被动锁模钛宝石激光器时序紊乱度的测量及控制

在实验研究的基础上提出了一套完整地用于测量被动锁模钛宝石激光器时序紊乱度的方案 ,即 :对于具有较小的时序紊乱度的激光器系统 ,频域法是主要的测量方法 ;对时序紊乱度较大的激光器系统的测量 ,频域法不再适合 ,而使用同步扫描相机的时域法具有更加精确的优点。采用腔长调变的方法对被动锁模钛宝石激光器的时序紊乱度进行了控制 ,使时序紊乱度由 6 .6 0ps降低到 0 .47ps。

长丝变形纱的紊乱结构

化纤长丝的变形加工是使规则排列的长丝束变成具有一定稳定度、结构排列相对混乱的过程,因而可以将变形纱在结构上的次序性特征定义为紊乱结构。紊乱结构是变形纱的基本结构特征之一,较好地解释了变形纱诸多物理现象。变形纱紊乱结构的数学模型可从熵变的角度出发,并最终表达线性体系中单丝片段无序性与其空间状态体积数的关系,同时也可为三维直角坐标系中单丝片段分布的密度函数。相对紊乱度、相对熵变值及变形纱膨松度指数是重要的紊乱度参数,可通过测量变形线性体的线密度、表观直径等参数进行计算。

变形纱成纱熵变和膨松性能的关系

纱线成形过程主要以纤维或丝束空间排列秩序性的变化为特征,因而存在着熵变现象,大多数变形加工过程具有熵增加的特点。熵是状态函数,因此变形纱熵变和其膨松性能关系密切,理论推导表明,成纱熵变和膨松指数的对数成正比,与膨松度呈正相关关系;变形纱紊乱度值与膨松指数在数值上相等,与膨松度呈正相关,实验结果与上述结论一致。由于变形纱紊乱度在数值上与纱线膨松指数值相等,因此可以通过测定纱线膨松指数的方法测量变形纱线的紊乱度值,进而量化研究成纱熵变的大小。

长丝变形纱缠结结构研究

缠结结构是变形纱的基本结构特征之一,较好地解释了变形纱的诸多物理现象,如变形纱结构的稳定性,空气变形纱抗弯刚度过高等等。变形纱的缠结结构与紊乱结构同时产生于变形加工过程中纤维片段的转移,因而二者关系密切,互为依存条件,可以用缠结点密度和缠结度表征变形纱缠结结构的锁节程度。采用物理质点轻质弹簧理论,分析系统中各结点的作用力学关系,可获得各结点运动的牛顿力学方程。变形纱缠结程度与其抗弯性能关系密切,可采用间接测试方法。

基于预处理和网格自适应的风力机翼型气动力计算

用预处理后的Navier-Stokes方程数值模拟低马赫数下风力机翼型的静态和动态绕流流动。为了提高计算的精度,运用了网格自适应技术:初始网格的流场计算收敛后,采用流场速度的紊乱度捕捉湍流区域;采用直接分裂初始父单元的H型网格加密方法对湍流区域进行局部加密。基于初始网格与自适应网格的计算结果与实验结果的对比表明,网格自适应方法提高了计算的精度。

利用RS和GIS技术对沈阳市城市边缘区扩展的研究

为深入分析沈阳市城市边缘区扩展的特征和趋势,利用RS技术,解译了沈阳市1979,1992,2010年的遥感影像,并采用景观紊乱度指数,对3年的沈阳城市边缘区范围进行界定。结合GIS技术的空间分析功能,从扩展数量、扩展方向、扩展形态和区域、扩展强度等方面对沈阳城市边缘区的扩展进行研究。结果表明:沈阳市城市边缘区扩展逐步加快,1979~2010年,沈阳市城市边缘区的范围增加1010.71km2,面积扩大3.7倍,平均每年扩展32.60km2。1992~2010年沈阳城市边缘区的扩展强度是1979~1992的5倍,在扩展数量、速度方面都远大于后者,呈现向东和南的扩展的趋势。这与沈阳市的经济发展情况基本相符,表明该方法具有可行性,同时该研究能为深入研究城镇化进程和编制相关规划提供依据。

