不同海拔下甲醇替代率和主喷正时对RCCI发动机性能的影响

为探究不同海拔条件下甲醇/柴油反应活性控制压燃（reactivity controlled compression ignition, RCCI）发动机的运行特性,该研究基于甲醇/柴油双燃料发动机试验台架,试验研究1 800r/min、100%负荷和3 200r/min、100%负荷下不同甲醇替代率、柴油喷射正时对发动机燃烧与排放性能的影响规律。结果表明：不同海拔条件下随着甲醇替代率的增加,缸压和瞬时放热率峰值逐渐升高,燃烧始点和燃烧中心前移,当量有效燃油消耗率（equivalent brake specific fuel consumption, ESFC）降低,有效热效率升高,NO_x和碳烟排放大幅降低,THC（total hydrocarbons）和CO排放增加。1 800 r/min、100%负荷工况下,甲醇替代率由0增至20%,0、1 000、2 000m海拔下最大缸压平均增加1.72MPa,瞬时放热率峰值平均升高25.08J/(°),ESFC平均降低4.67%,有效热效率平均升高4.90%,NO_x和碳烟排放分别平均降低16.63%和50%,THC和CO排放量分别平均增加142.03、388.18 mg/kg。3 200 r/min下甲醇替代率由0增至7%,不同海拔高度下ESFC平均降低1.76%,有效热效率平均升高1.79%,NO_x和碳烟排放量分别平均降低8.17%和20.70%。海拔高度由0升至2 000m,1 800r/min、20%甲醇替代率与3 200r/min、7%甲醇替代率下,瞬时放热率峰值分别降低4.80和8.08J/(°),燃烧中心分别推迟1.44°和1.43°,有效热效率分别降低0.82%和0.68%,ESFC分别升高2.10%和1.99%,NO_x排放量分别减少10.61%和7.35%,碳烟排放分别增加26.54%和32.12%,THC排放分别升高29.88%和15.45%,CO排放量分别增加22.42%和18.15%。固定甲醇替代率后,随着柴油主喷正时提前,不同海拔条件下缸压和放热率峰值逐渐升高,燃烧中心向上止点靠近,ESFC逐渐降低,有效热效率升高,碳烟排放减少,NO_x、THC和CO排放增加。1 800 r/min、15%甲醇替代率下,主喷正时从-1.5°提前至-7.5°,不同海拔高度下ESFC平均降低8.27%,有效热效率平均升高9.08%,碳烟排放平均减少90.94%。为提升高海拔条件下甲醇/柴油RCCI发动机的热效率和燃油经济性,可以适当增大柴油主喷正时。研究结果可为不同海拔环境下甲醇/柴油RCCI发动机燃烧与污染物排放控制优化提供参考。     

黄芪多糖注射液中非法添加林可霉素检查方法的研究

为建立黄芪多糖注射液中非法添加林可霉素的检查方法,采用薄层色谱法初筛出黄芪多糖注射液中非法添加林可霉素的样品,而后用HPLC-PDAD法检测,液相色谱条件:采用Atlantis~#174;T 3(十八烷基硅烷键合硅胶,4.6 mm×250 mm,5μm),流动相为0.02 mol/L的磷酸氢二铵-乙腈(70∶30),流速为1.0 m L/min,检测波长为194 nm,最后用LC-MS法进行确证。结合薄层色谱、高效液相色谱光谱图以及质谱的分子离子峰等方面信息,证明该样品中确实非法添加了林可霉素,其中HPLC-PDAD法平均回收率为97.8%,RSD为1.4%,检出限为6μg/m L。该检测方法准确可靠,可用于黄芪多糖注射液中非法添加林可霉素的检测。     

抗菌肽Thanatin转基因小鼠建立的初步研究

人工合成抗菌肽Thanatin基因的3条片段,利用重叠延伸PCR扩增技术得到完整的Thanatin基因,通过分子克隆方法构建出pIRES2-EGFP-Thanatin重组表达载体。然后与脂质体混合,采用睾丸打点注射将新构建的抗菌肽基因注入小鼠睾丸内,共注射公鼠5只。6周后与雌鼠交配,对新生仔鼠进行断尾,提取尾尖基因组DNA,利用PCR和Southern印迹方法对其进行检测。结果显示,得到的52只新生仔鼠中PCR检测阳性率为38.46%,Southern印迹检测阳性率为30.77%;在活体荧光成像系统下转基因小鼠呈现绿色荧光表达。通过睾丸注射法使Thanatin基因在小鼠的基因组中得到整合,为进一步研究抗菌肽的作用机理、培育抗病动物品种以及通过建立转基因动物生物反应器进行抗菌肽的大量生产奠定了基础。     

Injection of the insertion of the deep digital flexor tendon in horses using radiographic guidance

Insertional tendinopathies of the DDFT have been reported both as the sole lesion and as part of a multifocal lesion (Dyson et al. 2003). Computed tomography (CT) and magnetic resonance imaging allow specific diagnosis of deep digital flexor tendon lesions within the hoof capsule; however, direct intralesional treatment of such lesions is difficult because of the hoof's rigid structure. A technique designed to mimic intralesional injection of insertional tendinopathies of the DDFT in the standing horse using radiographic guidance was assessed. Radiographic and contrast CT imaging and sectioning of the limbs confirmed accurate injection in all cases although inadvertant administration of injectate into adjacent structures was also evident.     

