Chemical Mechanical Polishing of Glass Substrate with α-Alumina-g-Polystyrene Sulfonic Acid Composite Abrasive

Abrasive is the one of key influencing factors during chemical mechanical polishing（CMP） process. Currently, α-Alumina （α-Al2O3） particle, as a kind of abrasive, has been widely used in CMP slurries, but their high hardness and poor dispersion stability often lead to more surface defects. After being polished with composite particles, the surface defects of work pieces decrease obviously. So the composite particles as abrasives in slurry have been paid more attention. In order to reduce defect caused by pure α-Al2O3 abrasive, α-alumina-g-polystyrene sulfonic acid （α-Al2O3-g-PSS） composite abrasive was prepared by surface graft polymerization. The composition, structure and morphology of the product were characterized by Fourier transform infrared spectroscopy（FTIR）, X-ray photoelectron spectroscopy（XPS）, time-of-flight secondary ion mass spectroscopy（TOF-SIMS）, and scanning electron microscopy（SEM）, respectively. The results show that polystyrene sulfonic acid grafts onto α-Al2O3, and has well dispersibility. Then, the chemical mechanical polishing performances of the composite abrasive on glass substrate were investigated with a SPEEDFAM-16B-4M CMP machine. Atomic force microscopy（AFM） images indicate that the average roughness of the polished glass substrate surface can be decreased from 0.835 nm for pure α-Al2O3 abrasive to 0.583 nm for prepared α-Al2O3-g-PSS core-shell abrasive. The research provides a new and effect way to improve the surface qualities during CMP.

Substrate matters:The influences of substrate layers on the performances of thin-film composite reverse osmosis membranes

Thin-film composite(TFC) reverse osmosis(RO) membranes are playing the dominating role in desalination.Tremendous efforts have been put in the studies on the polyamide selective layers. However, the effect of the substrate layers is far less concerned. In this review, we summarize the works that consider the impacts of the substrates, including pore sizes, surface hydrophilicity, on the processes of interfacial polymerization and consequently on the morphologies of the active layers and on final RO performances of the composite membranes. All the works indicate that the pore sizes and surface hydrophilicity of the substrate evidently influence the RO performances of the composite membranes. Unfortunately, we find that the observations and understandings on the substrate effect are frequently varied from case to case because of the lack of substrates with uniform pores and surface chemistries. We suggest using track-etched membranes or anodized alumina membranes having relatively uniform pores and functionalizable pore walls as model substrates to elucidate the substrate effect.Moreover, we argue that homoporous membranes derived from block copolymers have the potential to be used as substrates for the large-scale production of high-performances TFC RO membranes.

Microstructure of Ni /WC Surface Composite Layer on Gray Iron Substrate

The surface infiltrated composite （Ni/WC） layers on gray iron substrate were fabricated through a vacuum infiltration casting technique （VICT） using Ni-based composite powder with different WC particles content as raw materials.The microstructures of surface infiltrated composite layer,the interface structures between surface composite layer and the substrate,the changes of macro-hardness with the increasing of WC content and the micro-hardness distribution are investigated.The infiltrated composite layer includes a surface composite layer and a transition layer,and the thickness of the transition layer decreases with the increasing content of WC.The thickness of transition layer with 20%WC content in the surface infiltrated composite layer was 170 μm which was the thickest for all transition layers with different WC content.The surface composite layer was mainly composed of WC,W2C,FeB and NiB,along with Ni-Cr-Fe,Ni （Cr） solid solution,Ni （Si） solid solution and Ni （Fe） solid solution.The transition layer was composed of Ni （Cr） solid solution,Ni （Fe） solid solution,Ni （Si） solid solution,Fe （Ni） solid solution and eutectic.The surface macro-hardness and micro-hardness of the infiltrated layer had been evaluated.The macro-hardness of the surface composite layer decreases with the WC content increasing,and the average macro-hardness is HRC60.The distribution of micro-hardness presents gradient change.The average micro-hardness of the infiltrated layer is about HV1000.

