Detection of infrared photons with a superconductor

A superconductor single photon detector based on NbN nanowire was fabricated using electron beam lithography （EBL） and reactive ion etching （RIE） for infrared photon detection. When biased well below its critical current at 4.2 K, NbN nanowire is very sensitive to the incident photons. Typical telecommunication photons with a wavelength of 1550 nm were detected by this detector. Data analysis indicates the repeating rate of the device with 200 nm NbN nanowire may be up to 100 MHz, and the quantum efficiency is about 0,01% when biased at 0.95/c.     

SHRIMP U-Pb zircon age of the Jinbaoshan ultramafic intrusion, Yunnan Province, SW China

SHRIMP U-Pb zircon dating gives ages of 260.6± 3.5 Ma and 260.7± 5.6 Ma for serpentinised wehrlite and plag-hornblendite in the Jinbaoshan ultramafic intrusion, respectively. The results indicate that the Jinbaoshan intrusion was emplaced at ca.260 Ma and contemporaneous with the Emeishan continental flood basalts (ECFB), similar to other mafic-ultramafic intrusions of the Emeishan large igneous province (LIP). The new ages provide a geochronological constraint on the origin of the Jinbaoshan ultramafic intrusion. It confirms that the Jinbaoshan ultramafic intrusion belongs to the Emeishan LIP that formed at ca. 260 Ma. Supported by Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX2-YW-111), National Natural Science Foundation of China (Grant Nos. 40573020 and 40773033) and National Basic Research Program of China (Grant No. 2007CB411408)     

Study on the specific interaction between angiogenin and aptamer by atomic force microscopy （AFM）

The specific interaction between angiogenin and aptamer has been investigated by using AFM. The specificity of the interaction is revealed by comparing the binding probability of aptamer to other elements in a series of control experiments. The results have shown that there is specific interaction force between angiogenin and aptamer. Moreover, the single molecular pull-off force between angiogenin and aptamer has also been determined using the Poisson statistical method to be 133.7±11.7 pN. These findings obtained are helpful to the better revelation of recognition mechanism between angiogenin and aptamer, which provided basis for further understanding the inhibition of the aptamer to angiogenic activity.     

Field emission characteristics of ZnO nanotetrapods and the effect of thermal annealing in hydrogen

Large-scale tetrapod-like ZnO nanostructures have been synthesized using a thermal chemical vapor deposition method on a silicon substrate. The high-purity nanotetrapods show sharp tips geometry with a wurtzite structure. The field emission properties of the uniform ZnO nanostructural material are investigated at different anode-cathode distances. The turn-on field for the ZnO nanotetrapods is found to be about 3.7 V/μm at a current density of 1 μA/cm^2. The field emission behavior obeys Fowler-Nordheim relationship. More importantly, the field emission properties are improved after annearing in hydrogen, and therefore high emission current and low turn-on field are obtained. These results indicate that tetrapod-like ZnO nanostructures are a promising candidate for cold cathode emitters.     

Engineering <Emphasis Type="Italic">Deinococcus radiodurans</Emphasis> into biosensor to monitor radioactivity and genotoxicity in environment

Based on a genetically modified radioresistant bacteria Deinococcus radiodurans, we constructed a real time whole cell biosensor to monitor radioactivity and genotoxicity in highly radioactive environment. The enhanced green fluorescence protein （eGFP） was fused to the promoter of the crucial DNA damage-inducible recA gene from D. radiodurans, and the consequent DNA fragment （PrecA-egfp） carried by plasmid was introduced into D. radiodurans R1 strain to obtain the biosensor strain DRG300. This engineered strain can express eGFP protein and generate fluorescence in induction of the recA gene promoter. Based on the correlation between fluorescence intensity and protein expression level in live D. radiodurans cells, we discovered that the fluorescence induction of strain DRG300 responds in a remarkable dose-dependent manner when treated with DNA damage sources such as gamma radiation and mitomycin C. It is encouraging to find the widely detective range and high sensitivity of this reconstructed strain comparing with other whole cell biosensors in former reports. These results suggest that the strain DRG300 is a potential whole cell biosensor to construct a detective system to monitor the biological hazards of radioactive and toxic pollutants in environment in real time.     

SCFP,a novel fiber-specific promoter in cotton

To investigate the expression pattern of GhSCFP which was isolated from cotton fiber cDNA library, a 1006 bp upstream fragment of the gene was cloned by chromosome walking and fused to GUSand GFP respectively. Histochemical GUS and GFP fluorescence analysis revealed that the expression of the report genes driven by the promoter sequence was detectable only in outer layer cells during the seed development in the transgentic tobaccos. In transgenic cotton, strong GUS activity was observed in spherical protrusions on 0 dpa （days post anthesis） ovule surface, and in the 2-36 dpa fiber cells, while no GUS signals were detected in the root, leaves, stem, corolla, anther and stigma. Our data demonstrated that GhSCFP upstream sequence is a cotton fiber-specific promoter and this promoter will be useful in the molecular research on fiber cell development and in cotton fiber improvements by genetic modification.     

