Correlation Analysis of Rice Seed Setting Rate and Weight of 1 000-Grain and Agro-Meteorology over the Middle and Lower Reaches of the Yangtze River,China

The purpose of this study is to reveal the effects of historic climate change on rice yield over the middle and lower reaches of the Yangtze River, China, and to better adapt to climate change in the future. This study presents the relation of temperature and precipitation and rice components from 1981 to 2003 at 48 early rice stations and 30 middle rice stations. It focuses on an analysis of three stages： flowering, pre-milk, and late milk. The results show that mean maximum temperature and mean daily precipitation at the stages of flowering and pre-milk are most related to early rice yield. Yield change of middle rice is mainly because of mean precipitation change at the flowering stage. Furthermore, percentage of undeveloped grain increases as mean maximum temperature rises at the flowering stage. Over-precipitation in the reproductive stage is a major reason for reduction in yield of early rice. Consecutive rainfall and continuous high temperature can have negative effects on middle rice yield. Global warming would affect middle rice more seriously than early rice.

Effect of 1, 25-Dihydroxyvitamin D_3 on Gastric Carcinogenesis Induced by N-Methyl-N'-nitro-N-nitrosoguanidine in Rats

The effect of 1, 25-dihydroxyvitamin D3 (1, 25 (OH)2D3) given in the post-initiation stage of gastric carcinogenesis induced by N-methyl-N-nitro-N-nitrosoguanidine (MNNG) was investigated in male Wistar rats. Gastric carcinogenesis in rats was induced by administration of MNNG (150 mg·L-1) in drinking water. Four weeks after MNNG exposure, the rats were switched to the diet containing 1, 25 (OH)2D3 (2. 5 μg·kg-1 and 5. 0 μg·kg-1) and maintained on the diet. Animals were killed at week 16 and week 32 for immunohistochemical and histopathological studies. At week 16, the proliferating cell nuclear antingen (PCNA) labeling index in epithelium from the glandular stomach of rats that received 1, 25 (OH)2D3 (5.0 μg·kg-1) in combination with MNNG (150 mg·L-1) were significantly higher when compared with the rats receiving MNNG alone. Supplementation of 1, 25 (OH)2D3 (5. 0 μg·kg-1) in the rats' diet caused a dramatic increase in carcinoma incidence, and the number of individual cancer foci in the glandular stomach of rats receiving MNNG at week 32. It was concluded that certain dose of 1, 25 (OH)2D3 enhanced gastric carcinogenesis induced by MNNG in rats.

Synthesis of 1-(4-Antipyrinyl)-3-(3-Chlorophenyl)-Triazene and Its Colour Reaction with Mercury

A uew diazoamino reagent 1-(4-antipyrinyl)-3-(3-Chlorophenyl)-triarene(APCPT)was synthesized. The colour reaction of APCPT with Hg(II) was studied. At pH=10,5~12.2, in the presence of Tween-80,APCPT reacts with Hg(II) to form a red complex witk higb sensitivity.The molar ratio of Hg(II) to APCPT is 1:2. The molar absorptivity is 1.87 × 105L . mor． cm-1.Beer's law is obeyed for Hg in the range of0-16μg/25ml

STUDIES ON THE SYNTHESIS AND BIOLOGICAL ACTIVITY OF 1-ARYLOXYACETYL-4-AROYLTHIOSEMICARBAZIDE DERIVATIVES

A series of new 1-aryloxyacetyl-4-aroylthiosemicarbazides were synthesized by means of solid-liguid phase transfer catalysis. The promoting effects of these new compounds on wheat growth were observed.

Dynamic Interference Photoelectron Spectra in Double Ionization:Numerical Simulation of 1D Helium

We report our numerical simulation on the dynamic interference photoelectron spectra for a one-dimensional （1D） He model exposed to intense ultrashort extreme ultraviolet （XUV） laser pulses. The results demonstrate an unambiguous interference feature in the photoelectron spectra, and the interference is unveiled to originate from the dynamic Stark effect. The interference photoelectron spectra are prompted for intense sub-femtosecond XUV laser pulses in double ionization. The stationary phase picture is corroborated qualitatively in the two-electron system. The ability of probing the dynamic Stark effect by the photoelectron spectra in a pragmatic experiment of single-photon double ionization of He may shed light on further investigation on multi-electron atoms and molecules.

SYNTHESIS OF 1, 1-DIALKYLTHIO—1, 3, 5—HEXATRIENES WITH α—OXOKETENE DITHIOACETALS

α-Oxoketene dithioacetals 2 via, 1,2-nucleophilic addition by allyl magnesium bromide afforded corresponding alcohols (3).Treated with water and catalyzed by Lewis acid, the alcohols 3 were converted regiospecifically to the conjugated 1,1—dialkylthio—1,3,5 hexatrienes (4). Both the alcohol 8 and its methoxy methyl ether 9 were sensative to dilute sulfuric acid and cyclized under this condition to form the aryl methylthio ether (10).

