共查询到20条相似文献，搜索用时 93 毫秒
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在现有文献的基础上,给出特定条件下热力学自发过程的定义,导出用(dG)_(T.P)(dA)_(T.V)作为过程方向和限度判据的式子。 相似文献
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3ar洋M如。水e.n63oBo八Bo碑.段p亡米a nocMoTpeJI BKa几价Ky:乡TO KO卯cTen已B CHoM应二。刀}rr‘:(螺栓)H旦工旦犯旦卫卫些目里少(打开护窗板).OHo:、p介二C怕。H。,a丽Mao3oyTp自~KH夕刀aeTB6pK。(一扇)().、。自,oH自PaenaxH夕二。eb,。M自Ma‘,T(5一To cKa劝二a KOI叉〕CTe旎。y.OHoT能T。,e认,丽二oKoT力eb(用臂肘支撑身体)。a no朋K6HHoK.OH么n闪ToHy二aP夕K。。e二么二a er6川,认6 B oa八6H只x、O。介He 3aMe、么几。,甘To(夕二。1、b,eM6Tp只T洋6六Ta. Ce碑水a Ro一iJ‘刀Bo江B6P讨eKa3自Jl: 一Ko… 相似文献
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Remember the first time you sawE.T.The Extra-Terrestrial? Didyou cry?Spend the next monthtelling your nearest and dearest to“phone home”in your best E.T.voice?We’ve got a slew(许多,大量)offacts andfigures to get you up to speed on every-thing E.T.And don’t worry,we won’ttell anyone we saw you crying in thetheater. 相似文献
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只JllC石JI自c~禅Tb,~卯袱江a巴rC只朋Hb.BH色之免~助直眼只成PsH益JIy互叻卫H耳a,a犯翩。怕H6从HT欣0 yx顿盯B r6Pbl,n妒从眼只(躲藏)Bry。心认淤JleHHT稗B自.r6pbl溢c~yJIbl角毗兄 H八的co刀Hue. E泊月地;M6P只nP~sy叨叻刀皿e,oH仑no而: 一3及声砚,y认,C加I卿,xo3加H诚Pa! 江娜,犯C6刀峰“M~· 一江师户犯夕Tpo!一~P众T c6JIH雌H no朋HM么二只砚赴B‘IuleH丽皿e一八杨户祀夕Tpo,npeK禅cHoe M6pe!Ho HenP‘Ira益Te,的刀Hbl!T仑坦e!八改H xor豆T Kyn应T心.H么及。,叼叹拓H毗M JllO及只M6‘I刀0 xopolll6. M6p… 相似文献
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项望楚 《湖南城市学院学报》1990,(6)
自由能判据(△G)是热力学中最重要的概念。它的使用贯穿整个物理化学的各个领域中,正确地使用自由能判据能解决很多的物理化学问题。然而正确地使用是建立在对自由能(G)的深入理解上,否则谈不上正确地使用,只会引出谬误来。本文的宗指在于深入讨论自由能(G)的物理意义的基础上,分析自由能判据(△G)使用的条件、范围及有关原则,从而达到对自由能判据在各种情况下使用融会贯通。 相似文献
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敦煌写本吐蕃文雇工契(P.T.12974)为探究吐蕃文契约的样貌及其雇佣关系的性质提供了弥足珍贵的实物资料。本件吐蕃文雇工契与同期汉文雇工契相比较,在文书格式上保持独立特色的同时,更多地承袭了汉文契的模式;在雇佣关系方面契约双方地位较为平等,基本上是以役力换取粮食,属于帮工性质。 相似文献
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H幽c八以兔B K6MHaTe:C以姐KaMo直H只.1五知H玖ecr呻uHa,时阳.Q肠KacH动T n6peJlp MH6益H cM6TpHT MHen妒Mo BrJI咖.H只怕袱e cMoTP自e益Br刀a滋. OH么c刀6BoX6二eKa劝TbM。从,冬、.OH么HeM么只(哑巴),oH么caM应以范盛He noHHM么郎,Ho只民n0HHM益拍. 只n0HHM白刃,。B台Ty MHH夕叮、BH曲H、MHe oB赶T叭H6HTo珊勺 yBCT印,互ToM仑神切守H应MH Her HHKaK6伪禅3HH双bl.M五I。及HH么KOBbT:B磁水江pM H3 Hac roP析Hc晚THTcH卿掀叨应6bl益OroH任K狱仑3HH. CMe厂bHa脚勿(突然来临),~H的(舞动)HaH的c… 相似文献
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放射性元素衰变通式:m=M_0(1/2)~(x/T),各物理量的含义是:M_0为放射性元素尚未发生衰变的原始质量,m为经时间x后元素衰变剩余下的质量——不是衰变的质量,T为放射性元素的半衰期. 相似文献
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水乙HbKa一cH卯T舀,~c悦TKo益H~如认.G民T悼e时He卯八H如一TeTKHHa劝qKa.八戒MoH么Ha碑肠祀,a说qepoMr滋朋T.OH应e的血n刀么T研r刀么及HT.卫沈任劝3u似的双印卯e加JI砒仑M yT幻r6M(熨斗).TooH么八夕价B”面,、二瘾(吐唾沫)HaHer6,。Ha成~HaHe苗caMO的p叮10 TPy砂. T改Ka怕、ePa助帕eT.伍么二么邢二H,qlooH么Hy由四哪(清洁工),H朋Moxo3直认Ka· Ha水仑HbKyl它1,Ka挽邵H似,卿oHM的ro ecT H HHqe苗He八eJIaeTB八《)Me. Ae耐Hex~,江劫a、.OH‘泛HeT如poM,旦望翌工竺丝塑丝丝呸卫塑塑卫丛(留什么吃什么)。H八改K… 相似文献
