Aurivillius-compound Bi3TiNbO9 (BTN) based high-temperature piezoelectric ceramics doped with mixed-valence cations (Mo1/3Cr2/3)(4+) at the lattice B-sites, Bi3Ti1-x(Mo1/3Cr2/3)(x)NbO9 (BTN-MC100x, x = 0 -0.07), were prepared via the solid-state reaction method. The incorporation of the (Mo1/3Cr2/3)(4+) ions into the BTN lattice promotes the preferential growth of grains along the a-axis, making it easier for polarization vector to flip. The optimized composition BTN-MC5 ceramic had a large d(33) of 20.3 pC/N with a high T-C of 901 degrees C. It was found that the donor doping effect of (Mo1/3Cr2/3)(4+) and the formation of (Cr-Ti'-V-O(center dot center dot)-Cr-Ti')(x) defect dipoles contribute to reduce the concentration of oxygen vacancies, thus increasing the resistivity (2.2 x10(5) Omega cm at 600 degrees C). In addition, the d(33) of the BTN-MC5 ceramic exhibits an excellent thermal stability against depoling temperature T-d. These findings indicate that the BTN-MC5 ceramic is promising candidate for the preparation of high-temperature piezoelectric sensors.

CaBi2Nb2O9 (CBN) with Aurivillius phase has an enormous potential in high-temperature piezoelectric devices due to their high Curie temperature and excellent free-fatigue characteristics. Nevertheless, simultaneous enhancement of electrical and mechanical properties in CBN-based ceramics are still a great challenge because of the trade-off between the electrical and mechanical properties. Herein, a strategy, the synergy effect of lattice distortion and oxygen vacancy, is designed to realize the enhanced electrical and mechanical properties of CBN-based ceramics via the domain structure and grain size engineering. The materials can simultaneously deliver a high piezoelectric property of 17.3 pC/N, large hardness of 4.68 GPa, and intensive bending strength of 113.07 MPa, which are enhanced by 346%, 197%, and 141% over those of unmodified CBN ceramics. We believe that the founding of this research opened up a novel and efficient guideline for exploring new bismuth-layered structure ceramics with excellent electrical and mechanical properties.

Bi4Ti3O12 (BIT), a typical layered-structure ferroelectric with a high Curie temperature (TC), is a promising material for high-temperature sensors. Herein, W/Cr co-substitution at the B-site of BIT ceramics (BITWC100x) is carried out to investigate the phase structure, domain structure, and electrical properties. The W/Cr addition apparently reduces the concentration of oxygen vacancies, effectively improving the ferroelectric and piezoelectric properties as well as the resistivity of the BIT ceramics. The BITWC2 ceramic exhibits a high piezoelectric coefficient (d(33) = 31.1 pC/N), a moderate TC (651 ?), a large remnant polarization (Pr = 12.2 mu C cm-1), and a prominent direct current resistivity (5.49 x106 omega.cm at 500 ?). Moreover, the BITWC2 ceramic possesses a large d33 of 26.6 pC/N at an annealing temperature of 600 ?, indicating the excellent thermal stability of the piezoelectric coefficient. Overall, the BITWC100x ceramics can be used in piezoelectric devices at temperatures up to 500 ?.(C) 2022 Elsevier B.V. All rights reserved.

Bi4Ti3O12 high-temperature piezoelectric ceramics composed of 0.03 mol (Nb, Ta)(5+) substituting B site and x mol CeO2 (x = 0-0.05, abbreviated as BCTNT100x) substituting A site were synthesized by the conventional solid-state reaction method. The effects of Ce additive on the structures and electrical properties of resulting Bi4Ti3O12-based ceramics were systematically investigated. In-situ temperature-dependent X-ray diffraction (XRD) confirmed that the phase structure of BCTNT100x ceramics change from orthorhombic structure to tetragonal structure as temperature increased. The ceramics at Ce content x = 0.03 illustrated optimal performances with superior piezoelectric constant (d(33) = 36.5 pC/N), high Curie temperature (T-C = 649 degrees C), and large remanent polarization (2P(r) = 21.6 mu C/cm(2)). BCTNT3 ceramics also possessed high d(33) of 32.5 pC/N at an annealing temperature of 600 degrees C, with electrical resistivity preserved at 10(6) omega cm at 500 degrees C. These results demonstrate that BCTNT100x ceramics can be used as high-temperature piezoelectric devices.

