埋地管道在地震波作用下的抗震性能分析

埋地管道是一种特殊的地下结构 ,地震时由于管道与砂土等介质的相互作用而引起管道运动 ,在管道中产生地震应力。针对地震波作用下埋地管道的运动特点 ,运用振动和抗震动力学理论 ,推导了埋地管道的振动运动方程和管土间相互作用的传递系数 ,进而求出了管道最大的轴向应力和弯曲应力。最后 。

梯度乳液聚合制备核壳结构丙烯酸酯乳液——性能表征

采用梯度种子乳液聚合方法,引入半连续单体滴加工艺和亲水性功能单体,制备了零VOC乳胶涂料专用的具有较高玻璃化温度(tg)、较低最低成膜温度(MFT)的核/壳结构的纯丙烯酸酯乳液.用差热扫描(DSC)测定了纯丙烯酸酯乳液的tg,用透射电镜(TEM)测定了乳胶粒子形态,用粒度仪测定了乳液的粒径大小及其分布.实验结果表明采用梯度种子乳液聚合工艺制备的丙烯酸酯乳液为典型的核壳结构.

持久性有机污染物对人类及环境的危害

持久性有机污染物作为工业化的伴生物,对人类生存繁衍和可持续发展构成重大威胁,并对环境造成难以修复的破坏。对持久性有机污染物的结构、特性及其对人类和环境的危害进行了论述。

增塑剂/成核剂对PLLA/PDLA共混熔体流变纺丝性能影响

研究了PLLA/PDLA中加入增塑剂(PEG)和成核剂(TMC-306)的共混样品在不同温度和不同剪切速率下的流变性能以及熔融纺丝制备纤维的热性能分析.结果表明:PEG对PLLA/PDLA共混熔体的流变性能有促进作用,TMC-306对PLLA/PDLA共混熔体的流变性能有抑制作用,而同时加入PEG和TMC-306时,PEG和TMC-306的作用效果相互抵消,使得PLLA/PDLA共混熔体的流变性能与纯PLLA/PDLA的流变性能相近;熔融纺丝制备的纤维中同时加入PEG和TMC-306的样品中sc-PLA的含量最高,耐热性能最好,且纤维的强力和延伸性能都得到提高.

社会募捐财物所有权之类型化研究

在现代社会,社会募捐作为一种以公益事业和他人利益为目的的行为,随着社会的进步和经济的发展日益增多。但是,爱心捐赠行为在给人们带来爱的同时,也引发了诉讼纠纷。由于法律规范的缺失,不同法院对此类案件往往做出大相径庭的裁判,而学者们的意见同样是众说纷纭。笔者大胆摒弃了以往的惯常思路,认为应当从类型化研究的全新视角出发,对不同募捐类型下捐赠钱物所有权的转移详加分析,这才是解决类似争议的正确路径。

关于(Ck-K)性质

引入了Banach空间的(Ck-Ⅰ),(Ck-Ⅰ′),(Ck-Ⅱ),(Ck-Ⅲ)性质,证明了如下结果:X是Lk-R(wL-kR,CL-kR,wCL-kR)分别等价于X具有性质(Ck-Ⅰ)((Ck-Ⅰ′),(Ck-Ⅱ),(Ck-Ⅲ)),并推广了文[1],[2]中的相关结论.

