光谱水平电极撒样法同时测定 化探样品中银、锡、钼、铋四元素的研究

本文采用碘化钾＋ 光谱基物＋ 石墨粉为缓冲剂，以背景为内标，一次摄谱同时测定化探样品中的 Ａｇ 、 Ｓｎ 、 Ｍｏ 、 Ｂｉ４ 元素，绝对检出限（ｕｇ／ｇ） 分别为０ ．０２１ 、０ ．７９ 、０ ．１７ 、０ ．２０ 。测定范围（ｕｇ／ｇ） ： Ａｇ 为０ ．０２ ～２０ ； Ｓｎ 为０ ．８ ～５００ ； Ｍｏ 为０ ．２ ～２００ ； Ｂｉ 为０ ．２ ～２００ ，均能满足化探试样中微痕量元素测定的要求。本法在１ ｍ 光栅摄谱仪上摄谱，具有广泛的适用性，并且简便、快速、灵敏度高，成本低。     

打桩振动对周围新浇混凝土的影响

质量和工期是工程的关键,构件混凝土在养生期怕震动,施工又不能等。施工场地的范围是有限的,本文通过实测,取得安全距离数据,为施工场地的布置提供了依据。     

Modification of 0+ perch foraging behaviour by indirect cues of predation risk

Abstract –  Intake rate and prey size selection of 0+ perch, Perca fluviatilis , from Lake Wallersee (Austria) was studied at different illumination (day light: 400 lx, twilight: 2 lx) during 5 days of habituation to novel surroundings in aquaria. The hypothesis was tested that high illumination and novelty of surroundings (transfer from holding to test aquaria) as indirect cues of predation risk influences 0+ perch foraging behaviour. Significantly lower total intake and lower proportion of large Daphnia magna (two prey size groups, 2.9 and 1.2 mm, were used) were observed at higher illumination and under novel surroundings. Habituation to novelty caused an increase in consumption of large prey and decrease in consumption of small prey. During the whole period of habituation, more large prey was ingested at twilight than at daylight; no light-induced difference in ingestion of small prey was found. Foraging 0+ perch responded to indirect nonspecific cues of predation risk by reduction of intake of large prey, which are costly in terms of handling time. This allows fish to be more vigilant without ceasing their foraging activity even in potentially dangerous situations. In the lake, young perch are most vulnerable to abundant piscivorous fish and birds during the day; in twilight perch can afford a more time-consuming foraging activity.     

敌敌畏农药对家蚕“两广二号”呼吸强度的影响

利用敌敌畏农药对“两广二号”家蚕（3龄）进行急性中毒的试验中，使用微量呼吸仪（SKW-2型）调查和研究家蚕中毒后呼吸强度的变化，结果表明：家蚕呼吸强度对敌敌畏的反应敏感，随农药浓度的加大，家蚕短期内耗氧量急增，最高达3．24μl／mg·h，但马上又迅速下降，直至最低的0．43μl／mg·h。随即出现耗氧抑制率升高，最高达73．81％；高浓度农药中毒后，家蚕呼吸强度比低浓度衰弱快，死亡也快。     

长江口中华鲟幼鱼趋光行为及其对摄食的影响

研究了长江口中华鲟幼鱼对光照强度的选择及其对摄食的影响，结果表明：个体实验时，中华鲟幼鱼选择暗区（1~2 lx）、过渡区（10~12 lx）和亮区（200~209 lx）的时间百分比分别是(1.32%±3.50%) 、(7.17%±13.5%)和 (91.52%±14.9%)；群体实验时，中华鲟幼鱼选择暗区、过渡区和亮区的数量百分比分别为(6.42%±4.13%)、(14.20%±7.45%)和(82.38%±15.2%)，个体实验的时间百分比和群体实验的数量百分比在3个不同亮度区内均存在显著差异（P＜0.05），中华鲟幼鱼具有明显的趋光行为。幼鱼在亮区围绕光源作圆周运动，其行为模式符合鱼类趋光的“信号适应”机制假说。中华鲟幼鱼猎食活体子陵吻虾虎鱼的摄食量（Fc）、摄食强度（Fi）、摄食率（Fr），在光照（206 lx）条件下，分别为(9.67±2.08) （尾/10尾·4 h）、（0.97±0.21）（尾/尾·4 h）、 （0.24±0.05）（尾/尾·h）；黑暗条件下（0 lx），分别为(10.67±2.31)（尾/10尾·4 h）、(1.07±0.23)（尾/尾·4 h）、(0.27±0.06)（尾/尾·h）。处理间（光照和黑暗之间），3项指标均无显著差异（P>0.05）。这一结果表明，中华鲟幼鱼的猎食效率与光照强度无关，即幼鱼不依靠视觉捕食，属非视觉摄食类型鱼类，因此，认为中华鲟幼鱼趋光行为中，光线的信号意义大于利用视觉捕食的意义，幼鱼以光线作为信号来寻找食物丰富的栖息地。     

