长寿县袁天奇积发展蚕桑致富

长寿县云集镇石堡村农户袁天奇充分挖掘土地潜力,积极育苗栽桑、养蚕,精心管理,短短几年时间成为长寿县闻名的最大养蚕专业户。1994年养蚕37张,生产蚕茧1418公斤,收入1万1千多元,全家人平蚕茧收入近2千元。 袁天奇富裕了。可是,他没有忘记周围的乡亲们。他家所处的四角头社,45户农民在他的帮助指导下,该社有41户调整产业结构,栽密桑园20多亩,94年养春蚕一季就收入2万多元,该社蚕农户平增收487.8元。该社94年仅养蚕一项就可增收5万余元。科学养蚕致富奔小康,已成为四角头社的一大经济支柱。

一些国外微积分教材的特色分析

对国外使用面比较广,知名度比较高的几部微积分教材进行了分析研究,考察了他们在结构体系、内容安排、概念引入以及理论应用等方面的特色和独到之处,为国内高等数学教学改革和教材建设提供了借鉴和参考.

广义Sugeno模糊积分的次线性性

在给定的K-拟可加模糊测度空间上,借助于引进新拟乘法算子""给出了广义Sugeno模糊积分定义,依据拟加法和拟乘法定义及运算性质,研究了这种广义Sugeno模糊积分的次可加性乃至次线性性,从而进一步丰富了模糊积分的理论。

Riemann积分与Lebesgue积分的本质区别

指出Riemann积分与Lebesgue积分的本质区别在于:区间[a,b]上所有Riemann可积函数所生成的空间是不完备的,而所有Lebesgue可积函数所生成的空间是完备的．

桂平航运枢纽水力发电首次突破一亿度大关

最近,广西桂平航运枢纽水力发电厂传出喜讯,今年上半年发电量超额26.5％完成半年度的生产计划,创历史最好水平。截止6月30日止,上半年累积发电12240.2万度,上网电量11740.7万度。上网电量占年度生产计划的76.5％。这是自1992年2月设电厂的三台发电机组全部投入运行以来,首次在半年时间的发电生产中,发电量突破一亿度大关。

轨道数值改进求解土星的质量和形状参数

采用Gauss-Jackson法数值积分Iapetus和Titan轨道,并选用1111个Iapetus-Titan星对的照相观测拟合轨道以求改进自由参数。土星的质量M_(sa)和形状参数J_2作为自由参数参加求解,归算得:M_(sa)=(2.858806±0.00014)10^(-4)(太阳质量),J_2=0.016118±0.00063,与其他学者的结果比较表明,这些由单个星对归算出的值与IAU(1976)推荐值相比尽管有一定差异,但仍在合理值允许范围内。

Effects of Nitrogen,Phosphorus and Potassium Application on Growth and Dry Matter Accumulation in Mulberry

In this paper, the effect of different fertilizer treatments on the main indexes of growth and development and dry matter accumulation of perennial mulberry, which is cut and pruned in summer, were studied with ‘3414’ field experiment design. The results showed that N, P, and K at proper amounts could promote mulberry growth and development, improve its dry matter content, increase its dry matter accumulation. The effects of N, P, K on leaf yield per plant were respectively expressed as follows： N2 N3 N1 N0 , P2 P1 P3 P0 , K2 K1 K3 K0 . It can be concluded that the recommended fertilizer amounts of dry matter accumulations in mulberry leaf were 694.36 kg/hm2 of N, 198.15 kg/hm2 of P, and 274.26 kg/hm2 of K and the dry matter achieved the maximum at 8 045.04 kg/hm2 . The recommended fertilizer amounts of accumulated dry matter in branch were 1 000.05 kg/hm2 of N, 242.04 kg/hm2 of P, and 218.01 kg/hm 2 of K, and the dry matter achieved the maximum at 5 969.05 kg/hm2 . The recommended fertilizer amount in young shoots were 883.76 kg/hm2 of N, 204.48 kg/hm2 of P and 426.59 kg/hm2 of K and dry matter achieved the maximum at 1 410.24 kg/hm2 . This paper could provide reference for the construction of highly-qualified mulberry field in Sichuan hilly area.

