平坦模与(P)性质的关系

运用交换代数与同调代数方法,利用平坦模刻画了环上的(P)性质,将局部环中平坦模与(P)性质的相关结果推广到了半局部环上,进而推广到任何环上,得到了在任何环下,环R上的(P)性质与平坦模以及同调维数的等价关系等一系列结论.

关于环的相伴性质

通过对环上(P)性质与平坦模关系的讨论,把文献(CommutativeCoherentRings[M].Berlin:HeidlbergSpringer Verlag,1989.)中的局部环上关于(P)性质的结论推广到了任意环上,从而使原来的结论变成了现在结论的特殊情况.并且讨论了满足(P)性质的环,并通过具体的例子作了说明.

Heteroepitaxial Growth and Heterojunction Characteristics of Voids-Free n-3C-SiC on p-Si(100)

Highly oriented voids-free 3C-SiC heteroepitaxial layers are grown onφ50mm Si (100) substrates by low pressure chemical vapor deposition (LPCVD).The initial stage of carbonization and the surface morphology of carbonization layers of Si (100) are studied using reflection high energy electron diffraction (RHEED) and scanning electron microscopy (SEM).It is shown that the optimized carbonization temperature for the growth of voids-free 3C-SiC on Si (100) substrates is 1100℃.The electrical properties of SiC layers are characterized using Van der Pauw method.The I-V,C-V,and the temperature dependence of I-V characteristics in n-3C-SiC/p-Si heterojunctions with AuGeNi and Al electrical pads are investigated.It is shown that the maximum reverse breakdown voltage of the n-3C-SiC/p-Si heterojunction diodes reaches to 220V at room temperature.These results indicate that the SiC/Si heterojunction diode can be used to fabricate the wide bandgap emitter SiC/Si heterojunction bipolar transistors (HBT's).

Reflection coefficients of P-SV waves in weak anisotropic media

We introduce the Thomsen anisotropic parameters into the approximate linear reflection coefficient equation for P-SV wave in weakly anisotropic HTI media. From this we get a new, more effective, and practical reflection coefficient equation. We performed forward modeling to AVO attributes, obtaining excellent results. The combined AVO attribute analysis of PP and PS reflection data can greatly reduce ambiguity, obtain better petrophysical parameters, and improve parameter accuracy.

Several Properties of p-w-hyponormal Operators

In this paper, let T be a bounded linear operator on a complex Hilbert H. We give and prove that every p-w-hyponormal operator has Bishop's property(β) and spectral properties; Quasi-similar p-w-hyponormal operators have equal spectra and equal essential spectra. Finally, for p-w-hyponormal operators, we give a kind of proof of its normality by use of properties of partial isometry.

Effect of Carrier Processing Temperature on Its Properties for Adsorption of Active Metals

The influence of the carrier pseudo-boehmite （PB）, which was impregnated with a Ni-Mo-P solution under over- saturation conditions and treated at different temperatures, on its property for adsorption of active metals （Ni, Mo） was studied. The results showed that the amount for adsorption of active metal was decreased with an increasing treatment tem- perature of the carrier. After phase transition of the carrier PB to γ-Al2O3, its capacity for adsorption of active metals was significantly reduced. The difference in properties for adsorption of active metals （Ni, Mo） by PB dried at 120℃ and γ-Al2O3 calcined at 600℃ was studied in detail. The results suggested that the ability of the PB carrier to adsorb metals was higher than that of theγ-Al2O3 carrier. Especially, the ratio of chemically adsorbed metals on the PB support was much higher than 3＇-alumina. The chemical adsorption sites on the PB carrier were proved to be much more than those on the γ-Al2O3 carrier. Ni and Mo chemical adsorption sites differed a lot on the carrier possibly because of the difference in chemical adsorption sites.