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采用溶胶-凝胶法,以硝酸铜、二氯化锡和钛酸四丁酯为原料,加入十六烷基三甲基溴化铵(CTAB)作软模板,制备CuO/SnO2/TiO2纳米复合物。分别用SEM、XRD、IR、UV-vis等对产物进行表征分析,CuO/SnO2/TiO2晶粒由锐钛矿相的TiO2、金红石相的SnO2和单斜晶系的CuO组成。以甲基橙为模拟污染物,研究其催化活性,结果表明CuO/SnO2/TiO2纳米复合物具有较好的光催化活性。 相似文献
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(K0.47Na0.47Li0.06)NbO3 (KNLN) lead-free ceramics were prepared by molten salt synthesis (MSS) method using k2CO3-Na2CO3 eutectic mixtures as the flux. The microstructure and piezoelectric properties when sintered at 980-1 030 ℃ were investigated. The calcined powders were examined by X-ray diffraction. The microstructure of the calcined powders and sintered bodies was observed using a scanning electron microscope (SEM).The piezoelectric constant d33 was measured using a quasi-static piezoelectric d33 meter. The planar coupling coefficient Kp was calculated by resonance-antiresonance method. The experimental data for each sample's performance indicators were the average values of 8 specimens. The relative densities of sintered specimens are above 97%, and the dielectric loss is below 0.03. It was found that (K0.47Na0.47Li0.06)NbO3 prepared by MSS is compact and lead-free. The piezoelectric constant d33 is 216 pC·N-1 and the planar electromechanical coupling factor Kp is 0.352. 相似文献
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The influences of the PbO-B2O3-CuV2O6 （PBC） additives on the microwave dielectric properties of （Pb0.5Ca0.5） （Fe0.5Nb0.5）O3 （PCFN） ceramics were investigated as a function of sintering temperature from 950 ℃ to 1 100 ℃. The sintering temperature of the specimens with the glass could be lowered from 1125 ℃ to 1 025℃ without the degradation of microwave dielectric properties. The microwave results showed that the dielectric constant cr was not significantly different while Qf values decreased with the increase of CuV206 content of PBC glass. For the specimens doped with PB-CV0.1 glass （81% PbO-9% B203-10% CuV2O6） and sintered at 1 025 ℃ for 3 h, the microwave dielectric properties of Qf=4 823 GHz, Cr=107.1 with TCF=＋15.03 ×10^-6/℃ were obtained. 相似文献
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This work investigated the microwave dielectric properties of A-site substitution by rare earth La3+in(Pb0.5Ca0.5)(Fe0.5Ta0.5)O3(PCFT) system.A single perovskite phase was obtained only when the doping content was 2%.Suitable La3+ doping improved microwave dielectric performances.Excessive La3+doping caused the formation of secondary phase,which resulted in the decreasing of permittivity εrand quality factor Qfvalues.Especially,when the doping content is 2%-5%,permittivity εrwas above 75 and Qfvalues were 6... 相似文献
