n 的多项式为系数的幂级数和函数注记

研究了以n的多项式为系数的幂级数的和函数的求解问题,给出了这类幂级数和函数的一种求解方法,并得到了其和函数的通用计算公式,通过实例验证了公式的正确性.文中还得到了两个关于组合数的等式.

Atmospheric nitrogen deposition affects forest plant and soil system carbon:nitrogen:phosphorus stoichiometric flexibility:A meta-analysis

Background:Nitrogen(N)deposition affects forest stoichiometric flexibility through changing soil nutrient availability to influence plant uptake.However,the effect of N deposition on the flexibility of carbon(C),N,and phosphorus(P)in forest plant-soil-microbe systems remains unclear.Methods:We conducted a meta-analysis based on 751 pairs of observations to evaluate the responses of plant,soil and microbial biomass C,N and P nutrients and stoichiometry to N addition in different N intensity(050,50–100,>100 kg·ha^(-1)·year^(-1)of N),duration(0–5,>5 year),method(understory,canopy),and matter(ammonium N,nitrate N,organic N,mixed N).Results:N addition significantly increased plant N:P(leaf:14.98%,root:13.29%),plant C:P(leaf:6.8%,root:25.44%),soil N:P(13.94%),soil C:P(10.86%),microbial biomass N:P(23.58%),microbial biomass C:P(12.62%),but reduced plant C:N(leaf:6.49%,root:9.02%).Furthermore,plant C:N:P stoichiometry changed significantly under short-term N inputs,while soil and microorganisms changed drastically under high N addition.Canopy N addition primarily affected plant C:N:P stoichiometry through altering plant N content,while understory N inputs altered more by influencing soil C and P content.Organic N significantly influenced plant and soil C:N and C:P,while ammonia N changed plant N:P.Plant C:P and soil C:N were strongly correlated with mean annual precipitation(MAT),and the C:N:P stoichiometric flexibility in soil and plant under N addition connected with soil depth.Besides,N addition decoupled the correlations between soil microorganisms and the plant.Conclusions:N addition significantly increased the C:P and N:P in soil,plant,and microbial biomass,reducing plant C:N,and aggravated forest P limitations.Significantly,these impacts were contingent on climate types,soil layers,and N input forms.The findings enhance our comprehension of the plant-soil system nutrient cycling mechanisms in forest ecosystems and plant strategy responses to N deposition.

论“N+Adj→Adj+(N)”组合构式中内含与凸显

组合性是复合词语意义生成的一种重要方式。在认知语言学研究的视阈里,英语复合词"N+Adj→Adj+(N)"构式中的不同语义成分合成有据、凸显有序、表征有异。全文以兰盖克(1987)建立的组合模型框架为基点,分析模型内不同成分凸显强弱,并作为认知解读的参照点,再结合考虑目标组合词语环境,我们发现该类组合词语经内在互动,激活整合出多种新的认知意义,与完全组合义差异明显。同时我们依据对英语为母语的美国大学生问卷调查结果,将此类合成词的组合性内部凸显现象分成三大类别:名词凸显,形容词凸显,整体凸显。

基于认知参照点理论的“Adj+N”结构阐释机制研究

"Adj+N"复合结构是一种很常见但又很难解释的语言现象。产生困难的原因在于在这类复合结构中,形容词和名词之间的语义关系非常复杂且变幻无常,很难对其进行全面系统的阐释。国内外大多数研究都集中于探究其形容词修饰名词的排列次序等问题,从认知角度对其进行的研究尚不多见。本文以认知语言学的参照点模式为理论框架,对"Adj+N"结构的认知机制进行了探讨。认知参照点模式也适应于阐释"N+N"结构和所有格结构等其它复合结构。

Effects of different levels of compost application on amounts and distribution of organic nitrogen forms in soil particle size fractions subjected mainly to double cropping

Effects of different levels of compost application on the amounts and percentage distribution of organic N forms in whole soils and particle size fractions were investigated. Soil samples were collected from three plots: (a) F, only chemical fertilizers;(b) F+LC, chemical fertilizers plus low level of compost;(c) F+HC, chemical fertilizers plus high level of compost. Each soil sample was divided into five fractions: coarse sand-sized aggregate (CSA), medium sand-sized aggregate (MSA), fine sand-sized aggregate (FSA), silt-sized aggregate (SIA) and clay-sized aggregate (CLA) fractions. The sand fractions were subdivided into decayed plants (DP) and mineral particles (MP). The amounts of total N and different organic N forms in the whole soils as well as size fractions generally increased with increasing the amount of compost. In the whole soils, percentage distribution of non-hydrolysable-N and amino sugar-N increased by compost application while the distribution values of the hydrolysable ammonium- N and unidentified-N decreased. The application did not affect the distribution degree of amino acid-N. In the size fractions, the distribution values of most organic N forms increased in the CSA-DP, MSA-DP and FSA-DP fractions by compost application. In the CLA fractions, the amounts and percentage distribution of organic N forms were the highest, although the application caused decreases in their distribution values. These findings indicate that the CLA fraction merit close attention as an important reservoir of various organic N.

