高纯氨包装容器中存在痕量水积累问题的理论探讨

充分干燥的高纯氨包装容器,经反复充装若干次以后,会残留积累愈来愈多的水分。水是高纯氨质量控制的主要指标之一,对于5 N电子级高纯氨,水含量应控制在<5 ppm,对于5.5 N以上纯度的超纯氨,水分更应控制在1 ppm以下。对高纯氨水积累原因进行探讨,并提出解决问题的方法。

不同氮水平下盐胁迫对大麦幼苗中某些氮化物积累的影响(简报)

在土培条件下,提高氮素供应水平和NaCl处理浓度后大麦幼苗地上部和根中的全氮,蛋白质氮和游离氨基酸总量增加;蛋白质氮占全氮的比值亦因NaCl处理浓度的增大而提高。在盐胁迫下,游离脯氨酸占氨基酸总量的百分比明显增加,而谷氨酸所占比例则下降。

Research Advance on Absorption Law of Cadmium by Rice and Safety Control Technology of Cadmium in Rice Grain

Heavy metal pol ution, especial y cadmium pol ution, has threatened the safety production of rice. The research advance on law of absorption, distribution and accumulation of cadmium in rice and on recent safety control technology of cadmium in rice grain was summarized in this paper. We hoped to lay a foundation for the safety production of rice.

Effect of Different Irrigation Maximums on Accumulation and Distribution of Material in Chinese Kale

[Objective] The aim was to explore effects of soil moisture on dry matter accumulation and distribution and growth of kai-lan. [Method] In the context of the same irrigation frequency, the influence of irrigation maximum was researched on growth rate, net assimilation rate, and dry matter distribution of kai-lan. [Result] The results showed that regulation on soil moisture extremely significantly affected accumulation of photosynthate. When soil moisture was insufficient, the growth term from seedling to mature extended and growth rate declined sharply. Besides, the growth term was of extremely significant negative correlation with growth rate. Meanwhile,leaf assimilation rate decreased considerably. For example, when soil moisture was65%, distribution of dry matter in plant organs tended to be rational. [Conclusion]Deficit irrigation would significantly lower growth rate, and improve dry matter distribution in organs and economic yield and quality of kai-lan.

Bioaccumulation of Nickel by Various Scenedesmus Species in Culture Solution Containing Nickel

Sixteen Scenedesmus species or strains have been employed to investigate the maximum capacity of nickel (Ni) accumulation in 10 mg/L Ni solution. The results showed that the capacity of accumulating Ni from aqueous solution in 16 Scenedesmus species or strains showed the diversity. S. quadricauda freshwater algae culture collection of the Institute of Hydrobiology (FACHB) 44 and S. quadricauda FACHB 506 performed much more capacity of Ni accumulation than other species such as Scenedesmus sp. FACHB 416 and Scenedesmus sp. FACHB 489. Sequestration of Ni ions from aqueous solution was very efficient (26.7 mg Ni/g dry weight, in the 100 mg/L Ni solution) in S. quadricauda FACHB 44. The kinetics of Ni binding indicated that Ni bioaccumulation, in algal cell of S. quadricauda FACHB 44, possessed a rapid biosorption (5 min) and an slow bioaccumulation (2-3 h). More than 70% of Ni binding in algal cell were accumulated by biosorption and the remaining 20%-30% were bioaccumulated by energy_consumed transportation. It is much more higher ratio of energy_consumed transportation in S. quadricauda FACHB 44 than in other algae. Both the transmission electron microscope (TEM) and the energy_dispersive X_ray (EDX) microanalyses also revealed the different mechanisms of bioaccumulation in the various subcellular regions: a very fast adsorption in the cell wall; and a time_dependent absorption in protoplasm, specially in starch and chromatin.