Bi4Ti3O12 (BIT) ceramic has great potential in high-temperature environment due to its high Curie temperature TC -675 degrees C. In this work, hot press sintering (HPS) is applied on the 0.01 mol Ce and Nb/Cr co-doped BIT (BCTNC) ceramics to enhancing the low piezoelectric coefficient (d33 < 7 pC/N) and resistivity. Extremely high d33 (-39 pC/N) together with high TC (-672 degrees C) and high dc resistivity rho (-1.49 x107 omega ecm at 500 degrees C) are obtained in HPS samples. The enhancement of piezoelectricity benefits from high density of domain and high poling electric field. Moreover, outstanding thermal stability of piezoelectric constant (d33 -35 pC/N after annealing at 650 degrees C) and low dielectric loss (tan delta -3.8% at 500 degrees C) are observed as well. These findings are instrumental in understanding HPS and provide a possible manipulation of crystallized mechanism and domains growing kinetics to enhance piezoelectric performances of BIT based ceramics.

An appropriate amount of (Li,Ce) ions are incorporated into bismuth layer-structured piezoelectric ceramics to reduce the oxygen vacancy concentration, limit the grain growth, and enhance the electrical properties and hardness of the ceramics. The existence of a pseudo-tetragonal phase region, the change in the domain structure, and the increase in the spontaneous polarization promote the enhancement of the piezoelectric properties. Additionally, the conductive mechanism in the high-temperature regions is discussed in terms of the direct-current resistivity. A moderate amount of the (Li,Ce) dopant ions can effectively improve the thermal depoling behavior of CaBi2Nb2O9 (CBN)-based ceramics. Consequently, the Ca-0.88(LiCe)(0.06)Bi2Nb2O9 ceramic exhibits an optimal d33 piezoelectric coefficient of 18.5 pC/N and an excellent thermal depoling behavior. Furthermore, the results of the Vickers indentation hardness test reveal that the hardness of CBN-based ceramics is improved to 3.78 GPa. (c) 2022 Published by Elsevier B.V.

Fluorine-doped Bi2WO6 samples were synthesized by a simple one-step hydrothermal method. The structure and the photocatalytic performance of the as-prepared catalysts were systematically investigated using a variety of characterization methods. Meanwhile, the possible mechanism of photodegradation was discussed. Combined with the analysis of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometry (EDS), it was proved that fluorine has been successfully doped into the Bi2WO6 (BWO) crystal lattice, and its crystal structure remains orthorhombic. With the doping of fluorine, the morphology of Bi2WO6 changed from a two-dimensional ultrathin nanosheet to a hierarchical nanoflower microstructure. This hierarchical nanoflower structure as well as the strong electronegativity of fluorine are the reasons for the enhanced degradation of pollutants (tetracycline, TC for short). For the optimum composition labeled as F-BWO4, the apparent rate constant (k) of degrading TC is about 4.5 times that of Bi2WO6, and the degradation rate decreased by only 10% over four cycle degradation experiments.

xTa-PNN-PZT piezoelectric ceramics with [0.55 Pb(Ni1/3Nb2/3)O3 - 0.45 Pb(Zr0.3Ti0.7)O3 - xwt%Ta2O5] + 1 wt% PbO composition (0 < x < 0.7) were prepared by conventional solid-state reaction method. Special attention was paid to the effect of Ta2O5 concentration on structural, dielectric, piezoelectric, and ferroelectric properties of these ceramics. In particular, rhombohedral-tetragonal morphotropic phase boundary was observed in PNN-PZT crystal structure near the composition of x = 0.5. At this point, volume fraction of rhombohedral phase was almost equal to that of tetragonal phase. In addition, the ceramic exhibited the optimum values of piezoelectric coefficient, bipolar strain, unipolar strain, and inverse piezoelectric coefficient, i.e., 1090 pC/N, 0.135%, 0.165%, and 1493 pm/V, respectively. Moreover, according to in-situ X-ray diffraction, piezoelectric force microscopy, and in-situ strain measurement results, phase structure of 0.5Ta-PNN-PZT revealed relatively stable piezoelectric behavior at 60 ?C.

