Prediction of the thermal conductivity of Mg–Al–La alloys by CALPHAD method

Mg-Al alloys have excellent strength and ductility but relatively low thermal conductivity due to Al addition.The accurate prediction of thermal conductivity is a prerequisite for designing Mg-Al alloys with high thermal conductivity.Thus,databases for predicting temperature-and composition-dependent thermal conductivities must be established.In this study,Mg-Al-La alloys with different contents of Al2La,Al3La,and Al11La3phases and solid solubility of Al in the α-Mg phase were designed.The influence of the second phase(s) and Al solid solubility on thermal conductivity was investigated.Experimental results revealed a second phase transformation from Al_(2)La to Al_(3)La and further to Al_(11)La_(3)with the increasing Al content at a constant La amount.The degree of the negative effect of the second phase(s) on thermal diffusivity followed the sequence of Al2La>Al3La>Al_(11)La_(3).Compared with the second phase,an increase in the solid solubility of Al in α-Mg remarkably reduced the thermal conductivity.On the basis of the experimental data,a database of the reciprocal thermal diffusivity of the Mg-Al-La system was established by calculation of the phase diagram (CALPHAD)method.With a standard error of±1.2 W/(m·K),the predicted results were in good agreement with the experimental data.The established database can be used to design Mg-Al alloys with high thermal conductivity and provide valuable guidance for expanding their application prospects.

危机情境、危机回应策略与政府回应有效性——基于40个案例的定性比较分析

危机频发逐渐成为社会常态,政府采取有效的危机回应策略对于提升其危机应对能力至关重要。然而,在过去的危机事件中,为何有的政府回应成功化解危机,而有的却“适得其反”?基于情境危机沟通理论(SCCT),论文以2015-2022年间40个政府通报引发次生舆情的危机事件为研究对象,应用定性比较分析方法,从危机情境(危机初始责任、强化要素、回应时机)和危机回应策略(指示性信息、否认、淡化、重建)7个条件因素出发,分析影响政府回应有效性的联动因素和作用路径,并通过案例回溯进行深度解读。研究发现:(1)危机情境、危机回应策略都不能单独作为政府回应失效的必要条件,单一要素并不构成限制政府危机治理能力的瓶颈;(2)二者联动导致政府回应失效的路径可概括为SCCT匹配系统不一致型、一致型两类,前者主要由危机回应策略与危机情境不匹配引致,后者则由回应程度、信息公开、措辞表达、情绪诉求、回应时机等其他方面不利因素引致;(3)基于案例回溯分析,不同策略引致政府回应效果“适得其反”的概率由大到小为:否认策略、淡化策略、重建策略、支持策略,相较于支持策略和重建策略,政府使用否认策略和淡化策略的失效风险相对更高。研究发现可丰富与补充SCCT和形象修复理论,并为政府危机应对、政府形象管理或危机公关等提供实践启示。

MCM-36 zeolites tailored with acidic ionic liquid to regulate adsorption properties of isobutane and 1-butene

Adsorption properties of an adsorbent or a catalyst towards adsorbates are crucial in the process of adsorption separation or catalytic reaction. Surface morphology and structure of adsorbents have a significant impact on the adsorption properties. In this study, a novel acidic ionic liquid, 1-butyl-3-(triethoxysilylpropyl)imidazolium hydrogen sulfate(i.e., [BTPIm][HSO_4]), was synthesized and subsequently grafted onto the MCM-36 zeolite for the regulation of its adsorption properties towards isobutane and 1-butene. The resultant [BTPIm][HSO_4]-immobilized MCM-36(i.e., MCM-36-IL) was characterized by FT-IR, XPS, XRD, SEM, TG/DTG and N_2 adsorption–desorption measurement. It was found that the specific surface area, micropore volume and mesopore volume of the MCM-36 support underwent a reduction upon the immobilization of ionic liquid,while the surface density of acid increased from 0.0014 to 0.0035 mmol·m^(-2). The adsorption capacity of isobutane and 1-butene on the MCM-36-IL was determined by a static volumetric method. Results demonstrated that the interaction between isobutane and MCM-36-IL was enhanced and the interaction between 1-butene and MCM-36-IL was reduced. As a result, a tunable adsorption ratio of isobutane/1-butene on MCM-36 was achieved.With the increase in surface density of acid and the tunable adsorption ratio of isobutane and 1-butene on the functionalized MCM-36, the acidic ionic liquid-immobilized zeolites are beneficial to obtain an improved reaction yield and a prolonged catalyst life in the reactions catalyzed by solid acid.

