Selection, propagation and cultivation of Pinus massoniana clones for pulp use

Based on the growth, wood property of the ortets, and rooting abilities of cuttings, 32 Pinus massoniana clones for pulp use were selected from forests of superior provenance, mixed families, and progeny test of seed orchard by two-step selection. The average height and DBH growth of three-year-old clones were 28.6% and 16.7%, respectively, higher than those from seedlings, and average gain of wood density reached 8.7%. Rooting rate of all these clones was over 80%, 28% higher than the clones selected by a single step. A cutting orchard of 0.33 hm² on the hillside was constructed to intensively produce cuttings according to the tests on construction methods, pruning, and fertilization. A total of 50,000 grade I, 37,500 grade II, and 62,500 grade III cuttings were collected per hectare of this cutting orchard each time, and were cut three times each year. With all the above techniques, 48 hm² of clonal forests for pulp use of those clones had been planted in five places in Fujian Province. Container stecklings are more likely to increase the planting survival rate. __________ Translated from Scientia Silvae Sinicae, 2004, 40(1): 64–69 [译自: 林业科学]     

不同年限毛竹—灵芝复合系统土壤质量评价

研究以不同年限(0 a、1 a和2 a)毛竹—灵芝复合系统为对象,对比分析灵芝不同种植年限的毛竹林土壤理化性质、酶活性等17个土壤质量指标的差异,并基于主成分分析对其土壤质量进行评价,旨在为毛竹林下种植灵芝提供参考。结果表明：随着灵芝种植年限的延长,毛竹林土壤含水率、孔隙度和通气度呈先升高后降低的变化趋势,而土壤容重呈先降低后升高的变化趋势;土壤pH值随种植年限的延长逐渐升高,有利于缓解土壤酸化;土壤有机质、全氮、全磷、全钾、速效养分含量和土壤酶活性均随种植年限的延长呈逐渐升高的变化趋势,且种植2 a显著高于0 a(P<0.05)。综合分析土壤理化性质以及酶活性等指标,毛竹林下种植灵芝后,其土壤质量指数均显著高于未种植的毛竹林地,且随种植年限的延长逐渐升高,说明灵芝种植有利于提高毛竹林地土壤质量。     

农机购置补贴“三合一”,让补贴更高效便捷

2020年1月5日,北京市农业农村局印发了《北京市农机购置补贴“三合一”试点方案》,预示着农机购置补贴申补方式改革又向前推进了一步,对提高农机购置补贴管理工作效率和科学性具有重要意义,使农户真正受益,国家的惠农政策发挥实效.     

Dynamic expression of thioredoxin 2 in myocardial mitochondria in selenium-deficiency rats during myocardial injury

AIM: To investigate the dynamic expression of thioredoxin 2 (Trx2) protein in the myocardial mitochondria under the condition of selenium deficiency. METHODS: A model of selenium deficiency was made using two-week-old SD rats. When the rats were fed for 20 weeks, 30 weeks and 40 weeks, the cardiac functions were detected by carotid artery intubation. The myocardial mitochondria were also extracted, and the protein expression of mitochondrial Trx2 was measured by Western blotting. The method of immunohistochemistry was used to detect Fas-associated death domain protein (FADD,a death marker protein) for determining the apoptosis of myocardial cells. The correlation between Trx2 and left ventricular systolic pressure (LVSP), maximum rate of left ventricular pressure rise(+dp/dtmax) and apoptotic index of the myocardial cells was analyzed. RESULTS: Compared with the corresponding period of normal control group, the expression of Trx2 protein in the selenium-deficiency rats was reduced. The expression of Trx2 protein was continuously reduced as the time of selenium deficiency prolonged. As the time of low-selenium feeding was going on, the systolic and diastolic functions of the heart were impaired, and the number of apoptotic myocardial cells was increased. The correlation analysis indicated that Trx2 had positive correlations with LVSP and +dp/dtmax, and had a negative correlation with the apoptotic index of myocardial cells. CONCLUSION: Selenium deficiency affects the expression of Trx2 protein,and causes impaired cardiac functions and the apoptosis of myocardial cells. Trx2 has a protective effect on myocardial cells.     