ZMF润滑剂的流变性与自密封性研究

通过实验对ZMF润滑剂的流变学与自密封性进行了研究 ,分析了它的流变学性质和自密封机理。

港澳发展差距的制度因素分析—制度效率比较及启示

澳门与香港的制度形式相似，实质则不同。在制度所涉及的产权制度、政府权威及法制状况等重要方面，澳门的制度效率及制度创新均同香港有着重大的差距，这也是导致两地经济差距悬殊的根本性原因。在产权制度方面，香港的“积极不干预”政策优于澳门的“基本不干预”政策；香港的土地政府垄断不排斥经营上的自由竞争，而澳门的赌业垄断专营则窒息了该行业的竞争与活力。在政府及制度创新方面，香港明显优于澳门，香港是强势高效的政府，而澳门则是弱势低效的政府。在法制建设方面，香港是一个法制社会，法律有效地调控经济运行及社会发展，而澳门则是一个法制不健全、调控乏力的社会，这反过来又制约了其制度实施的效率。制度是经济增长的根本性制约因素，制度及其效率差异决定了港澳两地经济增长状况的不同。香港在制度创新及实施效率方面的优势转化为经济优势和社会秩序的稳定；相反，澳门在制度创新及实施效率方面的劣优与不足阻碍了澳门经济的发展及社会的和谐稳定。因此，澳门的发展繁荣取决于回归后解决好制度创新问题。

高抗裂性高强度纯镍铸铁焊条的研究

本文主要研究了Ｃ、Ｙ、Ｃｏ、Ａｌ、Ｔｉ、Ｎｂ、Ｍｏ、Ｓｉ、Ｒｅ－Ｍｇ、Ｓｉ－Ｃａ对纯镍铸铁焊条冷焊时焊缝抗热型性的影响规律及其机理．在最大限度提高焊缝金属抗裂性，保持或改善接头加工性能的前提下，探讨了石墨球化剂Ｒｅ－Ｍｇ和细化晶位元素Ｔｉ对焊缝金属机械性能的影响．得到了抗裂性优良、加工性良好，机械性能较高的纯镍铸铁焊条．

超细丙纶的表面氯化改性

本文用次氯酸钠氯化超细丙纶纤维,探讨了不同氯化时间、介质pH值及次氯酸钠有效氯含量对纤维的含氯量、染色性能和牢度的影响,结果表明氯化能够改善丙纶的染色性能,确定了最佳氯化条件。

Windows支持下的铁路地理图形信息系统的研究

针对当前铁路线路情况复杂、信息量大的特点,建立了Windows支持下的铁路地理图形信息系统(WRGIS),为决策、规划和咨询,提供重要的技术支持。介绍WRGIS的主要研究内容和数据资源,并阐述了目前研究条件下实现的强大功能。

Influence of Nano-Al_2O_3 on Properties of Magnesia Chrome Refractories

Magnesia chrome bricks were prepared with fiLsed MgO- Cr2 O3 synthesized material, fused magnesite and ：hrome ore as main starting materials. Nano-Al2O3 was tdded into refractories （ 2% , 4% and 6% in mass ） ;ubstit,ting for Al203 micropowder. After m＆ing and ;haping, the bricks were fired at 1 550 ℃, 1 600 91℃, t 650 ℃ and 1 750℃, respectively. The microstruc-ure , sintering property, mechanical properties, thermal ;kock resistance and shtg resistance of the specimens with he addition of nano-Al2O3 were investigated. The results indicate that the performance of brick with 4 mass% of nano-Al2O3 is greatly improred afier firing at 1 650 ℃.

Influencing Factors of Properties of Castables for Hot Blast Stove Pipes

In order to prolong the service life of castables for hot blast stove pipes,effects of SiO2 micropowder addition and aggregate kind on properties of castables for hot blast stove pipes,and properties of silica sol bonded castables were researched using homogenized bauxite,andalusite particles,andalusite fines,white fused corundum fines,α-Al2O3 micropowder,pure calcium aluminate cement,SiO2 micropowder,and silica sol as starting materials. The results show that：（1） as SiO2 micropowder addition increases,the shrinkage rate of fired specimens increases; BD increases firstly,reaches the highest at 4 mass%,and then decreases; CMOR and CCS of all specimens increase gradually; so the appropriate SiO2 micropowder addition is 4 mass%;（2） the specimens with bauxite aggregate have better CCS and volume stability,but specimens with andalusite aggregate have better thermal shock resistance;（ 3） for castables for hot blast stoves using silica sol as binder,the addition of pure calcium aluminate cement can decrease the linear change rate after treatment at 1 400℃ and can slightly enhance CCS and CMOR,but has very little influence on AP and BD; and the introduction of citric acid worsens the thermal shock resistance of specimens.

