关于右R-模的强根

给出了强多余子模在补模中的性质,证明了如果B是M的强补子模且C/B是M/B的强补子模,则C是M的强补子模。同时,得到了右R-模的强根的若干性质,证明了如果环的根s.rad(RR)是Artin右模,则s.rad(RR)是幂零理想。

Hopenwasser理想的距离公式

在［１］中Ａ．Ｈｏｐｅｎｗａｓｓｅｒ讨论了Ｎｅｓｔ代数的一类超凝聚理想，称为Ｈｏｐｅｎｗａｓｓｅｒ理想，本文将给出这类理想的距离公式，这个结果一般化为［２］中的距离公式．特别地，我们得到了Ｎｅｓｔ代数的Ｊａｃｏｂｓｏｎ根和Ｌａｒｓｏｎ强根的距离公式．

结合环的σ-根

本文利用H—关系定义σ—根的概念,它是环的一类根的抽象与概括.文中研究了σ—根的性质,给出了下σ—根的构造.同时,以新方法解决了[1]的问题1,发展了强根、稳定根和严根的理论.

Influence of Gradient on Stability of Soil Slope Containing Roots

Abundant herbaceous and shrub roots play an important role in preventing water and soil erosion and increasing shallow slope stability. In order to make a quantitative analysis on the contribution of root system to slope stability under dif- ferent slope gradient, an unconsolidated and undrained triaxial compression test was conducted to measure the shear strengths of soil and root-soil composite in the two slopes in eastern Qinghai Province. In addition, under the protection of plant roots, the effect of gradient on stability of soil slope was investigated by limit equilibrium method. The results showed that the stability coefficient of soil slope planted with two kinds of brush was decreased with the increase in slope gradient, and the sta- bility coefficient increment of soil slope containing Atriplex canescens roots was higher than that containing Caragana korshinskii roots. When the slope gradient ranged from 25° to 50°, the stability coefficient of soil slope planted with Atriplex canescens or Caragana korshinskii ranged from 0.80 to 1.38. However, when the slope gradient exceeded 55°, the increment of stability coefficient of soil slope became small.

结合环的σ-根(Ⅱ)

结合环的一个关系σ称为H-关系,如果σ具有性质:(1)若IσR,则I≤R;(2)若IσR,φ是环R的同态,则φ(I)σφ(R);(3)若IσR,J△R,则I∩JσJ;(4)I△R,则IσR。称一个根类r是σ-根,若对任何环R,当I∈R,I∈r时,均有I_R∈r。

青梅丰产管理的几点体会

1990年至1994年间,我在1亩的自留地上栽种了青梅树30株,根据青梅树的生长特性,进行了一些丰产栽培措施的偿试,取得较为满意的效果.自1991年以来分别收获青梅果300公斤,550公斤,910公斤,1500公斤.我的主要体会有以下4点:

Effect of Freezing and Thawing on Ammonium Adsorption in Dryland Soil

[Objective] This study aimed to investigate the effect of freezing and thawing on ammonium adsorption in dryland soil. [Method] The lab simulation test was conducted to study the effect of freeze-thaw action on the total adsorbed amount of ammonium （deionized water extract） and strongly-adsorbed amount of ammonium （0.01 mol/L KCl solution extract） in the dryland soil of Sanjiang Plain. [Result] Compared with linear equation, Freundlich equation could better fit the total adsorbed amount of ammonium in dryland soil （R 2 0.99, SE1.69）. The freeze-thaw action almost had no influence on the total adsorbed amount of ammonium. When the initial concentration of NH 4 ＋ increased from 0 to 200 mg/L, the total adsorbed NH 4 ＋ amount increased from -0.52 to 39.0 mg/kg under freeze-thaw treatment （FTT）, while it increased from -0.70 to 38.5 mg/kg under unfreeze-thaw treatment （UFTT）. However, the strongly-adsorbed amount of ammonium presented linear relationship with the concentration of NH 4 ＋ （R 2 0.99, SE0.54）, and the strongly-adsorbed amount of ammonium increased significantly by FTT. When the initial concentration of NH 4 ＋ increased from 0 to 200 mg/L, the strongly adsorbed amount increased linearly from 2.36 to 28.81 mg/kg for FTT and from -4.25 to 25.12 mg/kg for UFTT. The freezethaw action decreases the concentration of NH 4 ＋ in soil solution when the net strongly-adsorbed NH 4 ＋ in soil is zero., therefore, FTT helped to reduce the leaching of ammonium ions in soil. Freeze-thaw action mainly influenced the exchangeable adsorbed NH 4 ＋ in soil. [Conclusion] This study provides theoretical basis for preventing excessive soil nitrogen from entering into water body and controlling water entrophication.

CLINICAL OBSERVATION ON TREATMENT OF NERVE-ROOT TYPE CERVICAL SPONDYLOSIS WITH ACUPUNCTURE, TRACTION PLUS SELF-EXERCISE OF QIGONG

Purpose: To observe the therapeutic effect of acupuncture combined with traction and Qigong exercise for treatment of nerve root type cervical spondylosis. Methods: A total of 130 nerve root type cervical spondylosis patients were randomly divided into acupuncture + traction + Qigong exercise (ATQE) group (n=59), acupuncture + Qigong exercise (AQE) group (n=40) and traction + Qigong exercise (TQE) group (n=31). Main acupoints used were Fengchi (GB 20) and cervical Jiaji (EX B 2) on the affected side. Results: After one month’s treatment, in ATQE, AQE and TQE groups, 43 (72.88%), 18 (45.00%) and 12 (45.16%) had remarkable amelioration, 14 (23.72%), 14 (35.00%) and 10 (32.26%) were effective, and 2 (3.39%), 8 (20.00%) and 7 (22.58%) had no apparent changes with the total effective rates being 96.61%, 80.00% and 77.41% respectively. The therapeutic effect of ATQE group was significantly superior to that of AQE and TQE groups (P<0.01).

