佛罗里达州柑桔投资的远景展望——GAMS仿真的案例(英文)

运用GAMS仿真展示了美国佛罗里达州柑桔生产投资的经济远景。仿真动态地、定量地回答了长期投资决策中的五个关键因素:期望净投资回收率、最低竞争价格、最大可接受的贷款利率、新建桔园的最优种植计划、最早获得盈利的年份(以净现值为表征)。该项研究有助于投资者作出正确的投资决策。

Improving the assessment method of seed vigor in Cunninghamia lanceolata and Pinus massoniana based on oxygen sensing technology

Oxygen sensing technology was employed to study the rapid methods for seed vigor assessment of Chinese fir （Cunninghamia lanceolata） and Masson pine （Pinus massoniana）. Firstly, seeds of five lots were performed using accelerated aging （AA） into three vigor levels. Then, four oxygen sensing indices, including increased metabolism time （IMT）, oxygen metabolism rate （OMR）, critical oxygen pressure （COP）, relative germination time （RGT） and the control indiees such as labora- tory germination indices, dehydrogenase activity （DA）, and electrical conductivity （EC） were analyzed by the tests of 15 samples. The results of correlation analysis between these indices and field emergence per- formances based on two-year and two-spot data showed that RGT and OMR should be indicated as the optimal oxygen sensing indices to rap- idly and automatically evaluate seed vigor of Chinese fir and Masson pine, respectively. On the basis, one-variable linear regression equations were built to forecast their field emergence performances by the two oxygen sensing indices.

A STUDY ON THE ECOLOGICAL CLIMATES OF SOME FAMOUS TEA GROWING AREAS IN HIGH MOUNTAINOUS REGIONS OF CHINA

The tea tree [Camellia sinensis (L) Kuntze] is one of the world’s economic crops. It is an especially important crop for southern China. Environmental factors related to the tea yield and quality in some high mountain areas of China are identified in this paper. These factors are: geology, topography, climate, hydrology, soil and vegetation. Climatological factors are the most important. Using data collected from meteorological stations which are situated at the summit and the base of high mountains, this paper discusses ecological climatic problems in growing tea in China. The ecological climatic characteristics of the famous tea areas mainly included are as follows: more . amounts of clouds and fog, less percentage of sunshine, abundant rainfall and high relative humidity in the air, temperatures that rise and fall slowly, daily and annual temperature ranges that are smaller, more days that are suitable for tea growing and low wind speeds in the lee-sides and valleys of mountains. All of these

Effects of La and Nd on the Fermentation of Alginic Acid Produced from the Strain 342 of Azotobacter Vinelandii

It is reported that fermentative liquids with various concentrations of La and Nd affect the fer- mentation of alginic acid from the strain 342 of Azotobacter vinelandii.The results are as follows:When the concentration of La or Nd was up to 100 ppm,the cell growth is stimulated and the production of alginic acid is promoted.The La or Nd in concentration higher than 200 ppm or 150 ppm inhibits the fermentation, respectively.As the concentration range of La is 0～100 ppm or that of Nd is 0～150 ppm,the yield of fixed nitrogen increases,and the ratio of c_M to c_G(c_M/c_G)decreases with the raise of the concentration of La or Nd.When the concentration range of La is 100～400 ppm and that of Nd is 150～400 ppm,the conclusion is contrary to the above mentioned result.

A New Method for the Synthesis of Ketone Diperoxide

A general method for the synthesis of ketone diperoxides and their structure information is reported. The highest yield of the title compound is 91 5%.

MASS SPECTRA OF SUBSTITUTED BENZYLGLYOXALS WITH DEUTERIUM EXCHANGE

Mass spectral behavior of some deuterated and non-deuterated substituted benzylglyoxals was characteristic in enolic structure which was also proved by NMR spectrum. Fragmentation of the title compounds in their mass spectra was ressonably explained in this paper.

Interval mapping of quantitative trait loci by molecular markers in rice (Oryza sativa L.)