Design and Analysis of Microstrip Antenna Arrays in Composite Laminated Substrates

In high performance aerospace systems where weight and aerodynamics are of major concern, fiber reinforced composite laminates can be tailored to achieve desirable mechanical properties and accommodate low-profile microstrip antenna. This work aims at the analysis of microstrip antenna array embedded in composite laminated substrates. The size of a single antenna is first calculated by spectral domain analysis to model the effects of the substrate’s electromagnetic property and the orientation of the laminate layers. The antenna array as well as the feed network, composed of microstrip transmission lines, quarter wave-length impedance transformers, and T-junction power dividers, is then tuned to accommodate the effects of the coupling between the antenna elements and the feed network loss. The performance of the 1 × 2, 1 × 4, and 1 × 8 linear array and 2 × 2 and 2 × 4 planar array are shown to have better directivity when embedded in composite laminated substrate compared with those when attached on isotropic substrate. Both 1 × 2 and 1 × 4 arrays at 2.4 GHz are validated experimentally to achieve better coverage.

Effect of Salinity on the Growth Performance, Body Composition, Antioxidant Indexes of Perinereis aibuhitensis and Total Nitrogen in the Substrate

In this study, the effects of different salinity levels (9, 12, 15, 18, 21, 24, 27, 30, and 33) on the growth performance, body composition, antioxidant indexes of Perinereis aibuhitensis (initial average mass, 20.4 ± 0.3 mg) and total nitrogen in the substrate were investigated. The survival rate, specific growth rate, feed coefficient, and protein efficiency ratio under different salinity levels were measured. The results showed that the survival rate of P. aibuhitensis at the salinity level of 9 was significantly lower than that of P. aibuhitensis at other salinity levels (P P. aibuhitensis at other salinity levels was not significant (P > 0.05). On the basis of quadratic polynomial fitting of the relationship between salinity levels and the specific growth rate, feed coefficient, and protein efficiency ratio, it was concluded that 25.36 - 25.9 is the most suitable salinity range for the growth performance of P. aibuhitensis. The main body composition (moisture, crude fat, crude protein, and ash content) was measured at different salinity levels. The results indicated that, with the increase in salinity, the moisture content of P. aibuhitensis decreased gradually;in contrast, the ash content increased gradually, as the salinity level increased. However, in the salinity range of 18 to 33, the difference in ash content was not significant (P > 0.05). Salinity had a significant influence on the crude protein content (P P. aibuhitensis specimens were cultured for 60 days was higher than the total nitrogen in the soil. With an increase in salinity, the total nitrogen content first decreased and then increased, and the lowest value was observed at the salinity level of about 24.

Effects of Different Substrate Composition on Growth of Gesneriaceae Plants

The cultivation experiment was carried out to investigate the effects of dif-ferent proportions of peat soil, perlite, vermiculite and yel ow mud on growth of Gesneriaceae species （Chirita gueilinensis, Sinningia speciosa, Lysionotus pauci-florus, Hemiboea henryi, Aeschynanthus acuminatus, Saintpaulia ionantha）. The growth traits of each plant growing in 7 different matrix materials were investigated. The plant height, crown width and chlorophyl content of each plant were mea-sured. The results showed that the best substrate ratio was peat soil∶vermiculite=2∶1 for C. gueilinensis, L. pauciflorus and H. henryi; peat soil∶perlite∶vermiculite = 2∶1∶1 for S. ionantha; peat soil∶vermiculite∶yel ow mud=2∶1∶1 for S. speciosa; peat soil∶per-lite∶vermiculite∶yel ow mud=2∶1∶1∶1 for A. acuminatus.

Growth and Characterization of InAs1-xSbx with Different Sb Compositions on GaAs Substrates

InAs1-xSbx with different compositions is grown by molecular beam epitaxy on （100）-oriented semi-insulating GaAs substrates. The increase of Sb content in the epilayer results in the deterioration of crystal quality and surface morphology. Hall measurements show that the carrier concentration increases with the composition of Sb. The electron mobility decreases initially, when Sb composition exceeds a certain value, and the mobility increases slightly. In this work, we emphasize the comparison of crystal quality, surface morphology and electrical properties of epilayers with different Sb compositions.

