硒功能化杯[4]芳烃对金属离子的识别及在PVC基质支撑液膜的传输作用

提出以PVC为基质的支撑液膜传输体系 ,研究了以新研制的硒功能化杯 [4 ]芳烃为活性载体 ,邻苯二甲酸二辛酯(DOP)为膜溶剂的PVC基质支撑液膜对金属离子的传输性能 .采用双层夹心膜电位法测定了活动载体 -金属离子在膜中的配合物生成常数 ,对离子在膜中的传输速率、选择性系数以及生成常数之间的相关性作了研究 .使用该体系发现 ,在 8种金属离子中汞具有最快的传输速率 ;进一步讨论了硒功能化杯 [4

浅谈数字化技术在广播电视传输中的作用问题

微波是广播电视节目重要传输手段之一。采取合适的手段，降低多种路径的衰减，是当前广播电视节目重要传输需要解决的关键问题。能实现空间分集并接收与具有自动适应均衡特性的设备，就可作为基本设备运用到微波通讯系统中去。微波数字化技术涉及发射机、收信机及天线反馈系统，在广播电视传输中发挥着重要作用。

芦苇在微咸水河口湿地甲烷排放中的作用

以长江口微咸水河口湿地为研究对象,通过模拟潮汐淹没和改进的静态箱法,针对芦苇在不同淹水条件下对甲烷的传输作用进行了研究。结果表明,长期淹没样点割除芦苇前后平均甲烷释放分别为1.60 mgCH4 m-2h-1和0.50 mgCH4 m-2h-1,而短期淹没样点割除芦苇前后平均甲烷释放分别为0.94 mgCH4 m-2h-1和0.55 mgCH4 m-2h-1。芦苇的存在增加了大约41.5%—69%的甲烷释放,割除芦苇导致长期淹没样点甲烷释放显著地减少。从淹水前到淹水后的一个潮周期内,长期淹没样点和短期淹没样点的甲烷释放分别在淹没期达到最小和最大释放(1.21 mgCH4 m-2h-1和1.18 mgCH4 m-2h-1),说明芦苇对甲烷的传输作用受到潮汐淹没程度的影响。实验室针对芦苇自身产甲烷的可能性进行的离体芦苇茎干和叶片的甲烷释放研究发现,离体茎干释放大约0.7μL/L和0.2μL/L甲烷,且下部茎干的甲烷释放量要明显高于上部茎干和叶片,随后均不再增加。结果进一步证实芦苇增加的甲烷排放来自对土壤气体的传输。同时,传输作用主要发生在植株的下部茎干。

白术对慢传输型便秘大鼠结肠组织Cajal间质细胞的影响

目的:运用免疫组化方法检测白术对慢传输型便秘(slow transit constipation,STC)大鼠结肠组织Cajal间质细胞(interstitial cells of Cajal,ICC)的影响,进一步阐释白术治疗STC的机制。方法:随机将成年健康SD大鼠60只分为空白对照组、模型对照组、白术低剂量组(30 g生药/kg)、白术中剂量组(60 g生药/kg)、白术高剂量组(120 g生药/kg),每组12只。应用大黄对除空白对照组以外的大鼠进行慢传输型便秘模型制备。造模成功后,空白及模型对照组给予生理盐水2 mL灌胃,白术低、中、高剂量组分别给予3 g生药/mL、6 g生药/mL、12 g生药/mL的白术水煎液2 mL,早晚2次,连续15 d。15 d中连续观察大鼠皮毛光泽、活动范围、进食量及排便情况。末次给药后用免疫组化法观察结肠ICC的形态和数量。结果:模型对照组大鼠结肠较其他各组粗大、迂曲,肠腔内有较大块较多粒粪便存留,差别有统计学意义(P<0.05或P<0.01)。各组大鼠在给药前体质量差别均无统计学意义(P>0.05),而处死前各组大鼠体质量差别均有统计学意义(P<0.05或P<0.01)。c-kit免疫组化法染色半定量分析,各组差别有统计学意义(P<0.05)。400倍光镜下白术低剂量组、白术中剂量组镜下所见与空白对照组相似,区别不大,ICC数量差异不大;而模型对照组及白术高剂量组ICC均有所改变,形态出现异常,体积变小,核周胞浆突起变钝、变短,ICC数量差异较大,差别有统计学意义(P<0.01)。结论:白术可以改善结肠组织中ICC形态并提高ICC数量,剂量60 g的生白术能将上述效应发挥最好。

Broadband ＆ Digital Content-Couple Subscriber Cooperative Relaying Networks for Uplink Transmission using Hierarchical Game Approach

