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加强设计阶段工程造价管理是控制工程项目投资的关键。针对目前造价管理中出现的问题,文中分析了设计阶段造价失控的原因,并提出了相应的解决措施。  相似文献   

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The wood pastures or hardwood rangelands of the southwestern Iberian Peninsula are complex social-ecological systems created from the long-term interaction of society and the landscape. Dehesa, oak woodlands managed for grazing, cropping, and other forms of production, is the most common rangeland system and one of the most distinctive landscapes. Traditionally characterized by multifunctional low-intensity management that enhances a wide range of ecosystem services, current management has shifted from the traditional toward more intensified models. This paper assesses the coproduction of ecosystem services on dehesa properties by exploring the relationship between biophysical and sociocultural factors and dehesa management practices. Based on 42 surveys we analyze 16 quantitative indicators using multivariate techniques. The results indicate that there are four main dehesa types as defined by their characteristics and management: large heterogeneous operations with diverse products; small and homogeneous operations focused on a reduced number of products; medium-large properties focused on crop production; and midsized properties with easy public access. Management is the result of the dynamics of interacting biophysical and sociocultural factors that influence manager priorities and investments. Management decisions group around the degree of multifunctionality of the operation, the relative importance of crop production, the degree of grazing pressure in the system, and how restrictive public access policy is. We find that in the study area, interactions between all the previously mentioned elements covary consistently, generating bundles of ecosystem services associated with each of three management models based on the intensity of management.  相似文献   

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概述了目前草坪单子叶杂草的防除进展和存在的问题。明确主要恶性单子叶杂草的生物学特性和发生规律,提高草坪的管理水平、选择和培育适合当地生长的草坪草种,采用混播栽培管理措施和合理运用化学方法来综合防除单子叶杂草。创造有利于草坪草生长而不利于单子叶杂草生长发育的环境,使杂草在竞争中自然淘汰。  相似文献   

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关中地区果草系统产草量与对杂草的控制   总被引:1,自引:0,他引:1  
于苹果园建植第1年的春季,在果树行间分别种植不同草种,以不种草为对照,研究不同草种的生长情况和其对杂草群落的影响。结果表明,在关中地区苹果园牧草春播后,白三叶(Trifolium repens)、红三叶(T.pratense)、多年生黑麦草(Lolium perenne)、紫羊茅(Festuca rubra)、高羊茅(F.arundinacea)出苗和生长较快,短期内能形成致密的草层,杂草种类、密度和盖度小,抑制杂草效果好;草地早熟禾(Poa pratensis)、匍匐剪股颖(Agrostis stolonifera)、百脉根(Lotus cornioulatus)、马蹄金(Dichondra repens)、狗牙根(Cynodon dactylon)出苗和保苗难度较大,到秋季才能完全覆盖地面,种植后前半年抑制杂草的作用较差,而在形成致密草层后,各草种均能很好地抑制杂草群落发展。第2年,除马蹄金、狗牙根外,其余草种均能在3月返青,11月后枯黄,绿期长。马蹄金匍匐茎水平生长速度适中,垂直高度常年保持在10~15 cm,既能很好地覆盖地面,又无需修剪,维护费用最低;白三叶、红三叶、百脉根生长速度适宜,在生长季可以根据需要决定修剪或不修剪;多年生黑麦草、高羊茅生长速度较快,生物量较大,种植当年需要修剪1次,第2年可根据需要确定修剪次数;匍匐剪股颖和紫羊茅生长速度相对较慢,可适当减少修剪次数;狗牙根返青晚、枯黄早,水平扩展速度和生长速度太快,不适合苹果园种植。说明各草种在果园中的适宜性不一,其不同的生长特性是种草果园管理的重要基础,草种盖度和其抑制杂草群落发展的效果密切相关。  相似文献   

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通过对三江源区人工草地常见三种毒杂草的危害性研究得知:就植物群落而言,甘肃马先蒿对垂穗披碱草的危害性最大,铁棒锤居中,黄帚橐吾较轻;就植物地上生物量而言,铁棒锤对垂穗披碱草的危害性最大,甘肃马先蒿次之,黄帚橐吾较轻。甘肃马先蒿、铁棒锤、黄帚橐吾的入侵,促使人工草地的逆向演替,导致了人工草地的极度退化。  相似文献   

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Background

The quantitative effect of strong electrolytes, unmeasured strong anions (UAs), pCO 2, and plasma protein concentrations in determining plasma pH can be demonstrated using the physicochemical approach. Plasma anion gap (AG) and strong ion gap (SIG) are used to assess UAs in different species.

