy security, energy strategy and law related energy problem. Though great progress has been made in energy security, there are many shortcomings, such as false energy prediction in some years, mainly because of the short industrialization history of China and weak researching on the complex energy system. It is the time to rethink energy security when China is turning from reliable energy provision to safe energy use. Based on researching, the paper points out that China should attach greater importance to energy security researching, including the phase of energy security, changing of energy consumption, energy management, energy price, law related energy problem and the development of renewable and new energy. The government should adapt its management to the market economy. Resource-price reform must be accelerated and prices should be decided by the market as much as possible. China must also develop its reproducible energy resources. In conclusion, solving energy security problem requires the participation of the entire nation.
Analysis Basic Situation of China''s Energy Secur ity

CAI Guotian,ZHANG Lei,

地理科学进展 , 2006,
Abstract: As one of the largest energy consumers and producers in the world, China has faced great challenge in energy security on the way of modernizing itself. Energy security mainly includes reliable energy provision and safe energy use. Reliable energy provision cares about whether a country's energy supply could meet its demand for population and economic development. Safe energy use tells us that we should reject the pattern of energy use at the cost of polluting environment. The paper analyzes the situation of China's energy security based on the analysis of energy resource base, balance between energy production and consumption, energy transportation and side effect of energy consumption. Owing to the pressure of economic development, China has placed much more emphasis on the security of energy provision than safe energy use, though it realized the importance of the latter in the past years. While it built its energy provision system, it polluted the environment greatly at the same time in such ways as lots of CO2 emissions, which contribute to the global warming, and the sinking of the earth's surface caused by coal mining. So it is time to rethink the goal of energy security. Energy security, as a determinant factor to the modern society, will become an increasingly sensitive issue in China when the country makes great strides in modernizing itself; and it could become even more sensitive in the next twenty to thirty years when China's population growth and economic development imposes more pressure on the national energy supply system continuingly. Based on the basic situation of China's energy security, this paper suggests that a new energy policy, including reliable energy provision and safe energy use, be needed for China's sustainable development in the future.
Fabrication of Mo+N-Codoped TiO2 Nanotube Arrays by Anodization and Sputtering for Visible Light-Induced Photoelectrochemical and Photocatalytic Properties
Min Zhang,Dandan Lu,Guotian Yan,Juan Wu,Jianjun Yang
Journal of Nanomaterials , 2013, DOI: 10.1155/2013/648346
Abstract: Mo,N-codoped TiO2 nanotube arrays (TNAs) were fabricated by a two-step method consisting of electrochemical anodization and subsequent magnetron sputtering of Mo. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The results showed that the Mo,N-codoped TiO2 nanotube arrays exhibited higher visible light absorbance and remarkably enhanced photocurrent density and photocatalytic activity compared with single N-doped TiO2. The highly efficient photoelectrochemical and photocatalytic activity is associated with the codoping effect between Mo and N, which plays a key role in producing new states, narrowing the bandgap, and reducing the recombination thereby effectively improving the visible light absorption and photocatalytic activity of TNAs. 1. Introduction TiO2 is one of the most studied compounds in materials science and widely used in the fields of photocatalysis, dye-sensitized solar cells, and biomedical devices owing to its outstanding chemical and physical properties, such as ease of synthesis, chemical stability, and long lifetime of electron/hole pairs [1]. Compared to other types of titania nanostructures, TiO2 nanotube arrays (TNAs) have the advantage of high surface-to-volume ratios and size-dependent properties for applications in photocatalysis, sensing, and photovoltaics [2–4]. TNAs with different sizes and geometrical shapes have been prepared using various physical and chemical synthesis routes [5–7]. Among these fabrication techniques, electrochemical anodization is an efficient and economical approach for the production of highly ordered TNAs with controllable tube size and morphology [8–10]. Highly ordered TNAs exhibited excellent photocatalytic properties due to their high-oriented uniform nanotube architecture and the rapid transfer of the photogenerated holes to the surrounding electrolyte and the extended electron lifetimes in the nanotubes [11, 12]. Due to its large band gap (about 3.2?eV), TiO2 fails to absorb a significant fraction of visible light effectively, resulting in a poor solar-to-hydrogen conversion efficiency. Doping, in particular the doping by N, has attracted increasing attention due to its effectiveness in realizing visible-light photocatalytic activity of TiO2 [13, 14]. However, single doping of nitrogen also creates some problems such as low UV light photoactivity, unstable N species after photocatalysis, and low oxidation power of the photogenerated hole.