New Aurivillius-type ceramics, (NaBi)(0.5-x)(LiMn)(x)Bi4Ti4O15 (NBTLM-100x), are prepared by using the solid-state reaction process with a lower sintering temperature (T-s) of 960 degrees C, the relationship between structure (grain, phase, domain and crystal structure) and high-temperature properties (piezo-/ferro-electric prop-erties and resistances) of Li/Mn doped NBT-based ceramics are investigated systematically. The results show that, the replacement of Na/Bi with Li/Mn frees up more space for cations at the center of the oxygen octahedrons, which increases the ferroelectric to paraelectric phase transition temperature (T-C), and changes the tilt and rotation of Ti-O octahedrons, leading to an increase in spontaneous polarization (P-s), NBTLM-2 ceramics have the maximum P-s along the a-axis of -43.24 mu C/cm(2). Meanwhile, in the Li/Mn substituted ceramics, the substitution for Bi and the lower T-s suppress the formation of oxygen vacancies, contributing to the domains switching and the promising piezoelectric properties. The high temperature conduction mechanisms of the NBTLM-100x ceramics are also fully explored, the decrease of hole concentration, attributing to the donor dopping and reduced oxygen vacancy concentration, favors the high resistivity. In this work, the NBTLM-2 ceramics obtain the excellent properties of TC = 664 degrees C, d(33) = 33 pC/N and rho(dc) (at 500 degrees C) = 1.55 x 10(7) Omega center dot cm, indicating the enormous potential in the high temperature piezoelectric devises. (C) 2021 Elsevier B.V. All rights reserved.

The molten‐salt method was used to synthesize CaBi_2Ta_2O_9 (CBTa) powder, and the influence of temperature on the structure and micromorphology of products was investigated using X‐ray diffraction and the scanning and transmission electron microscope. The results showed that highly crystalline CBTa nanoplates exhibit single orthorhombic symmetry and could be obtained in the temperature range of 850–900 °C. Among which, the nanoplates prepared at 900 °C have optimal properties (average grain size of 1.7 μm and uniform size distribution). Above 900 °C, various CaO–Ta_2O_5 binary compounds, Bi_2O_3, and BiTaO_4 formed due to the decomposition of CBTa and subsequent reactions of decomposition products, transforming plate‐like grains to cuboid nano‐particles with a small amount of prismatic grains. Possible reaction mechanisms at different synthesizing temperature were proposed. This work provides a method for the preparation of template grains to synthesize textured CaBi_2Ta_2O_9 high‐temperature piezoelectric ceramics by the template grain growth method.

我国家电企业的发展经历了从贴牌生产到企业自由品牌的创建,随着我国家电企业的发展,越来越多的中国家电品牌开始了国际化之路,逐渐在国际市场中活跃起来.在国际化过程中,我国家电品牌得到了一定的宣传,在国际市场中的认知度逐渐提升,国产家电品牌的品牌声誉也逐步建立起来.同样,我国家电企业在国际市场上良好的品牌声誉也会对企业的国际化产生一定的作用.因此,本文着重分析了我国家电企业在国际市场上的品牌声誉对我国家电企业国际化的作用机制,旨在提出建立国际品牌声誉的重要性,并提出品牌声誉提升的相关对策,为促进我国家电企业深入国际化提供相关参考.

Objective To investigate the diagnosis and treatment of invasive pulmonary aspergillosis (IPA) in children.Methods From January 2004 to July 2016,nine children with proven IPA or possible IPA in West China Second University Hospital,Sichuan University were included into this study.The risk factors,clinical manifestations,chest radiographic findings,microbiological and pathological evidence,treatment and prognosis were retrospectively reviewed in nine patients.Results Among nine patients (four boys,five girls),four cases were proven IPA,and five cases were possible IPA.The risk factors were found in seven cases.Pulmonary tuberculosis coexisted in three cases.Cough,fever,moist rales were the most common manifestations,and only two cases had hemoptysis.The most common chest imaging was nodules and patchy shadow.Halo sign was found in three cases,and air crescent sign was not found.Blood culture was negative in all nine patients.The positive children of sputum and bronchoalveolar lavage fluid (BALF) culture were two cases and four cases,respectively.Lung biopsy was conducted in three cases.Eight cases were treated with anti-fungal therapy (voriconazole,itraconazole,micafungin used alone),and only one case was treated with combination therapy (voriconazole and liposomal amphotericin B).Seven cases recovered,and two cases are still receiving treatment.Conclusions The clinical manifestations and chest imaging of IPA are nonspecific.Repeated sputum and BALF culture are essential to clinical diagnosis of IPA.The patients in whom the antifungal therapy are initiated early have a good outcome.