Preliminary Observation on Embryonic Development of Leiocassis crassilabris

[Objective] This study aimed to observe the embryonic development process of Leiocassis crassilabris. [Method] Wild L. crassilabris collected from the Nanjing section of the Yangtze River was used as parent fish for intensive breeding and propagation by artificial insemination. The entire embryonic development process of L. crassilabris from insemination to hatching out of larvae fish was observed consecutively. [Result] Fertilized eggs of L. crassilabris are spherical, and the egg diameter is about 2.2-2.4 mm after water absorption; under conditions of water temperature ranging from 27 to 28 ℃, the embryonic development of L. crassilabris from insemination to hatching out of larvae fish lasted 2 496 min, with a total accumulated temperature of 1 123-1 165 h·℃. [Conclusion] This study is advantageous to better understand the characteristics of embryonic development of L. crassilabris and provides basic biological data for protection and utilization of fish resources and other related work.

Relationship between Rice Planthopper Occurrence Area in China and Atmospheric Circulation Indices

[Objective] This study aimed to establish models based on atmospheric cir- culation indices for forecasting the area attacked by rice planthopper every year, and to provide guide for preventing and controlling planthopper damage. [Method] The data related to rice planthopper occurrence and atmospheric circulation were collected and analyzed with the method of stepwise regression to establish the prediction models. [Result] The factors significantly related to the area attacked by rice plan-thopper were selected. Two types of prediction models were established. One was for Sogatella furcifera （Horvath）, based on Atlantic-Europe circulation pattern W in October in that year, Pacific polar vortex area index in October in that year, North America subtropical high index in August in that year, Atlantic-Europe circulation pattern W in June in that year, northern boundary of North America subtropical high in February in that year, Atlantic-Europe polar vortex intensity index in October in that year and Asia polar vortex intensity index in November in the last year; the other type of prediction models were for Nilaparvata lugens （Stal）, based on the Eastern Pacific subtropical high intensity index in July in that year, northern hemi- sphere polar vortex area index in October in the last year, Asia polar vortex strength index in November in the last year, north boundary of North America-At- lantic subtropical high in September in that year, north boundary of North Africa-At- lantic-North America subtropical high in January in that year, sunspot in September of the last year and eastern Pacific subtropical high area index in September in that year. [Conclusion] With the stepwise regression, the forecasting equations of the rice planthopper occurrence established based on the atmospheric circulation indices could be used for actual forecast.

爱,一直在路上

每一个学生背后都是一个家庭,对每一个学生负责就是对千千万万个家庭负责,就是对祖国的未来尽责。要让学生相信生命因爱产生无尽的力量,每一个生命奋斗的过程也会因爱变得精彩,这就是曲建武老师在平淡中坚守的初衷。他真诚宽厚地爱着每一个学生,坚定而执着地追寻着作为一名普通教师的幸福。《北齐书·王昕书》中有句话,叫做＂以为人之师表＂。黑发积霜却充满正能量的曲老师身为世范、为人师表,走进了每一个学生的内心深处,为他们指明了方向。

Effect of Different Treatments on the Germination and Seedling Growth of Firmiana simplex

With Firmiana simplex （L.） W. F. Wight as an experiment material, the effects of different concentrations of GA3 （Gibberellin A3）, SA （Salicylic acid） and NAA （1-Naphthalene acetic acid） and stratification on the germination rate of seeds were studied firstly, and then the effects of GA3 and NAA on seedling growth were analyzed. The results showed that the germination rate could be improved by 0.075 g/L SA and stratification markedly. It was indicated by the experiment that the growth of the main root and main stem could be promoted by 0.050 g/L and 0.077 g/L NAA, respectively. However, the leaf length and leaf width decreased significantly in the GA3 and NAA treatments.

Ag Deposition Forms and Uniformity on Porous Silicon by Electrochemical Method

The electrochemical deposition technique was applied to achieve porous silicon （PS） surface passivated with Ag deposition for improving the properties of PS photoluminescence. The relation of Ag depositing forms to current density and the effect of PS hydrophilic surface on deposition uniformity were investigated. The experimental results indicated that there were two critical current densities （maximum and minimum） in which Ag was absent and electroplated on PS surface correspondingly, and the range of current density for deposition of Ag on porous silicon was from 50 μA/cm^2 to 400 μA/cm^2. The process of changing PS surface from hydrophobic into hydrophilic had positive effect on Ag deposition uniformity. Under the same experimental conditions, PS hydrophobic surface presented uneven Ag deposition.However, hydrophilic surface treated with SC-1 solution was even. Finally, the effect of PS surface passivation with Ag even deposition on photoluminescence intensity and stabilization of PS was studied. It was discovered that Ag passivation inhibited the degradation of PL intensity effectively. In addition, excessive Ag deposition had a quenching effect on room-temperature visible photoluminescence of PS.

