法律基础课教学内容与形式的优化

法律基础课教学是培养学生法律素质的重要途径,为了增强教学实效,就必须从教学内容与教学形式的优化两方面入手进行了探究,不断更新教学内容,完善和优化教学形式.     

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es and application of several major assessment methods,including assessment of the major components,assessment of hierarchical levels,assessment of coefficients of functional efficiency,holistic analysis and judgment and assessment based on compari     

省级重点实验室筹建策略探讨 ——以河北省作物生长调控重点实验室建设为例

以河北农业大学建设河北省作物生长调控重点实验室的过程为例，论述了高等农业院校在省部级重点实验室建设过程中的缘起、发展和确立，并就实验室建设过程中遇到的相关问题进行了初步分析，提出在资源稀缺条件下建设服务三农和适应市场经济发展的省级重点实验室的思路和策略     

黑龙江春玉米种植区高产品种籽粒灌浆、脱水特性及产量分析

为了研究不同高产玉米品种在黑龙江春玉米区种植的可行性,以‘先玉335’和‘郑单958’为试材,通过对比分析,探讨2个品种在该地区种植的灌浆和脱水特性。结果表明,‘先玉335’灌浆迅速,生理性脱水快,产量高;‘郑单958’灌浆持续期略长,前期和中期灌浆速率较‘先玉335’慢,但后期灌浆速率和自然性脱水速率都快,产量较高。从气温和降雨特点来看,在黑龙江春玉米种植区部分积温较高地区,可考虑将‘郑单958’作为品种更替及多样化的备选材料。     

利用GPS进行切沟侵蚀监测研究

切沟侵蚀在土壤侵蚀中占据重要位置,切沟侵蚀监测研究是切沟侵蚀研究的重要方面。目前进行切沟侵蚀监测研究主要利用摄影测量的方法,该方法存在一定的局限性。对利用GPS进行切沟侵蚀监测研究进行了探讨,对切沟在不同时间进行测量,获得多个时相的DEM,通过对比不同时相的DEM来获取该时间段的切沟侵蚀变化。最后以位于黑龙江省漫川漫岗黑土区的丰产电流域的一条切沟为研究实例,建立了2002,2003年10月两个时段分辨率为0.4 m的DEM,对比这两个时段的数据表明,该切沟沟头后退达13.78 m,侵蚀面积增大了711m~2,切沟的土壤侵蚀量增加了2377 m~3,展示了GPS在切沟侵蚀研究中精度高、速度快等优越性,可为切沟侵蚀监测研究提供参考。     

Prognosis of Methane Formation by River Sediments (9 pp)

Background   Under anoxic conditions typically prevailing in disposal sites for dredged sediment, methanogenesis is the terminal step during microbial degradation of sediment organic matter. Sediment gas production may pose several problems to site management and post-closure utilisation. Depending on the magnitude of gas/methane formation and the intended utilisation of the site, countermeasures will have to be effected during and after deposition of the dredged material. For this purpose it may be of interest to pre-estimate the extent of gas formation from simple sediment variables. Therefore, the aim of the investigations presented here was to analyse the interrelations between gas formation and sediment physical, chemical and biological qualities. Methods   Freshly sampled riverbed sediment from nine German federal waterways was analysed for standard solid physical and chemical parameters, pore water composition, cell counts of methanogenic and sulfate-reducing bacteria, and gas formation over a period of 500 days. Particle size and density fractionation were carried out in order to characterise organic matter quality. Correlations between methane formation and sediment chemical, physical and microbiological characteristics were tested using linear and multiple correlation analysis. Results and Discussion   The selected sediments, including two with marine influence, differed strongly regarding texture, chemical parameters, pore water composition, and methanogen cell counts. The course of methane formation was found to follow distinct phases. The commencement of methane formation was preceded by a lag phase of variable duration. The lag phase was followed by a strong increase of the methane formation rate up to a sediment-characteristic maximum of 5–30 nmol CH4 h–1 g dw–1. Eventually, the rate of methane formation decreased and reached a more stable, long-term level. The extent and amplitude of each phase varied strongly between sediments and could be correlated well with only a few standard analytical parameters, despite the strong heterogeneity of sediment with respect to chemical, physical, and biological characteristics. Lag phase duration depended strongly on the content of inorganic electron acceptors and also on the number of methanogens present at the beginning of the experiment. Maximum and steady state methanogenesis were mainly determined by sediment total nitrogen. As analysis of sediment density fractions revealed that total nitrogen reflected the share of readily degradable macroorganic matter. Conclusion and Outlook   The results imply that the observed methane formation is a function of the temporally changing balance of the availability of electron acceptors and H2, and the share of easily degradable organic matter. For fresh riverbed sediments, the latter may be deduced from total nitrogen content. Overall, the results showed that methane formation by freshly dredged material may well be pre-estimated from standard analytical data within the first few years of deposition. However, the differently degradable organic matter pools will change over time with respect to size, chemical nature and association with the sediment mineral phase. It can thus be expected that the correlations found in this study will not be readily transferable to older materials. Further studies on the gas formation and organic matter quality by older sediments, e.g. from older dredged material disposal sites of known age, should be conducted and results should be combined with existing organic matter degradation models in order to improve the prediction of sediment gas formation over time.     