Substrate Type Affects Growth, Yield and Mineral Composition of Cucumber and Zucchini Squash

The expansion of hydroponics in many countries of the world in the last few decades may be ascribed to the ability of soilless growing systems to avoid various problems arising from the use of the soil. Cucumber （Cucurnis sativus L.） and zucchini （Cucurbita pepo L.） plants were grown in closed-soilless culture under unheated-greenhouse conditions at the experimental farm of University of Tuscia, Central Italy to evaluate the effects of four substrates （rockwool, pumice, perlite, and cocofiber） on growth, yield and plant mineral composition. For both cultures, plants grown in cocofiber, perlite and pumice yielded more than those grown in rockwool. The better temperature regime in cocofiber, perlite and pumice was due to the greater thermal inertia compared to rockwool slabs. Thc concentration of N in zucchini and cucumber leaves was significantly higher in cocofiber, perlite and pumice in comparison to the rockwool treatment. The concentration of K was significantly affected by the substrate only for the zucchini squash with the highest value recorded on the organic substrate （cocofiber）, whereas the Ca concentration was significantly influenced by the growing media only for cucumber with the highest value observed on pumice. Finally, the lowest Mg concentration in leaf tissue was observed on plants grown with the rockwool substrate for both zucchini squash and cucumber. We can conclude that cocofiber, perlite and pumice are suitable for zucchini and cucumber production in closed soilless system, whereas the use of rockwool is more suitable for crops grown under heated greenhouse conditions.

Effects of current density on preparation and performance of Al/conductive coating/α-PbO_2-Ce O_2-TiO_2/β-Pb O_2-MnO_2-WC-ZrO_2 composite electrode materials

Al/conductive coating/α-Pb O2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2 composite electrode material was prepared on Al/conductive coating/α-PbO 2-Ce O2-Ti O2 substrate by electrochemical oxidation co-deposition technique. The effects of current density on the chemical composition, electrocatalytic activity, and stability of the composite anode material were investigated by energy dispersive X-ray spectroscopy（EDXS）, anode polarization curves, quasi-stationary polarization（Tafel） curves, electrochemical impedance spectroscopy（EIS）, scanning electron microscopy（SEM）, and X-ray diffraction（XRD）. Results reveal that the composite electrode obtained at 1 A/dm2 possesses the lowest overpotential（0.610 V at 500 A/m2） for oxygen evolution, the best electrocatalytic activity, the longest service life（360 h at 40 °C in 150 g/L H2SO4 solution under 2 A/cm2）, and the lowest cell voltage（2.75 V at 500 A/m2）. Furthermore, with increasing current density, the coating exhibits grain growth and the decrease of content of Mn O2. Only a slight effect on crystalline structure is observed.

Variation in Enzymes Activities of Rhizospheric Substrate and Influencing Factors during Nursing of Watermelon Seedlings

[Objective] This study aimed to investigate the effects of substrate en- zymes activities on nursing of watermelon seedlings. [Method] The composted mushroom residue was mixed with garden soil according to a certain proportion to prepare nursing substrate for watermelon seedlings. During the nursing, the activity variation in alkaline phosphatase, acid phosphatase, neutral phosphatase and urease was investigated. In addition, the correlations between pH value, total nitrogen con- tent, total phosphorus content and organic matter content in substrate and enzyme activity were studied. At different young seedling stages, the rhizospheric substrates with different formulas were sampled for determination of enzymes activities. [Result] The enzyme activity differed significantly among different substrates. The correlation analysis results showed that the higher the organic matter content and total nitrogen content in substrate are, the higher the urease activity is; the phosphatase activity was significantly related to the organic matter content, total nitrogen content and to- tal phosphorus content in substrate; the pH value of substrate was significantly relat- ed to rhizospheric alkaline phosphatase activity; the shoot dry weight was positively related to urease activity; there was a significant correlation between phosphatase activity and root dry weight. [Conclusion] Through determining enzymes activities in the rhizospheric substrate for nursing watermelon seedlings, the optimum substrate M3 was screened out. The activities of rhizospheric urease, alkaline phosphatase, acid phosphatase and neutral phosphatase in the substrate M3 were all higher than those in the substrate fertilized with manure.

