A Complex BPF with On Chip Auto-tuning Architecture for Wireless Receivers

A 3(rd) order complex band-pass filter (BPF) with auto-tuning architecture is proposed in this paper. It is implemented in 0.18um standard CMOS technology. The complex filter is centered at 4.092MHz with bandwidth of 2.4MHz. The in-band 3(rd) order harmonic input intercept point (IIP3) is larger than 16.2dBm, with 50 Omega as the source impedance. The input referred noise is about 80uV(rms). The RC tuning is based on Binary Search Algorithm (BSA) with tuning accuracy of 3%. The chip area of the tuning system is 0.28 x 0.22 mm(2), less than 1/8 of that of the main-filter which is 0.92 x 0.59 mm(2). After tuning is completed, the tuning system will be turned off automatically to save power and to avoid interference. The complex filter consumes 2.6mA with a 1.8V power supply.

Average energy loss measured in single and double electron capture collisions of He2 on Ar at low velocities

Employing the recoil ion momentum spectroscopy we investigate the collision between He2+ and argon atoms. By measuring the recoil longitudinal momentum the energy losses of projectile are deduced for capture reaction channels. It is found that in most cases for single- and double-electron capture, the inner electron in the target atom is removed, the recoil ion is in singly or multiply excited states (hollow ion is formed), which indicates that electron correlation plays an important role in the process. The captured electrons prefer the ground states of the projectile. It is experimentally demonstrated that the average energy losses are directly related to charge transfer and electronic configuration.

评估动物栖息地适宜性的两种方法比较:以大相岭山系大熊猫种群为例

采用景观因素赋值法(方法Ⅰ)和主成分分析法(方法Ⅱ)对大相岭山系大熊猫栖息地进行评价,结果表明,方法Ⅰ的结果中中等适宜、适宜等级和最适宜等级所占的面积分别为94.62、45.46和0.21 km2,分别占总面积的4.17%、2.00%和0.01%;而方法Ⅱ的结果中,中等适宜和适宜等级所占的面积分别为623.03和170.27 km2,分别占总面积的27.49%和7.51%。结合实际调查数据和景观因素,发现2种方法均能对大相岭山系大熊猫生境进行评价,但差异较大。方法Ⅰ评判因素较少,各因素所占比重较大,因素对整个评价结果影响很大,评价结果不精确,但所需人力、物力较少;方法Ⅱ所需评判因素较多,野外搜集所需资料困难,累计贡献率很难达到95%,而且需要大量的人力、物力。因此,为了减少评估误差,应将2种方法结合对动物生境进行评估。

Surprising arching sheet-like dendrites growing from BaF2 nanocubes

BaF2 nanocubes were prepared from quaternary reverse micelles of cetyl trimethyl ammonium bromide (CTAB), n-butanol, n-octane, and water. Interestingly, there are arching sheet-like dendrites growing between two neighbouring sides of these cubes. X-ray powder diffraction (XRD) analysis showed that the products were BaF2 single phase. Scanning electron microscopy (SEM) or transition electron microscopy (TEM) was used to estimate the size of the final products. The results showed that the shape and size of particles were strongly dependent on the reaction conditions, such as the temperature and reaction time. When the reaction temperature was 25 degreesC, we obtained cuboid-like particles with 'clean' surfaces (no dendrites growing on them), and when the temperature was 35 degreesC, we obtained nanocubes with dendrites growing from them between the neighbouring sides. The influence of reaction time at a temperature of 35 degreesC is also discussed.

合成醇Cu-CO催化剂中第Ⅲ组分对其催化性能的影响

在一般金属催化剂上,由CO和H_2选择合成高级醇是合成气化学的重要研究方向。IFP在1982年提出的Cu-Co催化剂至今还是重要的体系,对合成C_2醇有较好的选择性,但这类催化剂存在热稳定性差、活性低的缺点,为改善催化剂的性质需添加热稳定性高的载体和助剂。有关Cu-Co催化剂体系的研究已有不少报道,但加入第Ⅲ组分对其性质的影

综合利用低次烟叶中烟碱及其副产品芦丁的制备新工艺

本发明涉及一种综合低次利用烟叶中烟碱及其副产品芦丁的制备新工艺；含有下述工艺步骤：１.先将烟草完全按水提有机溶剂萃取烟碱生产工艺进行；２.浸提液先粗滤，硫酸调pＨ值，经沉淀后，吸取上清液过大孔吸附树脂床；３.经大孔吸附树脂床的流出液与有机溶剂混合萃取制备硫酸烟碱；４.用乙醇洗脱大孔吸附树脂床上的吸附物，回收乙醇后，喷雾干燥得副产品芦丁。本发明的工艺可提高硫酸烟碱的得率，解决由于乳化使分离后水相不能再用，产生大量的污水，派生出环境污染的问题；并能综合利用烟草中富含的芦丁，且其工艺简单、耗能少、收益大

一个用于机器人自然语言理解的英语句法分析系统

在低挡微机中速度较慢的串行处理硬设备条件下，利用本文提出的启发式概念，分层搜索和匹配策略以及设置最大搜索长度等方法，可使推理速度提高一个数量级以上．此外，通过引入语义信息，分阶段消除歧义，自顶向下与自底向上相结合，以及把一般疑问句一律变成相应陈述句的方法，解决了自动英语句法分析中的一系列难题，缩小了知识库的规模。