Cadmium Accumulation and Yield Difference of Different Rice Varieties under Cadmium Stress

The cadmium （Cd） contents in rice plants and Cd accumulation in different parts of rice under Cd stress were studied to screen out Cd-highly tolerant and high-yield rice varieties. With different vadeties of japonica and indica rice as the research objects, Cd contents and Cd accumulation of different rice varieties in harvest time were discussed by pot experiment, under two treatments of no adding Cd and Cd stress. Under both the two treatments, the Cd contents in different parts of rice all ranked as root〉stem〉leaf〉husk〉grain, and Cd was manly concentrated in dce roots. Cd accumulation and distribution differed among different rice varieties, especially among grains of different rice varieties. Among the 8 rice varieties, the increase of grain Cd content of Chunyou 84 was the smallest, indicating a weaker Cd accumulation ability. At the same time, the Cd accumulation in japonica rice was higher than that in indica rice under Cd stress. Under Cd stress, the yield of indica rice decreased significantly, while that of japonica rice increased. The lowest grain Cd content of Chunyou 84 indicated significant Cd tolerance. Although its yield was affected, it can still be recommended to be promoted in the Cd-polluted region of Hunan Province, considering the Cd security.

Signal Transduction from Water Stress Perception to ABA Accumulation

To cope with unpredictably environmental perturbations and sometimes stresses, plants have evolved with some mechanisms so that these developing stresses can be sensitively perceived and the physiology can be rapidly regulated. Such perception and regulation can be a kind of feed_forward mechanism and may involve many biochemical and physiological processes and/or the expression of many genes. Although many dehydration_responsive genes have been identified, much fewer of their functions have been known. Such stress_ induced responses should include the initial perception of the dehydration signal, then the complicated signal transduction and cellular transmission until to the final gene activation or expression. As an important plant stress hormone abscisic acid (ABA) mediates many such responses. We believe that starting from the initial perception of dehydration to the gene expression leading to the stress_induced ABA biosynthesis is the most important stress signal transduction pathway among all the plant responses to stresses. Identification of the genes involved and understanding their roles during stress perception and physiological regulation shall be the most important and interesting research field in the coming years.

Starch Accumulation Characteristics of Large-Seed Rice

[Objective] The paper aimed to provide the theoretical foundation for rational using the large-seed rice.[Method] Large-seed rice 31C122、31C125 （ nearly 50 g /1 000-weight） and normal rice varieties including Jiyujing and Fuyu 333 as materials,the accumulative process for sugar and starch in seeds was compared and analyzed.[Result] Sugar content of inferior grains was higher than superior grains in all tested materials,sugar content of large seeds was lower than conventional ones;starch content of superior grains was higher than inferior grains,starch content of conventional ones was higher than large-seed rice,amylopectin content was higher than amylose content in all tested materials,amylose content of large-seed rice was lower than conventional ones;the peak of accumulation starch for superior grains of large-seed rice was later than conventional ones,inferior grains advanced;active saving period of starch for superior grains of large-seed rice was longer than conventional ones.[Conclusion] The quality of large-seed rice was better than conventional ones.

A Simplified Model with Soil Water Limitation on Spring Wheat Growth

The authors constructed a simplified model of spring wheat (Triticum aestivum L.) carbon assimilation and dry matter accumulation (DMA) process which consisted of two independent variables, day length (L) and total daily radiation (TDR). Leaf water potential (Ψ) was incorporated into the simplified growth model based on the assumption that both light use efficiency (α) and CO 2 conductance of assimilation (g c) were depressed by water limitation. Finally,Ψ was estimated from a regression equation in which the independent variables were relative soil water content in the upper 80 cm (θ R,80 ), ambient temperature (T a), vapor pressure deficit (VPD), the cumulative leaf water potential below thresholds of -1.5 MPa (Ψ c,1.5 ). Some applications in research program of field experiment of atmosphere_land surface processes in Heihe River region were tested. The simulated data agreed well with the data observed at Linze oasis in 1989 for various levels of water supply and at Zhangye oasis in 1992 in the field. The analysis and simulation using the model demonstrated that the simplified growth model could describe very well the DMA process of spring wheat with and without water limitation in the region of HEIFE (Heihe field experiment).

