Sperm localization in the oviducts of artificially inseminated dairy cattle

Eight animals, 3 heifers and 5 primiparous cows, were artificially inseminated by intrauterine deposition of frozen-thawed semen. The insemination dose comprised 20×10⁶ or 200 × 10⁶ spermatozoa, frozen in French mini straws. Four animals were inseminated at fixed time interval (72 or 84 h) after cloprostenol injection. The remaining 4 animals were inseminated in spontaneous oestrus. Slaughter took place 2 or 12 h after insemination. After fixation the oviducts were cut into segments, which were serial-sectioned and stained. Six sections per segment were examined under the microscope for sperm recovery.The number of spermatozoa recovered from the oviducts varied considerably among animals. Recovery was poor (less than 50 spermatozoa) in 4 animals. Recovery was low when insemination took place in induced oestrus and with the lower sperm number (20×10⁶). In animals in which more than 50 spermatozoa were found the distribution varied both between animals and between oviducts within the same animal. Overall, more spermatozoa were found in the lower (UTJ, isthmus and AIJ) than in the upper (ampulla) parts of the oviducts. In 3 out of 4 animals more spermatozoa were recovered from the left than from the right oviduct. Only in 1 animal were the majority of spermatozoa found in the oviduct ipsilateral to the follicle-bearing ovary.     

浮顶罐刮蜡机构损坏的力学分析

从力学角度分析了浮顶罐刮蜡机构压筑大量断裂的原因：未按设计图安装压簧，导致其实际挠度超过设计挠度的８８％，使压簧根部的最大弯矩处正应力超出了许用应力值，应力集中使压簧折角处两边产生微裂纹；罐壁焊缝及施工中遗留的凸出焊点和残留物对刮蜡板产生卡阻和冲击荷载，压簧经长时间运行后发生疲劳断裂。针对上述原因，提出了具体维修方案。     

渭河流域(关中段)经济发展与水环境质量演变关系研究

通过对关中地区经济发展与渭河流域(关中段)水环境质量状况的分析,模拟了关中经济发展和渭河水环境质量演变关系,研究了演变关系的趋势,并提出相应的建议,以期为两者之间协调发展提供科学决策的依据。结果表明,关中地区人均GDP与高锰酸钾指数曲线近似"倒U型"曲线的右半段,走势良好。而人均GDP与氨氮指标的曲线与传统的EKC曲线不相吻合,类似"倒U+U"形。说明关中地区在渭河的治理过程中投入较大,环保措施得当,但近两年在氨氮控制上还需加大力度。     

亮叶忍冬嫩枝扦插繁殖技术研究

采用L9（3。）正交试验法,研究不同基质、生长素类型以及新梢枝段对亮叶忍冬（Loniceranitida‘Maigrun’）嫩枝扦插繁殖效果的影响。对扦插成活率、生根数、根系总长度、根鲜重、新梢数、新梢总长度、新梢鲜重等指标进行了测定分析,结果表明：以河沙或珍珠岩为扦插基质时,各测定指标均极显著高于草炭处理;吲哚丁酸（IBA）或萘乙酸和吲哚丁酸等量混合液（N＋I）处理的扦插成活率极显著高于萘乙酸（NAA）处理,其它各指标则均无显著差异;以新梢基部段位为插条时,生根数极显著高于其它枝段,基部和中部枝段为插条的新梢总长度和新梢鲜重极显著高于梢部,其余各测定指标在不同枝段间的差异不显著。综合各测定指标,进行亮叶忍冬嫩枝扦插繁殖时,以河沙或珍珠岩为扦插基质,采用亮叶忍冬新梢基部或中部段位作为插条,经浓度为1000mg·L。吲哚丁酸和萘乙酸等量混合液（N＋I）或吲哚丁酸（IBA）处理,可获得较高成活率（70％以上）以及较高质量的扦插苗。     

基于土地整治的三门峡库区(华阴段)现代农业发展模式研究

土地整治与现代农业的结合研究有利于区域现代农业的快速发展。三门峡库区(华阴段)自然社会条件复杂,农业经济基础薄弱,土地利用方式落后。针对土地整治后期效益不可持续性的问题,认为土地整治与现代农业在实现阶段和目标上存在耦合联系,并针对三门峡库区(华阴段)区域特征,将土地整治"3集"模式、生态农业建设模式和新农村发展模式有机统一,以期实现以土地整治为契机,加速区域现代农业模式快速发展。     

浅谈混凝土结构加固方案的选择

介绍了混凝土加固的各种方法及技术特点、加固原理及其在各类混凝土结构构件加固中的机理作用,阐明在确定加固方案时应综合考虑各种因素,最终选择正确合理的加固方案至关重要。     

浅谈桥梁博士计算变截面连续箱梁时通用截面拟合的应用

通过利用桥梁博士对变截面连续箱梁的结构计算,阐述了单箱双室截面、斜腹板的变截面连续箱梁（箱梁截面变化复杂,顶板、底板、腹板厚度,梁高均为变化值,且梁底呈二次抛物曲线变化）的建模过程。阐明若采用普通方法输入截面,需计算各个节点截面特性,然后逐个输入;采用通用截面拟合工具输入函数,可一次完成。     

金花茶成年树茎段离体器官发生

以金花茶成年树茎段为外植体进行离体器官发生研究。结果表明:分段消毒法是较为理想的消毒方式;附加2 mg.L-1BA及0.5 mg.L-1IAA的改良WPM培养基适合诱导腋芽萌发,萌发率达57.1%;芽苗在附加3 mg.L-1BA及0.2 mg.L-1IAA的改良WPM培养基上增殖效果较好;在附加4 mg.L-1或6 mg.L-1NAA的1/2MS培养基上可诱导芽苗生根。     

地方高校学费收入是否应纳入国库集中收付范畴的探讨

根据高等教育成本补偿理论,高校的学费收入是对接受教育服务正常支付成本的补偿,不属于政府的财政收入,也不同于其他事业单位的预算外资金。因此,笔认为：在现实条件下,将高等学校学费收入纳入财政统管或进行国库集中支付,不仅不利于高等学校的发展,也不利于政府管理角色与管理职能的转换。     

Surgical Correction of Uterine Torsion and Mare–Foal Survival in Advance Pregnant Equine Patients

This article describes the surgical management of uterine torsion by midline celiotomy and cesarean section on 12 mares presented with signs of colic to a teaching veterinary hospital. The mares were either in full term of gestation (n = 7) or in advanced stage of pregnancy (n = 5). Six mares were in first parity. Uterine torsion was diagnosed by per rectal and per vaginal examinations. For surgical intervention, mares were anesthetized using a combination of xylazine (1.1 mg/kg) and ketamine (2.2 mg/kg), intravenously. After intubation, the animals were maintained on halothane (n = 4) or isoflurane (n = 8) inhalation anesthesia. Midline celiotomy was performed, and foals were delivered by cesarean section. In 11 mares, before closing the abdominal wound, the uterus was detorted manually and confirmed for its normal position. Both anesthetic protocols using halothane and isoflurane were found satisfactory for surgical correction of uterine torsion. After long-term follow-up, the study reported 75.0% (9/12) survival rate for mares. One mare was euthanized because of devitalized, necrosed, and adhered uterus to the abdominal wall. Of the nine surviving mares, seven were successfully bred. Three foals were born alive, and only one could survive on long-term basis. Of the nine dead foals, two had umbilical cord torsion.