Characteristics of surface and interface for ITO/PTCDA/p-Si thin film device

Interface characteristics possess very important influence on the performance of thin film devices. ITO/ PTCDA/p-Si thin film device was set up with vacuum evaporation and sputter deposition method. The surface and interface electron states of ITO/PTCDA/p-Si were investigated by X-ray photoelectron spectroscopy （XPS） and argon ion beam etch techniques. Results indicate that at the interface of ITO/PTODA/p- Si,not only ITO/PTCDA-Si but also PDCDA-Si can produce diffusion. Moreover, the XPS spectra of each atom appear chemical shifts, and the chemical shifts of C1s and O1s are more remarkable.

Effect of acupuncture combined with Chinese medicine on the expression of interstitial cells of Cajal, substance P and nerve nitric oxide synthase in diabetic mice with gastroparesis antrum

Objective To explore the effect of acupuncture combined with Chinese medicine on expression of interstitial cells of Cajal（ICC）, substance P（SP） and nerve nitric oxide synthase（nNOS） in diabetic gastroparesis mice. Methods Eighty Kunming male mice were randomly divided into normal group（group A, 15 mice）, diabetic gastroparesis model mice group（group B, 12 mice）, acupuncture combined with Chinese medicine group（group C, 12 mice）, Chinese medicine group（group D, 13 mice） and western medicine group（group E, 13 mice）. The mice were intraperitoneally injected with steptozotocin and fed with high-fat diet-induced irregular except the normal group mice, that made mouse model of diabetic gastroparesis. And then, the ACM group were treated by acupuncture at the acupoints of Housanli（后三里 ST 36） and Zhōngw n（中脘 CV 12） combined with Chinese medicine, the CM group were only treated by Chinese medicine; the WM group were treated by domperidone and vitamin B 6. Numbers and expression of ICC, SP and n NOS were detected by immunohistochemical methods. Results After treatment, compared with normal group, ICC and SP indexes of model group were significantly reduced. Compared with model group, all indexes in ACM and CM groups were improved significantly（P0.05, P0.01）, but only the positive area and average optical density value in c-Kit and SP in WM group increased obviously（P0.05）. Compared with ACM group, no significant difference in c-Kit and SP of CM group were observed（P0.05）, but expression of nNOS were increased markedly（P0.01）. Besides, c-Kit and SP expressions of WM group were significantly induced was increased remarkably（P0.01）. Conclusion Acupuncture combined with Chinese medicine have much better therapeutic effects for diabetic gastroparesis mice, which may be due to repairing ICC damage, upregulating the expression of SP and lowering the expression of nNOS.

Effects of Wei Chang An pill(胃肠安丸) on enzyme activity and levels of vasoactive peptide and substance P in the small intestine of rats with compound diarrhea

OBJECTIVE:To investigate the regulatory effects of Wei Chang An Pill(WCAP) on enzyme activity and gastrointestinal hormones in the small intestine of rats with compound diarrhea.METHODS:Forty Wistar rats were randomly divided into a control,diarrhea model,and WCAP high,medium,and low dose groups.The control group was not treated,and the model group was administered intragastric distilled water.The WCAP groups were given WCAP suspension,80,60 or 40 mg · kg-1 · d-1,for 4 days.Stool properties were observed.After the experiment,thymus and spleen indices were measured,and the activities of lactate dehydrogenase(LDH),malate dehydrogenase(MDH),and disaccharidase(lactase) in the small intestinal mucous membrane,and levels of substance P(SP) and vasoactive peptide(VIP) in the colon were determined.RESULTS:Compared with the control group,thymus and spleen indices were significantly decreased,LDH,MDH,and disaccharidase activity in the small intestine was decreased,and SP and VIP levels in the colon were significantly increased inthe diarrhea model group.Compared with the model group,thymus and spleen indices were significantly increased,and LDH,MDH,and disaccharidase activity in the small intestine and SP and VIP levels in the colon were significantly decreased in theWCAP medium dose group.CONCLUSION:The diarrhea model rats exhibited pathological changes including atrophy of the thymus and spleen,decreased enzyme activity in the small intestine,and gastrointestinal hormone disturbance.WCAP can increase the activity of intestinal digestive enzymes and regulate gastrointestinal hormones,thereby relieving diarrhea.