Effects of diet, stocking density and environmental factors on growth, survival and metamorphosis of clam, Paphia malabarica (Chemnitz) larvae

A series of experiments were conducted to evaluate the effects of diet, stocking density and environmental factors on the growth, survival and metamorphosis of short neck clam Paphia malabarica larvae. These experiments examined the following factors: diet [ Isochrysis galbana , Nannochloropsis salina and a mixture of I. galbana and N. salina (1:1 w/w)], stocking density (1, 3, 5 and 7 larvae mL⁻¹), light intensity (unshaded, partially shaded and fully shaded) and water filtration (unfiltered and sand filtered). Results indicated that N. salina could replace 50% of I. galbana as a food source for the clam larvae with an increase in growth, survival (47.2%), metamorphosis (33.5%) and early settlement. Larval growth decreased significantly with increasing stocking density. A density of 1–3 larvae mL⁻¹ appeared to be optimal for normal growth of clam larvae. Neither diet nor stocking density used in the study had a significant effect on larval survival. Under partially shaded (light intensity=1000–5000 lx) and fully shaded (light intensity <1000 lx) conditions, larval growth was significantly faster than under direct sunlight (unshaded). Larvae grew significantly faster in the unfiltered water than in the filtered water.     

白三叶分枝格局的研究

研究不同施肥处理对白三叶分枝格局和土壤利用强度的影响，结果表明，白三叶最合适的分枝角度为６０°，分枝能容忍的最大拥挤是４０°的扇形区域；整个克隆以源株为中心向四周生长形成六边形轮廓。同源株的分枝角度存在某种调节机制，施肥对新形成的分枝角度有微调功能。低施肥处理时，白三叶表现“利用策略”；高施肥处理时，植株表现“占居策略”。     

烤烟品种提纯401种植密度探讨

选用闽西烤烟当家品种——提纯401进行不同种植密度试验,并对各处理的田间小气候,烟株个体的根、茎、叶生长状况和叶解剖性状进行观察。结果表明:每公顷16005株、19995株、22005株、25995株4种处理,随种植密度的提高,田间中、后期的光照强度减弱,根系分布的深度、宽度,密集范围,侧根数,茎径,叶片厚度、大小,单叶重均变小。烟叶产量、上等烟和中等烟的比例、级指、产指、均价,每公顷收益均以每公顷22005株的最高,且其烟叶产量与其他3种种植密度的烟叶产量之间有显著差异(P<0.01)。故认为烤烟品种提纯401在本试验的土壤、施肥和打顶水平下,以每公顷22005株左右的种植密度较为合理。     

Response of Biochemical Markers of Bone Metabolism to Exercise Intensity in Thoroughbred Horses

We studied the response of biochemical markers of bone metabolism to exercise intensity in horses. Four horses were walked on a mechanical walker for one week (pre-exercise). Then they performed low-speed exercise on a high-speed treadmill in the first week and medium-speed exercise in the second week and high-speed exercise in the third week of training. We measured two indices of bone resorption, serum hydroxyproline concentration and the urinary deoxypyridinoline/creatinine ratio, and serum osteocalcin (OC) concentration as an index of bone formation. Both indices of bone resorption gradually decreased during the experiment. Serum OC concentration did not change in the first week but was significantly lower in the second and the third weeks compared to in the pre-exercise period and in the first week. These results suggest that the low-speed exercise decreased bone resorption but did not affect bone formation, which possibly results in increasing bone mineral content and strengthening of bones. The high-speed exercise decreased bone formation and bone resorption, i.e., bone turnover was suppressed. The low-speed exercise may be preferable for increasing bone mineral content.