Establishment of a rhesus monkey model of middle cerebral artery ischemia and reperfusion using a microcatheter embolization method

Nonhuman primates are closest to humans in terms of lineage, and middle cerebral artery ischemia/reperfusion responses of nonhuman primates are most similar to ischemic stroke in humans. Therefore, nonhuman primates could be utilized to simulate the process of ischemic stroke in the human. Few studies, however, have reported the use of endovascular technology to establish a rhesus monkey stroke model. In the present study, seven adult, male, rhesus monkeys were selected and, following anesthesia, a microcatheter was inserted into one side of the middle cerebral artery via the femoral artery to block blood flow, thereby resulting in middle cerebral artery occlusion. After 2 hours, the microcatheter was withdrawn to restore the middle cerebral artery blood flow and to establish ischemia/reperfusion. Results from angiography and magnetic resonance angiography confirmed occlusion and reopening of the middle cerebral artery. Magnetic resonance imaging revealed the existence of ischemic brain lesions, and neurological examination showed sustained functional deficits following surgery. The rhesus monkey middle cerebral artery ischemia/reperfusion models established by microcatheter embolization had the advantage of non-craniotomy invasion and reproducibility. The scope and degree of ischemic damage using this model was controllable. Therefore, this nonhuman primate model is an ideal model for cerebral ischemia and reperfusion.

Kinetics, thermodynamics, and equilibrium of As(Ⅲ),Cd(Ⅱ), Cu(Ⅱ) and Pb(Ⅱ) adsorption using porous chitosan bead-supported MnFe_(2)O_(4) nanoparticles

A novel porous nanocomposite,cross-linked chitosan and polyethylene glycol(PEG) bead-supported MnFe_(2) O_(4) nanoparticles(CPM),was developed as an efficient adsorbent to remove metalloid(As(Ⅲ))and heavy metals(Cd(Ⅱ),Cu(Ⅱ),and Pb(Ⅱ)).The characteristics of CPM showed a porous structure,well dispersed MnFe_(2) O_(4),and several of hydroxyl and amino groups(-OH,-NH_(2)).Batch experiments demonstrated that the best adsorption property of As(Ⅲ),Cd(Ⅱ),Cu(Ⅱ),and Pb(Ⅱ) was achieved within 8 h with maximum adsorption capacities of 9.90,9.73,43.94,and 11.98 mg/g,respectively.Competitive and synergistic effects(particularly precipitation) were included in the co-adsorption mechanism of As(Ⅲ) and heavy metals.Thereinto,As(Ⅲ) was partly oxidized by MnFe_(2) O_(4) to As(V),and both were coordinated on MnFe_(2) O_(4) nanoparticles.Pb(Ⅱ) could also bind to MnFe_(2) O_(4) by ion exchange and electrostatic attraction.Furthermore,Cd(Ⅱ) and Cu(Ⅱ) tended to be coordinated on chitosan.Therefore,CPM can serve as a remediation material for water and soil co-contaminated with As(Ⅲ) and heavy metals.

Nonlinear Jordan Triple Derivations of Triangular Algebras

In this paper, it is proved that every nonlinear Jordan triple derivation on triangular algebra is an additive derivation.

Establishment of Fingerprint of Cryptolepis buchananii Roem. et Schult. by HPLC

[Objectives]This study aimed to establish the fingerprint of Cryptolepis buchananii Roem.et Schult.by HPLC.[Methods]Taking the peak of chlorogenic acid as the references,the 10 batches of C.buchananii Roem.et Schult.materials were detected by HPLC under the conditions of column of Thermo ODS-2 Hypersil(5μm,4.6 mm×250 mm),detection wavelength of 323 nm,column temperature of 25℃,mobile phase of methanol-0.1%phosphoric acid solution,gradient elution and injection volume of 20μL.The common peak identification and similarity evaluation were carried out according to Similarity Evaluation System for Chromatographic Fingerprint of Chinese Traditional Medicine(Version 2004 A).[Results]Among the HPLC fingerprints of the 10 batches of C.buchananii Roem.et Schult.materials,there are 13 common peaks,and their similarity is all greater than 0.9,indicating good similarity.[Conclusions]This study can provide a scientific basis for the quality evaluation of C.buchananii Roem.et Schult.

