浮萍对富营养化水体中磷的去除规律

磷是藻类增殖的限制因子,引起水体富营养化的关键营养物质。修复富营养化水体的重点在于磷的去除。通过对三种浮萍的磷吸收动力学特征和动态吸收特点研究,选择适合不同富营养化程度水体的修复植物。吸收试验结果表明,浮萍吸收磷的动力学特征可用Michaelis-Menten方程来描述。青萍对磷有较大的亲和力,适宜修复轻度富营养化水体;紫萍对磷有较大的最大吸收速率,适宜修复重度富营养化水体;而少根紫萍由于吸收速率小,生长速度慢,不适宜作为水体生态修复植物使用。     

冻存茶鲜叶多酚氧化酶动力学特性研究

采用分光光度法对冻存处理的茶树鲜叶的多酚氧化酶(PPO)进行了活性测定,研究了底物浓度、pH值及温度对冻存茶鲜叶PPO活性的影响,建立了茶树鲜叶冻存-萎凋过程的反应动力学方程.结果表明,冻存茶鲜叶PPO酶活的最适条件为:pH值介于4.6～5.0之间,温度35～60℃.由Michelis-Menten方程1/v=1.16...     

Kinetic mechanism of inorganic scale plugging removal atnear wellbore zone by high power ultrasonic technology

Based on the theory of solid and liquid coupling wave mechanics, the micro-dynamical characteristics caused by the transport of ultrasonic in porous media at near wellbore zone, including the elastic deformation of rock, the elastic crossflow of pore fluid and frame solid, and fluid squirt-flow produced by pore elastic deformation, are analyzed. Analysis of kinetics of peristaltic difference of porosity radius in porous media is presented. The characteristics of the removal of inorganic scale particle in porous media by using ultrasonic technology are also studied. Besides, by applying high power ultrasonic technology, the acoustic energy gathering in porous media at near wellbore zone leading to fracture of part rocks is illustrated. According to these analyses, the micro-dynamical mechanisms, such as inorganic scale fragmentation, ultrasonic cavitations, ultrasonic friction, ultrasonic peristaltic transport and ultrasonic fracture-making, occurred in inorganic scale plugging removal by high power ultrasonic technology are proposed.     

Differential impact of bushmeat hunting on monkey species and implications for primate conservation in Korup National Park, Cameroon

Bushmeat hunting is one of the primary threats to many large-bodied vertebrate species in African forests. However, species vary in their degree of vulnerability to hunting. We investigated the impact of hunting on monkey species in Cameroon’s Korup National Park (KNP) and examined how vulnerability to hunting varies among species. Data on primate abundance and hunting intensity were collected along 10 line transects, distributed across three survey areas in KNP. We assessed how the relative abundance of seven monkey species spatially varied between heavily and lightly hunted areas and evaluated temporal changes in the relative abundance and proportional representation of these species at a single hunted forest site and in bushmeat harvests. The putty-nosed and mona monkeys are most tolerant to heavy hunting pressure whereas the crowned monkey, drill, and red colobus are among the most vulnerable. At our heavily hunted survey site, the overall relative density of monkey groups increased through time but primate species richness declined. The proportional representation of Cercopithecus species, especially putty-nosed monkeys, increased through time, possibly due to competitive release. We also observed an increase in the proportional representation of the putty-nosed and mona monkeys and a reduced percent contribution of the red colobus and drill in hunter harvests. We conclude that hunting is driving some of Africa’s most threatened primate species (e.g., Preuss’s red colobus and the drill) to local extinction in KNP. We discuss intrinsic factors of species that might influence their degree of vulnerability and strategies to improve protection efforts in KNP.     

阿拉善流动沙漠区沙层CO2浓度与昼夜变化规律研究

利用红外CO2监测仪,对全球最高大的巴丹吉林诺尔图湖东大沙山、沙坡头流动沙丘和民勤流动沙丘进行了19个钻孔的CO2浓度昼夜观测。结果表明,阿拉善流动沙漠区空气中CO2浓度较1 m、2 m、3 m、4 m、5 m沙层中CO2浓度均低,表明在植物极稀少的流动沙漠区温暖季节会向空气中释放CO2,是大气CO2的来源区。沙层不仅白天向空气释放CO2,夜间也在释放CO2。在极端干旱的阿拉善流动沙漠区沙层2 m深处CO2浓度一般较1 m、3 m、4 m、5 m的大,但也有个别例外。流动沙漠区沙层CO2浓度的昼夜变化也具有明显的规律性,各个深度沙层CO2浓度从早8时至次日7时均呈现由低到高再到低的变化规律。沙层CO2浓度与昼夜温度变化呈显著正相关关系。在极端干旱的阿拉善流动沙漠区水分含量较高的沙层CO2浓度明显高,表明沙层含水量高低是决定沙层CO2浓度水平的主要因素。     