除湿机降低小麦面层水分的试验

利用除湿机降低粮仓内小麦的面层水分含量,可将其降至安全水分范围,且前期除湿效率显著高于后期。对小麦面层水分含量与仓内相对湿度做相关性分析,发现二者存在良好的线性关系(R2>0.9),在知道其中一个变量的情况下,可通过回归方程对另一个变量进行预测。通过对传统除湿和除湿机除湿的成本进行比较,发现利用除湿机除湿不仅可以降低成本,还能降低工作强度,提高工作效率。     

Model of Information Integrating in CIMS Based on the Object-oriented Method

Information integrating is the most important key to CIMS,which is the base of the function integrating and all others.Because of so many kinds,so complicated structure,so many different sources and uses that the information in CIMS has,it is necessary to build a popular Information Integrating Model. The model of information integrating in the thesis bases on the enterprise model,which is presented by ISO(International Organization for Standardization).According to the object-oriented method,the process of modeling begins with classifying the information,and then describes the definition of the attributes and the structural relation of those objects. By means of the idea of Encapsulation and Inheritance,the destination of information integrating can be arrive and the model of information integrating can be set up. The model which is based on the share information is helpful to finish the function integrating and the whole CIMS' construction. Moreover,the system which is developed following such program can be reused for many times and the developing circle of CIMS can be apparently shortened,too.     

土壤水分胁迫对冬小麦耗水规律及产量的影响

在温定盆栽和池栽防雨旱棚条件下，研究了土壤水胁迫对冬小麦耗水规律及产量的影响，结果表明，随土壤水分胁迫加剧，干物质积累减少，子粒千物质来自贮藏同化物的比例上升，产量下降，产量构成三因子中穗粒数，亩穗数下降均极显著，而千粒重下降较少，随水分胁迫加剧，拔节前耗水量占总耗水量的比率增高，从播种到拔节期，耗水量占总耗水量的比例愈高，拔节后植株衰老死亡愈早，产量降低就愈大，中度水分胁迫下，虽然水分生产率和经     

不同作物对VA菌根真菌的依赖性差异

以玉米、 小麦、 大豆、 三叶草四种作物为试材, 在低和高两个施磷水平下接种或 不接种泡囊-丛枝菌根真菌(VAMF), 研究不同作物的菌根依赖性及其影响因子。 结果表明 , 接种菌根真菌显著地促进了玉米、 大豆、 三叶草的生长, 但小麦无此效果, 菌根依 赖性的大小顺序为玉米＞大豆＞三叶草＞小麦。 菌根真菌提高作物的叶绿     

Real Time Economic Load burdening Method of the Regulating Peak Load about the Boiler Units of Power Plant

Basing on the combing the Equivalent Differential Increment Theory(EDIT) with the Equivalent Polyhedron Method(EPM),the optimum real time economical adjustment of regulating peak load for each boiler about power plant is presented. The results are applying in the site and the economical benefit is increased obviously. The method is simply,and cuts the time.     

抛秧水稻生长发育与产量形成的生态生理机制——I．活棵立苗及其生态生理特点

针对抛秧持有的秧苗直立过程，以洗根手插为对照，研究了抛秧稻活棵立苗及其生理生态特点。结果表明，抛秧稻带土秧苗抛后，平躺小苗、中苗、大苗一般分别在2－5、5－6、7－10天内直立。在活棵立苗期间抛秧稻苗体内水分、养分及肖合等状况明显优于同质洗根手插苗。根、叶、蘖等生长在数量、质量上也优于同质洗根手插苗。抛秧稻缓苗恢复的先后顺序为发根、出叶速度加快，体内养分含有率及干物重的递增。秧苗素质、苗龄、带土状况、苗姿以及水、温等一些内外因素均对抛秧稻活棵立苗有不同程度的间接或直接影响。