乐都县天然草地分类探讨

根据综合顺序分类法，将乐都县天然草地划分为四个类，九个亚类，二十六个草地型。草地类随海拔升高，依次分布着微温微干－微温微润－冷温潮湿－寒温潮湿类草地，呈明显的垂直分布规律。     

新疆草地生态系统服务功能与价值初步评价

对新疆草地生态系统的主要功能进行调查,重点估算了新疆草地生态系统不同服务功能和类型的生态价值。计算结果显示,新疆草地生态系统2003年提供的总服务价值为71.32×108美元。从草地各类功能价值看,草地的经济功能价值仅为21.26%,远低于草地的生态价值。从新疆草地类型看,温性荒漠草原、温性荒漠和低平地草甸是新疆草地的主体类型,占58%以上,而其贡献率为43.17%;低平地草甸提供的生态服务价值最高,占30.20%;沼泽和温性草甸草原虽然单位面积服务价值很高,但在草地生态系统中所占的地位很低。这些结论体现了新疆草地生态系统的特殊性及开发和保护的潜力。     

乐都县天然草地分类探讨

对乐都县天然草地分类进行了探讨，根据综合顺序分类法，乐都县天然草地可分为４个类，９个亚类，２６个草地型，同时指出，草地类随海拔升高，依次分布着微温微干类－微温微润类－冷温潮湿类－寒温潮湿类。并呈明显的垂直分布规律。     

天祝县草地资源特征及其生产力分析

对甘肃省天祝县天然草地资源类型、分布规律和特点及生产力进行分析和总结.结果发现,该区天然草地主要有温性草原、山地草甸、高寒草甸、灌丛草甸和疏林草甸5类;不同地区、年际和季节间的草地生产力与营养成分差异很大,草地饲用植物种类多,产量低.品质差.建议综合利用草地培育措施,实行草畜系统的半放牧半舍饲经营,以恢复草地植被,发展...     

山西典型天然草地碳分布特征及碳储量估算

通过对山西4种主要草地类型暖性草丛草地、暖性灌草丛草地、温性草原、山地草甸草原的地上现存生物量、凋落物、半分解层、根系和土壤有机碳密度的调查和测定,本研究估算山西天然草地生态系统的碳储量,旨在揭示山西不同类型天然草地固碳能力。结果表明:4种类型草地的植被碳密度、土壤有机碳密度、生态系统有机碳密度的大小顺序相同均为:暖性灌草丛草地山地草甸草原暖性草丛草地温性草原;山西草地植被平均碳密度为1759.07g·m~(-2),占整个草地生态系统的21.81%;土壤平均有机碳密度为6307.22g·m~(-2),占整个草地生态系统的78.19%;经估算,山西的草地面积为4.55×10~6 hm~2,草地总碳储量约为364.40Tg。     

不同利用方式对山地草甸线叶嵩草型草地植物群落特征的影响

为探讨禁牧、休牧和长年放牧等不同利用方式对草地植物群落的影响,于2003—2007年在天祝县抓喜秀龙乡山地草甸线叶嵩草型草地进行了连续5年的观测。结果表明,禁牧可提高山地草甸草原的植被盖度、高度、频度、产草量和优良牧草比例,对恢复草地生态具有重要意义;而长年放牧使各指标降低,毒杂草比例升高,导致草地生产力下降,草场退化;休牧为可食牧草的营养生长及种子成熟创造了条件,使草地植被群落特征保持稳定,既利用了草地的生产属性,又对生态不造成危害,是山地草甸比较理想的利用方式。     

青海省都兰县草地生态系统服务功能及其价值评估初探

对青海省都兰县不同草地类型的生态系统服务价值和类型功能价值进行了尝试性的估算。结果表明,草地系统年平均价值为55.40亿元,各类草地提供的生态服务总价值为:温性荒漠16.50亿元>温性草原13.64亿元>高寒草甸11.60亿元>高寒草原7.61亿元>低地草甸6.05亿元。草地各类功能价值中,提供食物生产的经济价值仅是草地服务价值的一小部分,草地生态系统提供给人类服务最主要的是其潜在的间接生态功能和服务价值。     

青海省都兰县天然草地资源生产力评价

青海省都兰县天然草地面积212.65万hm2,有荒漠草原类、山地草原类、高寒草原类、草原化荒漠类、干荒漠类、山地荒漠类、高寒草甸类、山地草甸类、沼泽类、高寒沼泽类、灌丛草甸类、疏林类草地12类。各类草地在全县的分布、面积和生产力各不相同:高寒草原类面积最大,为75.25万hm2,而山地草甸类面积最小,仅为273hm2;高寒沼泽类年生物量最高,平均产可食鲜草10791kg/hm2,高寒草原类年生物量最低,平均产可食鲜草1945kg/hm2。全县可利用草地155.42万hm2,可载畜140.94万个羊单位。     

都兰县天然草地植被固碳释氧价值评估

植被在固定CO2释放O2和大气与陆地生态系统碳循环中起着十分重要的作用,具有重要的生态功能,体现出生态服务价值。根据都兰县草地资源调查及相关资料,计算各种草地植被类型的净初级生长量,进而根据光合作用方程式、造林成本法、碳税法和工业制氧法估算其固定CO2和释放O2的物质量及其价值量。结果表明：都兰县草地植被年净初级生长量为364.04万t,固定CO2 593.38万t,释放O2 436.85万t。根据造林成本法和碳税法估算出都兰县植被固定CO2的价值为10.338 5亿元;利用造林成本法和工业制氧法估算出释放O2的价值为16.445 7亿元。都兰县草地植被固定CO2释放O2物质量和价值量中,干荒漠类贡献率最高,其次是高寒草原类、山地草原类、沼泽类和高寒草甸类。     

青海湖流域草地类型变化及其生态服务价值研究

结合 Costanza等人和国内草地生态服务价值研究的理论和方法对青海湖流域天然草地生态服务价值及其变化进行估算和分析.结果表明,流域内草甸类、草原类、灌丛类、沼泽类草地生态系统分布面积明显减少,荒漠类草地面积大幅增加等综合因素的影响,青海湖流域草地生态系统服务价值显著减少.研究时段内,流域草地生态系统服务年总价值减少8.93亿元,年均减少0.23亿元.     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.