Theoretical Analysis of Simulating the Locked-In Stress in Rock Pore by Thermal Expansion of Hard Rubber

Rocks are composed of mineral particles and micropores between mineral which has a great influence on the mechanical properties of rocks. In this paper, based on the theory of locked-in stress developed by academician Chen Zongji, the locked-in stress problem in underground rock is simulated by the thermal expansion of hard rubber particles. The pore inclusion in rock is assumed to be uniformly distributed spherical cavities. Using the thermal stress theory, the stress of rock with a spherical pore inclusion is equivalent to the thermal stress generated by the spherical hard rubber inclusion. The elastic theory formula of the temperature increment and the equivalent pore pressure of the spherical hard rubber inclusion is derived. The numerical simulation of the rock mass model with a spherical hard rubber inclusion is carried out and compared to the theoretical calculation results; the results show that they are consistent. The method proposed by this paper for simulating stress distribution in rock by thermal stress is reasonable and feasible; it has a positive meaning for further study of mechanic phenomenon of rock with micropore inclusion.

A glance on the effects of temperature on axisymmetric dynamic behavior of multiwall carbon nanotubes

In this paper the effects of temperature on the radial breathing modes （RBMs） and radial wave propaga- tion in multiwall carbon nanotubes （MWCNTs） are inves- tigated using a continuum model of multiple elastic isotropic shells. The van der Waals forces between tubes are simulated as a nonlinear function of interlayer spacing of MWCNTs. The governing equations are solved using a finite element method. A wide range of innermost radius-to-thickness ratio of MWCNTs is considered to enhance the investigation. The presented solution is verified by comparing the results with those reported in the literature. The effects of temperature on the van der Waals interaction coefficient between layers of MWCNTs are examined. It is found that the variation of the van der Waals interaction coefficient at high temperature is sensible. Subsequently, variations of RBM frequencies and radial wave propagation in MWCNTs with temperatures up to 1 600 K are illustrated. It is shown that the thick MWC- NTs are more sensible to temperature than the thin ones.

Effect of Heat Treatment Conditions on Photo sensitivity of CdSexS1-x Polycrystalline Films

The influence of thermal treatment on the lux-ampere characteristics of polycrystalline films from the CdSexS1-x solid solution obtained by the method of thermal evaporation in a vacuum has been investigated. It is shown that at low illumination intensities L μ of electrons increases with a power law μ ~ Lγ, first with the exponent γ > 1, then with γ ≈ 0.5, and their concentration n almost does not change. Starting from the intensity L > 12 - 15 lx, the electron concentration increases strongly n ~ Lβ from β ≈ 3.0, and the parameters n and μ reach relatively high values ~(1015 - 1016) sm-3 and ~(150 - 200) sm2/V·s, however further, at L > 50 lx, a weak dependence of n(L) and μ(L) with β, γ < 1.0 is found. The obtained experimental results are interpreted on the basis of a model of a semiconductor film with intergranular potential barriers when the concentration and barrier mechanisms of photoconductivity operate simultaneously.