Effect of Fertilizer Application on the Yield of Walnut (Juglans regia L.)

[Objectives] This study was conducted to explore the fertilization ratio of walnut, so as to provide a basis for rational fertilization of walnut. [Methods] Under the condition of gravelly yellow soil in Chaotian District, Guangyuan City, the orthogonal design of L_9(3~4) was used to test the fertilization ratio of nitrogen, phosphorus and potassium fertilizers. [Results] The effects of nitrogen, phosphorus and potassium fertilizers on walnut yield ranked as phosphate fertilizer>potassium fertilizer>nitrogen fertilizer. The different treatments had great effects on the yield of walnut, and for the land with gravelly yellow soil, the suitable annual fertilization amount of walnut was urea 1 200 g/plant + calcium superphosphate 1 500 g/plant + potassium sulfate 940 g/plant. [Conclusions] This study provides a theoretical basis for rational fertilization of walnut in Sichuan Province.

Synergistic effect of total ionizing dose on single-event gate rupture in SiC power MOSFETs

The synergistic effect of total ionizing dose(TID) and single event gate rupture(SEGR) in SiC power metal–oxide–semiconductor field effect transistors(MOSFETs) is investigated via simulation. The device is found to be more sensitive to SEGR with TID increasing, especially at higher temperature. The microscopic mechanism is revealed to be the increased trapped charges induced by TID and subsequent enhancement of electric field intensity inside the oxide layer.

贝伐珠单抗联合化疗对复治晚期非鳞非小细胞肺癌患者的疗效及预后分析

目的:探讨贝伐珠单抗联合化疗对复治晚期非鳞非小细胞肺癌(non-squamous non-small cell lung cancer,NSNSCLC)患者的疗效和安全性,分析影响预后的因素。方法:回顾性分析2013年2月至2017年6月北京胸科医院收治的41例复治晚期NSNSCLC患者的病例资料。其中腺癌38例,其他病理类型3例。19例患者为二线治疗,22例患者为二线以上治疗。表皮生长因子受体(epidermal growth factor receptor,EGFR)突变阳性18例,突变阴性23例。评价贝伐珠单抗联合化疗的疗效和安全性,对可能影响预后的因素进行单因素和多因素分析。结果:所有患者均接受化疗联合贝伐珠单抗的治疗,化疗的平均周期数为3.1个,贝伐珠单抗治疗的平均周期数为5.0个。41例患者均可评价疗效。全组患者客观缓解率(objective response rate,ORR)为12.2%,疾病控制率(disease control rate,DCR)为82.9%。二线治疗与二线以上治疗的患者疗效接近,ORR分别为10.5%、13.6%(P=0.572),DCR分别为89.5%和77.3%(P=0.271),差异无统计学意义。中位无进展生存期(progression-free survival,PFS)和中位总生存期(overall survival,OS)分别为4.6个月(95%CI:3.619~5.581)、11.9个月(95%CI:9.797~14.003)。单因素分析提示EGFR突变、贝伐珠单抗治疗周期数>4个及女性患者获得更长的生存(χ~2=19.673,P<0.001;χ~2=6.820,P=0.009;χ~2=6.374,P=0.012)。多因素分析显示,EGFR突变状态、贝伐珠单抗治疗周期数为影响患者预后的独立危险因素(HR=0.129,P=0.001;HR=0.336,P=0.012)。常见的不良反应有骨髓抑制、出血、高血压、蛋白尿等,多数为1~2级。结论:贝伐珠单抗联合化疗对复治晚期NSNSCLC患者疗效确切,不良反应可耐受,EGFR突变阳性、贝伐珠单抗使用4个周期以上的患者预后较好。

