“妃子笑”荔枝果实发育与温度关系的初步分析

通过对同一果园"妃子笑"荔枝连续5 a的果实发育期物候资料及同期温度等气象资料的对比分析,发现不同年份"妃子笑"荔枝果实成熟期早晚及果实全发育期与日生长温度高低关系密切:花序-果肉出现期间,日生长温度偏高的年份果实发育进程快,发育期间隔天数短,反之亦然;而果肉出现-可采成熟期间隔天数相对稳定。因此,果实成熟期早晚主要受花序-果肉期生长温度的影响。有关积温统计结果表明,"妃子笑"荔枝果实发育期间的有效生长积温更能反映温度条件对荔枝果实发育进程的影响。研究结果对开展"妃子笑"果实成熟期预报服务有积极意义。

陕西省酿酒葡萄气候区划初探

利用生长期（４ 月～９ 月）有效积温为一级区划指标和成熟期（７ 月～９ 月）的降水 量为二级指标，将陕西 ９２ 个县（市）分为暖热区（Ⅰ）、暖温区（Ⅱ）、中温区（Ⅲ）、凉爽区（Ⅳ）、最凉区（Ⅴ），每区又分为半干亚区（ Ａ）、半湿亚区（ Ｂ）、湿润亚区（ Ｃ）。Ⅰ区宜选择需热量大的半干、半甜及白兰地酒用葡萄品种；Ⅱ区宜发展优良中、中晚熟干红酒用品种；Ⅲ区宜发展白干及中熟干红酒用品种；Ⅳ区宜发展起泡酒用品种；Ⅴ区可选择少量极早、早熟品种。各葡萄品种和酒种宜优先在各区的 Ａ 亚区内发展。

Effects of Growing of Different Types of Crops on Constitution of Soil Available Nitrogen and Conversion and Utilization of Nitrogen Fertilizer

The soybean, cotton, maize and sorghum were planted in pot under low nitrogen, high nitrogen treatments, the soil available nitrogen constitution and con- version and utilization of nitrogen fertilizer were determined, so as to provide techni- cal guidance for reasonable use and improving use efficiency of nitrogen fertilizer for different types of crops. Compared with the control with nitrogen but unplanted crop, growing soybean, cotton, maize, sorghum significantly decreased the soil available N contents by 53. 48%, 51.54%, 33.10%, 55.03%,and influenced the constitution of soil available N. Thereinto, growing soybean, cotton, maize and sorghum significantly decreased soil inorganic N contents by 85.41%, 83.09%, 70.89% and 83.35%,but increased soil hydrolysable organic N contents by 1.41, 1.53, 2.11 and 1.28 times, respectively; growing soybean, cotton, maize and sorghum significantly decreased the rate of soil inorganic N to available N by 68.61%, 65.09%, 56.47% and 63.00%, but increased the rate of soil hydrolysable organic N to available N by 4.18, 4.21, 3.66 and 4.08 times, respectively. Compared with the control, growing soybean, cotton, maize and sorghum significantly increased the transform rate of ammonium nitrogen fertilizer by 93.66%, 38.19%, 32.58% and 38.31% respectively, and growing soybean treatment had the highest increasing range; the nitrification rates of ammo- nium nitrogen fertilizer of growing soybean, cotton, maize and sorghum treatments were negative values, and growing soybean treatment had the highest decreasing amplitude. The ammonium nitrogen fertilizer use efficiency of growing soybean, cot- ton, maize and sorghum treatments were 52.01%, 28.31%, 24.16% and 28.40% re- spectively and growing soybean treatment had the highest value. In conclusion, growing crops suppressed the soil nitrification and accelerated the development of soil hydrolysable organic nitrogen by the utilization of soil available nitrogen and the alteration of soil environment, and hence impacted the constitution of soil available nitrogen and the transform and use of ammonium nitrogen applied in soil. Legumi- nous crops had stronger ability of suppressing nitrification, making use of ammonium compared with non-Leguminous crops.