Photoelectrochemical and photocatalytic properties of N + S co-doped TiO2 nanotube array films under visible light irradiation
Guotian Yan,Min Zhang,Jian Houa,Jianjun Yang
Physics , 2011, DOI: 10.1016/j.matchemphys.2011.04.063
Abstract: In this paper, we report on the co-doping nitrogen and sulfur has been achieved in the TiO2 nanotube array films by treatment with thiourea and calcination under vacuum at 500 {\deg}C for 3 h. The samples were characterized by scanning electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy. XPS spectra revealed that N might coexist in the forms of NTiO and NOTi, S was incorporated into the lattice of TiO2 through substituting oxygen atoms in the N + S co-doped TiO2 nanotube array films. XRD patterns indicated that improved crystallinity was obtained for N + S co-doped TiO2 nanotube arrays as compared to that of undoped TiO2 nanotube arrays. In photoelectrochemical measurements, the photocurrent of N + S co-doped TiO2 nanotube array films was greatly enhanced compared to that of undoped samples under visible light irradiation. And the photocatalytic activities of the samples were evaluated on the removal of methylene blue under visible light irradiation. The N + S co-doped TiO2 nanotube array films showed a better photocatalytic activity than the undoped sample due to the N, S doping. Keywords: Nanostructures; Oxide; Thin films; Electrochemical properties
Effects of Calcination Temperatures on Photocatalytic Activity of Ordered Titanate Nanoribbon/SnO2 Films Fabricated during an EPD Process
Li Zhao,Jingrun Ran,Zhan Shu,Guotian Dai,Pengcheng Zhai,Shimin Wang
International Journal of Photoenergy , 2012, DOI: 10.1155/2012/472958
Abstract: Ordered titanate nanoribbon (TNR)/SnO2 films were fabricated by electrophoretic deposition (EPD) process using hydrothermally prepared titanate nanoribbon as a precursor. The formation mechanism of ordered TNR film on the fluorine-doped SnO2 coated (FTO) glass was investigated by scanning electron microscopy (SEM). The effects of calcination temperatures on the phase structure and photocatalytic activity of ordered TNR/SnO2 films were investigated and discussed. The X-ray diffraction (XRD) results indicate that the phase transformation of titanate to anatase occurs at 400°C and with increasing calcination temperature, the crystallization of anatase increases. At 600°C, the nanoribbon morphology still hold and the TiO2/SnO2 film exhibits the highest photocatalytic activity due to the good crystallization, unique morphology, and efficient photogenerated charge carriers separation and transfer at the interface of TiO2 and SnO2.
The Cyclase-Associated Protein Cap1 Is Important for Proper Regulation of Infection-Related Morphogenesis in Magnaporthe oryzae
Xiaoying Zhou,Haifeng Zhang,Guotian Li,Brian Shaw,Jin-Rong Xu
PLOS Pathogens , 2012, DOI: 10.1371/journal.ppat.1002911
Abstract: Surface recognition and penetration are critical steps in the infection cycle of many plant pathogenic fungi. In Magnaporthe oryzae, cAMP signaling is involved in surface recognition and pathogenesis. Deletion of the MAC1 adenylate cyclase gene affected appressorium formation and plant infection. In this study, we used the affinity purification approach to identify proteins that are associated with Mac1 in vivo. One of the Mac1-interacting proteins is the adenylate cyclase-associated protein named Cap1. CAP genes are well-conserved in phytopathogenic fungi but none of them have been functionally characterized. Deletion of CAP1 blocked the effects of a dominant RAS2 allele and resulted in defects in invasive growth and a reduced intracellular cAMP level. The Δcap1 mutant was defective in germ tube growth, appressorium formation, and formation of typical blast lesions. Cap1-GFP had an actin-like localization pattern, localizing to the apical regions in vegetative hyphae, at the periphery of developing appressoria, and in circular structures at the base of mature appressoria. Interestingly, Cap1, similar to LifeAct, did not localize to the apical regions in invasive hyphae, suggesting that the apical actin cytoskeleton differs between vegetative and invasive hyphae. Domain deletion analysis indicated that the proline-rich region P2 but not the actin-binding domain (AB) of Cap1 was responsible for its subcellular localization. Nevertheless, the AB domain of Cap1 must be important for its function because CAP1ΔAB only partially rescued the Δcap1 mutant. Furthermore, exogenous cAMP induced the formation of appressorium-like structures in non-germinated conidia in CAP1ΔAB transformants. This novel observation suggested that AB domain deletion may result in overstimulation of appressorium formation by cAMP treatment. Overall, our results indicated that CAP1 is important for the activation of adenylate cyclase, appressorium morphogenesis, and plant infection in M. oryzae. CAP1 may also play a role in feedback inhibition of Ras2 signaling when Pmk1 is activated.
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