Decoration of C60 nanorods with nickel and their magnetic properties

We studied the coating of C60 nanorods with nickel by electroless plating method and investigated their magnetic properties. The morphology and structure of the nickel layer coated on C60 nanorods were characterized by transmission electron microscopy （TEM）, energy-dispersive X-ray spectroscopy （EDX）, X-ray diffraction （XRD） and Raman spectroscopy. The coated nickel is in the form of nano-sized crystals and becomes a continuous layer as reaction time increases. The hysteresis loop shows a super paramagnetic characteristic similar to that of nanometer-sized nickel particle. These results suggest that the average size of nickel particles on C60 rods is below 10 nm. Our study has shown that electroless plating is an efficient and simple method for coating C60 nanorods with nickel.     

Decay of geometry for unimodal maps: The C2 case

We prove that a C2 unimodal interval map with critical order not greater than 2 has the decay of geometry property, by showing that all the cross-ratio estimates needed in the previous proof for the C3 case remain true.     

Novel azobenzene-phthalocyanine dyads―― design of photo-modulated J-aggregation

Based on the J-aggregation mechanism of α-aryl/alkoxy-substituted zinc phthalocyanines(Pcs) in non-coordinating solvents, two novel azobenzene-phthalocyanine dyads (3-azo-ZnPc and 4-azo-ZnPc) were synthesized with the aim of developing Pc compounds whose ability to form J-aggregation could be photo-modulated. It was found that 3-azo-ZnPc in chloroform could be effectively photo-controlled in a wide range. This phenomenon could be explained by the changes in the geometry and dipole moment of azobenzene during the photo-isomerization process. 4-azo-ZnPc did not have this ability at all, with or without UV light illumination. The positions of the oxygen atoms to which the aryl/alkoxy substitution was attached relatively were found important in determining the aggregation ability. Supported by the National Natural Science Foundation of China (Grant Nos. 20572059, 20502013 and 20773077), National Key Fundamental Research Program (Grant No. 2007CB808000)     

IL-8-induced L-selectin shedding regulates its binding kinetics to PSGL-1

L-selectin plays a crucial role in inflammation cascade by initiating the tethering and rolling of leukocytes on endothelium wall. While many L-selectin molecules are rapidly shed from the cell surface upon activation, the remaining membrane-anchored L-selectin may still play an important role in regulating leukocyte rolling and adhesion with different binding kinetics. Here we developed an in vitro model to activate Jurkat cells via interlukin-8 （IL-8） and quantified the two-dimensional （2D） binding kinetics, using a micropipette aspiration assay, of membrane-anchored L-selectin to P-selectin glycoprotein ligand 1 （PSGL-1） ligand coupled onto human red blood cells （RBCs）. The data indicated that L-selectin shedding reduced the amount of membrane-anchored L-selectin and lowered both its reverse and forward rates. These results suggested that the rolling dynamics of activated leukocytes was determined by two opposite impacts： reducing the surface presentation would enhance the rolling but lowering the kinetic rates would decrease the rolling. This finding provides a new insight into understanding how L-selectin shedding regulates leukocyte rolling and adhesion.     

Multivariate coupling mechanism of NOCTUIDAE moth wings’ surface superhydrophobicity

The surface shape, structure, biomaterial and wettability of moth wings (10 NOCTUIDAE species) from the northeast region of China were qualitatively and quantitatively studied by means of a stereoscopic microscope, a scanning electronic microscope, fourier transform infrared spectroscopy(FT-IR) and the interface contact angle measurement. The observation shows that there are scales arranged like overlapping tiles on the surface of the moth wings. The shapes of the scales are different between species. They overlap horizontally and there is particular space vertically in the direction of the wing veins. The surface of the scale is structured by micron-class grooves and nanometer-class vertical gibbosities. The biomaterial components of the moth wing scale are mostly made up of protein, lipids and chitin. The observation also shows that the contact angle for wings with scales is in the range from 144.8° to 152.9°, while that for those without scales is from 90.0° to 115.9°. It indicates that the surfaces of the wings with scales are more hydrophobic. According as Cassie model, the equation of wettability on the NOCTUIDAE moth wing surface is established and the hydrophobic mechanism is analyzed. It is concluded that the hydrophobicity of the moth wings is induced by the multivariate coupling of the shape, structures and biomaterial of the scales. Supported by the Key Research Project under the National Natural Science Foundation (Grant No. 50635030), Specialized Research Fund for Doctoral Program of Higher Education of China (Grant No. 20040183048) and Graduate Student Innovation Foundation of JiLin University (985 Project) (Grant No. 20080210)     

