大豆赤变过程中挥发性物质的研究

为减少大豆在储藏过程中发生赤变所导致的经济损失,研究其赤变过程中挥发性物质的变化,以期找到大豆赤变的特征挥发性物质。采用顶空固相微萃取-气质联用技术,对两个品种大豆(中黄35和中黄37)在赤变前期、中期和末期的挥发性物质进行检测和分析。结果表明:大豆赤变过程中挥发性物质烃类、醛类、酮类、酯类、芳香类和呋喃类均有所增加,其中烃类物质增加最多;烃类物质d-柠檬烯、正十二烷、十一烷、癸烷、2-甲基癸烷、3-甲基癸烷、3-甲基十一烷、2,6-二甲基癸烷,酮类物质3-辛酮,酯类物质α-戊基-γ-丁内酯和γ-戊内酯在正常大豆中未检出而在赤变样品中均检出。d-柠檬烯和3-辛酮变化显著,可作为大豆赤变的特征挥发性物质。

赤变大豆粗脂肪含量变化的实验测定

对走油赤变后的大豆其化学成分含量会发生变化,其中粗脂肪含量也有些变化。本文着重阐述经实验测定后表明,在加工过程中,赤变粒含量的多少,对粗脂肪含量的变化情况。

大豆储藏过程中浸油赤变的研究进展

大豆容易受到储存环境的影响发生浸油赤变,导致品质劣变,经济效益降低。文章主要综述了大豆储藏过程中发生浸油赤变的原因、对品质的影响和防治措施,以期为未来防控浸油赤变、保障大豆安全储藏方面的研究提供理论参考。

大豆种子贮藏技术

1.带荚暴晒,充分干燥。大豆种子贮藏时要严格控制水分,要将入仓的大豆种子含水量控制在12%以下,如超过13%就有霉变的危险,大豆干燥以带荚为宜。将收割后的大豆摊在晒场晒2～3天,待荚壳干透、有部分暴裂时,就可以脱粒,这样可以防止种皮发生裂纹和皱纹现象。

不同来源大豆对浸出制油过程和产品质量的影响

我国进口大豆主要来源于美国、巴西和阿根廷等地,由于大豆中蛋白质含量和含油率的差异,在预处理浸出过程中主要根据大豆蛋白质含量生产高、中、低蛋白含量的豆粕,因此生产的大豆油和豆粕质量存在差异。由于储存、环境气候和运输条件不同,大豆组织结构发生变化,出现各种损伤,特别是热损伤率高的大豆在生产过程中造成处理量下降,蒸汽、溶剂和电耗增加,豆粕蛋白质溶解度低,只能生产低蛋白质豆粕,豆粕贬值3%~5%,其毛油酸值和含磷量高,毛油贬值1%~2%,其副产品浓缩磷脂中卵磷脂含量低,无法生产食品级粉末磷脂,浓缩磷脂贬值4%~6%。

Effects of Mutagenesis by UV Irradiation and ^(60)Co-γ Irradiation on Fermentation of Xylose to Ethanol by Pichia stipitis

ln this study, effects of UV irradiation and 60Co-γ irradiation on fermenta-tion of xylose to ethanol by Pichia stipitis were analyzed to investigate the optimal mutagenic conditions. According to the growth curve and fermentation curve of P. stipi-tis, the optimal incubation duration and fermentation duration of P. stipitis mutant strain were 18 and 48 h, respectively. The cel concentration of original yeast liquid was 107 cel s/ml. After mutagenesis by UV irradiation and 60Co-γ irradiation, yeast liquid was incubated in 20 g/L xylose media for 48 h. According to the results, after UV irradiation for 45-75 s, transformation efficiency reached 0.3794 g/g, which was 74.39% of the theoretical value; after irradiation with 800-1 000 Gy 60Co-γ, transforma-tion efficiency reached 0.3165 g/g, which was 62.06% of the theoretical value. Therefore, both UV irradiation and 60Co-γ irradiation could improve the efficiency of xylose fermentation to ethanol by P. stipitis under appropriate conditions.