Effects of Planting and Irrigation Patterns on Water Consumption Characteristics and Dry Matter Production in Winter Wheat

[Objective] This study aimed to investigate the effects of different planting and irrigation patterns on water consumption characteristics and dry matter produc- tion and allocation of winter wheat. [Method] With high-yield winter wheat cultivar Jimai 22 as the experimental material, field experiment was conducted during 2008- 2010. A total of 3 planting patterns were designed, uniform row, wide-narrow row and furrow. Under each planting pattern, total four irrigation patterns were designed, no irrigation （Wo）, irrigation at jointing state （Wl）, irrigation at jointing and anthesis stages （W2） and irrigation at jointing, anthesis and milking stages （W3）, and the irri- gation amount per treatment was all 60 mm. [Result] Under the three planting pat- terns, with the increased irrigation amount, the total water consumption of the exper- imental field increased; the proportion of irrigation in the total water consumption in- creased, and that of soil water consumption in the total water consumption de- creased significantly. Compared with W0 treatment, various irrigation treatments sig- nificantly increased the post-anthesis dry matter accumulation in wheat plants; with the increased irrigation amount, the grain yield under the three planting patterns all increased, while the water use efficiency （WUE） decreased. Under the same irriga- tion conditions, compared with other two planting patterns, furrow planting increased the total water consumption of the experimental field, increased the proportion of soil water consumption in the total water consumption, and improved the WUE and wheat grain yield. [Conclusion] Under the experimental conditions, considering both wheat grain yield and WUE, furrow planting with moderately deficit irrigation at joint- ing and anthesis stages is more suitable for the winter wheat production in North China Plain.

Genetic Relationships Among Soluble Carbohydrates, Anthocyanins and Growth Characteristics in Leymus (Gramineae) Detected with Molecular Markers

Low-temperature soluble carbohydrate accumulations are commonly associated with anthocyanin coloration, attenuated growth and cold adaptation of cool-season grasses. The vrn-1 gene has potent effects on vernalization requirement, growth, and soluble carbohydrate accumulations of the winter-annual Triticeae species. Two hundred and four unmapped AFLP markers and genome-specific DNA markers genetically linked to the vrn-1 gene were used to detect QTL controlling soluble carbohydrate accumulations, anthocyanin coloration and growth characteristics in a segregating population derived from open pollinated Leymus cinereus x L. triticoides hybrids. These perennial Triticeae grasses are distinguished by adaptation and growth habit. As expected, positive trait correlations and pleiotropic gene effects were detected for soluble carbohydrate accumulations and anthocyanin coloration. Likewise, positive trait correlations and pleiotropic gene effects were detected for tillering, leaf development, leaf growth, regrowth and rhizome spread. However, soluble carbohydrate accumulations were not associated with attenuated growth. In fact, several DNA marker alleles, including one near vrn-Ns1, had positive effects on soluble leaf carbohydrate concentrations and low temperature growth. The corresponding DNA marker near vrn-Ns1 had more specific effects on tillering. We speculate that vrn-1 exerts quantitative effects on low-temperature soluble leaf carbohydrate accumulations and growth habit of the perennial Leymus. However, a number of other DNA markers displayed highly significant effects on soluble carbohydrate accumulations and various growth characteristics. Findings indicate that anthocyanin coloration may be a useful phenotypic marker for soluble carbohydrate accumulation. Although variation for soluble carbohydrates was not associated with attenuated growth in this population, this trait was under genetic control.