The program structure designing and optimizing tests of GRAPES physics

According to the modularization and standardization of program structure in Global/Regional Assimilation and Prediction System （GRAPES）, the plug-compatible and transplantable regional meso-scale and global middle-range physics software package is established. The package＇s component integrality is comparative with the other advanced models physics. A three-level structure of connecting GRAPES physics and dynamic frame has been constructed. The friendly interface is designed for users to plug in their own physics packages. Phenomenon of grid-point storm rainfall in numerical prediction is analyzed with the numerical tests. The scheme of air vertical velocity calculation is improved. Opti- mizing tests of physics schemes are performed with the correlative parameters adjusting. The results show that the false grid-point storm rainfall is removed by precipitation scheme improving. Then the score of precipitation forecast is enhanced.     

Simulation study of China’s net primary production

Spatial and temporal distribution of vegetation net primary production （NPP） in China was studied using three light-use efficiency models （CASA, GLOPEM and GEOLUE） and two mechanistic ecological process models （CEVSA, GEOPRO）. Based on spatial and temporal analysis （e.g. monthly, seasonally and annually） of simulated results from ecological process mechanism models of CASA, GLOPEM and CEVSA, the following conclusions could be made： （1） during the last 20 years, NPP change in China followed closely the seasonal change of climate affected by monsoon with an overall trend of increasing; （2） simulated average seasonal NPP was： 0.571±0.2 GtC in spring, 1.573±0.4 GtC in summer, 0.6±0.2 GtC in autumn, and 0.12±0.1 GtC in winter. Average annual NPP in China was 2.864±1 GtC. All the five models were able to simulate seasonal and spatial features of biomass for different ecological types in China. This paper provides a baseline for China＇s total biomass production. It also offers a means of estimating the NPP change due to afforestation, reforestation, conservation and other human activities and could aid people in using for-mentioned carbon sinks to fulfill China＇s commitment of reducing greenhouse gases.     

Fluorescence and sensitization performance of phenylene-vinylene-substituted polythiophene

A new kind of polythiophene derivative, Poly(3-{2-[4-(2-ethylhexyloxy)-phenyl]-vinyl}-2,2′-bithiophene) (PTh), was applied in dye-sensitized solar cell to extend the light response of nanocrystalline TiO2 electrode. UV-vis absorption and fluorescence spectra were employed to investigate the interaction of PTh with nanocrystalline TiO2. The absorption coefficient of the PTh was high in visible part of spec- trum, and the fluorescence emission of the PTh can be efficiently quenched by TiO2 nanoparticles ow- i...     

Pollen assemblage characteristics of lakes in the monsoon fringe area of China

This paper presents the pollen assemblages from 108 surface sediment samples from 4 lakes （the Lake Daihai, Lake Hongjiannao, Lake Hulunnao and Lake Duikounao） in the monsoon fringe area of China. The herb pollen taxa Artemisia, Chenopodiaceae, Poaceae and Compositae are the major components of pollen assemblages of the 4 lakes and Pinus, Betula, Quercus, Ulmus, Populus, Ostryopsis and Elaeagnaceae are frequently presented, which reflect regional and local vegetation well. The mean similarity coefficients for samples from the Lake Daihai, Lake Hongjiannao, Lake Hulunnao and Lake Duikounao are 0.66±0.17, 0.71±0.11,0.73±0.12 and 0.67±0.12 respectively, so pollen assemblages are relatively consistent in each lake, which shows that focusing and mixing effects have occurred before and after pollen deposition. However, pollen assemblages do differ between sampling sites in each lake. The largest difference is seen in the Lake Daihai, followed by the Lake Duikounao, Lake Hulunnao and Lake Hongjiannao （The mean Euclidean distance is 20.09 ± 11.11, 11.22 ± 3.64, 10.67 ± 4.03 and 8.44 ± 4.51 respectively）. These differences are possibly caused by the differences of focusing and mixing effects, pollen source areas, drainage areas and regional vegetation compositions. The Lake Daihai and Lake Hongjiannao have water deeper than 5 m and strong re-suspension, focusing and mixing effects occur in the lakeshore and shallow water areas, where pollen concentrations are lower than in deeper lake areas. In the Lake Hulunnao and Lake Duikounao, with depths less than 5 m, re-suspension and mixing effects are obvious across the whole lake area, so pollen assemblages and pollen concentrations are more consistent among sampling sites in each lake. Comparison between the lake samples and samples from the inflowing river reveals that wind is primary pollen transportation force in the Lake Hongjiannao, where the consistency of pollen assemblage is conspicuous, while there is greater variation in lakes where pollen input is do     