空气变形纱成纱熵变与外观光泽的关系

纱线的相对熵值在成纱过程中会发生明显的变化,因其与紊乱度直接相关,所以对纱线的外观光泽也存在较大的影响。为查明变形纱成纱熵变与其外观光泽之间的内在联系和作用方式,选择具有典型紊乱结构,且表面紊乱程度较大的空气变形类型的纱线为对象,对多种规格的原复丝进行了单因子试纺,并做相应测试分析。结果表明,空气变形加工可明显提高成纱结构的紊乱度和相对熵值,而异收缩多重变形也同样可以提高纱线的紊乱度和相对熵值,但增幅相对较小;随着相对熵值和紊乱度的增加,变形纱线的峰值反射率和反射率下降,峰宽率增加,光泽柔和,极光减退。

南宁市城郊结合部地域范围界定研究

该文以2006年LANDSAT-5卫星获取的TM影像为基础数据源,在ARCGIS和ENVI软件的支持下,应用景观紊乱度模型,分析熵值分布特点,以建成区边缘为内边界,以景观紊乱度值0.4为域值确定外边界,最终确定南宁市城郊结合部范围及各乡镇与城郊结合部的归属关系,为南宁市规划部门及管理部门提供科学依据.

新型滚筒式海带清洗机的设计与研究

针对现有海带清洗不彻底、结块杂质、表面残留重金属以及受损率高的清洗难题,设计新型滚筒式海带清洗机。该清洗机通过增强水流紊乱度和固体摩擦提高洗净率,利用超声波去除重金属,采用圆形滚筒和光滑摩擦凸起避免海带受损。清洗机的核心部件离心轴需承受较大的旋转扭矩,利用Hypermesh软件对其进行有限元分析,计算其应力最大值,验证离心轴强度,经验证完全符合材料许用强度。新型滚筒式海带清洗机可以实现较高的洗净率和较低的受损率。

固体激光器

TN248.1 2002053365LD泵浦Nd:YVO4/Cr:YAG被动调Q绿光激光器=LD-pumped Nd:YVO4/Cr:YAG passively Qswitchedgreen laser[刊,中]/郑权（中科院长春光机所.吉林,长春（130022））,赵岭（中科院上海光机所.上海 （201800））//激光与红外.—2001,31（6）.—338-339报道了一种LD近贴泵浦、KTP晶体腔内倍频的Nd:YVO4/Cr:YAG结构高重复频率被动调Q绿光激光器。在注入泵浦功率为750mW时。

Bone mineral density and disorders of mineral metabolism in chronic liver disease

AIM： To estimate the prevalence and identify the risk factors for metabolic bone disease in patients with cirrhosis. METHODS： The study was performed on 72 Indian patients with cirrhosis （63 male, 9 female; aged 〈 50 years）. Etiology of cirrhosis was alcoholism （n = 37）, hepatitis B （n = 25） and hepatitis C （n = 10）. Twenty-three patients belonged to Child class A, while 39 were in class B and 10 in class C. Secondary causes for metabolic bone disease and osteoporosis were ruled out. Sunlight exposure, physical activity and dietary constituents were calculated. Complete metabolic profiles were derived, and bone mineral density （BMD） was measured using dual energy X ray absorptiometry. Low BMD was defined as a Z score below -2. RESULTS： Low BMD was found in 68% of patients. Lumbar spine was the most frequently and severely affected site. Risk factors for low BMD included low physical activity, decreased sunlight exposure, and low lean body mass. Calcium intake was adequate, with unfavorable calcium： protein ratio and calcium： phosphorus ratio. Vitamin D deficiency was highly prevalent （92%）. There was a high incidence of hypogonadism （41%）. Serum estradiol level was elevated significantly in patients with normal BMD. Insulin-like growth factor （IGF） 1 and IGF binding protein 3 levels were below the age-related normal range in both groups. IGF-1 was significantly lower in patients with low BMD. Serum osteocalcin level was low （68%） and urinary deoxypyridinoline to creatinine ratio was high （79%）, which demonstrated low bone formation with high resorption. CONCLUSION： Patients with cirrhosis have low BMD. Contributory factors are reduced physical activity, low lean body mass, vitamin D deficiency and hypogonadism and low IGF-1 level.