Role of Black Carbon-Induced Changes in Snow Albedo in Predictions of Temperature and Precipitation during a Snowstorm

In this study the authors apply the chemistry version of the Weather Research and Forecasting model （WRF-Chem） to examine the impacts of black carbon （BC）-induced changes in snow albedo on simulated temperature and precipitation during the severe snowstorm that occurred in southern China during 0800 26 January to 0800 29 January 2008 （Note that all times are local time except when otherwise stated）. Black carbon aerosol was simulated online within the WRF-Chem. The model resuits showed that surface-albedo, averaged over 27-28 January, can be reduced by up to 10% by the deposition of BC. As a result, relative to a simulation that does not consider deposition of BC on snow/ice, the authors predicted surface air temperatures during 27-28 January can differ by -1.95 to 2.70 K, and the authors predicted accumulated precipitation over 27-28 January can differ by -2.91 to 3.10 mm over Areas A and B with large BC deposition. Different signs of changes are determined by the feedback of clouds and by the availability of water vapor in the atmosphere.

Effects of Waterlogging Time on Rice Cd Absorption and Accumulation under Cadmium Stress

A pot experiment with exogenous cadmium was utilized to study the effects of waterlogging time on rice yield and Cd accumulationin different growth stages including top tillering stage and filling stage.The results showed that the rice yields of all flooding treatments were lower than the CK(CI).The WI,T1,T2,T3 and T4 decreased significantly by 23.7%,16.0%,15.5%,20.2%and 18.6%respectively.The Cd content of brown rice decreased with the extension of waterlogging time.And WF was the lowest,at only 3.4%of the wet irrigation of the whole growth period(WI).Under the same waterlogging condition,the Cd content in brown rice with 1 to 4 weeks of flooding treatment at the top tillering stage decreased by 27.1%(P﹤0.05),46.6%(P﹤0.05),56.0%(P﹤0.05)and 35.2%(P﹥0.05)respectively,compared with the treatment at the filling stage.And the average decrease was 41.2%.The variation tendency of Cd content in stems and leaves was similar to brown rice.The translocation efficiency of Cd from stems and leaves to rice seeds decreased with the extension of waterlogging time.The Cd enrichment factor of stems and leaves,as well as brown rice,varied greatly with different treatments.Specifically,the Cd enrichment factors in brown rice and in stems and leaves under WI were 28.0 and 17.8 times higher respectively than those under WF.The findings of this study demonstrated that flooding could inhibit the uptake and accumulation of Cd in rice,with significant positive correlation between them.The inhibition effect of flooding treatment on Cd accumulation in rice at the top tillering stage was superior to that at the filling stage.

Screening of New Rice Lines with Low CadmiumAccumulation

In order to screen new rice lines with low cadmium accumulation,20 rice materials/lines bred by Hunan Rice Research Institute were planted in three cadmium-contaminated areas for three consecutive years.The contents of cadmium in rice were detected and compared with those of emergency varieties Xiangwanxian 13 and Yangdao 6,which had low cadmium accumulation and high cadmium accumulation respectively.The results showed that the cadmium contents of 20 materials were lower than that of Yangdao 6,and 16 materials were lower than that of Xiangwanxian 13.Among them,10 materials such as R1195 were significantly lower than that of Xiangwanxian 13 and 8 materials such as BG130 were most significantly lower than that of Xiangwanxian 13.The low cadmium accumulation male sterile lines W115S and restorer lines R1195 and R1514 were screened out.

Effect of diurnal temperature difference on lipid accumulation and development in Calanus sinicus(Copepoda:Calanoida)

Calanus sinicus,the dominant copepod in the Yellow Sea,develops a large oil sac in late spring to prepare for over-summering in the Yellow Sea Cold Water Mass(YSCWM).The lipid accumulation mechanism for the initiation of over-summering is unknown.Here,we cultured C3 copepodites at four constant temperatures(10,13,16,and 19℃) and at three temperature regimes that mimicked the temperature variations experienced during diurnal vertical migration(10-13℃,10-16℃,and 10-19℃) for 18 days to explore the effects of temperature differences on copepod development and lipid accumulation.C.sinicus stored more lipid at low than at high temperatures.A diurnal temperature difference(10-16℃ and 10-19℃)promoted greater lipid accumulation(1.9-2.1 times) than a constant temperature of either 16℃ or 19℃,by reducing the energy cost at colder temperatures and lengthening copepodite development.Thereafter,the lipid reserve supported gonad development after final molting.Only one male developed in these experiments.This highly female-skewed sex ratio may have been the result of the monotonous microalgae diet fed to the copepodites.This study provides the first evidence that diurnal temperature differences may promote lipid accumulation in C.sinicus,and provides a foundation for future investigations into the mechanisms involved in over-summering in the YSCWM.