Effects of N Forms and Rates on Vegetable Growth and Nitrate Accumulation

Experiments were carried out on a vegetable field with Peking cabbage (Brassica pekinensis (Lour.)Rupr.), cabbage (Brassica chinensis var. Oleifera Makino and nemoto), green cabbage (Brassica chinensis L.), spinach (Spinacia oleracea L.) and rape (Brassica campestris L.) to study the effects of N forms and N rates on their growth and nitrate accumulation. The results indicated that application of ammonium chloride,ammonium nitrate, sodium nitrate and urea significantly increased the yields and nitrate concentrations of Peking cabbage and spinach. Although no significant difference was found in the yields after application of the 4 N forms, nitrate N increased nitrate accumulation in vegetables much more than ammonium N. The vegetable yields were not increased continuously with N rate increase, and oversupply of N reduced the plant growth, leading to a yield decline. This trend was also true for nitrate concentrations in some vegetables and at some sampling times. However, as a whole, the nitrate concentrations in vegetables were positively correlated with N rates. Thus, addition of N fertilizer to soil was the major cause for increases in nitrate concentrations in vegetables. Nitrate concentrations were much higher in roots, stems and petioles than in blades at any N rate.

Soil Organic N Forms and N Supply as Affected by Fertilization Under Intensive Rice Cropping System

Changes of soil organic nitrogen forms and soil nitrogen supply under continuous rice cropping system were investigated in a long-term fertilization experiment in Jinhua, Zhejiang Province, China. The fertilizer treatments included combination of P-K, N-K, N-P, and N-P-K as well as the control. After six years of continuous double-rice cropping, total soil N and hydrolysable N contents remained stable in plots with N treatments, while the hydrolysable N contents were substantially reduced in those plots without N application. Compared to the unbalanced fertilization treatments, P and K increased the percentage of hydrolysable ammonium N in the total soil N with the balanced application of N, and also maintained higher rice grain yields and nitrogen uptake. Grain yield was positively correlated with total N uptake (r = 0.875**), hydrolysable N (r = 0.608**), hydrolysable ammonium N (r = 0.560**) and the hydrolysable unknown N (r = 0.417**). Total N uptake was positively correlated with hydrolysable N (r = 0.608**), hydrolysable ammonium N (r = 0.440**) and hydrolysable unknown N (r = 0.431**). Soil nutrient depletion and/or unbalanced fertilization to rice crop reduced N content in soil microbial biomass, and therefore increased C/N ratio, suggesting a negative effect on the total microbial biomass in the soil.

RESEARCH ON HOT FORMING PROCESS OF A RETAINING RING OF HIGH-NITROGEN STEEL

Mn18Cr18N, the high-nitrogen steel, is the 2nd generation material for manufacturing the retaining ring of firepower generators. In this paper, the hot deformation behavior of the material was investigated by thermo-mechanical modeling tests. And the flow stress curves of the steel were obtained for various combinations of the temperature and strain rate. Based on the results of the tests, the complex forming process of a retaining ring including punching, expanding and extrusion with an enclosure was put forward and simulated by means of numerical simulation method. The results indicate that the process is a novel and force-saved practical technology for manufacturing heavy retaining rings.

^(15)N NMR Spectroscopic Study on Nitrogen Forms in Humic Substances of Soils

Nitrogen forms of humic substances from a subalpine meadow soil, a latentic red soil and a weathered coal and the effect of acid hydrolysis on N structures of soil humic substances were studied by using 15N cross-polarization magic angle spinning nuclear magnetic resonance (CPMAS NMR) spectroscopy. Of the detectable 15N-signal intensity in the spectra of soil humic substances 71%-79% may be attributed to amide groups, 10%-18% to aromatic/aliphatic amines and 6%~11% to indole- and pyrrole-like N. Whereas in the spectrum of the fulvic acid from weathered coal 46%, at least, of the total 15N-signal intensity might be assigned to pyrrole-like N, 14% to aromatic/aliphatic ammes, and the remaining intensities could not be assigned with certainty. Data on nonhydrolyzable residue of protein-sugar mixture and a 15N-labelled soil fulvic acid confirm the formation of nonhydrolyzable heterocyclic N during acid hydrolysis. Project (No. 39790100) supported by the National Natural Science Foundation of China.