Schwarz lemma at the boundary of the unit polydisk in C^n

We establish a new type of the classical boundary Schwarz lemma for holomorphic self-mappings of the unit polydisk Dnin Cn. By using the Carath′eodory metric and Kobayashi metric of Dn, we obtain some properties of the complex Jacobian matrix Jf(p) at a boundary point p of Dnfor a holomorphic self-mapping f of Dn. Our results extend the classical Schwarz lemma at the boundary to high dimensions.

Controlled one step thinning and doping of twodimensional transition metal dichalcogenides

Two-dimensional(2 D) transition metal dichalcogenides(TMDCs) have drawn intensive attention due to their ultrathin feature with excellent electrostatic gating capability, and unique thickness-dependent electronic and optical properties. Controlling the thickness and doping of 2 D TMDCs are crucial toward their future applications. Here, we report an effective HAu Cl4 treatment method and achieve simultaneous thinning and doping of various TMDCs in one step. We find that the HAu Cl4 treatment not only thins thick Mo S2 flakes into few layers or even monolayers, but also simultaneously tunes Mo S2 into p-type. The effects of various parameters in the process have been studied systematically,and an Au intercalation assisted thinning and doping mechanism is proposed. Importantly, this method also works for other typical TMDCs, including WS2, Mo Se2 and WSe2,showing good universality. Electrical transport measurements of field-effect transistors(FETs) based on Mo S2 flakes show a big increase of On/Off current ratios(from 102 to 107) after the HAu Cl4 treatment. Meanwhile, the subthreshold voltages of the Mo S2 FETs shift from-60 to +27 V after the HAu Cl4 treatment, with a p-type doping behavior. This study provides an effective and simple method to control the thickness and doping properties of 2 D TMDCs, paving a way for their applications in high performance electronics and optoelectronics.

Nickel-coated silicon photocathode for water splitting in alkaline electrolytes

Photoelectrochemical （PEC） water splitting is a promising approach to harvest and store solar energy [1]. Silicon has been widely investigated for PEC photoelectrodes due to its suitable band gap （1.12 eV） matching the solar spectrum [2]. Here we investigate employing nickel both as a catalyst and protecting layer of a p-type silicon photocathode for photoelectrochemical hydrogen evolution in basic electrolytes for the first time. The silicon photocathode was made by depositing 15 nm Ti on a p-type silicon wafer followed by 5 nm Ni. The photocathode afforded an onset potential of -0.3 V vs. the reversible hydrogen electrode （RHE） in alkaline solution （1 M KOH）. The stability of the Ni/Ti/p-Si photocathode showed a 100 mV decay over 12 h in KOH, but the stability was significantly improved when the photocathode was operated in potassium borate buffer solution （pH ≈ 9.5）. The electrode surface was found to remain intact after 12 h of continuous operation at a constant current density of 10 mA/cm^2 in potassium borate buffer, suggesting that Ni affords good protection of Si based photocathodes in borate buffers.

Effects of p-type GaN thickness on optical properties of Ga N-based light-emitting diodes

The influence of p-type Ga N(p Ga N) thickness on the light output power(LOP) and internal quantum efficiency(IQE) of light emitting diode(LED) was studied by experiments and simulations. The LOP of Ga N-based LED increases as the thickness of p Ga N layer decreases from 300 nm to 100 nm, and then decreases as the thickness decreases to 50 nm. The LOP of LED with 100-nm-thick pG a N increases by 30.9% compared with that of the conventional LED with 300-nm-thick p Ga N. The variation trend of IQE is similar to that of LOP as the decrease of Ga N thickness. The simulation results demonstrate that the higher light efficiency of LED with 100-nm-thick p Ga N is ascribed to the improvements of the carrier concentrations and recombination rates.

A Class of Oscillatory Singular Integrals

LP mapping properties are considered for a class of oscillatory signular integral operators.Ketwords:Calderon-Zygmund kernel. oscillatory singular integral operator. polynomial growth estimate.