纳米硒喷施对绿豆芽生长特性、营养品质、酚类含量和抗氧化性的影响

为筛选出生产富硒绿豆芽最适宜的喷施浓度,采用不同浓度(0.00、0.06、0.19、0.38和0.57 mmol/L)纳米硒喷施处理绿豆芽,测定其生长指标(根长、下胚轴长和下胚轴茎粗)、营养指标(可溶性糖、可溶性蛋白和抗坏血酸)、抗氧化酶活性(超氧化物歧化酶和过氧化物酶)、酚类含量(总酚和总黄酮)、ABTS自由基清除力及硒含量。结果表明:纳米硒对绿豆芽生长具有双重效应,低浓度纳米硒能够促进生长,高浓度纳米硒对绿豆芽有毒害作用,会抑制其正常生长。0.19 mmol/L浓度纳米硒喷施处理绿豆芽的效果最佳,其下胚轴茎粗比对照提高2.91%,下胚轴长提高38.70%;可溶性蛋白、可溶性糖及抗坏血酸含量分别增加31.67%、 51.18%和44.32%;超氧化物歧化酶(SOD)和过氧化物酶(POD)活性分别提升108.04%和59.45%;同时总酚、总黄酮含量分别提高了88.37%和26.81%。而且0.19 mmol/L纳米硒喷施处理绿豆芽中硒含量为3.04 mg/kg,在安全标准范围内。因此,生产富硒绿豆芽以0.06～0.19 mmol/L纳米硒浓度喷施最佳。

Thermal Behaviors of 2-（Dinitromethylene）-1,3- diazacycloheptane （DNDH）

2-（Dinitromethylene）-1,3-diazacycloheptane （DNDH） was prepared by the reaction of 1,1-diamino-2,2-dinitro- ethylene （FOX-7） with 1,4-diaminoethane in NMP. Thermal decomposition behavior of DNDH was studied under the non-isothermal conditions with DSC method, and presents only one intensely exothermic decomposition process The kinetic equation of the decomposition reaction is da/dT= 103388× 3a2/3exp（--3.353 ×10^5/RT）/fl. The critical temperature of thermal explosion is 215.97℃. Specific heat capacity of DNDH was studied with micro-DSC method and theoretical calculation method, and the molar heat capacity is 215.40 Jomol-1,K-1 at 298.15 K. Adiabatic time-to-explosion was calculated to be 92.07 s. DNDH has same thermal stability to FOX-7.

Experimental research on thermal transport properties of crystallized palladium-based alloys

Palladium-based alloy is a kind of material with a high glass forming ability and can be easily formed into an amorphous state. After an annealing process, it can also be maintained at a crystallized state. To study the thermal and electrical transport properties of crystallized palladium-based alloys, the steady-state T-type method, standard four-probe method, and AC heating-DC detecting T-type method were used to measure the thermal conductivity, electrical conductivity, and Seebeck coeffi- cient of crystallized Pd4oNiloCu3oP2o and Pd43Nilo- Cu27P2o alloys respectively. The results show that compared to amorphous samples, the thermal conductivity and electrical conductivity of crystallized palladium-based alloys are significantly higher, while the Seebeck coeffi- cient is lower. The ratio of crystallized and amorphous thermal conductivity is higher for Pd43Ni10Cu27P2o alloy fiber which has a higher glass forming ability, while the ratio of electronic thermal conductivity almost remains constant for both alloy fibers. The results also show that the slope of electrical resistivity to temperature is a function of elemental composition for crystallized quaternary palla- dium-based alloy fibers. The sensitivity of thermal conductivity and electrical conductivity to the composition is high, while the correlation between Seebeck coefficient and composition is relatively weak.

HOMOLOGICAL PROPERTIES OF TORSION CLASSES UNDER CHANGE OF RINGS

ＨＯＭＯＬＯＧＩＣＡＬ ＰＲＯＰＥＲＴＩＥＳ ＯＦ ＴＯＲＳＩＯＮ ＣＬＡＳＳＥＳ ＵＮＤＥＲ ＣＨＡＮＧＥ ＯＦ ＲＩＮＧＳ ￥ＹＡＯＭＵＳＨＥＮＧＡｂｓｔｒａｃｔ：ＬｅｔＲｂｅａｒｉｎｇｗｉｔｈｉｄｅｎｔｉｔｙ，ｘｂｅａｃｅｎｔｒａｌｅｌｅｍｅｎ...