Effect of Fertilizer N Forms on Physiological Metabolism and Potassium Uptake of Flue-Cured Tobacco

The growth, chlorophyll composition, photosynthesis, respiration, K uptake and root K+ secretion offlue-cured tobacco as thected by different concentrations of N supplied as urea, NaNO3 and NH4NO3 werestudied under the experimental condition of sand culture. The results showed that the content of K in thefiue-cured tobacco was not merely related with root vitality and uptake but also closely related with root cellmembrane structure and K+ secretion.

SIMULATION OF HOT FORMING PROCESSION IN Mn18Cr18NSTEEL

In the hot forming of Mn18Cr18N steel, such problems as easy cracking, difficult controlling of forming paramenters often occur. In this paper,the variation rule of the plasticity of the steel, the starting mechanism of micro-crack and its generating characteristics were studied with the combination of thermodynamic simulation test, micro-simulation and FEM, the related data of microstructure change and hot forming parameters were produced. The hot forming process of 600MW generator retaining ring was analyzed as an example.

Adj.N号词组在句子中的信息功能

1.交际的目的一般说来是传递信息,作为最基本的交际单位,句子中所有成素的选择和组合,都要为传递信息服务。本文即拟从这个角度,讨论几类句子中的Adj.N词组。 Adj.N词组的词间联系,在句子之外是非必然的,称为弱联系。这在很大程度上是由名词的语义特点所决定的。广义地讲,名词就是事物的名称,而给事物命名,是以概括其某些属性的概念为基础。这些属性的集合,则是词义直接相关的所指(денотат)。

In the Atmosphere and Oceanic Fluids:Scaling Transformations,Bilinear Forms,Bäcklund Transformations and Solitons for A Generalized Variable-Coefficient Korteweg-de Vries-Modified Korteweg-de Vries Equation

The atmosphere is an evolutionary agent essential to the shaping of a planet,while in oceanic science and daily life,liquids are commonly seen.In this paper,we investigate a generalized variable-coefficient Korteweg-de Vriesmodified Korteweg-de Vries equation for the atmosphere,oceanic fluids and plasmas.With symbolic computation,beginning with a presumption,we work out certain scaling transformations,bilinear forms through the binary Bell polynomials and our scaling transformations,N solitons(with N being a positive integer)via the aforementioned bilinear forms and bilinear auto-Bäcklund transformations through the Hirota method with some solitons.In addition,Painlevé-type auto-Bäcklund transformations with some solitons are symbolically computed out.Respective dependences and constraints on the variable/constant coefficients are discussed,while those coefficients correspond to the quadratic-nonlinear,cubic-nonlinear,dispersive,dissipative and line-damping effects in the atmosphere,oceanic fluids and plasmas.

Mineralization and Transformation of Nitrogen Derived from Plant Materials in Soils over 10 Years

Results of a 10-year decomposition experiment indicated that the annual mineralization rate of organic N in newly-formed humus varied with the type of original plant materials and the water regimes for decomposition,ranging from 0.028 to 0.074.The mineralization rate under waterlogged conditions was higher than that under upland conditions.The proportion of α-amino acid N in humus newly-formed under waterlogged conditions was slightly higher than that under upland conditions.It decreased gradually with time,while the proportion of nonhydrolyzable N showed no consistent trend,irrespective of the water regines for decomposition.The distribution of amino acids in humus newly-formed from different plant materials under various water regimes was quite similar with that in original plant materials,and only minor differences could be found among them.For example,in comparison to original plant materials,the newly-formed humus contained higher proportions of isoleucine,cysting,γ-amino-butyric acid and ornithine,and lower proportions of phenylalanine and proline.Moreover the proportion of phenylalanine was higher in the humus newly-fored under waterlogged conditions than that under upland conditions.

值得注意的“adj.+of+n.(pron.)”结构

of 是个含义丰富的常用介词,可放在两个名词(代词)之间,表示两者是所属、主谓、动宾、同位等关系。但 of 放在形容词和名词(代词)之间,表示修饰与被修饰关系的用法却不为人们所注意。这种结构有如下几种情况:1.of 用在表示“摆脱”、“缺少”、“解脱”等含义的形容词后,表示“分离”,

Distribution of Forms of Sulphur and Their Relationships with Soil Attributes in Tea Growing Soils under Different Agro-climatic Zones of Northeastern India