Prevalence and dietetic management of mild gastrointestinal disorders in milk-fed infants

AIM: To assess the prevalence of mild gastrointestinal disorders in milk-fed infants in paediatric practice, and to evaluate the effectiveness and satisfaction with dietetic treatment.METHODS: A cross-sectional epidemiological study was first carried out. A total of 285 paediatricians included 3487 children seen during a period of one week. In a second phase an observational, prospective and multicentre study was conducted and 2069 milk-fed infants with mild gastrointestinal disorders (colic, constipation, regurgitation and diarrhoea) were included. There was a baseline visit (start of treatment) and a final visit four weeks later. The effectiveness of the various Novalac formulas, as well as the satisfaction of the parents/tutors and paediatricians with the dietetic treatment were assessed at the final visit.RESULTS: The prevalence of mild gastrointestinal disorders was 27.8% of all paediatrician consultations (9.2%, 7.8%, 6.1% and 4.6% in relation to colic, constipation, regurgitation and diarrhoea, respectively). The several Novalac adapted milk formulas resolved 88.4% of the mild gastrointestinal disorders. Depending on the type of disorder, differences in response rate were observed. The highest effectiveness was recorded with respect to diarrhoea (92.6%), followed by constipation (91.6%), colic (87.6%) and regurgitation (81%). Overall, 91% of the paediatricians and 88.8% of the parents/tutors were satisfied or very satisfied with the Novalac adapted milk formulas.CONCLUSION: Mild gastrointestinal disorders show a high prevalence in paediatric practice. The Novalac adapted milk formulas have been shown to be effective in treating mild gastrointestinal disorders in milk-fed infants in the context of routine clinical practice.

Study of virtual reality for mild cognitive impairment:A bibliometric analysis using CiteSpace

Objectives Non-invasive and low-cost virtual reality(VR)technology is important for early evaluation and intervention in mild cognitive impairment(MCI).This study aimed to demonstrate the current status of overseas and domestic research as well as the focus and frontier of VR technology among individuals with MCI through a bibliometric analysis.Methods Studies from the core collection of Web of Science™between 1995 and 2020 were used;furthermore,CiteSpace 5.7 R3 was utilized to analyse information on authors/cited authors,keywords,burst words,and cited references.Results In total,230 publications were identified.Most studies were published in the USA(45 publications)and Italy(41 publications),where Guiseppe Riva ranks first(14 publications),and Tarnanas I is the author with the highest centrality(0.44).The hot topics in VR applications in the MCI population are‘physical activity,’‘people,’‘single-blind,’‘disease,’‘walking,’‘technology,’‘working memory,’and‘risk’in recent years.The keyword‘mild cognitive impairment’has attracted extensive attention since 2012,showing the strongest citation outbreak(8.28).The clustering results of the literature show the research types and emerging trends,including‘exergame,’‘serious games,’‘spatial navigation,’‘activities of daily living,’‘exercise,’‘enriched environment’and‘wayfinding.‘Conclusions Cognitive assessment and nonpharmacological intervention research on patients with MCI have become the focus of dementia prevention in recent years.Virtual technology,combined with traditional methods such as exercise therapy,provides new ideas for innovative cognitive evaluation and cognitive intervention.

Study on application and numerical simulation of the airflow temperature distribution rule in drifting tunnel

According to the law of conservation in the state of turbulent flow, the differential equation describing the airflow temperature distribution in drifting tunnel is derived, By theoretical analysis and field measurement of the airflow and thermal process in mine, theoretical analysis and systematic flow are developed. By PHONENICS program, the numerical simulation is processed, and the changing rule of airflow temperature with various parameters in drifting tunnel is derived. The airflow temperature in drifting tunnel decreases as the airflow velocity increases in a way of negative power exponent, and elevates linearly as the temperature of the incoming airflow elevates.