Using an F2 as the mapping population derived from indica Zhaiyeqing 8 and japonica Jingxi 17 of rice, a linkage map was constructed, which consisted of 54 restriction fragment length polymorphism (RFLP) markers. By using the interval mapping procedure based on 2 flanking markers, 11 quantitative trait loci (QTLs) were mapped for 4 traits: days to heading (Dth1), tiller angle (Ta1), spikelet number per panicle (Sn1, Sn2, Sn3) and spikelet density (Sdn1-Sdn6). An example was taken for QTL mapping of rice, and the interval mapping was shown to be able to detect the QTL located between 2 flanking markers. For a specific trait, more than one QTL could be found on one chromosome. Genetically related traits could be controlled by the same group of QTLs or polygenic system.

CH_4 EMISSION FROM A CHINESE RICE PADDY FIELD

CH_4 emission rates have been measured continuously for the early rice of 1988 and late rices of 1987 and 1988 during entire growing seasons in a rice paddy field in Hangzhou,Zhejiang Province,China,by using an automatic sampling and analyzing system.During most parts of the seasons CH_4 emission rates showed strong diurnal variations.Bi-mode patterns with the highest value in the afternoon and a second peak at mid-night were generally found for the early rice,while the highest values were almost always found in the night for the late rice.Bi-mode patterns with a second peak in the afternoon were also found during the reproductive phase of the late rice plants.These diurnal variations may be explained by the diurnal variations of the soil temperature and the activity of rice plants.Strong seasonal variations with one peak in the tillering stage and two during the reproductive phase of rice plants were observed for all the three growing seasons.The seasonal variations may be explained by the activity of rice plants,availability of organic substrates in the soil,and the activity of soil bacteria related to soil temperatures,Fertilization did not show significant effects on the total seasonal CH_4 emissions but slightly changed the pattern of the seasonal variations of the CH_4 emission rates.Averaged over the measuring periods and 8 spots,CH_4 emission rates of 7.8 mg m^(-2) h^(-1) for the early rice and 28.6 mg m^(-2) h^(-1) for the late rice were obtained. Based on these measured data,the total global emission of CH_4 from rice paddies is estimated to be about 90 Tg/yr ranging from 70 to 110,accounting for 20% of the total source of CH_4.

Predicting Potential Geographic Distribution of Tibetan Incarvillea younghusbandii Using the Maxent Model

Incarvillea younghusbandii is a well-known Tibetan medicinal plant with considerable development and research value distributed widely throughout the Tibetan plateau.It is important to study spatial distribution patterns of the plant in order to develop effective protection measures.Based on field survey work and environmental data, the potential geographic distribution of Incarvillea younghusbandii was delineated using a Maximum Entropy (Maxent)model with 28environmental variables that screened for climate,topography,human activity and biological factors.Our results showed that the main geographic range of Incarvillea younghusbandii included the valley between the Yarlung Zangbo river and the Duoxiong Zangbo river,the valley in the middle section of the Himalaya Mountains,and the area between the north side of the east section of the Himalayas and the south bank of the middle reach of the Yarlung Zangbo river.Distribution may spread to parts of the eastern Himalayas.The Jackknife test indicated that soil types,ratio of precipitation to air temperature,extreme atmospheric pressure differences and annual precipitation were the most important predictive factors for the model,while other variables made relatively small contributions.

