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Eucalyptus grandis,a fast-growing timber species with outstanding economic efficiency,has been extensively planted as short-term industrial material in southern China.But what′s the difference of features in relation to water consumption between E.grandis and common or native tree species of Sichuan Province,whether or not the amount of water consumption of E.grandis would change the original water balance in its cultivation area remains to be answered.In this paper,the net photosynthetic rate(Pn),the transpiration rate(Tr) and the water use efficiency(WUE) of seedlings of E.grandis and other five tree species under different light intensities,air temperatures and atmosphere humidities were determined with the help of LI-6400 photosynthesis meter,the plant total leaf weight,biomass and the water consumption were measured using weighing method,then the water consumption characteristics of these species were evaluated and compared based on the indicators mentioned above.The results were showed as follows:(1) Of all the tested species,E.grandis possessed the highest Tr and the lowest WUE under the same condition,in addition the maximum water consumption per unit biomass,so the water consumption per plant of which was significantly larger than the others,its largest total leaf area was probably one of the important reasons.Its Pn was lower than that of P.× R270,but its biomass accumulation was the largest.We drew a conclusion that E.grandis was a tree species with strong photosynthesis,high transpiration,and low water use efficiency.(2) The Pn and the Tr of the broad-leaved tree species were obviously higher than those of the coniferous tree species,while the WUE of the former was lower than that of the latter.(3) Environmental factors(the light intensity,the air temperature and the atmosphere humidity) influenced the Pn,the Tr and the WUE of plants to a large extent.Particularly,the Pn was mainly affected by the light intensity,the Tr was most sensitive to the atmosphere humidity,and generally the WUE rose with the increase of the atmosphere humidity.In the range of variation temperature(24—32℃),which was set in the experiment,the photosynthesis of these tree species did not changed to a large extent.The light intensity of 800 μmol · m-2 · s-1 and the temperature of 28 ℃ in this study were observed most conducive to plant photosynthesis.(4) Fast-growing tree species such as E.grandis,grew more rapidly and were more potential to fix considerable carbon because of its comparatively stronger capability of photosynthesis,thus higher economic benefit could be obtained.However,in terms of the higher transpiration and lower water use efficiency,replacing the former vegetation(mainly composed by indigenous tree species) with large-scale plantations of E.grandis was more likely to be adverse to the environment of introduction areas because of more water consumption.Therefore,the area for E.grandis plantation should be in a good water condition,especially where abundant annual rainfall and uniform rainfall distribution were seen.Moreover,adequate attention should be paid to the scientific and rational water management.

To enlarge the grain size and decrease the effect of the defect between the grain boundaries on a p-Si film transistor,a phase modulated excimer laser crystallization technique is used to fabricate the uniform p-Si film with a large grain size.First,an energy window for super lateral growth is determined by measuring the grain size of p-Si film fabricated with different laser energy intensities.Then,the spatial distribution of the input laser is modulated by a phase mask with a period of 1 073 nm and an artificially controlled lateral temperature gradient is induced on the a-Si film,which leads the a-Si to be melten and crystallized into p-Si grains by super lateral growth.Finally,the characteristics of the prepared p-Si film are measured and compared with those of the a-Si film and the p-Si film fabricated by super lateral growth technique.The results show that the grain size of the p-Si film is 228.24 nm,which is ten times of that fabricated by super lateral growth under the same processing parameters;the electrical resistivity of the prepared sample is 18.9 Ω·m,which is lower by an order magnitude than that prepared by super lateral growth.Furthermore,the distribution of the grain is more uniform than that fabricated by other techniques.The reported technique can increase the electrical characteristics of the p-Si film greatly and is suitable for the fabrication of high quality p-Si devices.

A flexible mechanism which was considered as a key component of the moving mirror supporting in a Michelson interferometer based Fourier-transform spectrometer was researched.The flexible mechannism with double compensation rods was created on the basis of the flexible mechannism with a single compensation rod.By use of the finite element analysis softwares PATRAN and NASTRAN,the mechanism was simulated and the corresponding results were compared with the best theoretical calculation of the flexible mechannism with the single compensation rod.A simplified model was also fabricated according to the structral specifications from simulation calculation.Furthermore,the model was also tested and error analysis was conducted.It is shown that the vertical coupling displacement of the moving mirror introduced by this flexible mechannism with double compensation rods has been decreased by 93.2%.The results of error analysis indicate that the length tolerence of the flexible segment is a critical factor that would result in coupling displacement of the moving mirror.Therefore,it points out that when a supporting mechanism with high precision is machined for the moving mirror,the tolerences related to the flexible segments must be strictly controlled in fabrication.

To ensure high-precision calibration of gear measuring instruments,the international standard ISO / TR 10064-5:2005 recommends a Double-Ball Artifact(DBA) as calibration reference.The DBA employs a high-precision sphere to replace the involute and uses an error compensation technique to obtain a high-precision involute to realize the involate traceability.The theoretical issues relating to the DBA are discussed to provide a theoretical basis for the design and application of the DBA.The error of measurement principle of DBA and its calculation function are given under the conditions of ideal installation and with installed errors for the electronic generative metrology.According to the optimized arc thoughts,the formula of the optimized center distance between the two balls is derived by the least square method.Finally,the error compensation method is described.The DBA software is designed based on the above theory and a DBA is developed with a parameter of module in 2.268 1 mm,number of teeth in 40,and a pressure angle in 20 °.

International audience; The process of optical fiber probe production was introduced in this paper, as well as the attachment of silver nanoparticles, the enhanced effect of silver nanoparticles in fiber-optic probe inhomogeneous electromagnetic field of was simulated using the finite difference time domain method. Firstly, the electric field distribution of different shapes of the fiber polymer probe tip was discussed, and it provided a reference for the research of nanoparticles polarization effects; Secondly, the polarization affecting factors of single nanoparticle were simulated, the radius of silver nanoparticle and its distance to the probe were taken into consideration; Finally, taking two silver nanoparticles for example, the polarization effect of particles relative position were discussed,which proved that the silver nanoparticles outside the top of the fiber probe do not contribute to the polarization effect. The simulation results of this paper provided a theoretical support for the production of the fiber-optic probe and the attachment of metal nanoparticles.