A CONVENIENT ASYMMETRIC SYNTHESIS OF 1-AMINOALKYLPHOSPHONIC ACIDS^+

A convenient method for the asymmetric synthesis of 1-amino- alkylphosphonic acids was described.It involved the diastereoselctive alkylation of bicyclic chloromethylphosphonamide derived from(S)-2-ani- linomethylpyrrolidine followed by subsequent conversions leading to amino compounds by Staudinger method.Acid hydrolysis afforded the target molecule in good yield.

A NEW SYNTHESIS OF 1-SUBSTITUTED β-CARBOLINES

A new method to tetrahydro-β-carbolines(βCs) from tryptamine is described and the aromatization of THβCs to βCs by manganese dioxide is reported for the first time in this type of compounds.

Cyclopropanation of 1, 1-Dichloro-4-methyl-1,3-pentadiene with Diazoacetate

Several cyclopropanation catalysts for the synthesis of 3(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylates have been studied in this paper. Owing to electron deficiency of 1,1-dichloro-4-methyl-1,3-pentadiene, yield of this reaction is rather law compared with that of 2,5-dimethyl-2,4-pentadiene, Of all catalysts concerned. yield ranged from 25.1% to 47.2%.

Evaluation of 1-Chloroacetophenone (CN) and Dibenz (b, f)-1, 4 oxazepine (CR) Induced Respiratory Tract Sensory Irritation Following a Simple Inhalation Exposure Method in Mice

Sensory irritation of the upper respiratory tract was induced in mice by inhalation of vapors, generated under thermal stress of two tear gases viz. 1-chloroacetophenone (CN) and dibenz (b, f)-1, 4 oxazepine (CR) following a simple exposure technique. A known quantity of the irritant was kept in an adapter fitted with glass exposure chamber, heated, and the vapor thus generated was purged into the chamber. The restrained mouse inhaled the vapor, and the resultant depression of respiratory rate was recorded on a polygraph. Fifty percent depression of the respiration rate and the corresponding air concentration of the irritant was determined by obtaining the linear curve fitting equation and putting the value of Y=50. It was concluded that inhalation of CR vapor was 2. 66 times more irritating than that of CN in mice. The employed exposure method also proved to be simple, sensitive, easy t0 operate,and may also prove useful in evaluating irritation of upper respiratory tract fOllowing the inhalation of vapors of various chemicals.

REACTIONS OF 1-ACETOXY ALLYLIC PHOSPHONATES UNDER PALLADIUM(0) CATALYSIS

l-Acetoxy allylic phosphonates rearrange regioselectively to γ-acetoxy α,β-unsaturated phosphonates under the catalysis of Pd(0). l-Acetoxy allylic phosphonates act as the precursors of phosphonatedπ-allylic cations in palladium(0) catalyzed reactions[1]. The reactions of l-acetoxy allylic phosphonates under palladium(0) catalysis with nucleophiles have been reported. 1-4 These reactions are highly regio- and stereoselective. We wish to report here the palladium(0) catalyzed reaction of l-acetoxy allylic phosphonates in the absence of a nucleophile.

Studies on Agarofurans Ⅱ.Stereoselective Synthesis of 1α-and 1β-Methyl Agarofuran

1α- and 1β-methyl agarofuran 1 and 2 were stereoselectively synthesized. the key intermediates being synthesized through stereoselective Robinson annulation.The conjugated double bond was redined in an improved way. Alkylation of imine 7 with enone 8, 9, 10 was performed

Room-Temperature Annealing of 1 MeV Electron Irradiated Lattice Matched In0.53Ga0.47As/InP Multiple Quantum Wells

Long-term room-temperature annealing effects of InGaAs/InP quantum wells with different wells （namely triple wells and five wells embedded） and bulk InCaAs are investigated after high energy electron irradiation. It is observed that the photoluminescence （PL） intensity of bulk InGaAs materials is enhanced after low dose electron irradiation and the PL intensity for all the three samples is degraded dramatically when the electron dose is relatively high. With respect to the room-temperature annealing, we find that the PL intensity for both samples recovers relatively fast at the initial stage. The PL performance of multiple quantum-well samples shows better recovery after irradiation compared with the results of bulk InGaAs materials. Meanwhile, the recovery speed factors of multiple quantum-well samples are relatively faster than those of the bulk InGaAs materials as well. We infer that the recovery difference between the quantum-well materials and bulk materials originates from the fact that the radiation induced defects are confined in the quantum wells as a consequence of the free energy barrier between the In0.53Ga0.47 As wells and InP barrier layers.