以权谋私者戒

古人云:“天不变,道亦不变。”这是反辩证法的形而上学世界观。反其意,即是:“天变,道亦变。”这是合乎事物发展规律的辩证逻辑方法论。十一后三中全会以来,我们一反过去“左”的错误,从农村到城市实行了一系列改革,兴利除弊,强国富民,真是天翻地覆,沧海桑田,变化可谓大矣.这巨变令人鼓舞,催人奋进,每一个中国人无不为之拍手称快。

观赏绿化树木病害——松树

材线虫病俗称“食松虫”,松树枯萎受损,大都是由材线虫病引起的。初期发病症状是夏季至初秋,老叶由浅绿变黄并凋萎。在此之前,树内已发生异常,松脂停止蒸发下降、凋萎迅速,1个月后,树冠全部变红、枯死。当年感染发病的松树大部分到晚秋枯死,部分在冬季或翌年春季枯死。大树枯死表现较迟缓。引起松树枯萎受损的原因是由一种松树材线虫Bursaphelenchus Lignicolus Mamiyaet Kiyohara为害所致。病原线虫由松天牛传播,6～7月份松天牛成虫从前1年受害的松树中羽化出来,其体内保留有线虫、咬食健康松树嫩枝时,线虫从松天牛体内脱离出来,通过咬食的伤口侵入到松树体内。线虫侵入后经2～3个月,松树出现凋萎赤变症状。

南北美齐丰产 油脂油料弱势运行

2015年一季度,内盘油脂油料行情受"春节效应"主导走势有所分化。其中,连豆一受累于购销主体热情惨淡,交投匮乏,连续三个月弱势下行。其他油脂油料主力合约则演绎了"先扬后抑"行情。随着全球大豆的供应重心由北半球逐渐转向南半球,美豆洗船、南美天气炒作、工人罢工一度催生内外盘油脂油料飙升行情。春节之后,我国沿海油厂压榨利润稳固,开工率大幅提高,随之而来,大豆库存不同幅度收缩。接下来,马棕油出口关税恢复在即。

CLIMATOLOGICAL VARIATION OF GLOBAL CROSS-EQUATORIAL FLOWS FOR THE PERIOD 1948-2004

By using monthly NCEP/NCAR meridional gridpoint wind data at the levels of 1000, 850, 700, 600, 500, 400, 300, 200, 150 and 100 hPa from 1948 to 2004, the intensity of global cross-equatorial flows is calculated. The spatial and temporal variation of global cross-equatorial flows at the 850-hPa level are shown and discussed. The results show that the strength of the 850-hPa global cross-equatorial flows represent obvious long-term variation and interdecadal change during the period. Evidence suggests that the cross-equatorial flow of the passages at 45 - 50 °E in June to August, 105 - 115 °E in May to September, 130 - 140 °E in May to September and May to November and 20 - 25 °E in February to April intensified and that the cross-equatorial flow of the passages at 50 - 35 °W in June to August weaken in the past 57 years, with an increase of 0.25m/s/10a for summer Somali Jet and increase of 0.32 m/s/10a for cross- equatorial flow at 130 - 140 °E in May to September The results of Singular Spectrum Analysis （SSA） for the time series indicate that for the cross-equatorial flow at 850 hPa, the interdecadal and long-term trend changes are 35% - 45%, and the interarmual variation is no more than 30%, in variance contribution. The results also reveal that the interarmual variation of intensity of the summer cross-equatorial flows in the Pacific is significantly correlated with Southern Oscillation. With weak Southern Oscillation, strong crossequatorial flows in Pacific will happen, though the summer Somali Jet is only a little positively correlated with North Atlantic Oscillation （NAO）.

