某输电线路杆塔增加呼高的方案比选及处理措施

针对由于规划变动等原因导致路径变化,造成部分已加工杆塔呼高无法满足导地线对地距离要求的情况,笔者借鉴以往工程经验提出4个处理方案,并结合地形地貌、地质条件、施工技术可行性、施工安全及经济性等进行方案综合比选,最终确定最优方案。经计算分析,验证最优方案的合理性和可行性,为工程设计施工提供参考依据。

浅谈高压输电线路跨越通航河流的杆塔呼高选择

高压架空线路跨越通航河流时对船舶桅杆及建筑物等影响,按照其特点可以分为水平、垂直安全距离的限制,针对电力、航道规范的具体要求 , 不难发现水平距离的具体规定数值不如垂直距离对通航造成的不良影响来的严重,故垂直安全距离是影响通航安全的重点,在输电线路设计的时候应该严格执行规定并考虑相应的裕度要求。

计算机辅助铁塔包装的研究

介绍了应用计算机来辅助铁塔包装的软件,该软件使用方便可靠,同时能够迅速查询到零件的包装信息,软件已得到使用,包装效率、速度、准确性都得到了很大提高。

采用六相输电技术优化双回高压输电线路电磁环境的研究

随着输电线路电压等级的提升,特高压线路电磁环境问题已成为决定其杆塔尺寸的主要因素之一。文中对1 000 k V特高压双回线路和六相578 k V线路的电磁环境进行了计算和比较,结果显示采用同样的塔头和呼高情况下,六相线路的电磁环境优于三相线路。文中还研究了六相线路电磁环境随呼高的变化规律,地线及距地面最高的两根输电线的表面场强随呼高降低而降低,其余导体表面场强随呼高降低而增加;线路下方地面附近工频电场强度、无线电干扰及可听噪声均随着呼高的降低而增加。相比于同等相电压等级的三相线路,其导线表面电场强度更小。因此,六相输电可有效改善双回交流线路的电磁环境。

500KV晋家/晋港电力线路迁改施工方案及技术措施

本文介绍了京沪高速铁路施工过程中,500KV晋家/晋港电力线路迁改遇到的一些技 术难题及相关论证方法、安全技术措施。基于电力线路铁塔标高需满足倒杆距离目的, 采用搭设跨越架的方法,通过了计算铁塔呼高,得出抬高电力线路的方案可行的结论。为京沪高速铁路的建设节省建设费用,保证项目进度,确保新长铁路运行安全。

Changes in Plasma Angiotensin II and Circadian Rhythm of Blood Pressure in Hypertensive Patients with Sleep Apnea Syndrome Before and After Treatment

Objective To explore the changes in plasma angiotensin II （Ang Ⅱ） and circadian rhythm of blood pressure among hypertensive patients with sleep apnea syndrome （SAS） before and after continuous positive airway pressure （CPAP） or surgical treatment. Methods A total of 180 essential hypertension patients were enrolled in our study. The determination of plasma Ang Ⅱ concentration, ambulatory blood pressure （ABP）, and polysomnography （PSG） monitoring were performed before and 3 months after CPAP or surgical treatment. Results Patients were classified into three groups by their apnea-hypopnea index （AHI）： essential hypertension group （EH group, n=72; AHI〈5）, essential hypertension with mild SAS group （EH＋mild SAS group, n=60, 5≤AHI〈20）, and essential hypertension with moderate and severe SAS group （EH＋moderate-severe SAS group, n=48, AHI_〉20）. The concentrations of plasma AngⅡ in the above three groups were 13.42±3.27, 16.17±3.82, and 18.73±4.05 ng/mL respectively before treatment, and AngⅡ concentration in EH patients combined with SAS was significantly higher than that in EH group （all P〈0.05）. After treatment the values in the latter two groups significantly decreased to 14.67±2.56 and 15.03±3.41 ng/mL respectively （P〈0.05）. The incidence of non-dipper blood pressure curve in EH patients was 31.9%, and those in hypertensive patients with mild SAS and moderate-severe SAS were 51.7% and 58.3%, respectively before treatment. The incidence of non-dipper blood pressure curve in the EH patients with mild SAS was significantly higher than that of patients with EH alone （P〈0.05）. After CPAP treatment or surgery, the incidence of non-dipper blood pressure curve in the two SAS groups was significantly decreased to 38.3% and 39.6%, respectively （P〈0.05）. Conclusions Ang Ⅱ might play a role in blood pressure variability in patients with obstructive SAS. CPAP or surgical treatment can improve blood pressure disorder and decrease plasma Ang Ⅱ level in patients with obstructive SAS.