STUDIES ON OBSERVATION OF DAPI-DNA IN PROTOPLASTS FROM RICE (Oryza sativa)

The use of DAPI (4′, 6-diamidino-2-phenylindole) as a DNA specific fluoresoent probe to cells or protoplasts of higher plants was limited by its difficulty of being transported across membrane. We, however, have rendered DAPI to permeate in protoplasts from the

THE REMAINDER REPRESENTA-TION OF H-B INTERPOLATION

This letter extends Wang Xinghua’s result published in the No. 19 issue （1979） of this journal to the case of H-B interpolation. Let H be the interpolation polynomial of degree n of a function f, where α0,…,

SOLID CELLULAR INTERFACE BETWEEN CALCITE AND ARAGONITE FOUND IN THE SHELL OF Anodonta Woocliana wocdiana(LEA)

It was demonstrated by X-ray diffraction and SEM that the shell of Anodonta woocliana wocdiana consists of internal layer (lamellar aragonites with 0.37 μm of spacing) and external layer (prismatic calcites with 25--82 μm in diameter), and that the boundaries between the prismatic calcite and the lamellar aragonite appear cellular (Fig. la, b). It was also found that there are some arch growing lines (Fig.

ON THE K-FUNCTIONAL IN THE SOBOLEV SPACES

This letter extends the K-functional given by Johnen (Lecture Notes in Math., 571 (1977)) so that it may be applied to the study of simultaneous approximation of functions and their partial derivatives.

ON INTERPOLATION REMAINDERS OF FUNCTIONS OF LOW ORDER SMOOTHNESS

Let H（x） be the interpolation polynomial of degree n for function f, where the interpolation nodes a0, a1, …, an may be repeated, For the interpolation remainder and its

ON LINEARLY SIMULTANEOUS APPROXIMATION AND SMOOTH EXTENSION

Using the K-functional tool introduced by Peetre, DeVore(Approximation Theory Π, 1976) obtained some linear approximation degrees. We have extended this K-functional tool so that it may be used to study the simultaneous approximation

STUDY ON MECHANISM OF ETHYLENE CONTROL OF SEX DIFFERENTIATION IN Lagenaria siceraria

The sex expression of Lagenaria siceraria can be modified by phytohormones. This modification is related to "a certain bisexual stage" during floral bud differentiation. ACC (ethylene precursor) and STS (ethylene antagonist) can change the direction of sex differentiation of the floral buds in vitro. STS induces maleness by means of inhibiting ethylene action, directly promoting the development of the primordia of stamens, and then suppressing that of pistils. Hence, it can be deduced that ethylene induces femaleness by directly suppressing the development of the primordia of stamens and then promoting that of pistils. Such a regulation of the development of sexual organs is due to a change in the direction of assimilates to the pistils by ACC and to the stamens by STS. Therefore, ethylene induces femaleness by first limiting the sink strength of the stamens and then increasing that of the pistils.

ASSOCIATION-DNA, A NEW DISCOVERY RELATED TO MALE GERM UNIT IN THE POLLEN TUBE OF Camellia sinensis

Up to now, male germ units (MGUs)have been found in many angiosperms. This is an important advance in the studies of reproductive biology. However, there is little information on the interaction (the penetration and exchange of substances) between vegetative nucleus (VN) and generative cell (GC) or sperm cells within MGUs. If there exists, what kind of substance Will it be and how will it work, and what physiological function will it have? This is a very important problem which needs to be solved as soon as possible.

EXACT ESTIMATE OF A CLASS OF ERROR BOUNDS IN RADIO MEASUREMENT

Ⅰ. PRACTICAL BACKGROUND AND MAIN RESULTS Suppose that there exists a periodic wave with period T, where A1≠0 and ω= 2π/T.Then the distortion factor K（f） of f concerning the sinusoid-wave is defined

MSSBAUER STUDY OF MAGNETISM AND CONTENT OF KRASNOZEM MAGNETIC MINERALS

The magnetism and content of soil magnetic minerals are the foundation of the soil magnetic genesis research and the application of the soil magnetism to the applied geophysics, archaeology and the environmental science. According to Mssbauer spectra

ON ASYMPTOTIC BEHAVIOR OF A KIND OF TRIGONOMETRIC SERIES

The following theorems have improved the overall resalte summed up by Pak in §11 of his paper （35 （1980））. Let k,n∈{0,1,…}.Put △°λn=λn, △k+1λn=△kλn-△kλn+1 and En1-k=△kλn.