THE RELATIONSHIP BETWEEN GLOBAL WARMING AND THE VARIATION IN TROPICAL CYCLONE FREQUENCY OVER THE WESTERN NORTH PACIFIC

The relationship between global warming and the variation in tropical cyclone (TC) genesis frequency is analyzed using the data of the Tropical Cyclone Year Book by the China Meteorological Administration and the National Centers for Environmental Prediction (NCEP) reanalysis data from 1949 to 2007. The observational results indicate that the average sea surface temperature (SST) in the Intertropical Convergence Zone (ITCZ) region (10°N– 20°N, 100°E– 140°E) increases by 0.6°C against the background of global warming, while the frequency of tropical cyclone geneses in this region decreases significantly. Generally, the rise of SSTs is favorable for the genesis of tropical cyclones, but it is now shown to be contrary to the normal effect. Most of the tropical cyclones in the western North Pacific (WNP) are generated in the ITCZ. This is quite different from the case in the Atlantic basin in which the tropical cyclones are mostly generated from the easterly wave. Our research results demonstrate that the ITCZ has a weakening trend in strength, and it has moved much more equatorward in the past 40 years; both are disadvantageous to the formation of tropical cyclones. Furthermore, our study also found that the ridge of the subtropical high tends to shift slightly equatorward, which is another adverse mechanism for the formation of tropical cyclones.

Interannual variability of transport and bifurcation of the North Equatorial Current in the tropical North Pacific Ocean

The relationship of the interannual variability of the transport and bifurcation latitude of the North Equatorial Current （NEC） to the E1 Nifio-Southern Oscillation （ENSO） is investigated. This is done through composite analysis of sea surface height （SSH） observed by satellite altimeter during October 1992-July 2009, and correspondingly derived sea surface geostrophic currents. During E1 Nifio/La Nifia years, the SSH in the tropical North Pacific Ocean falls/rises, with maximum changes in the region 0-15~N, 130~E-160~E. The decrease/increase in SSH induces a cyclonic/anticyclonic anomaly in the western tropical gyre. The cyclonic/anticyclonic anomaly in the gyre results in an increase/decrease of NEC transport, and a northward/southward shift of the NEC bifurcation latitude near the Philippine coast. The variations are mainly in response to anomalous wind forcing in the west-central tropical North Pacific Ocean, related to ENSO events.

Change of Ecological Footprint and Analysis of Ecological Sustainability——Taking Zhangjiakou City as an Example

This paper researches the ecological sustainability of Zhangjiakou City, Hebei Province, China, using the ecological footprint model. According to the study we find that Zhangjiakou City was in the situation of ecological deficit from 1990 to 2000 and the deficit had the enlarging tendency. In 1990 the per capita ecological footprint was 0.964 and the per capita ecological capacity was 0.5 l 8, thus it can be calculated that the per capita ecological deficit was 4）.446. However in 2000, the per capita ecological footprint increased to 1.068, at the same time the per capita eco- logical capacity decreased to 0.471, then the per capita ecological deficit in 2000 was 4）.597. Furthermore, this paper studies the ecological sustainability of the city from the changes of the ecological footprint of per 10,000 yuan GDP and the productivity of ecological system. Finally the authors point out the shortage of the model and the way to improve it.

A time-dependent baroclinic model on NEC bifurcation

As it is well-known, the North Equatorial Current (NEC) bifurcates into the Kuroshio flowing northward and the equatorward Mindanao Current, which is well depicted by Munk's theory in 1950 in terms of its climatology. However, Munk's theory is unable to tell the NEC bifurcation variability with time. In the present paper, a time-dependent baroclinic model forced by wind, in which temporal and baroclinic terms are added to Munk's equation, is proposed to examine the seasonal variability of the NEC bifurcation latitude. An analytical solution is obtained, with which the seasonal variability can be well described: NEC bifurcation reaches its northernmost position in December and its southernmost position in June with a range of about 1° in latitude, consistent with previous results with observations. The present solution will degenerate to Munk's one in the case of steady and barotropic state.