Studies on monitoring hemodynamics and oxygen dynamics of adult respiratory distress syndrome secondary to high altitude pulmonary edema

To study monitoring hemodynamics and oxygen dynamics of adult respiratory distress syndrome (ARDS) secondary to high altitude pulmonary edema (HAPE),we performed clinic and laboratory studies in 8 patients who preliminarily developed high altitude cerebral edema (HACE) and then ARDS occurred at an altitude of 4 500 m. After an initial emergency treatment on high mountains,all the patients were rapidly transported to a hospital at a lower altitude of 2 808 m. The right cardiac catheterizations were carried out within 5 h after hospitalized. The monitoring hemodynamics and oxygen dynamics were studied via a thermodilution Swan-Gaze catheter. The results showed that before treatments at the beginning of monitoring,there presented a significant pulmonary artery hypertension with a decreased cardiac function,and a lower oxygen metabolism in all the 8 patients. However,after some effective treatments,including mechanical ventilation and using dexamethasone,furosemide,etc,four days later the result of a repeated monitoring showed that their pulmonary artery pressure had been decreased with an improved cardiac function with all the oxygen metabolic indexes increased significantly. Our studies suggested that performing monitoring hemodynamics in patients with ARDS secondary to HAPE will define the clinical therapeutic measures which will benefit the outcome.

Repetitive narrow QRS tachycardia in a 61-year-old female patient with recent palpitations

A 61-year-old female patient suffering from recent onset palpitations and dyspnea on exertion with hypertension and mitral valve prolapse in her past history came to our outpatient department. Echocardiography revealed a mild mitral valve prolapse, slightly decreased left ventricular （LV） function （LV ejection fraction： 51%） and a mild mitral regurgitation.

BAG3-Related Myofibrillar Myopathy Presenting as Hypercapnia:A Case Report and Literature Review

Objective BAG3-related myopathy is a rare condition so far reported in twenty patients worldwide.The purpose of this study was to draw attention to this rare disease and to the fact that BAG3-related myopathy should be considered as a rare differential diagnosis of hypercapnia.Methods We report a sporadic case of a 14-year-old Chinese girl with a de novo p.Pro209 Leu mutation in BAG3 and reviewed the literatures for reported cases related to this mutation.Results We described a 14-year-old Chinese girl who presented with gradually appearing symptoms of hypercapnia that required assisted ventilation.The muscle biopsy and the blood whole-exome sequencing results confirmed the diagnosis of myofibrillar myopathy with a de novo p.Pro209 Leu mutation in BAG3.Totally twentyone patients from twenty families with a confirmed diagnosis of BAG3-related myopathy were reported to date,including this patient and literature review.The male to female ratio was 11:10 and most showed initial symptoms in the first decade of life.Most patients presented toe/clumsy walking or running as the onset symptom,followed by muscle weakness or atrophy.Creatine kinase levels were elevated in fourteen patients and were normal in three.Eighteen patients developed respiratory insufficiency during the disease course and thirteen(one could not tolerate non-invasive assisted ventilation)required non-invasive assisted ventilation for treatment.Except for one not reported,heart involvement was found in seventeen patients during the disease course and seven underwent heart transplantation.Z-disk streaming and aggregation could be observed in most of the patients’muscle histology.In the long-term follow-up,five patients died of cardiac or respiratory failure.Conclusion BAG3-associated myopathy is a rare type of myofibrillar myopathy.It should be considered as a rare differential diagnosis of hypercapnia.

