深水采油树Spring-Seal密封圈接触模型构建与实验测试

为提高深水采油树在高压、高温、低温等工况下长时间工作的稳定性,对采油树密封圈进行重新设计,提出Spring-Seal密封圈(以下简称S密封圈);基于赫兹接触理论、填料密封接触理论,重新构建S密封圈接触力学模型;建立有限元仿真分析模型,分析不同条件下S密封圈的密封性能,同时验证新建接触模型的合理性;利用实验测试S密封圈的实际密封效果。研究结果表明:S密封圈在高压、高温、低温等工况下能够长时间稳定工作且密封性能良好。研究结果可为S密封圈的接触研究及工程运用提供理论参考。

原发于Waldeyer's环或鼻腔的非何杰金氏淋巴瘤的治疗

目的 比较原发于 Waldeyer's环或鼻腔的 NHL的各治疗方式的疗效和分析预后因子。方法 回顾性分析 5 3例患者的疗效和年龄、性别、临床分期、“B”症状等临床因素对预后的预示作用。结果 化疗 +放疗 +化疗单纯化疗能明显提高生存率 ;化疗 +放疗 +化疗较单纯放疗能明显提高无瘤生存率。治疗方式、年龄、临床分期和“B”症状是重要的预后因子 ,而性别不能预示预后。结论 化疗 +放疗 +化疗可能是此类疾病较好的治疗方式。出现高龄、晚期、有“B”症状的患者应加强化疗的份量。

S环形无碳小车结构设计与分析

依据全国大学生工程训练综合能力竞赛S环形赛道挑战赛要求,实现无碳小车完成S环形轨迹路径并通过设置障碍桩,详细设计了一辆利用斜推杆凸轮控制转向的无碳小车。文中对小车的整体结构进行了设计,基于设计尺寸模拟仿真出轨迹重合度最高的凸轮,设计出的无碳小车具有结构简单、可靠性高及成本低等优点。为此,利用SolidWorks软件建立三维模型,利用Creo规划轨迹图,利用MATLAB仿真小车行走路线并生成凸轮。文中设计的无碳小车对初次设计的人员具有指导意义。

S-平坦模和S-余挠模

通过引入并研究了S-平坦模和S-余挠模。证明了任意R-模都有S-平坦盖和S-余挠包。利用S-平坦模和S-余挠模刻画了S-vN正则环和完全环。通过一些例子来区别平坦模和S-平坦模,以及内射模,S-余挠模和余挠模。

CO_(2)/CO干扰下基于腔衰荡吸收光谱的痕量H_(2)S浓度测量

H_(2)S作为一种有毒且腐蚀性较强的气体污染物,实现其浓度的准确测量意义重大.实际工业过程中,H_(2)S测量常受其他排放产物的干扰,本文基于腔衰荡吸收光谱技术(CRDS)通过扫描6336—6339 cm^(-1)范围内的吸收光谱,实现了H_(2)S/CO_(2)/CO三组分物质浓度的同步测量,为实际工业过程中物质干扰下的H_(2)S浓度测量提供新思路.首先,对不同采样长度下提取衰荡时间的准确性进行分析,发现衰荡信号的采样长度约为衰荡时间的8倍时,衰荡时间提取效果最好;通过不同压力对比实验确定最佳实验压力工况为50 kPa,并将最佳采样长度与压力工况应用于H_(2)S浓度测量.随后,改变H_(2)S浓度对CO_(2)/CO干扰下系统对痕量H_(2)S浓度的测量效果进行检验,并对不同稀释比例下浓度测量结果的线性度进行分析.最后,对本文CRDS系统的检测限进行分析,通过对4组低浓度H_(2)S光谱的信噪比进行分析,得到H_(2)S的检出限为6.9 ppb (1 ppb=10^(-9));通过对系统长期测量结果进行Allan方差分析,得到系统对H_(2)S物质浓度的检测下限约在2 ppb左右.

APPROXIMATE CONVEXITY AND CONCAVITY OFGENERALIZED GROTZSCH RING FUNCTION

In this paper, the so-called approximate convexity and concavity properties of generalized Groetzsch ring function μa （r） by studying the monotonieity,convexity or concavity of certain composites of μa（r） are obtained.

