Crystal of barium boric oxide(BBO) crystallizes in trigollal system. Imperfections in two specimens of(001)plates (one being transparent and the other containing inclusions)in the crystals have been identified by X-ra...Crystal of barium boric oxide(BBO) crystallizes in trigollal system. Imperfections in two specimens of(001)plates (one being transparent and the other containing inclusions)in the crystals have been identified by X-ray topography.展开更多
Concentrations of serum calcium, phosphorus, sodium, chlorine and potassium of growing yak born from a nuclear breeding herd in 1995,1996 and 1997(classified as groups G3, G2 and G1) were determined bimonthly from Sep...Concentrations of serum calcium, phosphorus, sodium, chlorine and potassium of growing yak born from a nuclear breeding herd in 1995,1996 and 1997(classified as groups G3, G2 and G1) were determined bimonthly from September 1997 to July 1998. The result showed that the concentrations of serum macro-minerals demonstrated a month/season pattern and both calcium and phosphorus reached the highest in September(11.36mg/dl and 6.82 mg/dl, respectively). The animals in G1 had a very high serum phosphorus concentration due to their young age and incomplete weaning in the early times of sampling. The ratio of calcium to phosphorus was generally higher than that recommended for cattle and demonstrated a great variation in month/season. The results indicated that the deficiencies of phosphorus, sodium and probably calcium were common in the pasture on the Qinghai-Tibetan Plateau.展开更多
When the crystal grows from solution,a sharp variated fluid layer of the solute concentration exists against crystal surface.The sharp variated fluid layer is defined the boundary layer in crystal growth.The molecular...When the crystal grows from solution,a sharp variated fluid layer of the solute concentration exists against crystal surface.The sharp variated fluid layer is defined the boundary layer in crystal growth.The molecular structure of the boundary layers plays a key role in crystal composition,morphology,growth rate and crystal growth mechanism.However,owing to the lacking of suitable probe technique,it is difficult to obtain the information of the moving construction of the boundary layers.Here,the laser Raman Microprobe combining with holographic phase contrast interferometric microphotography is used to probe in situ the molecular structure of the boundary layers during the crystal growth processes of KH 2PO 4(KDP) and KD 2PO 4(DKDP).In supersaturations ranging from 1% to 14%,Raman scattering states at the different positions within the boundary layers have been investigated,and compared with the bands of different concentration solutions alone using laser Raman spectroscopy between 600 and 1350cm -1 .The changes in band parameters of the phosphates within the boundary layers of crystal growth are different from those in solution alone.The influence of the solution concentration on the band parameters of anion phosphate within the layers is nonlinear.With increasing supersaturation,the full width at half height of the P=O 2 symmetric stretch band increases.The new 918(938)cm -1 H(D)O P OH(D) asymmetric stretch,1120(DKDP 1200)cm -1 O P O asymmetric stretch,and extremely weak 1210cm -1 P O H in plane deformation bands appear in the characteristic boundary layers.These new bands show that the cations have direct effects on the phosphate group(aggregates).Under the driving of concentration gradient field of supersaturation,the effects of cations cause the changes of O P O bond angle,atomic charge redistribution,and lead to readjust geometry of anion phosphate group and desolvation.The trend of readjust is close to the geometry of the crystal structure unit and the formation of the cations phosphate crystallization unit.展开更多
Argon ion laser was used as the induced light source and ethane(C2H4) was selected as the precursor gas,in the variety ranges of laser power from 0.5 W to 4.5 W and the pressure of the precursor gas from 225×133....Argon ion laser was used as the induced light source and ethane(C2H4) was selected as the precursor gas,in the variety ranges of laser power from 0.5 W to 4.5 W and the pressure of the precursor gas from 225×133.3 Pa to 680×133.3 Pa,the experiments of laser induced chemical vapor deposition were proceeded for fabrication of micro carbon pillar.In the experiments,the influences of power of laser and pressure of work gas on the diameter and length of micro carbon pillar were investigated,the variety on averaged growth rate of carbon pillar with the laser irradiation time and moving speed of focus was discussed.Based on experiment data,the micro carbon pillar with an aspect ratio of over 500 was built through the method of moving the focus.展开更多
In order to make the humanoid robot walk freely in complicated circumstance, the reliable capabilities for obtaining plane information from its surroundings are demanded. A system for extracting planes from data taken...In order to make the humanoid robot walk freely in complicated circumstance, the reliable capabilities for obtaining plane information from its surroundings are demanded. A system for extracting planes from data taken by stereo vision was presented, After the depth image was obtained, the pixels of each line were scanned and split into straight line segments. The neighbouring relation of line segments was kept in link structure. The groups of three line segments were selected as seed regions. A queue was maintained for storing seed regions, and then the plane region was expanded around the seed region. The process of region growing continued until the queue of seed regions was empty. After trimming, the edges of the planes became smooth. In the end, extracted planes were obtained. In the experiment, two models were used： pipe and stairs. Two planes in pipe mode/and six planes in stairs model were extracted exactly. The speed and precision of algorithm can satisfy the demands of humanoid robot＇s navigation.展开更多
In order to improVe the pyroelectric properties of TGS crystals,the different dopants were selected according to crystal chemistry principle and pyroelectric effect of molecules and ionic group to grow new modified TG...In order to improVe the pyroelectric properties of TGS crystals,the different dopants were selected according to crystal chemistry principle and pyroelectric effect of molecules and ionic group to grow new modified TGS crystals. The experimental results show that some dopants can improve the pyroelectric proPerties of TGS crystals.展开更多
文摘Crystal of barium boric oxide(BBO) crystallizes in trigollal system. Imperfections in two specimens of(001)plates (one being transparent and the other containing inclusions)in the crystals have been identified by X-ray topography.