Study on Red Tide Remote Sensing Monitoring in the Bohai Sea in 2014

Since 2000, red tides have been reported in the Bohai Sea every year, whichoften made coastal waters of the Bohai Sea suffering from red tides. Satellite remotesensing technology and the ocean color observation satellite images have beensuccessfully used to identify and observe the initiation, evolution, and dissipation of redtide. However, due to different water bodies, remote sensing data and modelingmethods, a specific model of red tide inversion should be established for the watercharacteristics of the Bohai Sea. In this paper, the correlation analysis between MODISspectral reflectivity data and measured concentration of chlorophyll a in the Bohai Seawas carried out. The expression （B10-B8） / （B13-B8） was chosen as the indicator of redtide inversion in the Bohai Sea, the correlation coefficient reached 0.7815, showingsignificant correlation results. It was found that the spatial and temporal distribution ofred tide in the Bohai Sea in 2014 was obvious. The main causes of the large-scale outbreak of red tide in the Bohai Sea are due to the poor water exchange caused by thesemi-enclosed geomorphology and the large amount of terrestrial matter input fromcoastal runoff. The river input is the main source of land-based pollution into the sea.Then, a red tide inversion model based on a modified red tide index was established byusing GOCI remote sensing data with less cloud coverage, and proven effective indelineating the red tide in turbid waters. The hourly RI images on 15, 26 and 28 May2014 showed consistent evolution, and the area of red tide in the Bohai Sea changedsignificantly during one day. Vertical migration of the dominant species of red tide algaemay be the main reason for the short-term changes in the surface expression.

Interannual variations of North Equatorial Current transport in the Pacific Ocean during two types of El Ni?o

Interannual variations of Pacific North Equatorial Current （NEC） transport during eastern- Pacific E1 Nifios （EP-EI Nifios） and central-Pacific E1 Nifios （CP-E1 Nifios） are investigated by composite analysis with European Centre for Medium-Range Weather Forecast Ocean Analysis/Reanalysis System 3. During EP-E1 Nifio, NEC transport shows significant positive anomalies from the developing to decay phases, with the largest anomalies around the mature phase. During CP-EI Nifio, however, the NEC transport only shows positive anomalies before the mature phase, with much weaker anomalies than those during EP-El Nifio. The NEC transport variations are strongly associated with variations of the tropical gyre and wind forcing in the tropical North Pacific. During EP-E1 Nifio, strong westerly wind anomalies and positive wind stress curl anomalies in the tropical North Pacific induce local upward Ekman pumping and westward-propagating upwelling Rossby waves in the ocean, lowering the sea surface height and generating a cyclonic gyre anomaly in the western tropical Pacific. During CP-E1 Nifio, however, strength of the wind and associated Ekman pumping velocity are very weak. Negative sea surface height and cyclonic flow anomalies are slightly north of those during EP El Nino.

Relationships of Interannual Variability Between the Equatorial Pacific and Tropical Indian Ocean in 17 CMIP5 Models

Seventeen coupled general circulation models from the Coupled Model Intercomparison Project Phase 5 （CMIP5） are employed to assess the relationships of interannual variations of sea surface temperature （SST） between the tropical Pacific （TP） and tropical Indian Ocean （TIO）. The eastern/central equatorial Pacific features the strongest SST interannual variability in the models except for the model CSIRO-Mk3-6-0, and the simulated maximum and minimum are produced by models GFDL-ESM2M and GISS-E2-H respectively. However, It remains a challenge for these models to simulate the correct climate mean SST with the warm pool-cold tongue structure in the equatorial Pacific. Almost all models reproduce E1 Nifio-Southem Oscillation （ENSO）, Indian Ocean Dipole mode （IOD） and Indian Ocean Basin-wide mode （lOB） together with their seasonal phase lock features being simulated; but the relationship between the ENSO and IOD is different for different models. Consistent with the observation, an Indian Ocean basin-wide warming （cooling） takes place over the tropical Indian Ocean in the spring following an E1 Nifio （La Nifia） in almost all the models. In some models （e.g., GFDL-ESM2G and MIROC5）, positive ENSO and IOB events are stronger than the negative events as shown in the observation. However, this asymmetry is reversed in some other models （e.g., HadGEM2-CC and HadGEM2-ES）.