Subcellular Accumulation of Cadmium in Corn and WheatPlants at Different Levels of Phosphorus

Corn and wheat plants were grown in a nutrient culture solution at four levels of phosphorus (0, 0.12,0.60 and 3.0 mmol L-1) and two levels of cadmium (0 and 4.0 pmol L--1) in greenhouse for a 18-day period.The concentrations of phosphorus and cadmium in cell wall, cytoplasm and vacuoles of roots and leaveswere examined by cell fractionation techniques. With increasing phosphorus in medium, the contents of Pin cell wall, cytoplasm and vacuoles of corn and wheat roots and leaves increased. The highest content of Pwas observed in cell wall, next in vacuoles, and the lowest in cytoplasm. The wheat subcellular fractions inboth roots and leaves had higher concentrations of phosphorus than those of corn. Increasing phosphorus inmedium significantly inhibited the intracellular Cd accumulation in both species. However, at P concentrationup to 3.0 mmol L--1, the Cd content in cell wall was increased. Increasing phosphorus resulted in reductionof the subcellular Cd content in corn and wheat leaves. Compared with corn, the wheat roots had a higherCd content in the cell wall and vacuoles and a lower in cytoplasm, while in leaf subcellular fractions thewheat cell had a higher Cd content in its vacuoles and a lower one in its cytoplasm. The results indicate thatphosphorus may be involved in sequestration of Cd ionic activity in both cell wall and vacuoles by forminginsoluble Cd phosphate.

A modified Hoek-Brown failure criterion considering the damage to reservoir bank slope rocks under water saturation-dehydration circulation

After water is impounded in a reservoir, rock mass in the hydro-fluctuation belt of the reservoir bank slope is subject to water saturation- dehydration circulation （WSDC）. To quantify the rate of change of rock mechanical properties, samples from the Longtan dam area were measured with uniaxial compression tests after different numbers （1, 5, 10, 15, and 20） of simulated WSDC cycles. Based on the curves derived from these tests, a modified Hock- Brown failure criterion was proposed, in which a new parameter was introduced to model the cumulative damage to rocks after WSDC. A case of an engineering application was analyzed, and the results showed that the modified Hock-Brown failure criterion is useful. Under similar WSDC-influenced engineering and geological conditions, rock mass strength parameters required for analysis and evaluation of rock slope stability can be estimated according to this modified Hoek-Brown failure criterion.

Effects of Atmospheric CO_2 Enrichment, Applied Nitrogen and Soil Moisture on Dry Matter Accumulation and Nitrogen Uptake in Spring Wheat