Mechanism of nanoparticle aggregation in gas-liquid microfluidic mixing

Using gas-liquid segmented micromixers to prepare nanoparticles that have a homogeneous particle size, controllable shape, and monodispersity advantages. Although nanoparticle aggregation within a microfluid has been shown to be affected by the shear effect, the shear effect triggering conditions in gasliquid two-phase flow is unclear and the aggregation behavior of nanoparticles under the shear effect is difficult to predict, resulting in uncontrollable physical and chemical properties of nanoparticle aggregates. In this study, a numerical simulation of nanoparticle aggregation in gas-liquid two-phase flow under the shear effect is performed using the CFD-DEM method. Then, the effects of total flow rate,gas-liquid two-phase flow ratio, and particle volume fraction on particle aggregation were analyzed to achieve control of particle aggregation shape and size. Meanwhile, the triggering mechanism of the shear effect and the mechanism of the shear effect on the aggregation of nanoparticles were clarified. The results show that increasing the total flow rate or decreasing the gas-liquid two-phase flow rate ratio can induce the shear effect, which reduces the particle aggregation size and makes the morphology tend to be spherical. Moreover, increasing the particle volume fraction, and total flow rate or decreasing the gas-liquid two-phase flow rate ratio also increases the number of particle collisions and induce interparticle adhesion. Hence, particle adhesion and the shear effect compete with each other and together affect particle aggregation.

Patient-derived non-small cell lung cancer xenograft mirrors complex tumor heterogeneity

Objective:Patient-derived xenograft(PDX)models have shown great promise in preclinical and translational applications,but their consistency with primary tumors in phenotypic,genetic,and pharmacodynamic heterogeneity has not been well-studied.This study aimed to establish a PDX repository for non-small cell lung cancer(NSCLC)and to further elucidate whether it could preserve the heterogeneity within and between tumors in patients.Methods:A total of 75 surgically resected NSCLC specimens were implanted into immunodeficient NOD/SCID mice.Based on the successful establishment of the NSCLC PDX model,we compared the expressions of vimentin,Ki67,EGFR,and PD-L1 proteins between cancer tissues and PDX models using hematoxylin and eosin staining and immunohistochemical staining.In addition,we detected whole gene expression profiling between primary tumors and PDX generations.We also performed whole exome sequencing(WES)analysis in 17 first generation xenografts to further assess whether PDXs retained the patient heterogeneities.Finally,paclitaxel,cisplatin,doxorubicin,atezolizumab,afatininb,and AZD4547 were used to evaluate the responses of PDX models to the standard-of-care agents.Results:A large collection of serially transplantable PDX models for NSCLC were successfully developed.The histology and pathological immunohistochemistry of PDX xenografts were consistent with the patients’tumor samples.WES and RNA-seq further confirmed that PDX accurately replicated the molecular heterogeneities of primary tumors.Similar to clinical patients,PDX models responded differentially to the standard-of-care treatment,including chemo-,targeted-and immuno-therapeutics.Conclusions:Our established PDX models of NSCLC faithfully reproduced the molecular,histopathological,and therapeutic characteristics,as well as the corresponding tumor heterogeneities,which provides a clinically relevant platform for drug screening,biomarker discovery,and translational research.

Expression of nerve growth factor precursor, mature nerve growth factor and their receptors during cerebral ischemia-reperfusion injury

We investigated nerve growth factor precursor （proNGF） and mature NGF expression in ischemic and non-ischemic cortices after cerebral ischemia-reperfusion injury. In both ischemic and non-ischemic cortices, proNGF was found to be present in the extracellular space and cytoplasm. In addition, mature NGF was expressed in extracellular space, but with a very low signal. In ischemic cortex only, proNGF was significantly decreased, reaching a minimal level at 1 day. Mature NGF was increased at 4 hours, then reached a minimal level at 3 days. The p75 neurotrophin receptor （p75NTR） was significantly decreased after ischemia, and increased at 3 days after ischemia. These results confirmed that proNGF was the predominant form of NGF during the pathological process of cerebral ischemia-repeffusion injury. In addition, our findings suggest that ischemic injury may influence the conversion of proNGF to mature NGF, and that proNGF/p75NTR may be involved in reperfusion injury.

