额济纳绿洲胡杨生物生态学特性的调查

2001～2003年3年内对分布于额济纳国家级胡杨林自然保护区中的二道桥至七道桥的胡杨，进行其生境概况、物候期、生长发育状况、种子繁殖和营养繁殖等生物学、生态学特性的观测，观测结果表明：胡杨花芽每年的5月开始分化，种子可3天萌发，胡杨花序上的花一般为单性花，但也能观察到雄花序中夹杂着几朵雌花，或雌花序中夹杂着几朵雄花或夹有两性花，但比例极小。2m以上且具明显主茎的胡杨植株拥有2种以上叶形，披针形叶多分布在下层枝条，一枝多形叶，一树多形叶。胡杨是浅根性树种，横走根上产生不定芽，但芽形成的部位不产生不定根。不定芽发育成无性系小株，喜光、抗冻、耐温差、耐早力强、抗风沙、耐盐碱、耐腐蚀、具趋水性。     

宋培龙:带三千农户养兔奔小康

<正>在山东省梁山县韩岗镇,一提起宋庄村32岁的大学生宋培龙,干部群众都交口称赞:这小伙子,有知识,有远见。宋培龙通过养兔,带富了一方群众。日前,笔者慕名来到宋培龙创办的富仕达养兔场。走进养殖场,只见装满肉兔和种兔的6辆汽车整装待发,在23栋兔舍内10多名员工和几名大学生,聚精会神地摆弄着机器,给一排排兔舍上料、清理卫生,兔舍里整洁宜人,没有异味。场部办公室墙面上,挂满了省市县的各种奖状和荣誉证书。     

人类用隔离抗击疫情有三千年历史

题:从1918年西班牙大流感到新型冠状病毒:人类的隔离历史(记者阿夫里尔·菲利普斯)为遏制新型冠状病毒感染肺炎扩散,中国决定对疫情的“震中”武汉市进行封城隔离,并对其他多个城市也采取了严格的管控措施。流行病疫情并非新现象,为遏制病毒传播而隔离个人或社区的做法也早已有之。这种做法已经有大约3000年的历史了,只不过现在的技术含量越来越高罢了。那么,历史上的隔离措施是否都奏效了呢?     

黑城兴衰与额济纳绿洲环境演变的思考

为了防止黑城历史悲剧的重演,通过对黑城及其周围环境历史兴衰的探讨与思考,提出了维护和平与稳定、兴修水利、保护和更新植被等一系列抢救绿洲、治理和保护生态环境的建议和措施。考察和回顾历史,是为了给今天的人们带来更多的思考,从而达到学习历史经验,汲取历史教训,正确对待今天,建设美好未来的目的。从黑城的兴衰到额济纳绿洲的环境演变,可以得到一些启示和初步的结论。     

额济纳绿洲生态恶化的现状、成因与对策

1额济纳绿洲概况额济纳旗是内蒙古自治区阿拉善盟的一个县级行政区,位于我国西北部中蒙边界附近,是阿拉善高原的一部分,面积约114.606km2,绿洲面积仅存约3.288km2,分布于额济纳河东、西支流两岸。额济纳旗总人口只有约1.62万人,是一个以蒙古     

额济纳绿洲环境变迁与生态危机及其可持续发展对策

对额济纳绿洲环境变迁的历史与现状进行了分析,认为自然环境的不断恶化和近代人类活动的强度干扰是导致额济纳绿洲生态危机的主要原因.在此基础上,提出了恢复绿洲及其可持续发展的相应对策.     

胡杨枝叶的饲用价值

胡杨为杨柳科乔木树种。胡杨叶十分奇特,不同的生长阶段有不同的叶形,幼苗期叶都为长条形,幼树叶为条状披针形,成年大树叶为卵圆形,由于多态的叶形,为荒漠的森林自然景观增添了几分姿色。胡杨在我国主要分布在新疆、甘肃、内蒙     

胡杨花粉的毒理学安全性研究

为了评价胡杨花粉作为食品开发的安全性,采用小白鼠经口急性毒性试验、30 d喂养试验、骨髓细胞微核试验、精子畸形试验进行检测.结果:急性毒性试验显示LD50大于15.0 g/kg,属实际无毒级;30 d喂养试验未显示明显毒性;骨髓微核试验、精子畸形试验均为阴性.     

额济纳荒漠红砂泌盐特征的研究

选择额济纳荒漠3个典型红砂群落作为样地,通过测定土壤盐分含量、红砂体内盐分含量及叶片的泌盐量,分析红砂的泌盐特征及其与土壤盐分状况、红砂体内盐分含量的关系.结果表明:样地土壤、红砂体内及分泌的主要盐分离子为K+、Na+、Ca2+、Mg2+、Cl-、SO42-,样地土壤中阳离子Na+和Ca2+含量较高,阴离子SO42-含...     

苏州的井水与水井

在我看来,水有两种,一种是躺着的,一种是站着的.躺着的水是江河湖泊,站着的就是井水.当然还有一种天落水,也就是雨.至今民间还有把雨叫成"天落水"的. 《东坡志林》里有《论雨井水》:"时雨降,多置器广庭中,所得甘滑不可名,以泼茶煮药,皆美而有益,正尔食之不辍,可以长生.其次井泉甘冷者,皆良药也."     