Hypotheses

Strong ions are a major factor influencing changes in plasma pH of hospitalized foals. AG and SIG accurately predict severe hyper‐l‐lactatemia ([l‐lac] > 7 mmol/L).

Animals

Seven hundred and ninety three hospitalized foals < 7 days old.

Methods

Retrospective study. The relationship between measured pH and physicochemical variables, and the relationship between plasma [l‐lac] and AG and SIG, were determined using regression analyses. Optimal AG and SIG cut points to predict hyper‐l‐lactatemia were identified using an ROC curve analysis.

Results

Combined, the measured strong ion difference and SIG accounted for 54–69% of the changes in the measured arterial pH of hospitalized foals. AG and SIG were significantly associated with plasma [l‐lac] (P < .0001). The receiver operator characteristics (ROC) AUC of AG and SIG for prediction of severe hyper‐l‐lactatemia were 0.89 (95%CI, 0.8–0.95; P < .0001) and 0.90 (95%CI, 0.81–0.96; P < .0001), respectively. Severe hyper‐l‐lactatemia was best predicted by AG > 27 mmol/L (sensitivity 80%, 95%CI, 56–94, specificity 85%, 95%CI, 73–93; P < .0001) and SIG <−15 mmol/L (sensitivity 90%, 95%CI, 68–98; specificity 80%; 95%CI, 68–90; P < .0001).

Conclusion and clinical relevance

Altered concentrations of strong ions (Na+, K+, Cl) and UAs were the primary cause of acidemia of hospitalized foals. AG and SIG were good predictors of hyper‐l‐lactatemia and could be used as surrogate tests.  相似文献   

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针对新时期高校院系办公室的工作特点和存在的主要问题,提出了运用人本管理思想、规范化管理思想和组织学习理论等创新管理理念,结合工作实践,通过管理育人、完善制度、知识共享等途径,来达到提高办公室管理工作水平的目的。  相似文献   

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There are few published reports of equine enterocutaneous fistulae, and they are almost always related to umbilical hernias. Colocutaneous fistula as a result of a penetrating wound has not been reported in horse. In this case report, surgical treatment of a traumatic colocutaneous fistula in an 8-year-old stallion is described. Under inhalation anesthesia, the fistula was removed completely, and the resultant defect on the left ventral colonic wall was closed. The defect of abdominal wall was closed routinely. The horse regained his previous performance, and no surgical complication was observed at 1 year’s follow-up.  相似文献   

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为了有的放矢地推进兽药使用管理和确保兽用使用安全,对宁夏省规模养殖场(园区)兽药使用管理的技术力量、兽药贮存条件、兽药来源及贮存方式、兽药使用及休药期执行情况等进行了调查分析,表明规范兽药使用管理已具备有利条件,同时探讨了规范兽药使用管理的主要内容和重点措施。  相似文献   

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Research that advances the practice of poultry nutrition covers a wide range, including fundamental studies that explore mechanisms in cells or a small number of birds and applied research that determines product yield in authentic production facilities. Ultimately, the applied research informs the economic analysis necessary for implementation of novel nutritional strategies or products. Nutritional controversies arise from applied research experiments that were not designed and interpreted based on the realities learned from mechanistic work. The experimental design and measurements selected for comparing nutrient sources or setting nutrient recommendations should be informed by underlying mechanistic information, such as the relative priorities of cells and tissues for the nutrient and the shape of the dose response relationship across a wide range of added dietary levels of the nutrient. Integrating mechanistic and applied research provides more robust results that can be used across wider ranges of diets and husbandry conditions.  相似文献   