Spring wheat (Triticum aestivum L. cv. Dingxi No. 8654) was treated with twoconcentrations of atmospheric CO_2 (350 and 700 μmol mol^(-1)), two levels of soil moisture(well-watered and drought) and five rates of nitrogen fertilizer (0, 50, 100, 150, and 200 mgkg^(-1) soil) to study the atmospheric CO_2 concentration effect on dry matter accumulation and Nuptake of spring wheat. The effects of CO_2 enrichment on the shoot and total mass depended largelyon soil nitrogen level, and the shoot and total mass increased significantly in the moderate to highN treatments but did not increase significantly in the low N treatment. Enriched CO_2 concentrationdid not increase more shoot and total mass in the drought treatment than in the well-wateredtreatment. Thus, elevated CO_2 did not ameliorate the depressive effects of drought and nitrogenstress. In addition, root mass decreased slightly and root/shoot ratio decreased significantly dueto CO_2 enrichment in no N treatment under well-watered condition. Enriched CO_2 decreased shoot Ncontent and shoot and total N uptake; but it reduced root N content and uptake slightly. Shootcritical N concentration was lower for spring wheat grown at 700 μmol mol^(-1) CO_2 than at 350μmol mol^(-1) CO_2 in both well-watered and drought treatments. The critical N concentrations were16 and 19 g kg^(-1) for the well-watered treatment and drought treatment at elevated CO_2 and 21 and26 g kg^(-1) at ambient CO_2, respectively. The reductions in the movement of nutrients to theplant roots through mass flow due to the enhancement in WUE (water use efficiency) and the increasein N use efficiency at elevated CO_2 could elucidate the reduction of shoot and root Nconcentrations.

Growth and Phosphorus Uptake of Oat (Avena nuda L.) as Affected by Mineral Nitrogen Forms Supplied in Hydroponics and Soil Culture

Plants show different growth responses to N sources supplied with either NH4^＋ or NO3^-. The uptake of different N sources also affects the rhizosphere pH and therefore the bioavallability of soil phosphorus, particularly in alkaline soils. The plant growth, P uptake, and P availability in the rhizosphere of oat （Arena nuda L.） grown in hydroponics and in soil culture were investigated under supply with sole NH4^＋-N, sole NO3-N, or a combination. Sole NO^- -fed oat plants accumulated more biomass than sole NH4^＋ -fed ones. The highest biomass accumulation was observed when N was supplied with both NH^＋ -N and NO3^- -N. Growth of the plant root increased with the proportion of NO3^- in the cultural medium. Better root growth and higher root/shoot ratio were consistently observed in NO3^- fed plants. However, root vigor was the highest when N was supplied with NO3^- ＋NH4^＋. NH4^＋ supply reduced the rhizosphere pH but did not affect P uptake by plants grown in soils with CaHPO4 added as P source. No P deficiency was observed, and plant P concentrations were generally above 2 g kg^-1. P uptake was increased when N was supplied partly or solely as NO3^--N, similarly as biomass accumulation. The results suggested that oat was an NO3-preferring plant, and NO3^- -N was essential for plant growth and the maintenance of root absorption capacity. N supply with NH4^＋ -N did not improve P nutrition, which was most likely due to the absence of P deficiency.

Study of Water Relations and Solutes Accumulation in Two Rice Genotypes under NaCI Stress during Seedling Stage

In order to study osmotic adjustment and accumulation of anions and cations in rice （Oryza sativa L.） seedlings under NaCl stress, a greenhouse experiment was conducted using two rice cultivars including IR651 （tolerant） and IR29 （sensitive）. Seedlings were grown in Youshida nutrient solution. Salinity treatments were imposed 21 days after sowing with 0 and 100 mM NaCI and seedlings were harvested 0, 72, 120 and 240 hour after salinization. Water （ψw） and osmotic （ψs） potentials, total soluble sugars and inorganic ions （Na＋. K＋, Cl-, Ca2＋ and Mg2＋） concentrations and osmotic adjustment were determined in sixth （youngest） leaf. Salinity caused a substantial biomass reduction in rice seedlings, ψs reduction in IR29 was occurred more than IR651. Water potential decreased in both the cultivars under stress conditions, but IR651 was able to maintain higher ψw and kept better growth till the end of the experiment. Osmotic adjustment was observed in IR651 was about 10 times more than in IR29. K＋ accumulation decreased in both cultivars under stress condition while Na＋ accumulation increased in both the cultivars with higher increase in IR29 seedlings. CI concentration increased in youngest leaf of both IR29 and IR651. Our results showed that tolerant cultivar was able to make osmotic adjustment faster than the sensitive cultivar using high accumulation of solutes especially total soluble sugars.