Overview of Urban PM_(2. 5) Numerical Forecast Models in China

This paper made an overview and introduction of urban PM_(2. 5)numerical forecast models in China,and mainly introduced air quality simulated forecast system of Beijing,Shanghai,and Nanjing. On this basis,it discussed development direction and existing problems of urban PM_(2. 5)forecast models in China. Besides,it revealed significance of numerical models for air quality forecast. In a heavy air pollution of Beijing- Tianjin- Hebei in October 6- 12 th of 2014,the forecast results indicated that pollutants was transported from south to north,so the regional transport exerts great influence on concentration of PM_(2. 5).

Construction of hydrangea-like core-shell SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi microspheres for tunable electromagnetic wave absorbers

Ti_(3)C_(2)T_(x)MXene shows great potential in the application as microwave absorbers due to its high attenuation ability.However,excessively high permittivity and self-stacking are the main obstacles that constrain its wide range of applications.To tackle these problems,herein,the microspheres of SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi with the hydrangea-like core-shell structure were designed and prepared by a combinatorial electrostatic assembly and hydrothermal reaction method.These microspheres are constructed by an outside layer of CoNi nanosheets and intermediate Ti_(3)C_(2)T_(x)MXene nanosheets wrapping on the core of modified SiO_(2),engendering both homogenous and heterogeneous interfaces.Such trilayer SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi microspheres are“magnetic microsize supercapacitors”that can not only induce dielectric loss and magnetic loss but also provide multilayer interfaces to enhance the interfacial polarization.The optimized impedance matching and core-shell structure could boost the reflection loss(RL)by electromagnetic synergy.The synthesized SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi microspheres demonstrate outstanding microwave absorption(MA)performance benefited from these advantages.The obtained RL value was-63.95 dB at an ultra-thin thickness of 1.2 mm,corresponding to an effective absorption bandwidth(EAB)of 4.56 GHz.This work demonstrates that the trilayer core-shell structure designing strategy is highly efficient for tuning the MA performance of MXene-based microspheres.

Enhanced Protective Efficacy of H5 Subtype Influenza Vaccine with Modification of the Multibasic Cleavage Site of Hemagglutinin in Retroviral Pseudotypes

Traditionally, the multibasic cleavage site (MBCS) of surface protein H5-hemagglutinin (HA) is converted to a monobasic one so as to weaken the virulence of recombinant H5N1 influenza viruses and to produce inactivated and live attenuated vaccines. Whether such modification benefits new candidate vaccines has not been adequately investigated. We previously used retroviral vectors to generate wtH5N1 pseudotypes containing the wild-type HA (wtH5) from A/swine/Anhui/ca/2004 (H5N1) virus. Here, we generated mtH5N1 pseudotypes, which contained a mutant-type HA (mtH5) with a modified monobasic cleavage site. Groups of mice were subcutaneously injected with the two types of influenza pseudotypes. Compared to the group immunized with wtH5N1 pseudotypes, the inoculation of mtH5N1 pseudotypes induced significantly higher levels of HA specific IgG and IFN-γ in immunized mice, and enhanced protection against the challenge of mouse-adapted avian influenza virus A/Chicken/Henan/12/2004 (H5N1). This study suggests modification of the H5-hemagglutinin MBCS in retroviral pseudotypes enhances protection efficacy in mice and this information may be helpful for development of vaccines from mammalian cells to fight against H5N1 influenza viruses.

A Study of the Artificial Vegetation Restoration Technology in the Wenchuan Earthquake Area

The situation of plants on the slope can reflect the effect of vegetation restoration during the process of artificial vegetation recovery.Taking the typical damaged slope of Wenchuan earthquake area as the research object,through observing the vegetation situation of deserted slope,the results show that compositae plants and gramineous plants are suitable for being pioneer plants and dominant in community; during the vegetation succession,many compositae and gramineous species invade,but there is no magaphanerophytes invading; as time goes by,the herbaceous species and diversity increase gradually,so the ecosystem becomes more stable and the gradient is important for the vegetation restoration.