关注操作体验 促进学生数学素养的提升

《义务教育数学课程标准(2011年版)》指出:"要让学生在参与的特定数学活动中,在具体情境中初步认识对象的特征,获得一些体验。"显而易见,数学学习应该是学生自我感知、自我体验、自我建构、自我内化的过程,在这一过程中,学生可以习得知识、掌握技能、积累经验、感悟数学思想方法,并初步形成数学素养。因此,小学数学核心素养的培养过程应侧重学生的自主探究和自我体验方面,更多地让学生在实践中摸索、积累和感悟。

呼和浩特地区2种冷季型草坪草需水规律研究

【目的】为解决城市园林供水与社会水资源供需矛盾,建立节水型草坪。【方法】本研究以猎狗5号和美洲虎4G为试验材料,分别设置15%~20%(最少灌溉),20%~25%(轻度灌溉),25%~30%(中度灌溉),30%~40%(充分灌溉)4种不同的水分供给条件,测定了植物的净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)、脯氨酸(Pro)、丙二醛(MDA)、叶绿素含量(Chl)和草坪质量。【结果】猎狗5号的生长水分条件下限为25%~30%(中度灌溉),美洲虎4G为20%~25%(轻度灌溉)。【结论】美洲虎4G对水分的需求最低限度低于猎狗5号,具有更好的草坪节水潜力;猎狗5号在20%~25%(轻度灌溉)的水分条件下能够满足较低的草坪质量需求的绿地景观;美洲虎的景观效果和绿期维持能力更稳定。

Physiological responses of macroalga Gracilaria lemaneiformis(Rhodophyta) to UV-B radiation exposure

This paper aims to evaluate the effects of ultraviolet-Bradiation(UVBR) on Gracilaria lemaneiformis,a commercial red macroalga and an important source of agar. To study the in-vitro effect of UVBR on G. lemaneiformis,this plant was cultivated and exposed to photosynthetically active radiation(PAR) at 40 μmol photons/(m2 ·s) and enhanced UVBR(0,0.36,0.72,1.08,1.44,and 1.80 k J/(m 2 ·d)) for 13 days. The samples were processed for histochemical analysis,and the growth rate,photosynthetic pigment contents,photosynthetic performance,reactive oxygen species levels,membrane permeability,malonyl dialdehyde contents and antioxidant capacity of G. lemaneiformis were investigated. After 13 days of exposure to PAR+UVBR,G. lemaneiformis showed photodamage and photoinhibition of photosynthetic pigments(chlorophylla and phycoerythrin),leading to a decreased photosynthetic efficiency. Further,there was a corresponding decrease in the relative growth rates and depigmentation and partial necrosis of the apical segments were noted after exposure to PAR+UVBR. Additionally,UVBR induced excess production of superoxide radicals and hydrogen peroxide,eliciting a marked cellular membrane damage and antioxidative response.

Effects of Rice Straw Incorporation and Soil Pre－Flooding on the Fate of Applied （^（15）NH_4）_2SO_4－N and Growth of Rice

A pot experiment was conducted to investigate the effects of straw incorporation and soil pre-flooding on the fate of (￣(15)NH_4)_2SO_4-N and the growth of rice. Excessive application of rice straw when incorporated with (￣(15)NH_4)_2SO_4 at the C/N ratio of 40 reduced the loss of (￣(15)NH_4)_2SO_4-N and retarded the growth and development of rice significantly, while no adverse effects were observed on dry weight of panicle and the total recovery of (￣(15)NH_4)_2SO_4-N when rice straw was incorporated with (￣(15)NH_4)_2SO_4 at a C/N ratio less than 25. There were no significant effects of duration of soil pre-flooding within 6 weeks on (￣(15)NH_4)_2SO_4-Nuptake by rice and on rice growth, but, less loss of (￣(15)NH_4)_2SO_4-N was observed in the soil with a longer period of pre-flooding.

Application of Soil Amendments Reduced Cadmium Bioavailability but Restrained Soybean Growth

The soybean is a crop which easily accumulates cadmium(Cd),which threatens human health.To assess the impact of the application of classic soil amendments on the Cd concentration in the soybean and the Cd bioavailability in the soil,a field study was conducted in Xiangtan Country(XT)and Liling City(LL),with inorganic-organic-microbial matter(T1)and silicon-calcium-magnesium oxide from natural minerals(T2)as two soil amendments in this study.The results indicated that the soil pH in the two sites increased significantly,up to 0.7~1.1 units and the Cd concentration in the stem,leaf,husk and seed in the two sites decreased differently.Of which,the soil available Cd in Xiangtan County(XT)decreased by 11.9%~16.0%,the enrichment factor(EF)and translocation factor(TF)reduced by 37.9%and 23.5%,respectively.Both soil amendments were effective in increasing the soil pH,reducing the seed and soil available Cd,but the soil organic matter,total N,stem length and grain yields decreased slightly.In conclusion,the Cd bioavailability was reduced but the soybean growth was restrained with the application of the soil amendments.