Distribution of different forms of sulphur(S)and carbon-nitrogen-sulphur relationships were studied in surface and subsurface soils of some tea growing areas of Northeastern India.The soils were strongly acidic in reaction(pH-4.0 to 5.5),low to very high in organic carbon(4 to 54 g kg^-1),with cation exchange capacity(8.8 to 19.2 cmol(p+)kg^-1)and base saturation(50 to 77%).Organic S mostly contributed to the total-sulphur(62 to 77%)followed by Non sulphate S(28.8 to 37.2%)and sulphate S(0.7 to 1.4%).Except sulphate S,other forms of sulphur showed significant positive correlation among themselves as well as with organic carbon and total nitrogen.The C:N,C:S,N:S and C:N:S ratio varied from 8.2 to 10.0,6.18 to 71.57,0.62 to 7.26 and 100:10.1:1.4 to 100:12.2:16.2 respectively.Wider C:N:S ratios in all the surface and sub-surface soils indicated that the major portion of nitrogen and sulphur in tea growing soils of Northeastern India is locked up in organic combination which might pose as a potential threat towards tea plantation if application of sulphur is continuously ignored.

Nitrogen Forms of Maillard Polymers Derived from Xylose and ^(15)N-Labelled Glycine

Water-soluble, nondialyzable Maillard polymers were prepared by reacting D-xylose with 15N-glycine (and/or glycine) at 68 ℃ and pH 8.0 at equimolar concentrations of 1, 0.5 and 0.1 mol L-1, respectively,for 13 days and partitioned into acid-insoluble (MHA) and acid-soluble (MFA) fractions. The nitrogen forms in these polymers were studied by using the 15N cross polarization-magic angle spinning nuclear magnetic resonance (CPMAS NMR) technique in combination with chemical methods. The 15N nuclear magnetic resonance (NMR) data showed that while the yield, especially the MHA/MFA ratio, varied considerably with the concentrations of the reactants, the nitrogen distribution patterns of these polymers were quite similar.From 65% to 70% of nitrogen in them was in the secondary amide and/or indole form with 24%~25% present as aliphatic and/or aromatic ammes and 5% to 11% as pyrrole and/or pyrrole-like nitrogen. More than half (50%~77%) of the N in these polymers were nonhydrolyzable. The role of Maillard reaction in the formation of nonhydrolyzable nitrogen in soil organic matter is discussed.

造孔剂脱除方式对VPO催化剂性能的影响

制备了正丁烷氧化制顺酐的VPO催化剂,采用XRD和XPS对催化剂进行了表征,研究了造孔剂脱除对催化剂性能的影响,包括造孔剂含量、造孔剂脱除顺序以及低温减压脱除造孔剂对催化剂性能的影响,并考察了催化剂的稳定性。实验结果表明,降低造孔剂含量不能有效提升催化剂的性能;采用先脱除造孔剂后活化的方法制备VPO催化剂,在408℃熔盐温度下正丁烷转化率达到80.6%、顺酐收率可达94.3%(w),催化剂性能有所提升;采用低温减压的方法脱除造孔剂,VPO催化剂在408℃熔盐温度下正丁烷转化率达到82.5%、顺酐收率达到95.1%(w),可以显著提升催化剂的性能,且在反应50 d内正丁烷转化率维持在82.0%以上、顺酐收率稳定在94.0%(w)以上。

土壤水分状况和氮肥施用及品种对稻田N_2O排放的影响

土壤水分状况和氮肥施用及品种对稻田Ｎ２Ｏ排放有明显影响．当稻田持续淹水时，几乎没有Ｎ２Ｏ排放，而当稻田经历干湿交替循环特别是烤田时，有较高的Ｎ２Ｏ排放通量．稻田持续淹水、干湿交替及烤田期间５个处理的平均Ｎ２Ｏ排放通量分别为１．０２、２３．８７和４７．９９μｇ·ｍ－２·ｈ－１．化学氮肥的施用增加了稻田Ｎ２Ｏ的排放量，且硫铵能比尿素排放更多的Ｎ２Ｏ．施用硫铵氮１００和３００ｋｇ·ｈｍ－２引起的Ｎ２ＯＮ损失率分别为０．０４％和０．２６％，而施用尿素氮的分别为０．０３％和０．１５％．

^(15)N尿素在兔体内消化吸收及利用机理研究 Ⅰ.兔对^(15)N尿素利用的氮平衡状况及形态分配

应用稳定同位素１５Ｎ尿素示踪技术，经兔消化代谢试验，研究尿素氮平衡状况，测定其消化率和利用系数，并对在兔体内形成蛋白质沉积及其它含氮化合物形态与分配进行了讨论，肯定了尿素氮作为补充兔日粮中粗蛋白营养不足的价值。研究发现，１５Ｎ尿素在胃和小肠内容物中，具有与盲肠中相似的由微生物转化合成极易被兔消化利用的游离氨基酸１５Ｎ和蛋白质１５Ｎ等化合物的功能，从而促进了兔对日粮尿素的消化吸收和利用。