羊角小镇物语

第一次岩崩诞生了羊角小镇,或许还有第二次岩崩,那时我们将无法挽留。
　　羊角豆腐干
　　这张小小的名片,来自
　　一个名叫羊角的小镇
　　阳光缓缓地俯下身来
　　大豆,这些不安分的作物
　　像汗滴样被依次唤醒     

Forelimb Conformation,Sales Results,and Lifetime Racing Performance of 2-Year-Old Thoroughbred Racing Prospects Sold at Auction

To determine associations between carpal and fetlock conformation and later performance, 292 two-year-old (2YO) Thoroughbred horses were examined at a public auction. Two observers graded carpal and fetlock conformation in the frontal view, and subject weights were estimated (weight tape), and height was measured. Subject age, gender, and workout distance and time were retrieved from sales data. Lifetime racing data was retrieved from the Jockey Club database. Mild to moderate deviations from straight forelimb conformation at the carpus or fetlock occurred in 85% of 2YO Thoroughbreds and had no substantive effect on lifetime racing performance. Carpal and fetlock conformation are associated. Greater age, female gender and faster workout were associated with better short and long-term racing outcomes. The ability to start a race at 2YO was associated with improvements in several measures of racing success. The lack of an association of forelimb conformation with most measures of racing performance will assist producers and consumers of young racing stock in the determination of the need for corrective procedures in young horses and the importance of deviations at purchase. Speed of workout and the ability to start at 2YO were associated with each other and with an improvement in several racing outcomes.     

“瓦子”和城市

曾几何时,城里是一个极为严肃的地方,君王在那儿面南端坐,周围的宗庙威严、祭师冷酷、杀殉无情,钟磬之声,令人战栗匍匐.后来,社会开放,商人得了自由,游手好玩的人也得了自由,彼此相聚城郭,致使城市买卖玩闹的气氛大增.住在一角的君王,也有禁不住诱惑,微服的出来玩耍的.放眼看一看中国城市的发展史,至少有三次从肃清到繁华的变革高潮,一次在春秋战国,一次在北宋,还有一次可算是眼下.当然,三者的性质迥异,从怎样的肃清变到怎样的繁华,各不相同,而且变出来的东西的名称也不一样.     

Blood biochemical characteristics of cattle at sea level and at moderately high altitude (3,000 m).

We investigated the biochemical composition of blood from Holstein cows, native breed (criollas), and cows descended from fighting bulls (Vacas de lidia) raised at an altitude of 3,000 m (moderately high altitude, MHA), and compared the results with those from Holsteins and cows of similar genetic ancestry as the criollas (scrub cows), both raised at sea level (SL), to determine blood biochemical values characteristic of adaptation to high altitude. Only potassium and calcium concentrations were similar among groups. Glucose concentration was lower in MHA cows, with the exception of Vacas de lidia. Serum bicarbonate concentration was lower in MHA cows; this finding can be explained by hyperventilation in the hypoxic environment. Serum magnesium concentration was lower in SL and MHA Holsteins than in other groups. Serum phosphate concentration was lower in scrub cows, MHA Holsteins, and criollas than in other groups. Cholesterol concentrations were lower in SL Holsteins, whereas triglycerides were higher in scrub cows and MHA Vacas de lidia. Concentration of high-density lipoprotein was significantly greater in Vacas de lidia and less in MHA criollas than in the other groups. Uric acid and total protein were higher in MHA groups. Using radioimmunoassay for human proteins, thyroxine-binding globulin was undetectable. Total and free thyroxine and free triiodothyronine were higher in scrub cows, followed by Vacas de lidia; lower values were detected in SL and MHA Holsteins and MHA criollas.     

系在水边的古镇沙沟

中国叫沙沟的地方很多,比如钱钟书先生就住在北京一个叫沙沟的地方,张承志先生的《心灵史》中也写到了沙沟……而我们要说的沙沟,在江苏泰州兴化,是一座具有两千多年历史,却被时光遗忘了的衰败的古镇.衰败的美是一种令人心疼的美,尤其是一个在水中央的古镇,更是让人心疼.好在沙沟古镇还有清澈的水,它依旧被"两湖五荡"——大纵湖、郭正湖、南荡、花粉荡、官庄荡、王庄荡和团头荡环抱着."两湖五荡"里,有万亩荷塘和无边无际的芦苇,油菜花开的时候,浓郁的花香几乎把古镇抬到了空中.     

从斜桥镇看重点地区蚕桑生产的问题与对策

<正>斜桥镇位于海宁市中北部,是海宁市蚕桑生产重点镇之一,全镇现有桑园面积565hm2,养蚕农户9967户,全年饲养蚕种2万张左右,是农民增收的重要传统产业之一。近年来,由于茧价下跌、中秋蚕气候恶劣以及"两新"工程的推进,蚕桑生产面临着前所未有的冲击。