Biochar Supported Nanoscale Zero-valent Iron Composites for the Removal of Petroleum from Wastewater

Considering the need for efficiently and rapidly treating oily wastewater while preventing secondary pollution,the nanoscale zero-valent iron(nZVI)was supported on biochar prepared by using a spent mushroom substrate(SMS),to produce an iron-carbon composite(SMS-nZVI).The ability of the SMS-nZVI to treat wastewater containing high concentration of oil was then comprehensively evaluated.The morphology,structure,and other properties of the composite were characterized by using scanning electron microscopy,transmission electron microscopy,the Brunauer-Emmett-Teller nitrogen sorption analysis,and the Fourier transform infrared spectroscopy.The results show that the biochar prepared by using the SMS can effectively prevent the agglomeration of nZVI and increase the overall specific surface area,thereby enhancing the absorption of petroleum by the composite.Experiments reveal that compared with the SMS and nZVI,the SMS-nZVI composite removes petroleum faster and more efficiently from wastewater.Under optimized conditions involving an nZVI to biochar mass ratio of 1:5 and a pH value of 4,the efficiency for removal of petroleum from wastewater with an initial petroleum concentration of 1000 mg/L could reach 95%within 5 h.Based on a natural aging treatment involving exposure to air for 30 d,the SMS-nZVI composite retained an oil removal rate of higher than 62%,and this result could highlight its stability for practical applications.

Morphology of alpha-lead dioxide electrodeposited on aluminum substrate electrode

Alpha-lead dioxide was deposited by anodization of alkaline solution containing HPbO2- anions. Scanning electron microscopy (SEM) results show that the morphology is remarkably affected by the current density, concentration of HPbO2- anions, bath temperature and electroplating time. Compact and well adherent layers are possibly obtained under conditions of current densities ≤3 mA/cm2, electrolyte containing 4 mol/L NaOH and 0.12-0.14 mol/L lead (Ⅱ ), bath temperature of 40 ℃, and electroplating time of 2 h. EDS analyses show that the PbO2 deposited in alkaline condition is highly non-stoichiometric at high current density.

Germination and Early Seedling Growth of Moringa oleifera Lam with Different Seeds Soaking Time and Substrates at the Yongka Western Highlands Research Garden Park (YWHRGP) Nkwen-Bamenda, North-West Cameroon

Moringa oleifera is a multipurpose tree used to remedy problems related to food insecurity and soil fertility degradation. Proper husbandry of this crop is contingent on the use of seedlings of good quality. This study aimed at assessing the germination and early seedling growth with different soaking durations and substrates composition. The seeds were obtained from the Far North region of Cameroon. A randomized complete block design with three replications was used. Two factors were tested;soaking duration with 4 treatment levels of 0 day, 4 days, 8 days and 12 days and substrates with 8 treatment levels: 100% soil, 75% soil + 25% poultry manure (PM), 50% soil + 50% PM, 25% soil + 75% PM, 100% sand, 75% sand + 25% PM, 50% sand + 50% PM and 25% sand + 75% PM. Germinated seeds and growth parameters were collected after every 5 days. The results showed that soaking duration and substrate composition influence germination and initial development of M. oleifera (p ≤ 0.05). At 25 days after soaking (DAS), soaking durations of 0 day (68.7%) and 8 days (53.1%) showed the highest germination percentages while seeds soaked for 12 days occupied the least position with 37.5%. At the same time, 75% soil + 25% PM (68.7%), 100% sand (64.5%) and 100% soil (60.5%) with the unsoaked seeds showed the highest germination percentages. The least germination percentages were represented by 50% sand + 50% PM and 25% sand + 75% PM with 35.5% and 27%, respectively. Unsoaked seeds with the substrates of 50% soil + 50% PM are the best practice for M. oleifera seedling production in the nursery.