一株胶质芽胞杆菌对磷矿石风化作用的实验研究

以一株质芽孢杆菌为例研究实验条件下微生物对磷矿石的风化作用。以直接作用和间接作用的方式研究培养基中胶质芽孢杆菌对磷矿粉的风化作用，即在装有100目磷矿石粉的液体培养基中接种，研究该菌对磷矿石粉的直接风化作用；同时，将装有100目磷矿石粉的透析袋放入液体培养基中再接入该菌，研究其对磷矿石粉的间接风化作用。按不同时间取培养液上清液，过滤，用电感耦合等离子体发射光谱（ICP—OES）测定滤液中Ca^2＋、Mg^2＋、Na^＋、Mn^2＋、Al^3＋、Fe^3＋和K^＋等浓度，比色法测定水溶性P（Pws）和水溶性Si（Siws）的含量；滤膜上的固体物称重并消解后，同上方法测定Ca^2＋、Mg^2＋、Na^＋、Mn^2＋、Al^3＋、Fe^3＋和K^＋等浓度以及Pws和Siws含量。此外，细菌风化作用后的矿物残渣用电子探针作表面微观形态分析和XRD矿物物相分析。结果表明：胶质芽孢杆菌对磷矿石粉风化的直接作用强度大于间接作用；对不同矿物的风化强度不同，对粘土矿物的风化作用较明显。提出细菌对磷矿石的风化作用源自细菌生长导致的机械破坏作用、胞外分泌物的生化降解作用以及多种因素之间的协同作用.

新疆哈密香山基性—超基性杂岩体的岩石学和地球化学

香山基性—超基性杂岩体位于新疆哈密境内，地理坐标为东经94°30'-94°37'，北纬42°15'-42°20'。本文研究了该岩体的岩石学、地球化学、矿物学特征。最后提出了关于香山岩体成因的假设。香山岩体的主体是辉长苏长岩，它占整个杂岩体出露地表面积的绝大部分，其它岩石类型有斜长方辉橄榄岩、（斜长角闪）二辉橄榄岩，（斜长角闪）单辉橄榄岩、（角闪）橄榄辉长（苏长）岩，辉长岩。岩体中各种岩石均为中粗粒结构，块状构造。显微结构最特征的是包含结构，还有辉长结构，反应边结构，金属矿物较多时具海绵陨铁结构。主要蚀变类型有蛇纹石化，还有绿泥石化，透闪石化，滑石化、绢石化、钠黝帘石化、碳酸盐化等。杂岩体中的超基性岩的m/f = 1.9-4.6，属于铁质超基性岩，为与铜镍矿床有关的岩石类型。各种岩石在久野（1966）的Na_2O + K_2O → SiO_2变异图中，大部分属于碱性玄武岩系。但由于在CIPW标准矿物组成和薄片不均未发现富碱矿物（霞石或白榴石），因此，认为岩体的母岩浆是一种过渡型的碱性橄榄玄武岩浆。岩石的微量元素含量，从方辉橄榄岩至辉长苏长岩，随着基性度减小，Ti、V、Zn、Sr、Ba逐渐增加。Cr、Ni、Co、Cu逐渐减小。所有岩石均呈轻稀土富集型，从方辉橄榄岩、二辉橄榄岩、单辉橄榄岩直至辉长苏长岩，稀土总量和轻重稀土比L/HREE逐渐增加。方辉橄榄岩有Eu轻微正异常 、二辉橄榄岩Eu轻微负异常。单辉橄榄岩是具较大的Eu正异常，辉长苏长岩有正的或负的Eu异常，所有的岩石均具Ce轻微负异常。岩体中各种造岩矿物橄榄石为贵橄榄石，单斜辉石为顽透石或普通辉石，斜长石为拉长石，角闪石则为钙角闪石。岩石中各种矿物的结晶温度（用不同方法计算的结果比较一致）分别为：橄榄石1455～1654 ℃，单斜辉石976～1150 ℃（与母岩类型有关），斜长石1100 ℃左右，角闪石812-1002 ℃（与母岩有有关。岩体的母岩浆是在1200 ℃，25.9Kb（约80 KM深处）条件下上地幔岩经8-9%的部分熔融产生的（用平衡部分熔融状型计算得出）。岩浆结晶过程可用F_o-D_i-An三元相图定性说明，依次结晶生成：纯橄榄岩（未见）→ 辉石橄榄岩（方辉橄榄岩、二辉橄榄岩、单辉橄榄岩） → 橄榄辉长苏长岩，由于实际情况复杂，还有其它岩石类型生成。

Adaptabilidade e estabilidade de híbridos comerciais de milho no Meio-Norte brasileiro, na safra 2007-2008.

Na safra 2007/2008, 42 híbridos comerciais de milho foram submetidos a nove ambientes do Meio-Norte brasileiro, visando conhecer a adaptabilidade e a estabilidade para fins de recomendação. Utilizou-se o delineamento experimental em blocos ao acaso com duas repetições. Constataram-se, na análise de variância conjunta, diferenças entre os híbridos e os ambientes e um comportamento inconsistente desses ante as variações ambientais, no tocante ao caráter rendimento de grãos. Os municípios de Teresina, Urucuí e Bom Jesus ,PI, e São Raimundo das Mangabeiras, Colinas e Paraibano, MA, mostraram-se mais propícios ao cultivo do milho. Os híbridos que apresentaram rendimentos médios de grãos acima da média geral (8.068 kg ha-1), expressaram melhor adaptação. Os híbridos 2 B 688 e P 30 S 40, por serem exigentes nas condições desfavoráveis e responderem à melhoria ambiental, destacaram-se para os ambientes favoráveis. Os híbridos que evidenciam adaptabilidade ampla, a exemplo dos híbridos 2 B 688,2 B 710, P 30 P 70, DAS 8480, AG 7088, DKB 177 entre outros, consubstanciamse em alternativas importantes para a agricultura regional.