An environmental gradient change of Picea mongolica seedling from the center of a forest canopy gap in forest-steppe ecotone in Inner Mongolia Autonomous Region of China

In sandy forest with a forest canopy gap for a period of over 30 years, the spruce（Picea mongolica） seedlings were monitored on two 5-m- wide transects from the center of a large gap into the surrounding forest. The farther they were to the far center, the taller grew the seedling and the more is the number of seedling. There were many seedlings under the canopy but almost all seedlings died before they grow up. Along the forest edge, growth of seedlings was temporarily enhanced by lateral penetration of light from the gap. The implications for natural forest regeneration dynamics are discussed. Our results prove that in P mongolica forest a gap disturbance creates a non-uniform environment for regeneration of the species, and determines that the forest was a non-even aged forest.

Mechanisms of Difference in Mn Efficiency Between Wheat and Oilseed Rape

By solution culture experiment, three wheat genotypes (Ttiticum aestivum L.) and two oilseed rape genotypes (Brassica napus L.) differing in Mn efficiency under Mn-deficient conditions were used to study mechanisms of the difference in Mn efficiency between wheat and oilseed rape. The results showed that there were significant differences in the abilities of MnIV reduction and acidification in root rhizosphere between the two species. Compared with wheat, oilseed rape had much higher reducing capacity and intensity of rhizosphere acidification under Mn-deficient conditions. Moreover, the higher ratio of functional leaves Mn/old leaves Mn in oilseed rape than in wheat was also an important factor for the different Mn efficiencies between the two species.

Phosphorus fertilizer induced changes in the soil available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory

A study was carried out to investigate changes in the soil plant-available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory,broom（Cytisus scoparius L.） or ryegrass（Lolium multiflorum） on Orthic Allophanic Soil,following the application of three rates of triple superphosphate（TSP）（0,50,and 100 mg·kg^-1P） under a glasshouse condition.The application of P fertilizer enhanced P availability in the rhizospheric of radiata seedlings and the bulk soils in a P-deficient site.P availability in the rhizospheric soils of ryegrass and broom,grown in association with radiata,were also increased by the presence of radiata roots.P concentrations in new shoot needles,old shoot needles,stem and roots of radiata pine increased with increase rates of TSP application,but the effects of ryegrass and broom on P nutrition of radiata seedlings depended on the soil P status.In the absence of P fertilizer addition（control treatment）,P concentrations in new shoot needles,old shoot needles,stem,and roots of radiata grown in association with broom were higher than those with ryegrass,whereas,when P fertilizer was added（50 and 100 mg·kg^-1） the P concentration was lower.This is probably related to the growth of broom that may have removed much of the plant-available P in the soil as indicated by the consistently lower Bray-2 P concentration in the rhizosphere soil of radiata in association with broom than that in the rhizosphere soil of radiata in association with grass at the two high P rates.Furthermore,in the high P fertile soil（application rate of 100 mg·kg^-1）,the dry matter yield of radiata was lower when it was grown with broom than with ryegrass.This result suggests that in moderate to high P fertile soils,P.radiata seedlings grow better with ryegrass than with broom,because broom grows vigorously in high P fertile soil and competes with P.radiata for P and perhaps for other nutrients as well.

Effect of microbial inoculants on Albizia saman germination and seedling growth

Microbial Inoculants as Effective Microorganisms （EM） were applied to find out their effects on germination and seedling growth of Albizia saman in the nursery. The seedlings were grown in a mixture of sandy soils and cow dung （3：1） kept in polybags. The EM solution at different concentrations （0.1%, 0.5%, 1%, 2%, 5% and 10%） was incorporated before and after a week of sowing seeds. Germination and physical growth parameters, including shoot and root length, vigor index, collar diameter, leaf number, fresh and dry weight of shoot and root and total biomass increment over the control were measured. The nodulation status influenced by EM was also observed along with the estimation of chemical parameters like chlorophyll a, chlorophyll b and carotenoid. Both germination and the measured physical growth parameters were found significantly （P〈0.05） higher in seedlings treated with different concentrations of EM solution in comparison to the control. Maximum growth was found at 2% followed by 1% EM solution. Nodulation was higher at 0.1% concentration but it normally decreased with the increase of concentrations. Although there were a higher amount of pigments in leaves of the treated seedlings than of the control, the variations recorded with respect to chlorophyll a, b and carotenoid were not significantly higher in most of the treatments. Treated seedlings showed variable results along with the increment of EM applications and most of the parameters showed best results at the medium range of concentrations. The study indicates that the Microbial Inoculant （EM） technology might be useful to improve the growth of seedlings in the nursery. This also indicates that the associated beneficial organisms along with the polybag soils might be of value in improving the degraded soil or poor field soil for better nutrient and water uptake during the initial growth of transplanted seedlings.