Synthesis of 1H-thiopyrano[3,4-b] Quinolin-4(3H)-one and TheirHeterocycle Fused Compounds

1H-Thiopyrano[3,4-b] quinolin-4(3H)-one 1, a new series of heterotricyclic ketone and their heterocycle fused compounds (2 and 3) were prepared by a simple procedure in good yields.

Validation of 1D model for methane/air/Pt combustion in stagnation flow

A 2D model is built on the package of FLUENT to study the effects of radial aspect ratio （R/W）, length-to-width ratio （L/W）, strain rate （SR）, and buoyancy （Ri=Gr/Re^2） on the validation of the simplified 1D model. In the present 2D model, the methane/air homogeneous reaction mechanism of Peters and the methane/air/platinum heterogeneous reaction mechanism of Deutschmann are applied. By comparison between the 1D and 2D numerical results, it is found that the validation of 1D model is highly related with the catalytic stagnation reactor configuration. For length-to-width ratio L/W = 1 configuration, 1D laminar model is applicable when the radial aspect ratio R/W 〉 0.4. For R/W = 0.6, the reactor exhibited 1D characteristics when L/W 〈 1. Compared with the temperature and species profiles, the velocity distribution along the axis is more sensitive to the change of radial aspect ratio and length-to-width ratio. With increasing of the strain rate, the flame front goes closer to the catalytic wall surface and the difference between the 1D and 2D results decreases. For a valid 1D simulation, it is recommended that the strain rate should be convection can be neglected when Ri〈 5. greater than 20 s^-1. The effects of natural

Disposition and Metabolism of 1 -Nitropropane in Rats and Chimpanzees

The metabolic fate of 1 -nitropropane (1-NP) has not been previously reported. In this study male rats and chimpanzees were given single doses of 40 mg/kg ip and 5 mg/kg iv 1-[1-^(14)C]NP, respectively. The quantitative extent of urinary and fecal elimination was similar in both species. The rats excreted 16.5% ofthedosein urine and 1.7% in feces. For chimpanzees the respective values were 14.8 and 1.2%. Experiments with rats demonstrated that the major route of elimination was by exhalation. With a total elimination via the lungs of 72.6%, rats expired 10.3% of the dose as unchanged 1-NP. Five polar metabolites were isolated from the urine of chimpanzees. The two major metabolites were identified as 3-hydroxypropionic acid and 7V-methyl-N-2-(methylsulfinyl)ethylpropionic acid amide (NMPA). Both substances were also excreted in rat urine. The two identified metabolites indicate that 1-NP was degraded to propionic acid, part of which was modified to 3-hydroxypropionic acid or NMPA. A hypothetical pathway for the biochemical generation of NMPA is suggested.(c)1989 Academic Press, Inc.

STUDY ON THE ADDITION REACTION OF 1-IODO-4-CHLOROPERFLOROBUTANE TO 1-HEXENE UNDER REDUCTIVE CONDITIONS

Promoted by various reductants,the addition of 1-iodo-4-chloro- perfluorobutane to 1-hexene giving 1:1 adduct is reported.Based on these facts,several new redox systems are proposed.

Study on Room-Temperature Phosphorescence of 1-Bromonaphthalene in Media of Surfactant and β-Cyclodextrin

Sdrictants(S) induced room-ternperature phorphorescence(RTP) frorn l-bromonaplithalene(l-BrN) in aerated aqueous solutions of o-cyclodextha(β-CD) hasbeco mvestigated m detail. lt has been fotmd that the partial incIu5ion and coil ofhydIocarbon chain of edctans at the mouth of the 6-CD ca\4ty' is reSPoedle foTbright RTP

STRUCTURE OF 1-BROMOMETHYL-7, 7-DIMETHYLBICYCLO[2.2.1]HEPT-2-YL ACRYLATE AND THE PROPERTIES OF ITS POLYMER

In this paper, the structure of 1-bromomethyl-7,7-dimethyl btcyclo[2.2.1]hept-2-yl acrylate has been studied by X-ray diffraction, and the relation between the molecular structure and the properties of polymerization and its polymer have been discussed.

SYNTHESIS AND CRYSTAL STRUCTURE OF NEODYMIUM COMPLEX OF 1-METHYL-1,4,7,10-TETRAAZACYCLODODECANE

The complex [Nd(L)(CH_3CN)(CF_3SO_3)_3] has been synthesized, where L=1-methyl-1,4,7,10-tetraazacyclododecane. The crystal structure of the complex has been determined by a fourcircle X-ray diffractometer to a final R value of 0.0370 and Rw value of 0.0385 respectively. The crystal is triclinic system, space group P1 with a=8.738(2), b=12.870(3), c=12.900(3), α=85.63(2), β=87.25(2), γ=78.30(2)°, V=1415.71(60)~3, Z=2, Dc=1.92g/cm^3. The neodymiumion is eight-coordinated, forming a distorted square antiprism.