目的:探讨宫颈残端癌的临床病理特点,为临床诊治及预防提供参考.方法:收集31例宫颈残端癌患者的临床病理资料并进行回顾性分析,采用PCR-反向点杂交法检测人乳头瘤病毒(HPV),寿命表法计算生存率.结果:31例患者平均47.77±7.64岁;临床表现以阴道不规则流血为主,共16例(51.61％);子宫次全切除原因以子宫肌瘤为主,共21例(67.74％).入院后检测HPV阳性率83.87％ (26/31),高危型HPV阳性率77.42％(24/31),且其中6例子宫次全切除术前与宫颈残端癌术前的高危型HPV感染情况一致.31例患者均采用手术治疗,术后补充放化疗20例.术后病理检查示原位癌累腺2例,浸润性鳞癌22例,腺癌6例,腺鳞癌1例.31例患者随访时间6 ～ 96个月,5年生存率78.20％.结论:宫颈残端癌的临床表现与一般宫颈癌相似,病理类型以鳞癌为主.HPV感染率高于正常人群.高危型HPV的检测、慎重选择子宫次全切除术以及子宫次全切除术后的严密随访对预防宫颈残端癌的发生尤为重要.

1临床资料<br>　　患者,女,40岁, G2 P0,平素月经规律,末次月经( LMP)：2013年7月5日。停经2+月,因反复阴道流血30d,于2013年10月30日入院。入院前60d因“双侧输卵管阻塞”外院行“冻胚移植术”。入院前30 d开始间断阴道流血,B超示“宫内孕囊伴散乱胚芽,考虑胚胎停止发育”予以药物流产。25 d前阴道排出胎囊,周围见水泡状物,送病检示“绒毛组织”。20 d前复查B超示“宫腔占位,大小约2．9cm ×2．3cm ×1．1cm,行清宫术。15 d前再次阴道淋漓流血,妇检：宫体：前位、如孕50+d大小、质软、无压痛。右附件：扪及一6 cm ×5cm ×4cm包块。 B 超：宫体4．6cm ×5．5cm ×4．5cm,左侧宫角处查见大小4．2 cm ×4．7 cm ×4．2 cm 的不均质增强回声,团块周边探及丰富的环状血流包绕,肌壁回声均匀,未探及明显异常血流信号。右附件区查见大小5．8 cm ×5．0 cm ×4．7 cm 的分隔状囊性占位。血β-HCG200000mIU/mL,临床考虑“宫角妊娠？”收入院。行腹腔镜下异位病灶清除+右卵巢囊肿剥除术,术中见子宫增大如孕60 d大小、质软；左侧宫角突起,切开后见多个大小不等的水泡样组织；右卵巢可见6 cm囊肿,囊液清亮；双输卵管伞闭锁(见图1)。术后病检：左宫角异位病灶清除物为完全性葡萄胎。 IHC：P57阴性,滋养细胞 Ki67阳性率为90%。术后第1 d 开始MTX 50 mg肌注,隔日1次,共肌注3次后因肝功能异常暂停化疗。术后25 d复查B超：子宫左后壁近宫底查见强回声团,大小2．0cm ×2．0cm ×2．4cm,团块内查见小泡状暗区,团块周边探及环状血流信号,疑滋养细胞疾病肌壁浸润病灶；血β-HCG为12298 mIU/mL；术后39d肝功好转后改用MA( KSM+MTX+CF)方案化疗四次,术后84 d血β-HCG降至正常水平。术后125 d复查B超：子宫肌壁回声尚均匀,考虑滋养细胞疾病治疗后改变。血β-HCG恢复正常后继续巩固化疗2次,患者随访至今,动态血β-HCG及B超均正常。