Numerical study on freezing-thawing phase change heat transfer in biological tissue embedded with two cryoprobes

A two-dimensional model for freezing and thawing phase change heat transfer in biological tissue embedded with two cryoprobes was established.In this model,the blood vessels were considered as tree-like branched fractal network,and the effective flow rate and effective thermal conductivity of blood were obtained by fractal method.The temperature distribution and ice crystal growth process in biological tissue embedded with two cryoprobes during freezing-thawing process were numerically simulated.The results show that the growth velocity of ice crystal in freezing process from 200 to 400 s is more rapid than that from 400 to 600 s. Thawing process of frozen tissue occurs in the regions around cryoprobes tips and tissue boundary simultaneously,and the phase interfaces are close to each other until ice crystal melts completely.The distance of two cryoprobes has a more profound effect on the temperature distribution in freezing process at 400 s than at 800 s.

Effects of AsN 1980 phytase on growth and phosphorus utilization of broilers

The experiment was conducted with 180 one-day-old AA broilers that were randomly divided into one control group and one trial group to study the effects of AsN1980 phytase on broilers growth performance and P utilization in low available phosphorus diets. Results showed that phytase supplement decreased F/W by 12.4%-13.4%and increased phosphorus availability by 7.63%-8.27%, both of which were significantly superior to the control group (P< 0.05).

The Influence of Different Single Radiation Dose on Delayed Growth of Transplanted Tumor in Athymic Mouse

OBJECTIVE To reveal the biological effects and effective dosage in radiotherapy model which applies high single-dose irradiation by animal experiment. METHODS We inoculated subcutaneouly human pancreatic carcinoma cell line （MIA PaCa-2） in the lateral of the right lower extremity of the athymic mouse to grow transplantation tumor. While the median diameter of transplantation tumor reached 10 mm approximately, the animals were randomly divided into 7 groups （6 animals per group） and irradiation by different dose in one fixed with consciousness for fraction （0, 2, 5, 10, 17, 25, 35 Gy）. All were kept on to be bred for observation of the change in gross tumor volume, calculation of delayed growth time and delayed growth curve. RESULTS With increased dose per fraction, cutaneous reaction on the neoplasma surface of the animal, which was mainly moist yellow effusion was more and more severe. When dosage is less than 10 Gy, all animals showed similar effects, that＇s the delayed tumor growth was not obvious. Tumors receiving more than 10 Gy in one fraction showed very good biological effect and the delayed tumor growth was obviously related to dosage. The difference in delayed tumor growth between the 2 groups was statistically significant. The delayed tumor growth time in 10, 17, 25 Gy group was respectively 3 weeks, 6 weeks and more. CONCLUSION The biological effect of the model which applies high single-dose irradiation （more than 10 Gy in one fraction） was very good. The effect of delayed tumor growth was obviously related to the dosage after transplantation tumor was radiated. Because of its higher dose per fraction and biological effects, the model of high single-dose irradiation can get better clinical effects.

Developmental Differences, Yield and Late Blight （Phytophthora infestans）Infection of Potato Plants Grown under Organic and Conventional Systems

In the years 2008-2010, an experiment was conducted Phytophthora infestans under organic and conventional production on four potato cultivars differing in maturity and resistance to systems. During the growing season, plant growth was evaluated by measuring plant height, stem number, leaf and stem biomass and leaf area index （LAI）. Photosynthetic active radiation （PAR） absorption and leaf chlorophyll content were also measured. The rate of late blight development, tuber yield, tuber size, and harvest index was assessed. There were significant differences between the two production systems in the most studied parameters. Plants growing in the organic system were characterized by reduced plant development compared to plants growing in the conventional system. As a result of lower plant growth, tuber yield was reduced by 22% and tuber size was smaller. Harvest index did not differ significantly between production systems. A positive effect of the reduced development of aboveground plant parts in the organic system was later appearance of the first symptoms of late blight and slower spread the disease.