氟苯尼考肠溶缓释包衣微粒的制备及体外评价

采用湿法制粒、流化床包衣制备肠溶缓释微粒,正交法进行微粒处方、工艺参数的筛选,通过溶出度试验对其释放特性进行考察,筛选最佳工艺处方。在此优选处方和工艺条件下制得的微粒体外释放特性良好,在人工胃液中几乎不溶,而在人工肠液中释放达80％以上。本品处方合理,制备工艺简单,达到了肠溶缓释的目的,为氟苯尼考制剂的优化提供了依据。     

不同形式的氮源对活体外瘤胃氨氮释放和发酵参数的影响

选用普通尿素、两种包被缓释尿素(快速型和慢速型)、糊化淀粉尿素和大豆分离蛋白作为五种处理因子,采用单因子试验设计,利用活体外人工瘤胃产气法,研究不同形式的氮源对活体外瘤胃氨氮释放速度和发酵参数的影响.结果表明:在0～12h发酵过程中,不同形式氮源显著影响活体外瘤胃氨氮释放规律,其中两种包被尿素的氨氮浓度在各时间点均低于...     

Relationship between the oil and sugar content in olive oil fruits from Moraiolo and Leccino cultivars during ripening

In our previous work (Cherubini et al., 2009), sugar concentration was proposed as an accurate, reproducible index for technological ripening of olive oil fruits. During 2009 crop season, sugar and oil content of olive oil fruits from Moraiolo and Leccino cultivars were measured during ripening. The sugar content of olive oil fruits was determined both by titration and by using a portable refractometer.     

侧深施氮对机械直播水稻产量及氮素利用的影响

为探究侧深施肥对川西平原区机械直播水稻产量形成和氮素利用的影响,本研究以常规籼稻黄华占为试验材料,采用单因素随机区组试验设计,研究不施氮肥(N0)、尿素2次撒施(TF)、尿素1次撒施(UB)、尿素侧深施(UM)、尿素和缓释尿素混合侧深施(SRUM)对机械直播水稻干物质积累,氮素积累、转运、分配,产量形成及氮素利用的影响。结果表明,直播水稻干物质积累、氮素吸收总量、氮肥吸收利用率、氮肥农学利用率和产量均表现为SRUM>UM>TF>UB>N0。SRUM和UM茎叶氮素表观转移量、茎叶转移的氮对籽粒氮的贡献率均显著高于其他处理。SRUM茎叶干物质转运量显著高于UB和UM,增幅分别为28.97%和4.17%。SRUM和UM有效穗数显著高于其他处理,处理间差异达显著水平(P<0.05),产量分别较UB增长8.00%和12.95%。与TF相比,UM、SRUM氮肥吸收利用率分别提高11.35%、46.94%,氮肥农学利用率分别提高7.22%、25.88%。相比其他施氮处理,SRUM能够显著提高直播水稻的有效穗数、干物质积累量、氮素吸收总量、茎叶氮素表观转移量和茎叶干物质转...     

不同粒径生物炭包膜尿素缓释肥性能及缓释效果

为探究生物炭粉包膜处理对尿素缓释效果的影响,该研究以不同粒径稻壳生物炭粉为包膜材料,对尿素颗粒进行不同层数包膜处理,分别制备了3种生物炭包膜尿素缓释肥C_1（0.15 mm生物炭粉包膜）、C_2（内层0.15 mm,外层0.25 mm生物炭粉包膜）和C_3（内层0.15 mm,中层0.25 mm,外层0.425 mm生物炭粉包膜）,并对生物炭包膜尿素缓释肥性能及缓释效果进行了分析研究。研究结果表明3种生物炭包膜缓释肥粒径主要分布在2.90～4.80 mm,随着包膜层数的增加,包膜缓释肥粒径随之增大,C_2和C_3粒径显著高于C_1(P<0.05)。C_1、C_2和C_3的抗压强度为20.40～48.00 N,满足工业生产需求。与C_1和C_2相比,C_3颗粒表面较光滑,切面具有致密且孔隙结构丰富的层状结构,吸水倍率最小（1.69）,耐水性也显著优于C_1与C_2(P<0.05),氮元素缓释效果优于C_1与C_2。综上可以看出,3层包膜尿素缓释肥膜壳强度高于单层和双层包膜尿素缓释肥,通过控制不同膜层生物炭的孔隙结构和孔径,减缓水分的渗入及养分的流出过程,缓释效果突出,为生物炭包膜缓释肥的开发应用提供一个新技术路径。