Ring-opening Polymerization ofε-Caprolactone Using Lanthanide Tris(4-tert-butylphenolate)s as a Single-component Initiator

The ring-opening polymerization of e-caprolactone (CL) initiated by novel single lanthanide tris(4-tert-butylphenolate)s [Ln(OTBP)3] is reported. Single-component La(OTBP)3 can effectively prepare polycaprolactone (PCL) with over 90% yield and viscosity average molecular weight about 60 x 10 under quite mild conditions: molar ratio of CL to initiator is 1000, 60 C, 2 h in toluene. Mechanism study indicates that the monomer inserts into the growing chain via the break of acyl-oxygen bond of CL.

<i>S</i>-Injective Modules and Rings

We introduce and investigate the concept of s-injective modules and strongly s-injective modules. New characterizations of SI-rings, GV-rings and pseudo-Frobenius rings are given in terms of s-injectivity of their modules.

The Kemeny’s Constant and Spanning Trees of Hexagonal Ring Network

Spanning tree(τ)has an enormous application in computer science and chemistry to determine the geometric and dynamics analysis of compact polymers.In the field of medicines,it is helpful to recognize the epidemiology of hepatitis C virus(HCV)infection.On the other hand,Kemeny’s constant(Ω)is a beneficial quantifier characterizing the universal average activities of a Markov chain.This network invariant infers the expressions of the expected number of time-steps required to trace a randomly selected terminus state since a fixed beginning state si.Levene and Loizou determined that the Kemeny’s constant can also be obtained through eigenvalues.Motivated by Levene and Loizou,we deduced the Kemeny’s constant and the number of spanning trees of hexagonal ring network by their normalized Laplacian eigenvalues and the coefficients of the characteristic polynomial.Based on the achieved results,entirely results are obtained for the M鯾ius hexagonal ring network.

Energy Gap in Saturn’s Rings

In this article, we consider, based on the super-diamagnetic model, the new problems of Saturn’s rings discovered by Cassini, such as: 1) anomalous purity of water ice;2) Saturn’s magnetic field alignment with the planet’s rotation axis;3) “ring rain” of the submicron particles;4) the deviation in the qualitative composition of the “rain” from the composition of the rings;5) “dirt” concentrated in the ring gaps;6) “plateaus” in Saturn’s C ring;7) age of the rings;8) roll-off in the spectrum of Saturn’s rings, and 9) “propellers” in Saturn’s A ring. Interpretation of Cassini’s observations of spectral roll-off in Saturn’s rings in the wavelength range from 100 micrometers to 0.5 mm is given. It was concluded that the substance of the rings could be in the superconducting state. An explanation of the Cassini spectral data is given using the hypothesis of the existence of a superconducting energy gap in the substance of rings.

Goldbach's Problem in the Matrix Ring over a Principal Ideal Domain

In this paper, we consider the Goldbach＇s problem for matrix rings, namely, we decompose an n × n （n 〉 1） matrix over a principal ideal domain R into a sum of two matrices in Mn,（R） with given determinants. We prove the following result： Let n 〉 1 be a natural number and A = （aij） be a matrix in Mn（R）. Define d（A） ：= g.c.d{aij}. Suppose that p and q are two elements in R. Then （1） If n 〉 1 is even, then A can be written as a sum of two matrices X, Y in Mn（R） with det（X） = p and det（Y） = q if and only if d（A） [ p - q; （2） If n 〉 1 is odd, then A can be written as a sum of two matrices X, Y in Mn（R） with det（X） = p and det（Y） = q if and only if d（A） ｜ p ＋ q. We apply the result to the matrices in Mn（Z） and Mn（Q[x]） and prove that if R = 7. or Q[x], then any nonzero matrix A in Mn（R） can be written as a sum of two matrices in Mn（R） with prime determinants.

A COMMUTATIVITY CONDITION FOR S-UNITAL RINGS

Let R be an s-unital ring, and we prove a commutativity theorem of R satisfying the following conditions: (l ) For each x, y∈ R,there exist bounded positive integers k =k (x,y), s=s (x,y), t =t (x,y)(where, at least one of k, s, t is not equal to 1) such

On the Convexity of Generalized Grotzsch Ring Function

In this paper,the authors study the monotoneity and convexity of certain combinations and composites defined in terms of the generalized Grotzsch ring function μa (r), which appears in Ramanujan' s generalized modular equations,and obtain some inequalities for this function.