Response of Soil Phosphorus Required for Maximum Growth of Asparagus officinalis L. to Inoculation of Arbuscular Mycorrhizal Fungi

Fertilizer application efficiently increases crop yield, but may result in phosphorus(P) accumulation in soil, which increases the risk of aquatic eutrophication. Arbuscular mycorrhizal fungi(AMF) inoculation is a potential method to enhance P uptake by plant and to reduce fertilizer input requirements. However, there has been limited research on how much P application could be reduced by AMF inoculation. In this study, a pot experiment growing asparagus(Asparagus officinalis L.) was designed to investigate the effects of AMF inoculation and six levels of soil Olsen-P(10.4, 17.1, 30.9, 40.0, 62.1, and 95.5 mg kg-1for P0, P1, P2, P3, P4 and P5treatments, respectively) on root colonization, soil spore density, and the growth and P uptake of asparagus. The highest root colonization and soil spore density were both obtained in the P1treatment(76% and 26.3 spores g-1soil, respectively). Mycorrhizal dependency significantly(P < 0.05) decreased with increasing soil Olsen-P. A significant correlation(P < 0.01) was observed between mycorrhizal P uptake and root colonization, indicating that AMF contributed to increased P uptake and subsequent plant growth.The quadratic equations of shoot dry weight and soil Olsen-P showed that AMF decreased the P concentration of soil required for maximum plant growth by 14.5% from 67.9 to 59.3 mg Olsen-P kg-1. Our results suggested that AMF improved P efficiency via increased P uptake and optimal growth by adding AMF to the suitable P fertilization.

Black Locust Transpiration Responses to Soil Water Availability as Affected by Meteorological Factors and Soil Texture

On the Loess Plateau of China, a dry soil layer may form due to excess transpiration, leading to degradation of black locust(Robinia pseudoacacia) stands. In order to better manage projects involving black locust, this study was intended to investigate the response of black locust transpiration rate to soil water availability as affected by meteorological factors using two representative soils(loamy clay and sandy loam) on the Loess Plateau. Four soil water contents were maintained for black locust seedlings grown in pots initially outdoors and then in a climate-controlled chamber, by either drying or irrigating the pots. In both environments, daily transpiration rates were related by a power function to air temperature and by a logistic function to reference evapotranspiration(ET0). Transpiration rates were more susceptible to changes in the meteorological conditions in the sandy loam than in the loamy clay soil. The transpiration rate in the well-watered treatment was greater for black locust grown in the sandy loam than in the loamy clay soil. Normalized transpiration rates were unaffected by ET0 until a critical value of soil water content(θc) was attained; the θc value decreased significantly for the loamy clay soil but increased significantly for the sandy loam soil when ET0 increased. These suggested that the effect of the meteorological condition on the transpiration characteristics of black locust was dependent on soil texture.

Conocarpus Biochar Induces Changes in Soil Nutrient Availability and Tomato Growth Under Saline Irrigation

Thermally modified organic materials commonly known as biochar have gained popularity of being used as a soil amendment.Little information, however, is available on the role of biochar in alleviating the negative impacts of saline water on soil productivity and plant growth. This study, therefore, was conducted to investigate the effects of Conocarpus biochar(BC) and organic farm residues(FR) at different application rates of 0.0%(control), 4.0% and 8.0%(weight/weight) on yield and quality of tomatoes grown on a sandy soil under drip irrigation with saline or non-saline water. The availability of P, K, Fe, Mn, Zn and Cu to plants was also investigated. The results demonstrated clearly that addition of BC or FR increased the vegetative growth, yield and quality parameters in all irrigation treatments. It was found that salt stress adversely affected soil productivity, as indicated by the lower vegetative growth and yield components of tomato plants. However, this suppressing effect on the vegetative growth and yield tended to decline with application of FR or BC, especially at the high application rate and in the presence of biochar. Under saline irrigation system, for instance, the total tomato yield increased over the control by 14.0%–43.3% with BC and by 3.9%–35.6% with FR. These could be attributed to enhancement effects of FR or BC on soil properties, as indicated by increases in soil organic matter content and nutrient availability. Therefore, biochar may be effectively used as a soil amendment for enhancing the productivity of salt-affected sandy soils under arid conditions.