Hospitalized ulcerative colitis patients have an elevated risk of thromboembolic events

AIM: To compare thromboembolism rates between hospitalized patients with a diagnosis of ulcerative colitis and other hospitalized patients at high risk for thromboembolism. To compare thromboembolism rates between patients with ulcerative colitis undergoing a colorectal operation and other patients undergoing colorectal operations. METHODS: Data from the National Hospital Discharge Survey was used to compare thromboembolism rates between (1) hospitalized patients with a discharge diagnosis of ulcerative colitis and those with diverticulitis or acute respiratory failure, and (2) hospitalized patients with a discharge diagnosis of ulcerative colitis who underwent colectomy and those with diverticulitis or colorectal cancer who underwent colorectal operations. RESULTS: Patients diagnosed with ulcerative colitis had similar or higher rates of combined venous thromboembolism (2.03%) than their counterparts with diverticulitis (0.76%) or respiratory failure (1.99%), despite the overall greater prevalence of thromboembolic risk factors in the latter groups. Discharged patients with colitis that were treated surgically did not have signifi cantly different rates of venous or arterial thromboembolism than those with surgery for diverticulitis or colorectal cancer.CONCLUSION: Patients with ulcerative colitis who do not undergo an operation during their hospitalization have similar or higher rates of thromboembolism than other medical patients who are considered to be high risk for thromboembolism.

High-resolution 3D Structures Reveal the Biological Functions of Reoviruses

Viruses in the family Reoviridae are non-enveloped particles comprising a segmented double-stranded RNA genome surrounded by a two-layered or multi-layered icosahedral protein capsid.These viruses are classified into two sub-families based on their particle structural organization.Recent studies have focused on high-resolution three-dimensional structures of reovirus particles by using cryo-electron microscopy (cryo-EM) to approach the resolutions seen in X-ray crystallographic structures.The results of cryo-EM image reconstructions allow tracing of most of the protein side chains,and thus permit integration of structural and functional information into a coherent mechanism for reovirus assembly and entry.

Response of Ecosystem Respiration to Experimental Warming and Clipping at Daily Time Scale in an Alpine Meadow of Tibet

The alpine meadow, as one of the typical vegetation types on the Tibetan Plateau, is one of the most sensitive terrestrial ecosystems to climate warming. However, how climate warming affects the carbon cycling of the alpine meadow on the Tibetan Plateau is not very dear. A field experiment under controlled experimental warming and clipping conditions was conducted in an alpine meadow on the Northern Tibetan Plateau since July 2008. Open top chambers （0TCs） were used to simulate climate warming. The main objective of this study was to examine the responses of ecosystem respiration （Reco） and its temperature sensitivity to experimental warming and clipping at daily time scale. Therefore, we measured Reco once or twice a month from July to September in 2010, from June to September in 2011 and from August to September in 2012. Air temperature dominated daily variation of Reco whether or not experimental warming and clipping were present. Air temperature was exponentially correlated with Reco and it could significantly explain 58-96% variation of Redo at daily time scale. Experimental warming and clipping decreased daily mean Reco by 5.8-37.7% and -11.9-23.0%, respectively, although not all these changes were significant. Experimental warming tended to decrease the temperature sensitivity of Reco, whereas clipping tended to increase the temperature sensitivity of Reco at daily time scale. Our findings suggest that Reco wasmainly controlled by air temperature and may acclimate to climate warming due to its lower temperature sensitivity under experimental warming at daily time scale.

Meta-analysis of effects of obstructive sleep apnea on the renin-angiotensinaldosterone system