Dose-adjusted EPOCH-R vs.R-CHOP in frontline management of Waldeyer’s ring diffuse large B-cell lymphoma:a retrospective study from a single institution

Background: To compare the efficacy and safety of dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin plus rituximab (DA-EPOCH-R) with standard rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in Waldeyer’s ring diffuse large B-cell lymphoma (WR-DLBCL) at a single institution. Methods: This retrospective study included 115 newly diagnosed patients with WR-DLBCL, of whom 68 patients received R-CHOP, and 47 patients received DA-EPOCH-R as their first-line treatment. The baseline features of the two groups were well balanced using a 1:1 propensity score matching method, and a total of 84 cases were obtained, including respective 42 cases in the R-CHOP and DA-EPOCH-R groups, for further survival and prognosis analysis. The primary objectives included progression-free survival (PFS) and overall survival (OS). Results: During a median follow-up of 45 months, there were nine (21.4%) deaths in the R-CHOP group and two (4.8%) in the DA-EPOCH-R group. Kaplan-Meier analysis showed statistically significant improvements in PFS and OS in patients with DA-EPOCH-R compared with those treated with R-CHOP (log-rank test, P = 0.025 and P = 0.035, respectively). The 2-year PFS and OS rates in the DA-EPOCH-R group were 90.1% (95% confidence interval [CI]: 81.4-99.8%) and 95.2% (95% CI: 89.0-100.0%), respectively, and 80.5% (95% CI: 69.3-93.6%) and 90.5% (95% CI: 52.8-99.8%) in the R-CHOP group. Patients without B symptoms and elevated lactate dehydrogenase levels had a higher PFS in the DA-EPOCH-R group, with P values of 0.038 (hazard ratio [HR]: 0.11;95% CI: 0.01-0.88) and 0.042 (HR: 0.19;95% CI: 0.04-0.94), respectively. There were no statistically significant differences in clinical responses and treatment-related toxicities between the two groups. Conclusion: Compared with patients received R-CHOP, those treated by DA-EPOCH-R had superior PFS, OS, and controlled toxicity in patients with WR-DLBCL.

Classic of Mountains and Seas and the Origin of White Jade Worship： On the Myths of the Yellow Emperor＇s Eating Jade and Queen Mother of the West＇s Presenting the White Jade Ring

The white jade worship, born in the Shang and Zhou Dynasties, brought about a ＂Protestant Revolution＂ in the development history of Chinese jade mythology, which had deep influence on the nation＇s ideology and material production in the following 3,000 years. The myths of the Yellow Emperor＇s eating the white jade cream and the Queen Mother of the West living in Kunlun Jade Mountain, as recorded in Classic of Mountains and Seas, are mythological imaginations of the historical reality that the jades were spread from the West to the East and recreated by people living in the early state of the Central Plains. All such motifs, no matter the white jade cream that produced black jades, the Yellow Emperor＇s planting the jade flowers, the Kunlun Jade Mountains （the Mountain of Jades） where the Queen Mother of the West lives or the Jade Lake, clearly show Chinese indigenous worship for the white jades. Scholars like Su Xuelin and Ling Chunsheng think that Queen Mother of the West is the goddess of the moon that originated from the old West Asian civilization. However, such idea is full of contradictions and flaws after the discovery of Chinese unique worship for white jades and the holy mountain of Kunlun. The book Classic of Mountains and Seas, with records of 140 mountains that produce jades and 16 mountains that produce white jades, can be the white jade worshippers＇ bible to explore the holy material resources.

Nilpotent Elements and Nil-Reflexive Property of Generalized Power Series Rings

Let R be a ring and (S,≤) a strictly ordered monoid. In this paper, we deal with a new approach to reflexive property for rings by using nilpotent elements, in this direction we introduce the notions of generalized power series reflexive and nil generalized power series reflexive, respectively. We obtain various necessary or sufficient conditions for a ring to be generalized power series reflexive and nil generalized power series reflexive. Examples are given to show that, nil generalized power series reflexive need not be generalized power series reflexive and vice versa, and nil generalized power series reflexive but not semicommutative are presented. We proved that, if R is a left APP-ring, then R is generalized power series reflexive, and R is nil generalized power series reflexive if and only if R/I is nil generalized power series reflexive. Moreover, we investigate ring extensions which have roles in ring theory.

SINGLE LANTHANUM TRIS(N-PHENYLETHYL-3,5-DI-t-BUTYLSALICYLALDIMINATO)S INITIATOR FOR RING-OPENING POLYMERIZATION OF 1,4-DIOXAN-2-ONE IN BULK

A rare earth Schiff base complex:lanthanum tris(N-phenylethyl-3,5-di-t-butylsalicylaldiminato)s [La(OPEBS)_3] was successfully applied as single component initiator for the ring-opening polymerization of 1,4-dioxan-2-one (PDO) in bulk.The influence of reaction conditions,such as polymerization temperature,the molar ratio of the monomer to initiator (M/I) on the monomer conversion and molecular weight of the polymer has been investigated.Poly(1,4-dioxan-2-one) with a viscosity-average molecular weight (My) o...