Lipid disorders and lipid peroxidation associated with the malignant transformation of colorectal adenoma

Objective:The aim of this study was to investigate lipid disorders and lipid peroxidation associated with the malignant transformation of colorectal adenoma.Methods:Analyses were based on data from 100 subjects with histologically confirmed adenomas(cases) and 50 adenoma-free control subjects,all of whom had colonoscopy.The subjects were divided into two groups:those with no adenoma and those with adenoma.According to subsite of adenomas the subjects with adenoma were divided into group of distal adenoma and group of proximal adenoma.According to histology of adenomas the subjects with adenoma were divided into group of villiform adenoma and group of tubular + tubulo-villous adenoma.Among the groups,the serum levels of triglyceride(TG),total cholesterol(TC),high density lipoprotein cholesterol(HDL-C),lowdensity lipoprotein cholesterol(LDL-C),and lipid peroxidation product malondialdehyde(MDA) were compared in all the patients.Results:Plasma total cholesterol and MDA level in group of adenomas were significantly higher than that in group of control subjects,but plasma HDL-C level was low in group of adenomas(P<0.05).Plasma total cholesterol and MDA levels were positively related to distal and villiform adenomas(P<0.05).Conclusion:The findings suggest that altered lipid metabolism may be differentially associated with colorectal adenomas.

Electronic and Transport Properties of Carbon Nanotubes with Impurities and Structure Disorder

Electron relaxation time and density of states near the Fermi level were calculated for ＂dirty＂ carbon nanotubes taking into account multiple elastic electrons scattering on impurities and structural inhomogeneities of a short-range order type. A possible explanation of low-temperature behavior of density of states and electrical conductivity depending on defect structure, impurities and chirality is presented.

Condition Metabolic Balance Disturbance in Patients with Cor Pulmonale： Prevalence, Diagnosis, Risk Factors

To study the risk factors for the development of cor pulmonale （CP） in patients with chronic pulmonary diseases in the Republic of Uzbekistan, the disbalance in parameters of stable metabolites oxides of the nitrogen （SMNO）, of blood oxygen saturation （SaO2）, of respiratory function and on lipid peroxidation of cell membrane were measured. The authors evaluated the effect of base therapy and ozone therapy （OT） in patients with CP. Basis therapy and OT resulted in good parameters of SMNo, SaO2 and metabolic activeness of cell, significant positiveness of hypoxemia and parameters of pulmonary ventilation ability and hemodynamics of pulmonary arteria.

肠道微生物在肝细胞癌发生发展中的作用机制及其作为诊断指标的可行性

尽管肝细胞癌和肠道微生物群落之间的关系已得到实验和临床证实,但目前这些关系在指导临床诊断和治疗上的应用仍十分罕见。本文就肠道微生物群落与肝细胞癌的关系及其在肝细胞癌诊断中的应用进行综述,并阐述了当前阻碍肠道微生物群落分析用于肝细胞癌诊断的主要因素。此外,我们还讨论了一种新的肠道微生物群落综合指标用于肝细胞癌诊断的可行性和实用性,尽管该指标中使用的细菌类群仍然值得进一步优化。最后,我们对用于该指标计算的细菌类群的筛选提出了建议。

和谐论

创建和谐社会不仅是操作层面上的问题, 更是价值观、伦理观方面的问题,而价值观、伦理观包括道德问题,需要从自然和生命的本源来科学地加以认识和解决,否则收效甚微。和谐是自然、社会两个世界的客观要求,人类只有遵循自然及社会的客观规律,感恩自然珍惜对方,才能最大限度地降低发展成本,才能真正构建起和谐社会。

Visceral and somatic hypersensitivity, autonomic cardiovascular dysfunction and low-grade inflammation in a subset of irritable bowel syndrome patients

The pathophysiology of irritable bowel syndrome（IBS） is complex and not fully understood, so the aim of this study was to evaluate whether visceral and somatic hypersensitivity, autonomic cardiovascular dysfunction, and low-grade inflammation of the gut wall are associated with diarrhea-predominant IBS（D-IBS）. Sixty-two patients with D-IBS and 20 control subjects participated in the study. Using the ascending method of limits（AML） protocol, we demonstrated that D-IBS patients had significantly lower sensory thresholds compared with healthy controls（P〈0.001）. Using diverse methods, especially the ischemic sensitivity test, for the first time in China, we confirmed that D-IBS patients have somatic hypersensitivity. They had a significantly higher systolic blood pressure and heart rate after a cold stimulus, indicative of autonomic cardiovascular dysfunction. Compared with the control group, D-IBS patients had a significantly higher level of calprotectin（P〈0.001）. We also found significant correlations between visceral and somatic hypersensitivity, visceral hypersensitivity and autonomic cardiovascular dysfunction, and somatic hypersensitivity and autonomic cardiovascular dysfunction. Our findings may provide valuable suggestions for the treatment of D-IBS.