Ultrahigh resolution optical coherence tomography with femtosecond Ti:sapphire laser and photonic crystal fiber

Optical coherence tomography （OCT） with ultrahigh axial resolution was achieved by the super-continuum generated by coupling femtosecond pulses from a commercial Ti：sapphire laser into an air-silica microstructure fiber. The visible spectrum of the super-continuum from 450 to 700 nm centered at 540 nm can be generated. A free-space axial OCT resolution of 0.64 pm was achieved. The sensitivity of OCT system was 108 dB with incident light power 3 mW at sample, only 7dB below the theoretical limit. Subcellular OCT imaging was also demonstrated, showing great potential for biomedical application.     

On the development of the GRAPES——A new generation of the national operational NWP system in China

Numerical weather prediction （NWP） has become one of the most important means for weather forecasts in the world. It also mirrors a nation＇s comprehensive strength in meteorology. In 2000, China Meteorological Administration （CMA） established the National Innovative Base for Meteorological Numerical Prediction in the Chinese Academy of Meteorological Sciences （CAMS）, to work on developing a new generation of the national operational NWP system-Global/Regional Assimilation and PrEdiction System （GRAPES）, to enhance meteorological services in China in the new century. In recent years, the GRAPES has witnessed a fast development. The GRAPES has been set up as an integration of the model framework, data assimilation, regional and global NWP system, which can be commonly used for both operation and research. In this paper, a brief review is made for illustrating the GRAPES system, including the advanced designs of the GRAPES, its diverse applications in multi-fields, and efficiencies of the regional and global GRAPES in operational applications based on hindcast results.     

A four-state memory cell based on magnetoelectric composite

A four-state memory can store four states in each memory cell. We designed a four-state memory cell using Co/PZT magnetoelectric composite and observed a broad magnetoelectric hysteretic output loop on applying magnetic field. Based on magnetoelectric hysteresis, we developed a read method by applying a bias magnetic field on the memory cell. Results gave clearly four-state signals of 15.8, -4.4, 5.5 and -11.3μV, which demonstrated the feasibility of our design.     

Study on the photosynthetic performances of Enteromorpha prolifera collected from the surface and bottom of the sea of Qingdao sea area

In this work, the photosynthetic performances of Enteromorpha prolifera thalli collected from the surface and bottom of the sea of Qingdao sea area were studied with chlorophyll fluorescence and oxygraph technology. The samples with the highest photosynthetic activity among their kinds, the floating thalli from the sea surface of the south of the Qingdao Olympic Sailing Center and the sedimentary thalli from the mud surface of the bottom Tuandao bay, were chosen as representatives of surface thalli and bottom thalli, respectively. The results showed that the maximal PSII quantum yield of the floating thalli was significantly lower than the normal level although their photosynthetic activities were relatively high; the photosynthetic potential of the thalli form the mud surface was extremely low. Thus, it is indicated that the floating thalli are seriously stressed by their environment and the thalli from the mud surface are already dead or are dying. On the other hand, the results of the laboratory cultivation showed that the sedimentary thalli cannot regain normal photosynthetic activity even under normal illumination conditions. Thus, the thalli from the mud surface cannot become reproductive source of the alga even if they can reach sea surface again. Therefore, a preliminary conclusion can be reached that, up to mid-July 2008, the environmental conditions of the Qingdao sea area are not suitable for the growth of the alga E. prolifera and for this reason the biomass of E. prolifera, in the area, could be declining. Supported by National Natural Science Foundation of China (Grant No. 30830015), Key Projects in the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period (Grant No. 2006BAD09A04) and National High Technology Research and Development Program of China (Grant Nos. 2006AA10A402, 2007AA09Z406, 2006AA05Z112, 2006AA10A413)     

An in-pipe micro robot actuated by piezoelectric bimorphs

A novel in-pipe micro robot providing stable and accurate locomotion inside a tubular structure with diameters ranging from 16 mm to 18 mm is presented in this paper. Driven by impulsive voltages, deflections of the piezoelectric bimorphs are generated and then converted into translational locomotion by the principle of the Impact Drive Mechanism （IDM）. Theoretical analysis of the proposed system is performed based on a simplified mechanical model. Then dynamic simulations of the dynamic behavior are performed. Finally, an experiment is conducted to investigate the moving ability of this device. The results demonstrate that a maximum translational velocity of 3.5 mm/s can be obtained under an im- pulsive driving voltage with peak value at 50 V and frequency of 1100 Hz. Both theoretical analysis and experimental trials prove that the principle of IDM actuated by piezoelectric bimorphs is feasible and robust for achieving accurate locomotion of the micro robot in pipes with diameters of less than 20 mm.