解决长江流域尖锐矛盾的决策和办法

整个长江流域,是上游和支流水能资源丰沛,而下游和干流地区的电力奇缺。地处长江上游的四川境内,水能资源虽得天独厚,但供电不足。解决这个尖锐矛盾:第一、必须把东部经济发展和西部能源开发紧密结合,同步进行,做到互相依存、互相支持、互相促进;第二、必须按系统工程的原理办事,先上游,后下游,先支流,后干流,切不可与此相反;第三、必须首先开发长江上游和支流的水能资源,使我国西部广大“老少边穷”地区脱贫致富,成为全国的战略后方;第四、必须抓紧建设长江上游和支流的蓄水工程,促使现有电站挖潜改造,彻底解决全流域和毗邻地区冬季缺电的迫切问题。保证这些决策顺利实现:1、要坚决实行大中小水电并举的方针;2、要坚决搞流域规划,实行梯级开发;3、要在开发长江上游水能资源的同时,尽快把四川省建成长江水源涵养林基地;4、要千方百计搞活经济,广开财路,为四川水电建设筹集资金。     

岷江上游23年生油松纯林下凋落物与土壤截留降水的效应

为了评价人工林下凋落物与土壤截留降水的能力,定位监测和分析了岷江上游23年生人工油松纯林下凋落物层和土壤层对65次降水事件的截留与分配过程。结果表明,65次林外降水总量为400.9 mm,其中208.726mm以穿透雨、33.388 mm以树干茎流进入林地,凋落物层、土壤层分别截留25.695,214.375 mm,截留率分别是6.41％,53.47％。但林外降水量<0.3 mm时,不产生林内降水,凋落物与土壤层不能截留降水。在0.3～10 mm降水范围内,土壤截留量随着降水增大呈增加趋势,而凋落物层截留率先增后减,但降水量>10 mm后,土壤截留率逐渐趋于稳定,呈较小波动(63.46％～73.58％),而凋落物截留率趋于稳定,并略有下降趋势;土壤截留量与林内外降水量、土壤截留量与茎流量均呈显著线性相关关系。综合分析表明,人工油松林凋落物层和土壤层对降水均有一定的拦蓄截留效应,其中:土壤层>凋落物层,土壤层的截留量达同期林外降水量的1/2以上。     

CO_2浓度、氮素和水分对春小麦碳素固定的影响

试验设350μmolmol-1和700μmolmol-12种CO2浓度水平,湿润、干旱2种水分处理和施N0、50、100、150和200mgkg-15个水平。结果表明,CO2浓度增加,春小麦地上部碳固定量和碳固定总量均增加,但与氮肥施用水平有关。在中氮和高氮时,CO2浓度增高,地上部碳固定量和碳固定总量明显增加,而不施氮肥和低氮时,增加则不明显。不同水分处理地上部碳固定量和碳固定总量也没有明显差别,这表明,CO2浓度升高对氮素和水分胁迫及对春小麦碳固定并没有补偿作用。     

牛不同生长发育时期卵泡AKP酶与G-6-P酶的活性变化

用组织化学方法观察了AKP酶(碱性磷酸酶)和G-6-P酶(葡萄糖-6-磷酸酶)在牛各生长发育时期卵泡的活性变化.结果表明:不同发育时期的卵泡数量与AKP酶和G-6-P酶活性反应阳性之关系极为显著,其中有腔卵泡的酶活性反应显示之数量多于腔前卵泡;但G-6-P酶活性反应之阴性卵泡显著多于阳性卵泡.AKP酶活性强于G-6-P酶.腔前卵泡酶活性位置显示之主要在颗粒细胞和卵母细胞上,而有腔卵泡酶活性位置则主要在内膜细胞上.