OBJECTIVETo investigate the antibacterial activity of glycyrrhizic acid (GA) against Streptococcus mutans (S. mutans) under acidic environment in vitro.METHODSWorking culture were prepared by inoculation of S. mutans into TPY broth followed by static incubation under anaerobic condition at 37 degrees C for 24 h. TPY broth was supplemented with three kinds density of GA (0.78, 1.57, 3.13 mg x mL(-1)), whose acidity was regulated to pH7.0, pH 5.5 and pH4.0. And the group of pH 7.0 was used as negative control. The growth of S. mutans was measured by A600 of bacteria suspension and counting colony forming unit (CFU). In addition, the survival rate of S. mutans was calculated.RESULTSIn pH 5.5 groups, the survival rates of 0.78, 1.57 and 3.13 mg x mL(-1) GA groups were 60.96%, 60.27% and 45.58%, respectively, and in pH4.0 groups, the survival rates were 68.75%, 53.12% and 45.83%. In 0.78, 1.57 and 3.13 mg x mL(-1) GA groups, the survival rates of pH5.5 and pH4.0 were 52.25% and 39.05%, 74.39% and 43.11%, 86.38% and 55.30%, respectively.CONCLUSIONGA could inhibit the growth of S. mutans under acidic environment, which the effect is improved as the acidity increased.

针对"90后"大学生这一群体责任感缺失现象进行原因分析,从而提出对策建议。

Objective To investigate the antibacterial activity of decoction of Radix glycyrrhizae against Streptococcus mutans (S. mutans) in vitro. Methods The decoction of Radix glycyrrhizae was prepared by boiling particles of Radix glycyrrhizae, the diameter was 0.2-3.2 mm. In distilled water and filtered, the filtrate was collected for study. The minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) of the decoction against S. mutans were detected using double dilution. The effect of decoction on growth and acidogenic profile of S. mutans were investigated by detecting the Abs of bacteria suspension and the pH value of medium at definite time intervals(0, 3, 7, 12, 23, 40 h) during cultured. Results The MIC determined for decoction was 50 mg x mL(-1) and there was no bactericidal effect when concentration of decoction lower than 100 mg x mL(-1). The decoction inhibitted multiplication of bacteria significantly and the effects became stronger with concentration increasing. The decoction also inhibitted S. mutans producing acid and the effect became stronger with concentration increasing. The most efficient inhibition were observed when incubated 12 hours. Conclusion The decoction of Radix glycyrrhizae can inhibite the growth and acid-production of S. mutans in vitro.

OBJECTIVE To investigate the antibacterial activity of decoction of Radix glycyrrhizae against Streptococcus mutans (S. mutans) in vitro. METHODS The decoction of Radix glycyrrhizae was prepared by boiling particles of Radix glycyrrhizae, the diameter was 0.2-3.2 mm. In distilled water and filtered, the filtrate was collected for study. The minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) of the decoction against S. mutans were detected using double dilution. The effect of decoction on growth and acidogenic profile of S. mutans were investigated by detecting the Abs of bacteria suspension and the pH value of medium at definite time intervals(0, 3, 7, 12, 23, 40 h) during cultured. RESULTS The MIC determined for decoction was 50 mg x mL(-1) and there was no bactericidal effect when concentration of decoction lower than 100 mg x mL(-1). The decoction inhibitted multiplication of bacteria significantly and the effects became stronger with concentration increasing. The decoction also inhibitted S. mutans producing acid and the effect became stronger with concentration increasing. The most efficient inhibition were observed when incubated 12 hours. CONCLUSION The decoction of Radix glycyrrhizae can inhibite the growth and acid-production of S. mutans in vitro.

OBJECTIVE:To establish an efficient and stable method for protein extraction of Streptococcus mutans.METHODS:The collected bacteria were treated by freeze-thaw and ultrasonic (method 1), ultrasonic (method 2), boiling (method 3), boiling and ultrasonic (method 4), respectively. The index such as state of bacteria broken, concentration of extracted protein and SDS-PAGE of protein were employed to evaluate the effects of above four methods.RESULTS:Beside the method 3, the other three methods could break the bacteria effectively, of which ultrasonic was the key factor. The pattern of SDS-PAGE which treated by method 1, method 2 and method 4 was almost same, but method 1 resulted in the best abundance. There was significantly difference among the four protein concentration extracted by four methods (P < 0.05). All methods exhibited good stability and reproducibility.CONCLUSION:Method of freeze-thaw and ultrasonic resulted in an efficient proteins extraction of Streptococcus mutans which demonstrated good stability and reproducibility and easy to handle.

当今中国正逐步步入老龄化社会,养老问题,特别是农村养老问题就成为了一个战略难题,对家庭养老的研究又成为农村养老研究中的重要内容.本文主要就中国人口学核心期刊-<人口研究>和<人口学刊>(1994年-2006年)中学者们围绕农村家庭养老的讨论进行了简单总结.