Study on the performance of thin-film VCSELs on composite metal substrate

Thin film p-side up vertical-cavity surface-emitting lasers(VCSELs)with 940 nm wavelength on a composite metal(Copper/Invar/Copper;CIC)substrate has been demonstrated by twice-bonding transfer and substrate removing techniques.The CIC substrate is a sandwich structure with a 10µm thick Copper(Cu)layer/30µm thick Invar layer/10µm thick Cu layer.The Invar layer was composed of Iron(Fe)and Nickel(Ni)with a proportion of 70:30.The thermal expansion coefcient of the composite CIC metal can match that of the GaAs substrate.It results that the VCSEL layers can be successfully transferred to CIC metal substrate without cracking.At 1 mA current,the top-emitting VCSEL/GaAs and thin-flm VCSEL/CIC had a voltage of 1.39 and 1.37 V,respectively.The optical output powers of VCSEL/GaAs and VCSEL/CIC were 21.91 and 24.40 mW,respectively.The 50µm thick CIC substrate can play a good heat dissipation function,which results in improving the electrical and optical characteristics of thin flm VCSELs/CIC.The VCSEL/CIC exhibited a superior thermal management capability as compared with VCSEL/GaAs.The obtained data suggested that VCSELs on a composite metal substrate not only afected signifcantly the characteristics of thin film VCSEL,but also improved considerably the device thermal performance.

Near-stoichiometric Ti:LiNbO3 strip waveguide with varied substrate refractive index in waveguide layer

We report the near-stoichiometric Ti：LiNbO3 strip waveguides fabricated by vapour transport equilibration （VTE） at 1060~^{／circ}C for 12 h and co-diffusion of 4--8~／mu m wide, 115-nm thick Ti-strips. Optical studies show that these waveguides are monomode at 1.5~／mu m and have losses of 1.3 and 1.1~dB/cm for the TM and TE modes, respectively. In the waveguide width/depth direction, the mode field follows a Gauss/Hermite--Gauss profile. A secondary ion mass spectrometry study reveals that the Ti profile follows a sum of two error functions along the width direction and a complementary error function in the depth direction. Micro-Raman analysis shows that the Li-composition in the depth direction also follows a complementary error function. The mean Li/Nb ratio in the waveguide layer is about 0.98. The inhomogeneous Li-composition profile results in a varied substrate index in the guiding layer, and the refractive index profile in the guiding layer is given.

电流体喷印电磁功能微阵列结构

提出一种基于电流体喷印技术的复合材料衬底电磁功能微阵列结构制造工艺方法。通过间距补偿工艺策略,降低复合材料衬底功能结构线宽尺寸误差的47.4%,有效提高了复合材料衬底喷印精度。系统分析了电流体喷印参数对功能结构质量的影响关系,实现复合材料衬底上多尺寸、多类型电磁功能微阵列结构的按需制造。确定了电磁功能微阵列结构的最优固化条件,得到线宽60μm金属结构电阻率为9.18×10^(-8)Ω·m。所制造的带阻型电磁功能微阵列结构在中心频率23.64 GHz处能够将电磁波有效抑制,透射系数为-42.89 dB,有效验证了电流体喷印技术制造电磁功能结构的能力与实现效果。

太阳电池阵弧形基板结构振动分析及优化设计

针对弧面型太阳电池阵新型基板结构,在满足结构安全的前提下以多参数轻量化设计为目标。本文基于等效板理论获得弧形太阳电池阵基板的各向异性等效性能参数,建立新构型太阳电池阵基板的三维有限元数值模型,并通过正弦扫频振动试验验证了模型的可靠性,进而初步实现了结构薄弱区域定位。最后结合工程实际,基于参数化建模结合多目标迭代优化的方法,分析结构在典型随机振动载荷作用下的最大应力随各特征参数的变化规律,从而获得满足结构安全条件下的补强优化方案,相比于原始结构,可使面板最大应力下降21%,若加强结构为单向无纬布,结构最大应力可进一步下降15.6%,为新构型太阳电池阵基板的轻量化设计提供支撑。

