Search Results - (Author, Cooperation:X. D. Wang)

2018-01-31

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2018-02-26

Wiley-Blackwell

0007-0963

1365-2133

Medicine

2018-02-03

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2018-02-03

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2018-10-31

Institute of Physics (IOP)

1755-1307

1755-1315

Geography

Geosciences

Physics

2011-11-19

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; *Biodiversity ; Carbon Dioxide ; Carbon Isotopes ; China ; *Ecosystem ; *Extinction, Biological ; Fires ; *Fossils ; Geologic Sediments ; Invertebrates/classification ; Isotopes ; Lead ; Mass Spectrometry ; Methane ; Oceans and Seas ; Plants/classification ; Radioisotope Dilution Technique ; Radiometric Dating ; Seawater/chemistry ; Time ; Uranium ; Vertebrates/classification

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

Electrochemically etched tungsten scanning tunneling microscope (STM) tips are dc sputter coated with 20 nm of gold (0.04 nm/s and 10 mTorr of argon). Transmission electron microscope (TEM) images of typical etched tips and gold-coated etched tips are presented. The gold layer forms as a series of spherical sections having a mean height of 6.7 nm and mean width of 19.6 nm. STM images are reported for the uncoated W tips, and for gold-coated graphite after coating the tip with gold. We also provide scanning electron microscopy (SEM) and STM images of the surface of a thin CuTCNQ film. The STM image taken with a gold-coated W tip compares very well to the SEM image of the same sample. Gold coating provides a relatively inexpensive and easy way to produce chemically stable tips of well known electronic structure for use in ambient atmosphere STM studies of morphology (structures ≥10 nm) where atomic resolution is not required.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

A potassium titanyl phosphate phase modulator was used to mode lock a diode laser pumped Nd:LiYF4 laser at 270 MHz. The autocorrelation was 15 ps and the spectral bandwidth 73 GHz. The phase noise of the laser was found to be 70 fs for frequencies (approximately-greater-than)100 Hz using a radio frequency spectrum analyzer technique. The high damage threshold and low absorption losses make this material well suited for the future development of high peak and average power laser systems. In addition, the low phase noise should be important for applications which require low timing jitter between a mode-locked laser source and an electronic reference signal.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

We report on an experimental study of a hydrothermally grown KTiOPO4 (KTP) Pockels cell, utilizing the effective electro-optic coefficient, rc1=28 pm/V. Compensation of the static birefringence of KTP, when it is used as amplitude modulator, has been achieved by temperature tuning. Our study revealed that a KTP Pockels cell does not suffer from piezoelectric-induced parasitics (acoustic ringing). Stable high-repetition rate pulse slicing has been obtained at 30 kHz. Intracavity use of a KTP Pockels cell also has been successfully demonstrated in a Q-switched Nd:YLF laser system.

Electronic Resource

1439-0523

Blackwell Publishing Journal Backfiles 1879-2005

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

In the present study, three types of coloured fibre cottons, i.e. white, brown and green, were compared for their fibre quality and yield. The comparison of fibre quality suggested that coloured fibre cotton was inferior as compared with white fibre cotton. To understand the effect of cellulose, mineral elements [nitrogen (N), phosphorus (P) and potassium (K)] and pH of fibre cells on the quality of fibre, these components were studied at different fibre cell developed stages in all three fibre cotton types. The cellulose content is closely associated with the quality of fibre. The higher fibre quality of white fibre cotton might be the result of the high cellulose content in it compared with coloured fibre cotton. A rapid and slow decrease in pH in white and coloured cottons, respectively, might have some effects on fibre elongation. Among the mineral contents, potassium is positively correlated with the fibre quality traits. The pigment development patterns in brown and green fibre cottons are not similar. In green fibre cotton it takes more time to deepen in colour as compared with brown fibre cotton. Possible strategies for the improvement in quality of coloured fibre cotton are discussed. The results of heterosis studies in coloured fibre cotton suggest that heterosis could improve yield and quality of coloured fibre cotton. In the present study, the hybrids between ZJU12A x ZJU05R and ZJU18A x ZJU01R, having an acceptable lint colour types plus better fibre quality and high yield performance, may be exploited further for their heterotic advantages.

