深松旋耕全层施肥联合整地机施肥量影响因素分析

针对深松旋耕全层施肥联合整地机在作业过程中存在施肥不均、精度较低等现象,对影响施肥量因素进行分析,确定排肥轴转速、排肥器开度以及肥箱料位高度为影响因素,设计三因素五水平正交试验,以施肥量变异系数为评价指标,进行极差分析和方差分析得出影响因素主次顺序:肥箱料位高度>排肥轴转速>排肥器开度,其中料位高度对施肥量变异系数的影响高度显著,为后续肥箱肥料监测系统提供理论基础。施肥量变异系数在0.19%~3.12%之间,满足试验要求。运用最小二乘法建立施肥量关于排肥轴转速、排肥器开度和肥箱料位高度之间的数学模型。经检验:数学模型值与实测值的相关系数达到0.889,可以作为施肥精量控制相关技术参数的选择依据。     

适宜两熟制种植的早熟冬小麦新品种冀麦37号的选育及应用

根据遗传学原理,将６个具有不同遗传背景的亲本,经过组配－选择－再组配－再选择以及辐射等方法,使多个早熟材料的早熟基因以及其它目标性状逐步重组、累加、选育出集早熟、抗寒、高产、优质于一体的冀麦３７号新品种。该品种一般产量为６０００－７５００ｋｇ／ｈｍ＾２,与对照相当,高的可超过９０００ｋｇ／ｈｍ＾２。交对照早４－５ｄ,能为下茬多提供积温１００－１３０℃。它的育成填补了河北省冀中南两熟制种植区早熟冬小     

赖氨酸对紫丁香蘑菌丝生长的影响

为了研究赖氨酸成分对紫丁香蘑菌丝体生长的影响,采用不同浓度的赖氨酸-PDA培养基进行紫丁香蘑菌丝体生长的对比试验,确定最适合紫丁香蘑菌丝生长的赖氨酸浓度。结果表明,紫丁香蘑菌丝生长的最适赖氨酸浓度分别为30μg/mL和90μg/mL,此项研究为紫丁香蘑的规范化生长提供帮助。     

Hydroxyl Radical Generation and Contaminant Removal from Water by the Collapse of Microbubbles Under Different Hydrochemical Conditions

The present study addresses the mechanism of hydroxyl radical (·OH) generation by the collapse of microbubbles in water solution. The influence of gas supply and flow rate, solution pH, and ionic strength on the aeration efficiency, free radical generation, and contaminant removal (take methylene blue as an example) are elucidated. The results showed that the degradation rate of methylene blue by ·OH increased with flow rate as well as in acidic or alkaline solutions compared to that in neutral conditions. ·OH was shown to be produced by the reaction between protons and oxygen radicals generated by the decomposition of O₂ rather than water molecules. A greater concentration of O₂ or H⁺ thus promoted the reaction, resulting in effective removal at a high flow rate or low pH. Nevertheless, there was considerable methylene blue removal at high pH, driven by the production of the dye cation through the dissociation of methylene blue and the high electronegativity of bubbles at high pH, thus enhancing interface adsorption and degradation, as well as by the high ionic strength of the solution helping to generate ultrafine bubbles and maintaining them through ionic shielding. The current work provides useful insights into the application of microbubble as a promising technique.     

Hybridization between Crassostrea hongkongensis and Crassostrea ariakensis at Different Salinities

To evaluate the survival and growth performance of hybrid larvae and juveniles, we conducted hybridization experiments between Crassostrea hongkongensis and Crassostrea ariakensis at three salinities (15, 23, and 30 ppt). Hybrid fertilization occurred in one direction (C. hongkongensis ♀ and C. ariakensis ♂), and the fertilization rates did not differ significantly among the three trial salinities. Molecular genetics analysis revealed that hybrid progenies were true hybrids. Hybrid juveniles survived better than C. hongkongensis juveniles at a salinity of 30 ppt. Hybrid larvae and juveniles showed intermediate growth between C. hongkongensis and C. ariakensis progenies. The growth of hybrid juveniles was significantly greater than that of C. hongkongensis juveniles at a salinity of 30 ppt. Overall, C. hongkongensis has a high economic value but favorable hatchery and farm of this species is restricted to lower salinity sites. Because the hybrids were shown to have greater growth and survival characteristics at high salinity, hybrids may be a more desirable candidate to be cultured in those areas of China with higher salinities, such as the Bohai Sea of China where the salinity is usually 30 ppt.     

犬4种皮肤病的诊治

北京市密云县某社区统计饲养宠物犬约375只,其中约200只能够得到精心饲养,定期进行洗浴。调查发现,在定期洗浴的所有犬中,仅有少部分患有轻微皮肤病,个别患病严重;未定期洗浴的犬中,患皮肤病的现象十分普遍,并且相当一部分病情严重。在动物疫病预防控制中心就诊的23个病例中,犬被螨虫感染或真菌感染的概率都很高,分别为10/23、8/23,比例相当。犬同时被2者感染的概率较低,为4/23。其中,雄性患病率13/23;雌性患病率10/23,并未发现犬的皮肤病与性别有关。经过用药治疗,在2周内康复的病例为3例,第3周康复的为7例,4周以后康复病例较多,但其中1例继发感染,死于败血症。