文摘Concentrations of serum calcium, phosphorus, sodium, chlorine and potassium of growing yak born from a nuclear breeding herd in 1995,1996 and 1997(classified as groups G3, G2 and G1) were determined bimonthly from September 1997 to July 1998. The result showed that the concentrations of serum macro-minerals demonstrated a month/season pattern and both calcium and phosphorus reached the highest in September(11.36mg/dl and 6.82 mg/dl, respectively). The animals in G1 had a very high serum phosphorus concentration due to their young age and incomplete weaning in the early times of sampling. The ratio of calcium to phosphorus was generally higher than that recommended for cattle and demonstrated a great variation in month/season. The results indicated that the deficiencies of phosphorus, sodium and probably calcium were common in the pasture on the Qinghai-Tibetan Plateau.
文摘When the crystal grows from solution,a sharp variated fluid layer of the solute concentration exists against crystal surface.The sharp variated fluid layer is defined the boundary layer in crystal growth.The molecular structure of the boundary layers plays a key role in crystal composition,morphology,growth rate and crystal growth mechanism.However,owing to the lacking of suitable probe technique,it is difficult to obtain the information of the moving construction of the boundary layers.Here,the laser Raman Microprobe combining with holographic phase contrast interferometric microphotography is used to probe in situ the molecular structure of the boundary layers during the crystal growth processes of KH 2PO 4(KDP) and KD 2PO 4(DKDP).In supersaturations ranging from 1% to 14%,Raman scattering states at the different positions within the boundary layers have been investigated,and compared with the bands of different concentration solutions alone using laser Raman spectroscopy between 600 and 1350cm -1 .The changes in band parameters of the phosphates within the boundary layers of crystal growth are different from those in solution alone.The influence of the solution concentration on the band parameters of anion phosphate within the layers is nonlinear.With increasing supersaturation,the full width at half height of the P=O 2 symmetric stretch band increases.The new 918(938)cm -1 H(D)O P OH(D) asymmetric stretch,1120(DKDP 1200)cm -1 O P O asymmetric stretch,and extremely weak 1210cm -1 P O H in plane deformation bands appear in the characteristic boundary layers.These new bands show that the cations have direct effects on the phosphate group(aggregates).Under the driving of concentration gradient field of supersaturation,the effects of cations cause the changes of O P O bond angle,atomic charge redistribution,and lead to readjust geometry of anion phosphate group and desolvation.The trend of readjust is close to the geometry of the crystal structure unit and the formation of the cations phosphate crystallization unit.
基金Project supported by Scientific Research Fund of Centre South University of Forestry and TechnologyProject supported by Teaching Innovation Fund of Centre South University of Forestry and Technology
文摘Argon ion laser was used as the induced light source and ethane(C2H4) was selected as the precursor gas,in the variety ranges of laser power from 0.5 W to 4.5 W and the pressure of the precursor gas from 225×133.3 Pa to 680×133.3 Pa,the experiments of laser induced chemical vapor deposition were proceeded for fabrication of micro carbon pillar.In the experiments,the influences of power of laser and pressure of work gas on the diameter and length of micro carbon pillar were investigated,the variety on averaged growth rate of carbon pillar with the laser irradiation time and moving speed of focus was discussed.Based on experiment data,the micro carbon pillar with an aspect ratio of over 500 was built through the method of moving the focus.
基金Project(60776816) supported by the National Natural Science Foundation of China and Civil Aviation Administration of ChinaProject(8251064101000005) supported by the Natural Science Foundation of Guangdong Province,China
文摘In order to make the humanoid robot walk freely in complicated circumstance, the reliable capabilities for obtaining plane information from its surroundings are demanded. A system for extracting planes from data taken by stereo vision was presented, After the depth image was obtained, the pixels of each line were scanned and split into straight line segments. The neighbouring relation of line segments was kept in link structure. The groups of three line segments were selected as seed regions. A queue was maintained for storing seed regions, and then the plane region was expanded around the seed region. The process of region growing continued until the queue of seed regions was empty. After trimming, the edges of the planes became smooth. In the end, extracted planes were obtained. In the experiment, two models were used： pipe and stairs. Two planes in pipe mode/and six planes in stairs model were extracted exactly. The speed and precision of algorithm can satisfy the demands of humanoid robot＇s navigation.
文摘In order to improVe the pyroelectric properties of TGS crystals,the different dopants were selected according to crystal chemistry principle and pyroelectric effect of molecules and ionic group to grow new modified TGS crystals. The experimental results show that some dopants can improve the pyroelectric proPerties of TGS crystals.