Removal Mechanism of Hexavalent Chromium by a Novel Strain of Pichia anomala Isolated from Industrial Effluents of Fez （Morocco）

Hexavalent chromium （Cr（VI）） pollution has become one of the most serious environmental problems today. One removal strategy comprises the microbial reduction of Cr（VI）, is regarded as a cost-effective biotechnology for the treatment of high volume and low concentration complex wastewaters. In this work a yeast strain that exhibits high Cr（VI） resistance was isolated from soil sediment. The isolated yeast was identified as Pichia anomala by sequencing analysis. The yeast showed a remarkable capacity to completely reduce 25 and 50 mg/L of Cr（VI） in 48 h under aerobic conditions. The increase of initial Cr（VI） concentration influenced reduction, growth and specific growth rate. This strain also exhibited multiple heavy metal tolerance. The presence of anions and cations in the medium had a great influence on chromium reduction. Fractionation of the cells showed that the mechanism of Cr（VI） removal by this strain is ＂adsorption-coupled reduction＂ and the hexavalent chromate reductase activity was expressed constitutively. FTIR analysis of the biomass exposed to chromium showed that the binding process of the chromium ions involves the active participation of functional groups present in the external surface of biomass. High Cr（VI） concentration resistance and high Cr（VI） reducing ability of this strain make it a suitable candidate for bioremediation.

Weakening of the biennial relationship between Central American and equatorial South American rainfall in recent decades

There is a rainfall variability biennial relationship between Central America （CA） and equatorial South America （ESA） over the tropical western hemisphere, which is known to have arisen due to the combined effects of ENSO and tropical North Atlantic （TNA） SST. Here, the authors report that this biennial rainfall relationship between CA and ESA has weakened remarkably since 2000, with weakening in both in-phase and out-of-phase rainfall transitions. The observed decadal changes in the biennial relationship between CA and ESA rainfall can be attributed to changes in the effects of ENSO and TNA SST since 2000, which may be associated with more frequent occurrences of the central Pacific or＇Modoki＇ type El Ni^o. The weakening of the association with ENSO for CA rainfall since 2000 might have given rise to the weakening of the in-phase rain transition from CA rainfall to the following ESA rainfall. The weakened linkage between boreal-winter ESA rainfall and the subsequent boreal-summer TNA SST since 2000 may have resulted in the weakening of the out- of-phase rainfall transition from boreal-winter ESA rainfall to the subsequent boreal-summer CA rainfall.

Seasonal variability of the North Equatorial Current transport in the western Pacific Ocean

Seasonal variability of the North Equatorial Current （NEC） transport in the western Pacific Ocean is investigated with ECMWF Ocean Analysis/Reanalysis System 3 （eRA-S3）. The result shows that NEC transport （NT） across different longitudes in the research area shows a similar double-peak structure, with two maxima （in summer and winter）, and two minima （in spring and autumn）. This kind of structure can also be found in NEC geostrophic transport （NGT）, but in a different magnitude and phase. These differences are attributable to Ekman transport induced by the local meridional wind and transport caused by nonzero velocity at the reference level, which is assumed to be zero in the NGT calculation. In the present work, a linear vorticity equation governing a 1.5-layer reduced gravity model is adopted to examine the dynamics of the seasonal variability of NGT. It is found that the annual cycle of NGT is mainly controlled by Ekman pumping induced by local wind, and westward-propagating Rossby waves induced by remote wind. Further research demonstrates that the maximum in winter and minimum in spring are mostly attributed to wind east of the dateline, whilst the maximum in summer and minimum in autumn are largely attributed to that west of the dateline.