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家庭蚕桑适度规模经营的实践探索   总被引:1,自引:0,他引:1  
推地蚕桑适度规模经营是提高蚕桑生产经济效益的一项主要途径。海宁市对蚕桑适度规模经营进行了试点实践和调查,并就提出该课题的依据,可能性,典型蚕户的经营分析,适度规模经营的指标,优缺点进行了有益探讨。  相似文献   

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江南冷季型草坪建植与养护技术要点   总被引:7,自引:0,他引:7  
冷季型草坪在美化江南城市中起了很大作用 ,对江南冷季型草坪建植与养护技术进行了探讨 ,以促进对这些技术的掌握 ,从而提高冷季型草坪在江南城市中推广。  相似文献   

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The aim of the study was to evaluate the fecal fermentation of partial replacing steam rolled corn with soybean hulls (SH) or prickly pear cactus (PC) as energy source in horse diets, in the presence of Saccharomyces cerevisiae. Steam rolled corn was replaced with SH at 0% (control), 7.5% (SH75), and 15% (SH150) in the first trial, whereas it was replaced with PC at 0% (control; the same of the first trial), 7.5% (PC75), and 15% (PC150) in the second trial. Yeast of S. cerevisiae was added at 0, 2, and 4 mg/g dry matter (DM) of incubated substrates. Fecal inoculum was obtained from four adult English Thoroughbred horses fed on an amount of commercial concentrate and oat hay ad libitum. Interactions observed between PC rations and yeast doses for the asymptotic gas production (GP), the rate of GP and carbon dioxide (CO2) production during some incubation hours. Moreover, with no effect due to SH rations (P > .05), increased (P < .05) rate of GP was observed with the ration PC75 compared with other rations. Besides, PC75 and PC150 rations with 0 mg yeast/g DM linearly decreased (P < .05) CO2 production at some incubation hours. However, SH75 and SH150 ration had increased (P = .005) DM degradability (DMD). Yeast addition at 2 mg/g DM increased the asymptotic GP (P = .048) with the SH75 and PC150 rations. The level of 4 mg yeast/g DM increased the asymptotic GP (P = .048) from the SH150 ration. Yeast addition at 2 and 4 mg/g DM increased (P < .05) ​the asymptotic GP from PC75 and PC150 rations, respectively, with increasing DMD with the both doses. Yeast addition increased (P < .05) CO2 production from SH75, SH150, PC75, and PC150 rations. It could be concluded that SH and PC can replace steam rolled corn at levels of 7.5% to 15% without negative effect of fermentation kinetics and with better fermentation performance in the presence of yeast at 2 mg/g DM of substrates.  相似文献   

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通过对成都地区草坪的多点实地调查,发现了管理养护中存在的问题,并针对存在的问题提出了相应的对策和建议。  相似文献   

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文章从饲养管理方面对安格斯肉牛育成母牛的饲养管理进行实践总结。安格斯育成母牛是指7月龄到初配受胎这段时间,相对于犊牛和成年母牛而言,育成母牛对环境的适应能力已大大提高。无妊娠、产奶的负担,疾病较少,饲养管理相对较容易,育成母牛饲养的主要目的是通过合理的饲养,使其按时达到理想的体型,体重标准性成熟,按时配种受胎。并为其一生的高产打下良好的基础。2016年甘肃宏福现代农牧产业有限责任公司从澳大利亚引进纯种500头,笔者进行了技术服务,根据工作实践、体会浅谈安格斯肉牛育成母牛的饲养管理技术,以供参考。  相似文献   

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Biotechnological procedures are valuable tools for an efficient reproductive management in a commercial pig production. Artificial insemination, puberty induction, estrus synchronization, early pregnancy diagnosis and induction of parturition are routinely used since years already and have significant impact for the herd management of sows. Embryo transfer (ET) can also be efficiently applied. But surgical procedures are required for the recovery and transfer of embryos. ET related biotechniques such as cryopreservation of ova and embryos, in vitro production of embryos, cloning and gene transfer are still at an experimental stage but will most likely gain significance shortly.  相似文献   

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