Background Obstructive sleep apnea （OSA） is the most common cause of resistant hypertension, which has been proposed to result from activation of the renin-angiotensin-aldosterone system （RAAS）. We meta-analyzed the effects of OSA on plasma levels of RAAS components. Methods Full-text studies published on MEDL1NE and EMBASE analyzing fasting plasma levels of at least one RAAS component in adults with OSA with or without hypertension. OSA was diagnosed as an apnea-hypopnea index or respiratory disturbance index 〉 5. Study quality was evaluated using the Newcastle-Ottawa Scale, and heterogeneity was assessed using the 12 statistic. Results from individual studies were synthesized using inverse variance and pooled using a random-effects model. Subgroup analysis, sensitivity analysis, and meta-regression were performed, and risk of publication bias was assessed. Results The meta-analysis included 13 studies, of which 10 reported results on renin （n = 470 cases and controls）, 7 on angiotensin II （AnglI, n = 384）, and 9 on aldosterone （n = 439）. AnglI levels were significantly higher in OSA than in controls [mean differences = 3.39 ng/L, 95% CI： 2.00-4.79, P 〈 0.00001], while aldosterone levels were significantly higher in OSA with hypertension than OSA but not with hypertension （mean differences = 1.32 ng/dL, 95% CI： 0.58-2.07, P = 0.0005）. Meta-analysis of all studies suggested no significant differences in aldosterone between OSA and controls, but a significant pooled mean difference of 1.35 ng/mL （95% CI： 0.88-1.82, P 〈 0.00001） emerged after excluding one small-sample study. No significant risk of publication bias was detected among all included studies. Conelusions OSA is associated with higher AnglI and aldosterone levels, espe- cially in hypertensive patients. OSA may cause hypertension, at least in part, by stimulating RAAS activity.

Relationship between sleep apnea hypopnea syndrome and cardiovascular events in elderly Chinese snorers

OBJECTIVE: To investigate the relationship between sleep apnea hypopnea syndrome (SAHS) and some cardiovascular abnormalities in elderly snorers, as well as the effectiveness of nasal continuous positive airway pressure on those with SAHS. METHODS: With the use of polysomnography, 73 elderly snorers (older than 60 years) were examined and placed into either the SAHS group or the control group. Using ambulatory electrocardiogram (ECG) and blood pressure measurement, daily nocturnal rhythm of blood pressure, hypertension, heart rate variability, some arrhythmia and angina pectoris of coronary heart disease (CHD) were monitored and compared between the two groups before and after 5 - 7 days of treatment with nasal continuous positive airway pressure on the SAHS group. RESULTS: This study indicated a higher incidence (47.9%) of sleep apnea syndrome in elderly snorers and demonstrated that there was a significantly higher incidence of hypertension, disappearance in daily nocturnal rhythm of blood pressure, poor effectiveness of nitrate on angina pectoris of coronary heart disease, decreased heart rate variability during sleep, increased arrhythmia and lower pulse oxygen saturation (SpO(2)) levels in the SAHS group than in the control group. After nasal continuous positive airway pressure treatment during sleep, snoring control, significantly higher SpO(2) levels and lower index of apnea/hypopnea were achieved in the SAHS group; heart rate variability (HRV) and blood pressure day nocturnal rhythm were returned to normal levels. CONCLUSION: This research suggests that there is a close relationship between the development of sleep apnea syndrome and some cardiovascular diseases. Continuous positive nasal airway pressure is effective not only on SAHS but also on coexisting cardiovascular disorders.

Seasonal and diurnal variation in ecosystem respiration and environmental controls from an alpine wetland in arid northwest China

Wetlands store large amounts of carbon stocks and are essential in both global carbon cycling and regional ecosystem services.Understanding the dynamics of wetland carbon exchange is crucial for assessing carbon budgets and predicting their future evolution.Although many studies have been conducted on the effects of climate change on the ecosystem carbon cycle,little is known regarding carbon emissions from the alpine wetlands in arid northwest China.In this study,we used an automatic chamber system(LI-8100A)to measure ecosystem respiration(ER)in the Bayinbuluk alpine wetland in northwest China.The ER showed a significant bimodal diurnal variation,with peak values appearing at 16:30 and 23:30(Beijing time,UTC+8).A clear seasonal pattern in ER was observed,with the highest value(19.38μmol m-2 s-l)occurring in August and the lowest value(0.11μmol m-2 s-1)occurring in late December.The annual ER in 2018 was 678 g C m-2 and respiration during the non-growing season accounted for 13%of the annual sum.Nonlinear regression revealed that soil temperature at 5 cm depth and soil water content(SwC)were the main factors controlling the seasonal variation in ER.The diurnal variation in ER was mainly controlled by air temperature and solar radiation.Higher temperature sensitivity(Qio)occurred under conditions of lower soil temperatures and medium SWC(25%≤SWC≤40%).The present study deepens our understanding of CO,emissions in alpine wetland ecosystems and helps evaluate the carbon budget in alpine wetlands in arid regions.