CoFe/NiFe复合自由层对自旋阀磁电阻变化率的影响

研究CoFe/NiFe复合自由层对自旋阀磁电阻变化率的影响。在实验中通过固定溅射功率、时间和气流,调节靶基距(TSD)得到不同厚度及均匀性的复合自由层CoFe/NiFe薄膜,进而达到优化自旋阀结构提高其磁电阻率的目的。实验结果表明:在TSD分别为8.382 cm、8.890 cm时,制备的CoFe和NiFe单层膜性能最优,电阻标准偏差分别为1.33%、0.98%。通过磁性能综合测试平台对优化后的CoFe/NiFe复合自由层的自旋阀结构进行了测试,磁电阻变化率(MR)较优化前提高了约0.84%。该研究可为高性能自旋阀结构的制备提供参考。

羊肚菌轮作及其菌渣还田对烤烟根际土壤环境及产量与品质的影响

【目的】探明羊肚菌轮作及其菌渣还田对植烟土壤改良及烤烟产质量调控的效应,合理优化烤烟种植制度。【方法】以烤烟品种云烟87为材料,采用双因素裂区设计,研究烤烟种植模式(A1,烤烟—羊肚菌—烤烟;A2,烤烟—冬闲—烤烟)和羊肚菌菌渣施用方式(B1,不施;B2,机械旋耕施;B3,塘施)对烤烟根际土壤理化特性、微生物、烟株生长及产量、烤烟化学成分的影响。【结果】种植模式及羊肚菌菌渣施用方式均可调控植烟土壤理化特性及烟叶化学成分,其中以种植模式及羊肚菌菌渣施用方式互作效应最大,单施菌渣方式次之。A1B2、A1B3、A2B2、A2B3组合可有效改善土壤容重、孔隙度和大粒径团聚体含量,调节土壤阳离子交换量(CEC)、pH及土壤养分,其中以A1B2作用最明显,其土壤有机质、水解性氮、有效磷、速效钾含量较A1B1分别显著提高22.71%、5.07%、20.94%、32.55%。与A1B1和A2B1相比,A1B2、A1B3、A2B2、A2B3组合能显著提高土壤真菌、细菌、放线菌数量1.13~2.93倍,微生物量碳、氮含量及其碳氮比分别增加42.19%~77.46%、25.68%~59.97%、3.55%~28.99%;同时能显著提高烟叶叶面积、上等烟比例、产量和产值,其中以A1B2产值增幅最大,较A1B1、A2B1产值分别显著提高15.05%、29.12%。各因子对烟叶化学成分可用性指数调控效应:A×B互作>菌渣施用>种植模式。其中,与A1B1、A2B1相比,A1B2、A1B3、A2B2、A2B3显著降低烟叶总糖、总氮含量,提高钾含量;施用菌渣使烟叶总氮、烟碱含量下降,钾含量增加;种植模式主要影响烟叶总氮和钾含量。【结论】采用烤烟—羊肚菌—烤烟种植模式,在烟田旋耕施入羊肚菌菌渣,有利于改善土壤通透性及团聚体结构,提升土壤肥力,增加土壤微生物群落丰度,促进烟叶生长,提高烟叶产量、产值,烟叶化学成分更协调。

预热温度对激光选区熔化成形30%SiC_(p)/AlSi10Mg复合材料力学性能的影响

基板常温工况下激光选区熔化成形中等体积分数SiC_(p)/Al复合材料存在孔洞、裂纹等冶金缺陷,从而导致成形零件致密度低、力学性能差等问题。首先研究了固定优化成形工艺参数时,基板预热温度(200~400℃)对45μm的30%(质量分数,下同)SiC_(p)/AlSi10Mg成形零件表观致密度和力学性能的影响;进一步提高SiC_(p)质量分数至50%,再次评价了上述基板预热温度对成形性能的影响。结果表明,当SiC_(p)质量分数为30%时,升高基板预热温度可以减少成形零件的孔洞和裂纹,成形零件的表观致密度及力学性能显著提高;当基板预热至400℃时,成形零件表观致密度最高达到97.98%,与此同时极限抗压强度和极限抗拉强度分别为578 MPa和56 MPa;随着SiC_(p)质量分数进一步增加至50%,基板预热温度对成形零件致密化和力学性能的强化效果逐步减弱。本研究证明高温预热基板能够有效抑制激光选区熔化成形中等体积分数SiC_(p)/Al复合材料的冶金缺陷,为增材制造SiC_(p)/Al复合材料提供了工程应用解决方案。