碳环渗入的结晶氮化碳S型同质结及其光催化析氢

通过人工光催化将水分解为可再生的氢能燃料,是解决全球能源问题的重要途径之一.石墨氮化碳(g-C_(3)N_(4))作为一种极具发展前景的新型半导体光催化剂,因其成本低、能带位置合适和化学稳定性好等优点受到广泛研究.为了克服原始g-C_(3)N_(4)光生电荷易复合和电导率低等缺点,从而提高光催化析氢效率,研究人员通过纳米结构设计、增大比表面积、负载单原子和掺杂元素等方法改善g-C_(3)N_(4)基光催化剂的性能.然而,由于脱胺不完全导致石墨氮化碳层内载流子难以迁移,仍旧极大地限制了其可见光利用率.因此,如何有效改善载流子传输,构建新的电子迁移通道依然需要探索和研究.本文采用热聚合法制备g-C_(3)N_(4)(CN-C),将碳元素以碳环的形式逐渐渗透到结晶氮化碳表面,从而实现光生电子在内层和外层之间的快速空间转移,并运用高分辨透射电镜(HRTEM)、二次离子质谱(SIMS)、密度泛函理论(DFT)和飞秒瞬态吸收光谱(fs-TA)等手段研究了所制备半导体材料的结构和光催化机理.HRTEM结果表明了氮化碳与碳环的晶格条纹的存在,证实了结晶氮化碳与碳环的形成.SIMS通过对碳和氮元素在制备的光催化剂的不同深度的比值分析证实了碳环的分布,表明碳环成功从氮化碳表面渗透.DFT结果表明,分子中的内层和外层产生不同的费米能级形成S型同质结并在氮化碳内部建立了的内置电场,从而有效地消除了由于丰富的界面缺陷引起的载流子陷阱的影响,并抑制光生载流子的复合.CN-C内层与外层形成的S型同质结在界面的两侧诱导能级弯曲,形成层间电荷转移通道.此外,fs-TA结果证明碳环与氮化碳结合的共轭平面内也形成了面内光生电荷转移通道,这种双向电子转移通道极大地提高了光生电子解离效率,制备的CN-C在光催化析氢的最大量子效率为15.56%.由此可见,在结晶氮化碳内部成功构建了面内和层间的定向电荷传递路径.综上,本文通过将石墨化碳环渗透到结晶g-C_(3)N_(4)的共轭网络来提高光催化性能,改性的g-C_(3)N_(4)改善了层间电荷转移,而碳环共轭面则大大促进了面内光生电荷对的分离和迁移.CN-C平面内和层间设计的两个电荷转移通道大大缓解了光生电子-空穴对的复合,在可见光照射下,利用10vol%TEOA作为牺牲剂同时负载3wt%Pt作为助催化剂对所有样品进行光催化产氢测试,证实了最优样品具备稳定且较好的光催化制氢性能(93.76μmol h^(–1)),远优于原始的g-C_(3)N_(4)光催化剂(5.19μmol h^(–1)).

基于D-S理论的飞机装配尺寸链修配环选择评价方法

针对制造企业主要依据经验选择飞机装配修配环的问题,提出一种基于D-S理论的飞机装配尺寸链修配环选择方法。首先确定了影响修配工作的主要因素,据此建立了修配环选择的评价指标模型,通过加权处理评价指标属性值的不确定性和应用两级D-S理论进行修配环选择评估,实现了修配环的选择。以一个飞机实验组件为例,验证了所提方法的有效性。

Waldenstrm巨球蛋白血症病理细胞的特殊形态学改变二例报告

Waldenstr m巨球蛋白血症 (WM)是由B淋巴细胞克隆异常增殖所致的血液系统恶性肿瘤 ,其病理细胞具有分泌单克隆免疫球蛋白M的功能。本研究对 2例WM患者的诊断经过及形态学特点进行了分析。结果表明 ,2例患者的细胞学检查均发现特殊的“泡沫状细胞” ,其细胞化学染色具有淋巴细胞的特征 ,而不具有单核巨噬细胞或脂肪细胞的特点。结论 :本文所描述的细胞为印戒样淋巴细胞的特殊亚型 ,可以将其描述为“宝石镶戒样淋巴细胞”。