Establishment of Detection Methods for Dexamethasone Sodium Phosphate in Injections by UPLC-PDA

A detection method of dexamethasone sodium phosphate in houttuynia injection,bupleurum injection,vitamin C injection,lincomycin hydrochloride injection,and asragulus polysacharin injection was established by UPLC-PDA.The Waters ACQUITY UPLC^® BEH C18 column(2.1 mm×50 mm,1.7 μm) was used,the mobile phase consisted of 0.75% triethylamine phosphatic liquor/solution (pH 3.0)-methyl alcohol-acetonitrile(50:45:5),the flow rate was 0.3 mL/min,the column temperature had remained 25℃,photodiode array detector wavelength range was 190 to 400 nm,the recorded wavelength was 242 nm,the injection volume was 10 μL.The linear range of dexamethasone sodium phosphatel was 10.0 to 200.0 mg/L (R²=0.9999),the mean recovery and RSD for dexamethasone sodium phosphate in houttuynia injection,bupleurum injection,vitamin C injection,lincomycin hydrochloride injection and asragulus polysacharin injection were 97.54% and 1.14%,101.59% and 0.19%,100.92% and 0.92%,99.82% and 0.73%,100.08% and 0.62%,respectively.This method was accurate,easy and fast,it was suitable for detection of dexamethasone sodium phosphatein houttuynia injection and other four kinds of injections.     

低压空气辅助缸内直喷汽油机进气道设计

以2.0L四气门进气道喷射汽油机为样机,设计低压空气辅助缸内直喷汽油机,运用CFD仿真技术与气道稳流试验相结合对其进气道进行设计.建立了原进气道喷射汽油机进气道的三维仿真模型并进行计算和分析,表明气道流通能力不够强,有强滚流运动;气道内部三维流场分析结果说明部分区域存在气体滞留现象,通过气道稳流试验台对仿真结果进行了验证.根据低压空气辅助直喷汽油机对缸内气流运动特性的要求,在CFD仿真软件中对进气道结构进行了优化,通过调整气门杆附近的截面积、削弱滚流强度,提高了进气道的流通能力,同时改善了局部气流滞留现象.     

氧化乐果对雄性小鼠睾丸琥珀酸脱氢酶和精液质量的影响

试验旨在研究有机磷农药氧化乐果对雄性小鼠睾丸琥珀酸脱氢酶(SDH)和精液质量的影响作用。将40只健康昆明雄性小鼠随机分为4组,即低、中、高3个染毒组和对照组,其中染毒组分别灌胃1.0、2.0、4.0 mg/kg氧化乐果,对照组灌胃生理盐水,采用等容量灌胃法(0.2 mL/10 g体重),连续灌胃14 d。随着氧化乐果染毒剂量的逐渐增加,小鼠睾丸琥珀酸脱氢酶(SDH)活力、精子密度、存活率均明显降低,与对照组相比差异显著(P＜0.05);小鼠体重、睾丸重、附睾及其脏器系数与对照组相比差异均不显著(P＞0.05)。氧化乐果对小鼠精子密度和精子存活率有一定的损伤作用,对睾丸琥珀酸脱氢酶有明显的抑制作用。     

The addition of calcium ion chelator,EGTA to thawing solution improves fertilizing ability in frozen–thawed boar sperm

In our previous study, seminal plasma effectively suppressed the induction of sperm to capacitation‐like status and acrosome loss during the thawing process. However, because boar seminal plasma is contaminated with various kinds of bacteria and/or viruses, it is necessary to develop a thawing solution without animal‐derived materials. In this study, we focused on the increase of intracellular Ca²⁺ ([Ca²⁺]_i) in sperm after thawing and the negative effects of sperm qualities. After thawing, the fluorescent intensity of [Ca²⁺]_i indicator, Fluo‐3/AM, and the level of phosphorylated tyrosine residue of protein were increased in the sperm. Next, we investigated whether the addition of Ca²⁺ chelators (ethylenediaminetetraacetic acid (EDTA) and ethyleneglycoltetraacetic acid (EGTA)) improved post‐thawed sperm motility. When the frozen–thawed sperm were treated with 6 mmol/L EDTA + 6 mmol/L EGTA, sperm motility was significantly increased as compared with control (6 mmol/L EDTA alone) at all incubation periods (P < 0.05). The combinational treatment significantly suppressed the elevation of [Ca²⁺]_i and the tyrosine phosphorylation, which improved the acrosomal status and fertilizing ability in vitro. Furthermore, when the thawing method was applied for artificial insemination, the fertilization rate was significantly higher than control (P < 0.05, 33% vs. 82%). Thus, we conclude that the addition of EDTA + EGTA to thawing solution is a beneficial tool for artificial insemination using frozen–thawed boar sperm.     

复方恩诺沙星注射液对人工诱发猪气喘病的治疗效果研究

复方恩诺沙星注射液能有效控制猪气喘病感染,缓解症状,降低支原体感染猪的发病率和死亡率,并在一定程度上减少成活猪的体重下降,效果优于单方的恩诺沙星注射液和磺胺嘧啶钠注射液,在临床上有一定的实用价值。作者采用 0.04、0.08、0.12 mL/kg体重的2.5%复方恩诺沙星注射液分别对人工诱发猪气喘病进行肌肉注射治疗,结果表明,肌肉注射0.08 mL/kg体重复方恩诺沙星效果较好。