Nitrification intensity and ammonia-oxidizing bacteria and archaea in different wetland plant rhizosphere soils

In order to explore the nitrogen removal process in constructed wetlands(CW s),the moisture,ammonia nitrogen(NH4+-N),nitrate nitrogen(NO3"-N)and nitrification intensity in three wetland plant rhizosphere soils(Acorns calamus,Typha orientalis,Iris pseudacorus)were investigated at a relatively normal temperature range of15to25The relative abundance of ammonia-oxidizing bacteria(AOB)and ammonia-oxidizing archaea(AOA)were also achieved using fluorescence in situ hybridization(FISH).It is found that T.orientalis achieves the highest nitrification intensity of2.03m g(h?kg)while the second is I.pseudacorrs(1.74m g/(h?kg)),and followed by A.calamus(1.65m g/(h?kg))throughout the experiment.FISH reveals that the abundance of bacteria(1010g_1wet soil)is higher than that of archaea(109g_1wet soil),and AOBare the dominant bacteria in the ammonia oxidation process.The abundance of AOB in te rhizosphere soils from high to low T.orientalis(1.88x1010g"1),I pseudacorus(1.23x1010g1),A.calamus(5.07x109g"1)while the abundance of AOA from high to low ae I.pseudacorus(4.00x109g1),A.calamus(3.52x109g"1),T.orientalis(3.48x109g"1).The study provides valuable evidence of plant selection for nitrogen removal in CWs.

Prediction of representative deformation modulus of longwall panel roof rock strata using Mamdani fuzzy system

Deformation modulus is the important parameter in stability analysis of tunnels, dams and mining struc- tures. In this paper, two predictive models including Mamdani fuzzy system （MFS） and multivariable regression analysis （MVRA） were developed to predict deformation modulus based on data obtained from dilatometer tests carried out in Bakhtiary dam site and additional data collected from longwall coal mines. Models inputs were considered to be rock quality designation, overburden height, weathering, unconfined compressive strength, bedding inclination to core axis, joint roughness coefficient and fill thickness. To control the models performance, calculating indices such as root mean square error （RMSE）, variance account for （VAF） and determination coefficient （R^2） were used. The MFS results show the significant prediction accuracy along with high performance compared to MVRA results. Finally, the sensitivity analysis of MFS results shows that the most and the least effective parameters on deformation modulus are weatherin~ and overburden height, respectively.

Hereditary Radicals and Strongly Semisimple Radicals in Normal Classes of Algebras

Puczylowski established the general theory of radicals of the class of objects called algebras. In this paper, we make use of the method of lattice theory to characterize the general hereditary radicals and general strongly semisimple radicals and investigate some properties of them in normal classes of algebras. This extends some known studies on the theory of radicals of various algebraic strutures.

Allocation strategies of carbon,nitrogen and phosphorus following a gradient of wildfire severities

Wildfire is crucial in the regulation of nutrient allocation during the succession of boreal forests.However,the allocation strategies of carbon(C),nitrogen(N)and phosphorus(P)between leaves and fine roots in response to wildfire severities remain poorly studied.We aimed to explore the allocation strategies of C,N and P between leaves and fine roots among different fire severities.We selected four wildfire severities(unburned,low,moderate and high severity)after 10 years recovery in the Great Xing’an Mountains,northeast China,and compared C,N and P concentrations in leaves and fine roots of all species among fire severities using stoichiometry theory and allometric growth equations.Compared with unburned treatment,C concentrations in leaves and fine roots increased at low severity,and leaf N concentration was the greatest at high severity,but the lowest fine root N concentration occurred at high severity.Plant nutrient utilization tended to be P-limited at high fire severity according to the mean value of N:P ratio>16.More importantly,C,N and P allocation strategies between fine roots and leaves changed from allometry to isometry with increasing fire severities,which showed more elements allocated to leaves than to fine roots with increasing fire severities.These changes in patterns suggest that the allocation strategies of elements between leaves and fine roots are of imbalance with the wildfire severity.This study deepens our understanding of nutrient dynamics between plant and soil in ecosystem succession.

Plant size,environmental factors and functional traits jointly shape the stem radius growth rate in an evergreen coniferous species across ontogenetic stages

Aims Plant size,environmental conditions and functional traits are important for plant growth;however,it is less clear which combination of these factors is the most effective for predicting tree growth across ontogenetic stages.Methods We selected 65 individuals of an evergreen coniferous species,Pinus koraiensis,with diameters at breast height(DBH)from 0.3 to 100 cm in Northeast China.For each individual,we measured the stem radius growth rate(SRGR,µm/year)for the current year,environmental factors(light,soil nutrient and soil water)and functional traits(leaf,branch and root traits).Important Findings SRGR increased with DBH when the DBH was lower than 58 cm,whereas it decreased with DBH when the DBH was larger than 58 cm.Structural equation modeling analysis suggested that,when the DBH was 0–15 cm,plant size had a direct negative influence on SRGR and an indirect positive influence on SRGR due to the light intensity above the plant.Plant size had direct positive and negative effects when the DBH was 16–58 cm and 59–100 cm,respectively.When the DBH was larger than 15 cm,soil parameters were more important than light intensity for SRGR.The functional traits selected for use in the best model were changed from the specific leaf area and wood density to the root nitrogen concentration with increasing tree size.In summary,plant size,environmental factors and functional traits jointly shaped tree growth,and their relative influence varied with size,suggesting that the resources limiting tree growth may change from light to soil nutrient with increasing tree size.