Analysis on Relationship between Adjustment of Agricultural Structure and Urbanization Development

As a part of certain region,agricultural development has inevitable connection with regional urbanization,and they are highly heterogeneous and complementary in space. Their internal relationship is manifested as agricultural structure suits demand of urbanization development through adjustment in the process of urbanization,while urbanization is based on development of regional agriculture. From history of world agriculture and urbanization development,agriculture firstly provides primitive accumulation for urbanization development,and drives regional urbanization through promoting agricultural development. When urbanization develops to certain stage,urbanization accumulation increases and reaches the goal of " boosting urbanization through agriculture". If urbanization develops slowly,agricultural adjustment will lack motive force. On the contrary,weak agricultural development will lead to stagnation of urbanization. Therefore,adjustment of agricultural structure and urbanization development are interconnected,mutually promoted and restricted,and interdependent.

Study of Differential Expression of COP9,JAK2,HSPs and NADH Genes in Taxol-Resistant Ovarian Carcinoma Tissues

OBJECTIVE To study the differential expression of COP9,JAK2,HSPS and NADH genes and their relationship with taxol resistance in ovarian carcinoma.METHODS The up-regulated genes for JAK2,HSPs and NADH,and the down-regulated COP9 gene,which have been demonstrated by a micro-array from our previous study,were examined by the reverse transcription-polymerase chain reaction(RT-PCR) and real-time-PCR in 33 tissue samples from ovarian cancer patients who previously had received taxol-based chemotherapy(Group1),and from 21 ovarian cancer cases who had never received chemotherapy before operation(Group2).RESULTS The expression rate of COP9 in Group 1 was shown to be markedly lower compared to Group 2(P = 0.000).However the expression rates of JAK2,HSPs and NADH in Group 1 were significantly higher than those in Group 2(all P = 0.000).The expression of COP9,HSPs and NADH showed no significant differences related to the histological grade.However,signifi cant higher expression of JAK2 was seen in Grade 3 compared to Grade 1～2(P = 0.000).We performed real-time PCR to conf irm the above fi ndings showing that the level of COP9 gene copies of Group 1 was much lower than that of Group 2(P = 0.007).Similarly,HSPs and NADH had significantly higher copy numbers in Group 1 compared to those patients who had not undergone chemotherapy(Group 2)(P = 0.018,P = 0.024,respectively).We also found that the JAK2 gene copy concentration in a TAX group was higher than in a non-TAX group(P = 0.001).In addition,we conf irmed a higher copy concentration of the JAK2 gene in Grade 3 compared to Grade 1～2 tumors(P = 0.000),though no signifi cant difference in the expression rates and gene copy concentrations of the 4 genes were seen among variable tumor types.CONCLUSION The down-regulation of COP9 and up-regulation of JAK2,HSPs,and NADH genes are related to the mechanism of drug-resistance in ovarian cancers.

Biomass and Nutrient Accumulation Characteristics of Young Stands of Alnus cremastogyne

To investigate plant biomass and nutrient distribution and accumulation in organs of Alnus cremastogyne at different ages from 1 to 4 years, the biomass, N, P, K, Ca, Mg, Fe and Zn were tested. The results showed that the average biomass of the whole tree and the biomass of leaf, branch, stem, and root were in positive correlation with tree age, but the growth rate of biomass had a decreasing trend with the tree age increasing, and only the biomass proportion of the trunk in the whole individual plant showed an increasing trend with age. The contents of nutrient elements in organs showed an order of N 〉 Ca 〉 K 〉 Mg 〉 P 〉 Fe 〉 Zn ; and the contents of N, P and K were higher in the leaf than in other organs, and the contents of Ca, Mg and Fe in the root were higher than in other organs. The accumulations of N, P, K, Ca, Mg and Zn were the highest in the trunk, and that of Fe was the highest in the root. The annual net accumulations of N, P, K, Ca and Mg in the average trees from 1 to 4 years old were 17.07, 40.79, 95.82 and 106.71 g, respectively, and the annual net accumulations of microelements （Fe and Zn） were 335.04, 577.26, 1267 and 1525.27 mg, respectively.