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利用磁控溅射技术在玻璃基片上分别沉积ZnOx薄膜、TiO2-y薄膜和TiO2-y/ZnOx双层透明薄膜,改变薄膜沉积过程中的氩气(Ar)和氧气((O2)的比例,获得具有不同氧含量的ZnOx薄膜和TiO2-y薄膜.采用椭偏仪测定所有样品的折射率,仔细研究薄膜中氧含量对折射率的影响.分别选择具有较大的折射率TiO2-y薄膜和具有较小的折射率ZnOx薄膜的生长条件,制备TiO2-y/ZnOx双层薄膜,获得光密媒质/光疏媒质双层结构,并观察到He-Ne激光从ZnOx薄膜入射到TiO2-y/ZnOx界面上发生的全反射现象.研究成果适用于大学生物理实验中的研究型实验或大学创新实验. 相似文献
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CuO-doped(K0.5Na0.5)Nb0.9Ta0.1O3 lead-free piezoelectric ceramics have been prepared by conventional sintering technique and the effects of CuO on the phase structure and piezoelectric properties of the ceramics have been studied.The results show that a small amount of CuO can improve the densification of the ceramics,consequently,the electric properties are improved.Good piezoelectric and dielectric properties of d33=125 pC/N,Kp=0.38,εr=700,Qm= 248,and Tc=370°C were obtained for the K0.5Na0.5Nb0.9Ta 0.1O3 ceramics doped with 0.5mol% CuO sintered at 1000℃ for 2h. 相似文献
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Long Jiang Hanrui Du Le Li Xiangjiu Guan Yihao Zhang Liwei Li Xiaoxu Liu Lei Li Yingcheng Tian Li Zhang Shuai Wang Jie Chen Shaohua Shen 《天津大学学报(英文版)》2023,(6):462-472
The high exciton binding energy and lack of a positive oxidation band potential restrict the photocatalytic CO2 reduction efficiency of lead-free Bi-based halide perovskites Cs3Bi2X9(X=Br,I).In this study,a sequential growth method is presented to prepare a visible-light-driven(λ> 420 nm) Z-scheme heterojunction photocatalyst composed of BiVO4 nanocrystals decorated on a Cs3Bi2I9 nanosheet for photocatalyt... 相似文献
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In order to obtain anatase TiO2/expanded graphite with high expansion volume, titania gel was introduced to expandable graphite surface by sol-gel process, and then the composite was expanded and calcined at high temperature. The samples were analysed by using scanning electron microscope (SEM), X-ray diffraction(XRD), energy disperse spectroscopy(EDS), and differential scanning calorimetry(DSC). The optimal conditions for preparation are as follows: the molar ratio of tetrabutyl orthotitanate to triethanolamine is 1∶0.4, and the calcination and expansion temperature is in the range of 650-750 °C. Under such conditions, the expansion volume of composites could reach 98 mL/g, and the mass loss ratio is less than 5%. The analysis shows that lower temperature and smaller particle size of graphite are helpful to the formation of anatase-type of TiO2, but larger particle size will lead to lower mass loss ratio, and higher temperature and larger particle size will lead to higher expansion volume. 相似文献
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