Synthesis and Photoluminescence of Amorphous Silicon Oxycarbide Nanowires

Synthesis of amorphous SiCO nanowires was carried out by means of direct current are discharge. Free-standing SiCO nanowires were deposited on the surface of a graphite crucible without any catalyst and template. The SiCO nanowires were analyzed by XRD, SEM, TEM, XPS, and FTIR. The SiCO nanowires were typically 20-100 gm in length and 10-100 nm in diameter as measured by SEM and TEM. The XPS and FTIR spectroscopy analysis confirmed that the Si atoms share bonds with O and C atoms in mixed SiCO units. The PL spectrum of the SiCO nanowires showed strong and stable white emissions at 454 and 540 nm. A plasma-assisted vapor-solid growth mechanism is proposed to be responsible for the formation of the SiCO nanowires.

Effects of Transplanting Nutrient Soil on Growth and Dry Matter Accumulation of Tobacco Seedlings

In order to select the suitable soil for transplanting tobacco in Hunan to- bacco growing areas, pot experiment was conducted to study the effects of different transplanting nutdent soils on the growth and dry matter accumulation of tobacco. The results indicated that the treatments of transplanting with nutrition soils were better than the control group. For the underground part, transplanting nutrient soil could effectively improve the root activity of tobacco plants, and increase root volume, root surface area, total root length, as well as the number of root tips and the number of root branches. For the aboveground part, transplanting nutrient soil could remarkably improve the plant height, stem girth, leaf number and maximum leaf area, and could simultaneously significantly increase the dry matter accumulation. By comparison, peat ＋ mushroom residue ＋ saw dust ＋ straw powder ＋ bicchar ＋ root promoting nutrient solution was the most effective treatment, and the effect of sole application of nutrient solution was limited. In conclusion, transplanting with nutrition soil could effectively promote the growth and dry matter accumulation of tobacco.

Importance of Percutaneous Radiofrequency Ablation for Recurrent Hepatocellular Carcinoma

Objective: To study the importance of percutaneous radiofrequency ablation (PRFA) guided by ultrasound for inoperable recurrent hepatocellular carcinoma.Methods: Forty-seven patients with inoperable recurrent hepatocellular carcinoma underwent percutaneous radiofrequency ablation (PRFA) under ultrasond between October 1999 and July 2001. Twenty-four patients had single recurrent tumor and 23 patients had multiple lesions. Twelve patients had single lesion with less than 3.5 cm in diameter. All patients were followed up to examine the value of AFP, MRI or CT after PRFA. Kaplan-Meier estimation was used to analyze the survival rate.Results: The 1-, 2- and 3-year survival rate in single lesion group was 65.2%, 37.5% and 37.5% respectively. The survival rate of 1 and 2 years was 41.7% and 19.5% in the multiple lesions group. The 1-, 2-and 3-year survival rate in single lesion groups with less than 3.5 cm in diameter was 83.3%, 51.4% and 51.4% respectively.Conclusion: PRFA is one of the important comprehensive methods for recurrent hepatocellular carcinoma. According to the size, number and recurrent time, PRFA can be performed separately or combined with transcatheter arterial chemoembolization for inoperable recurrent hepatocellular carcinoma. This method can control the recurrence and increase the survival rate effectively. Key words recurrence - hepatocellular cacinoma - radiofrequency ablation

Complications and treatment of migrated biliary endoprostheses:A review of the literature

Endoscopic biliary stent insertion is a well-established procedure. It is especially successful in treating postoperative biliary leaks, and may prevent surgical intervention. A routine change of endoprostheses after 3 mo is a common practice but this can be prolonged to 6 too. We reported a colonic perforation due to biliary stent dislocation and migration to the rectosigmoid colon, and reviewed the literature.