Electronic Resource

1439-0523

Blackwell Publishing Journal Backfiles 1879-2005

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Paired A- and B-lines, cytoplasmic male-sterile (CMS)-lines and main-tainer lines, respectively, were crossed with R-lines (restorer) to produce A × R, R × B and B × R hybrids, which were used in 1993 and 1996 to predict the performance of three lypes of CMS cotton lines available in China. A significant difference in yield and yield components was revealed between paired A × R and B × R hybrids. This difference was greatly influenced by both CMS cytoplasm and the interaction between cytoplasm and nuclear genotypes. It is suggested that there are detrimental effects of CMS cytoplasm on yield and yield components. General combining ability of near-isogenic CMS lines was also affected by this negative effect. The detrimental effect was closely related to an increased number of immature seeds per boll, which might be caused by partial female sterility associated with CMS cytoplasm. The possibility of developing specific combinations of CMS Upland × Upland restorer hybrids that express enough heterosis for yield to overcome the detrimental effect of the CMS cytoplasm is discussed.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Momentum profiles of the valence orbitals of methylpropane, also known as isobutane (CH3CH(CH3)CH3), have been studied by using a high resolution binary (e,2e) electron momentum spectrometer (EMS), at an impact energy of 1200 eV plus the binding energy, and using symmetric noncoplanar kinematics. The coincidence energy resolution of the EMS spectrometer is 0.95 eV full width at half-maximum. The experimental momentum profiles of the valence orbitals are compared with the theoretical momentum distributions calculated using Hartree–Fock (HF) and density functional theory (DFT) methods with the two basis sets of 6-31G and 6-311++G**. The B3LYP functionals are used for the DFT calculations. In general, the experimental momentum distributions are well described by the HF and DFT calculations. The pole strengths of the main ionization peaks from the orbitals in the inner valence are estimated. © 2001 American Institute of Physics.

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Abstract The time course of loading and transport of assimilate in sunflower leaves was examined by pulse labelling with 14CO2, followed by freeze drying or freeze substitution, and dry autoradiography at both low and high resolution. The five classes of veins, V1-V5 (V5 being smallest), show a division of function: V5 and V4 are engaged in loading and short distance transport; V3 to V1, in long distance translocation. The first high concentration of 14C is found in two or three phloem parenchyma cells (intermediary cells) of V5 and V4 veins. The sieve elements of V5 and V4 veins do not show comparable concentrations of 14C at any time. Recently assimilated 14C is transported by the intermediary cells for distances of about 0.5 mm to the V3 veins. In V3 to V1 veins translocation is in the sieve tubes. Transport in V5 and V4 veins is in two directions, that in V3 to V1, in one direction towards the petiole. The high concentration of 14C formed in the intermediary cells does not increase further as the assimilate moves to the sieve tubes of the V3 veins, and so is probably the origin of the gradient that drives translocation.

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The cellular pathway of sucrose transfer from the endosperm cavity to the starchy endosperm of developing grains of wheat (Triticum turgidum) has been elucidated. The modified aleurone and sub-aleurone cells exhibit a dense cytoplasm enriched in mitochondria and endoplasmic relicilium. Significantly, the sub-aleurone cells are characterized by secondary wall ingrowths. Numerous plasmodesmata interconnect all cells between the modified aleurone and starchy endosperm. The pro-tonophore carbonylcyanide-m-chlorophenyl hydrazone (CCCP) slowed [14C]sucrose uptake by grain tissue slices enriched in modified aleurone and sub-aleurone cells but had no effect on uptake by the starchy endosperm. The fluorescent weak acid sulphorhodamine G (SRG) was preferentially accumulated by the modified aleurone and sub-aleurone cells, and this uptake was sensitive to CCCP. The combined plasma membrane surface areas of the modified aleurone and sub-aleurone cells appeared to be sufficient to support the in vivo rates of sucrose transfer to the starchy endosperm. Plasmolysis of intact excised grain inhibited [14C]sucrose transfer from the endosperm cavity to the starchy endosperm. The sulphydryl group modifier p-chloromercuribenzenesulphonie acid (PCMBS) decreased [14C]sucrose uptake by the modified aleurone and sub-aleurone cells but had little effect on uptake by the starchy endosperm. In contrast, when PCMBS and [14C]sucrose were supplied to the endosperm cavity of intact excised grain, PCMBS slowed accumulation by all tissues equally. Estimates of potential sucrose fluxes through the interconnecting plasmodesmata were found to be within the published range. It is concluded that the bulk of sucrose is accumulated from the endosperm cavity by the modified aleurone and sub-aleurone cells and subsequently transferred through the symplast to the starchy endosperm.

Electronic Resource

0003-9861

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0003-9861

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0005-2760

Intestinal perfusion ; Polar metabolite ; Portal vein ; Retinoic acid ; β-Carotene

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Medicine

Physics

Electronic Resource

0039-6028

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0039-9140

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0039-6028

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource