环的最小无幂零元根的构造

仿照Bear根的构造方法,构造环的最小无幂零元根;并给出Bear根的另一种形式。

路在脚下——记著名朝鲜族专家白元根研究员

1958年美国科学家基尔比发明世界第一块集成路,使人们多年的梦想变成现实,震撼了整个世界,类社会由此开始进入了微电子时代。当今世界,谁拥集成电路的优势,谁就会在激烈的国际竞争中拥有主动权。有人说:“海湾战争就是集成电路芯片的战争。”由此可见集成电路是何等重要,也证明了它在世界新技术革命的中心地位。

Coordination and Supramolecular Assemblies from Alkali+-Cucurbit[5]uril-[CdCl_(4)]^(2-)Systems

Thispaper has investigated the coordination and supramolecular assemblies of alkali metal ions,cucurbit[5]uril(Q[5]),and[CdCl_(4)]^(2-)to confirm whether[CdCl_(4)]^(2-)can produce the“honeycomb effect”,induce coordination of alkali metal ions to Q[5],and form linear coordination polymers.In this work,the effect of alkali metal ions on the construction of Q[5]-Cd^(2+)ion system under acidic conditions was investigated.Five complexes were successfully obtained by solvent evaporation method.Among the five crystal structures obtained,it can be observed that the presence of[CdCl_(4)]^(2-)did not result in the complexation of alkali metal ions by the Q[5]molecule.Instead,a bowl-like Cd^(2+)@Q[5]complex was formed.Indeed,[CdCl_(4)]^(2-)did not produce the honeycomb effect but led to the formation of Q[5]-based honeycomb frameworks with hexagonal cellsoccupied by[CdCl_(4)]^(2-).The experimental results show that cadmium ion showed stronger ability to coordinate to Q[5]in HCl solution.

文化气根现象与新移民文学心态——兼论澳门新移民文学中的文化气根现象

一个新移民文艺家,即便是'扎根'澳门再久、再深,他们的作品也难以真正对澳门社会文化实现'零距离'的表现。由于文化认同与心理、情感认同产生的机制不同,移民文人对于异地文化元根的表现总会有些隔膜,他们表现的文化可以描述为文化气根——一种与深入到泥土内部的文化元根并不一样。文化气根既彰明较著又相当浅显,这是移民文学家普遍的创作现象,对于澳门新移民文学而言,这是它的部分特色。

文化气根现象与新移民文学心态——兼论澳门新移民文学中的文化气根现象

一个新移民文艺家,即便是"扎根"澳门再久、再深,他们的作品也难以真正对澳门社会文化实现"零距离"的表现。由于文化认同与心理、情感认同产生的机制不同,移民文人对于异地文化元根的表现总会有些隔膜,他们表现的文化可以描述为文化气根——一种与深入到泥土内部的文化元根并不一样。文化气根既彰明较著又相当浅显,这是移民文学家普遍的创作现象,对于澳门新移民文学而言,这是它的部分特色。

Effects of Ca^(2+)concentrations on accumulations of mineral elements in the components of Pteroceltis tatarinowii

The bark of Pteroce/tis tatarinowii is a raw material for manufacturing XuanPaper. The effects of Ca^(2+) concentrations on the accumulation of mineral elements in the bark,leaf and root of Pteroceltis tatarinowii were studied under controlled conditions. The types ofHoagland nutrient solution with three Ca^(2+) concentrations levels (200, 400 and 600 μg·g^(-1))and a control (without Ca^(2+)) were designed to culture Pteroceltis tatarinowii. After 6 months,contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and barkwere analyzed. The results indicated that Ca accumulations content in the root, leaf and bark hadpositively relation with Ca^(2+) concentrations (200, 400, 600 μg · g^(-1)), and the order of theCa content in the three components was root>leaf>bark. Ca content in the root treated with 600 μg·g^(-1) Ca^(2+) concentrations was 5.5 times as high as that of the control, and about 1.4 times ashigh as that of the root treated in 200 and 400 μg/g Ca^(2+) concentrations respectively. On thecontrary, K and Mg contents in the root, leaf and bark were negatively related to Ca^(2+)concentrations, especially in the bark, and their accumulation trend followed the order ofleaf>root>bark. K content in the bark treated with 600 μg ·g^(-1) Ca^(2+) concentrations was 39.3%of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200 μg ·g^(-1)and 400 μg ·g^(-1) Ca^(2+) concentrations respectively; Mg content in the bark treated with 600μg ·g^(-1) Ca^(2+) concentrations was 23.4% of that of the control, and was 27.1% and 35.4% ofthat of the bark treated with 200 and 400 μg·g^(-1) Ca^(2+) concentrations respectively. Comparedwith the control, the general tendency of Mn, Zn and Cu content decreased with increasing of Ca^(2+)concentrations and their contents were in the order: root>leaf>bark. Based on the results of thisstudy, the experiment has been useful for providing academic bases in improving the bark quality ofPteroceltis tatarinowii on non-limestone soil.

Expression Activity of CLCuV Bidirectional Promoter in Agrobacterium tumefaciens

Cotton leaf curl virus (CLCuV) belongs to the subgroup III of geminiviruses with single strand DNA genome. Study demonstrated that the bidirectional promoter of CLCuV had activity in Agrobacterium tumefaciens (Smith et Townsend) Conn. This is the first report for the activity of the bidirectional promoter of geminivirus in A. tumefaciens. Results showed that the activity of the complementary sense promoter was stronger than that of virion sense promoter, and was detected 2-fold higher than that of CaMV 35S promoter in A. tumefaciens. Moreover, the promoter 5' deletion analysis indicated that the mean GUS activity driven by a 287 nucleotides complementary sense promoter fragment (from-287 to the translation initiation site) is 4 times higher than that driven by the whole complementary sense promoter in A. tumefaciens. This result suggested that there might exist negative regulatory elements in this deleted fragment. The function of other cis-elements included in CLCuV complementary sense promoter was also discussed in this paper.

Effects of PVP K30 on Aqueous Solubility and Dissolution Propertiesof Daidzein

AimTo study effects of PVP K30 on the aque ou s solubility and dissolution properties of daidzein. Methods To measure the aqueous solubility and dissolution rates of daidzein in three diffe rent states (within solid dispersions, physical mixtures and as a pure drug) and investigate drug-polymer interactions in the solid state using X-ray powder d iffraction and fourier-transform infrared spectroscopy. Results The negative values of the Gibbs free energy and enthalpy of transfer explaine d the spontaneous transfer of daidzein from phosphate buffer solution (PBS) to a solution of PVP in PBS. X-ray powder diffraction patterns showed that the drug was in the amorphous state (ratio of the drug ∶ PVP<1∶5) when dispers ed i n PVP K30. The infrared spectra indicated there exist interactions between the O H of daidzein and the C=O of PVP K30. Conclusionthe dispersion of daidzein in PVP K30 considerably enhances the solubility and dissolution rat e.

中高水头水轮机机型选择及参数设计

以四川省甘孜州九龙县元根一级水电站的水轮机机型选择及参数设计为例,从投资、制造难度、运行稳定性及维护等各方面,对冲击式水轮机和混流式水轮机进行了比较。参考目前该水头段内的机型应用情况,最终选择了混流式水轮机,并对选定的最佳水轮机主要技术参数进行了设计计算。

Nutrient characteristics in rhizosphere of pure and mixed plantations of Manchur ian walnut and Dahurian larch

A comparison study was made for the characteristics of pH value, orga nic matter content, nutrient element N, P and K contents in rhizosphere soils of pure and mixed plantations of Manchurian walnut and Dahurian larch and in bulk soils. The results show that the pH values of rhizosphere soil for all the plant ations except the pure walnut stand, which was slightly higher, were lower than those of bulk soils, while the organic matter contents in the rhizosphere soil f or all the plantations except the mixed plantation, which was slightly lower, we re higher than that in bulk soil. There exists a relative nitrogen accumulation in the rhizosphere and the extent to which the nitrogen accumulates is closely r elated to tree species and mixed pattern. As far as the total P and K contents a re considered, there exists a deficient tendency in rhizosphere in comparison wi th bulk soil. The element N, P and K are all mobilized in the rhizosphere of the pure or mixed plantation, characterized by the higher contents of the available N, P and K in the rhizosphere. The available N content in the rhizosphere of th e larch in mixed plantation was obviously higher than that of its pure plantatio n, whereas the available P and K contents in the rhizosphere of walnut in the mi xed plantation, on the other hand, were significantly higher than those of its p ure plantation.

The rhizosphere pH change of Pinus koraiensis seedlings as affected by N sources of different levels and its effect on the availability and uptake of Fe, Mn, Cu and Zn

Dark brown forest soil was collected from the upper 20 cm soil layer in Changbai Mountain Research Station of Ecosystem, Chinese Academy of Sciences. The soil was amended with two different forms of nitrogen fertilizers: NO3- as Ca(NO3)2, NH4+ as NH4Cl at the concentrations of 50, 100, 200 and 400 mgkg-1 respectively. The experiment was carried out with 2-yr-old Pinus koraiensis seedlings in pot. The pH change of rhizosphere soil and the contents of available Fe, Mn, Cu, and Zn in soil and leaves were analyzed. The result indicated that the addition of NH4--N decreased the rhizosphere pH value, while the addition of NO3--N increased the rhizosphere pH value in contrast with the control treatment. The direction and extent of the pH change mainly depended on N source and its concentrations applied. The rhizosphere pH change had a remarkable influence on the availability of the micronutrients in the rhizosphere, and thereafter affected the nutrient uptake by the seedlings. The contents of available mineral nutrients had a negative correlation with the pH value in the rhizosphere soil. The contents of available mineral nutrients in leaves were positively correlated to the levels of the available nutrients in the rhizosphere soils.

立足生本观念,注重学生发展——语文生态课实践

所谓＂生态＂即和谐、自然。而打造语文的生态课堂,实际上是营造开放、平等、和谐的课堂环境,帮助学生在语文学习的过程中,发现美好,提升自我。构建注重生命成长的生态化课堂,给学生一双自由思维的翅膀,做到导入重趣味,预设有空间,对话多层次,设题开放性,真正为提升学生的能力而提供助力。

割菜子儿

星期天早上,我跟爷爷、奶奶一起去割菜子儿。沉甸甸的菜子儿压弯了菜秆,狭长的果实在阳光的照耀下黄灿灿、亮闪闪的,子粒饱满得快要蹦出来似的。因为是第一次下地,我早已抑制不住内心的激动,拿起一把大镰刀,迅即“尉刷刷”地左一撇右一捺,乱砍一通。可是,非但没砍下几根菜秆,

江西省人民政府关于黄富华等同志职务任免的通知

赣府字[2016]24号2016年2月29日各市、县(区)人民政府,省政府各部门:经省人民政府研究决定,任命:黄富华为省质量技术监督局副局长(试用期一年)。免去:左银宝的省工业和信息化委员会副巡视员职务;

Microwave digestion polarography for determining seven trace elements in Salvia Miltiorrhiza Root and compound Salvia Miltiorrhiza Root injection simultaneously

The sensitive second derivative waves of Cu(Ⅱ),Pb(Ⅱ),Cd(Ⅱ),Ni(Ⅱ),Zn(Ⅱ),Fe(Ⅱ)and Mn(Ⅱ),forming in the substrate solution(pH=9.26)consisting of ammonia,ammonium chlorid,gelatin and ascorbic acid were researched.The peak potentials of the polarographic waves of the seven ions are at about 0.48,0.63,0.79,1.04,1.28,1.44 and 1.60 V respectively.Combining with microwave technique,a new method for the simultaneous determination of the seven trace elements in Chinese traditional medicine was developed.The method is easy to operate,rapid,simple and convenient.When the signal-to-noise rate equals 3,the detection limits of Cu,Pb,Cd,Ni,Zn,Fe and Mn are 4.2×10 3,5.3×10 3,2.1×10 3,5.8×10 4,3.0×10 3,7.7×10 4 and 1.1×10 3 μg/mL respectively.Well linear relationships exist between the concentrations and the peak currents when Cu,Pb,Cd,Ni,Zn,Fe and Mn concentrations are within 8.5×10 3 10,9.7×10 3 10,4.5×10 3 10,1.2×10 3 10,6.4×10 3 10,1.5×10 3 10 and 2.8×10 3 10 μg/mL,respectively.The method has been used to the simultaneous determination of the seven trace elements in Salvia Miltiorrhiza Root and compound Salvia Miltiorrhiza Root injection,the relative standard deviations(RSDs)of the Cu,Pb,Cd,Ni,Zn,Fe and Mn in the two medicines are 3.9% and 5.8%,4.0% and 4.1%,4.3% and 5.7%,4.9% and 5.3%,4.4% and 4.7%,3.5% and 4.0%,0.51% and 2.8%,respectively;the comparisons of the determination results with the values obtained by the standard method indicate that the presented method has very well veracity.

Organic matter contribution to soil fertility improvement and maintenance in red Alder (Alnus rubra) silvopastoral systems

An investigation was conducted to quantify fine roots and roots nodules over the four seasons in forestry and agroforestry alder （Alnus rubra） stands in North Wales. Soil samples collected in each season were excavated at three sampling points （0.30 m, 0.57 m and 1.00 m distance from the base of each tree） from nine trees of the agroforestry and forestry plots. Result showed that the density of live fine root had significant differences in between seasons and treatments （P 〈 0.001）. The mean weight density of live fine root over the four seasons in agroforestry and forestry was 0.27±0.01 kg·m^-3 and 0.54±0.03 kg·m^-3, respectively. Weight density of dead root in each system remained constant throughout the year. The mean weight density of dead root was also significantly different （P 〈 0.01） between forestry and agroforestry systems. Weight density of live and dead root nodule was both constant throughout the year and between the different sampling distances. The mean weight densities of live and dead root nodule over the four seasons were 0.09±0.03 kg·m^-3 and 0.05±0.03 kg·m^-3 in agroforestry and 0.08±0.02 kg·m^-3 and 0.03±0.01 kg·m^-3 in the forestry plots, respectively.

Enhancement of NH_4^+ Uptake by NO_3^- in Relation to Expression of Nitrate-Induced Genes in Rice (Oryza sativa) Roots

This study aimed to survey the expression of genes involved in rice N uptake and aasimilatory network and to understand the potential molecular mechanisms responsible for the NO3^-enhanced NH4^＋ uptake. By using quantitative real-time polymerase chain reaction （PCR）, the genes related to N nutrition, including ammonium transporters （AMTs） and ammonium assimilatory enzymes （GS and GOGAT）, were transcriptionally analyzed in rice plants grown in the absence and presence of NO4^- in the NH4^＋-containing medium. The results showed that NH4^＋ uptake by rice was enhanced by the NO3^- supply to the medium. At the same time and in parallel, the amount of transcripts of seven genes （OsAMT1;1, OsAMT1;2, OsAMT4;1, OsGLNP, OsGLU1, OsGLT1, and OsGLTP） was increased in rice roots, but the expression of two genes （OsGLN1;1 and OsGLN1;P） was decreased and that of OsAMT1;3 remained without change. Up- or downregulation of these genes involved in NH4^＋ uptake and assimilation correlated with the increase in NH4^＋ uptake in the presence of NO3^- in rice roots.

Behaviour of Potassium and Trace Elements in Rhizosphere of Flue-Cured Tobacco (Nicotiana Tabacum L.)

The study on the behaviourof potassium, phosphate and trace elements, Fe, Mn, Cu and Zn, in the rhizosphere of different varieties of flue-cured tobacco (Nicotiana tabacum L.) with high and low potassium application rate with rhizobag technique showed that soil available K, soil available P, and slow available K was in depletion status, whereas DTPA extractable Fe, Mn, Zn and Cu accumulated obviously in rhizosphere. The depletion and accumulation rates of mineral nutrients differed in degree with K application rate, soil type, and tobacco variety. The content of a vailable K in both rhizosphere and bulk soil and K concentration in tobacco leaf increased significantly, and the available P in rhizosphere dropped with more K applicatin. The DTPA-Fe content of red soil much lower in pH was higher than that of calcareous soil in bulk soil. But the DTPA-Fe content of calcareous soil was much higher than that of red soil in rhizosphere, which was considered perhaps to be mainly related to releasing of Fe phytosiderophore. Nitrate could increase depletion of available K in rhizosphere and also soil pH in comparison with ammonium.

Some Notes on the Positive Definite Problem of a Binary Quartic Form

In this paper, we discuss the positive definite problem of a binary quartic form and obtain a necessary and sufficient condition. In addition we give two examples to show that there are some errors in the paper [1].