Cooperation allows wireless network users to benefit from various gains such as an in- crease in the achieved rate or an improvement in the bit error rate. In the paper, we propose a distributed Hierarchical Game （HG） theoretic framework over multi-user cooperative communication networks to stimulate cooperation and improve the network performance. First, we study a two- user decision making game in the OFDMA based subscriber cooperative relaying network, in which subscribers transmit their own data in the first phase, while helping to retransmit their partner＇s or choosing to freeride in the second phase. Instead of consulting to a global optimal solution, we decouple the cooperation resource allocation into two level subproblems： a user level Nash game for distributed cooperation decision and a Base Station （BS） level coalition game for centralized resource allocation. In the proposed HG algorithm, where mutual cooperation is preferred and total payoff is transferable, we prove it converges to a unique optimal equilibrium and resolve the subcarrier as-signment and power allocation among the couples. Besides, we discuss the existence of the publishing and rewarding coefficients in order to encourage cooperation. Then, we extend the HG to multi-user cases by coupling among subscribers according to the location information. The simulation results show that the proposed scheme with the distributed HG game achieves a well tradeoff between fairness and efficiency by improving the transmission efficiency of adverse users and outperforms those employing centralized schemes.

Comment on “Approximate and Conditional Teleportation of an Unknown Atomic State Without Bell-State Measurement with Two-Photon Interaction”

In a previous work [Commun. Theor. Phys. 45 （2006） 79] a scheme was presented for approximate and conditional teleportation of an unknown atomic state in a QED-cavity without Bell-state measurement via two-photon Jaynes-Cummings model in the effective Hamiltonian approach. This comment presents an alternative method, based on the so called ＂full two-photon Jaynes-Cummings Hamiltonian approach＂. Accordingly, it describes the evolution of the two-photon degenerate process for arbitrary average photon number inside the cavity, as the correct way to implement teleportation in this scenario.

An Analytical Approach to Thermal and Electrical Transport in a Mesoscopic Conductor

In order to consider the thermal and electrical coherent transport in a mesoscopic conductor under the influence of electron-electron interaction, in this paper, we establish a method in terms of which one can analytically obtain the Hartree self-consistent potential instead of computing it by the numerical iterative procedure as usual, which is convenient for us to describe the thermal and electric current flow through a mesoscopic conductor. If we study the electron-electron interaction at the Hartree approximation level, the Hartree potential satisfies the Poisson equation and Schroedinger equation, so when we expand the action function S（x） by Planck constant h, the self-consistent potential and the wavefunction can be solved analytically order by order, and the thermal and electrical conductance can thus be obtained readily. However, we just show the quantum corrections up to the second order.

Boron and Zinc Transport Through Intact Columns of Calcareous Soils

Leaching of boron （B） and zinc （Zn） can be significant in some pedomorphic conditions, which can cause contamination of shallow groundwater and economic losses. Boron and Zn adsorption and transport was studied using 8.4 cm diameter × 28 cm long intact columns from two calcareous soil series with differing clay contents and vadose zone structures： Lyallpur soil series, clay loam （fine-silty, mixed, hyperthermic Ustalfic Haplargid）, and Sultanpur soil series, sandy loam （coarse-silty, mixed, hyperthermic Ustollic Camborthid）. The adsorption isotherms were developed by equilibrating soil with 0.01 tool L^-1 CaCl2 aqueous solution containing varying amounts of B and Zn and were fitted to the Langmuir equation. The B and Zn breakthrough curves were fitted to the two-domain convective-dispersive equation. At the end of the leaching experiment, 0.11 L 10 g L^-1 blue dye solution was also applied to each column to mark the flow paths. The Lyallpur soil columns had a slightly greater adsorption partition coefficient both for B and Zn than the Sultanpur soil columns. In the Lyallpur soil columns, B arrival was immediate but the peak concentration ratio （the concentration in solution at equilibrium/concentration applied） was lower than that in the Sultanpur soil columns. The breakthrough of B in the Sultanpur soil columns occurred after about 10 cm of cumulative drainage in both the columns; the rise in effluent concentration was fast and the peak concentration ratio was almost 1. Zinc leaching through the soil columns was very limited as only one column from the Lyallpur soil series showed Zn breakthrough in the effluent where the peak concentration ratio was only 0.05. This study demonstrates the effect of soil structure on B transport and has implications for the nutrient management in field soils.

Teleportation of Unknown Atomic Entangled States Using GHZ Class States

We propose two physical schemes, which can teleport unknown atomic entangled states from user A （Alice） to user B （Bob） via GHZ class states as quantum channel The two schemes are both based on cavity QED techniques. In the two schemes, teleportation and distillation procedures can be realized simultaneously. The second teleportation scheme is more advantageous than the first one.

Transferring Multi-Dimensional Quantum States and Preparing Quantum Networks in Cavity QED

In this paper we propose a scheme for transferring quantum states and preparing quantum networks. Compared with the previous schemes, this scheme is more efficient, since three or four-dimensional quantum states can be transferred with a single step and information interchange of three-dimensional quantum states can be realized, which is a significant improvement. It is based on the resonant interaction of a three-mode cavity field with an atom. As a consequence, the interaction time is shortened greatly. Furthermore, we give some discussions about the feasibility of the scheme.

Entanglement Transfer via Heisenberg Interaction in a Four-Qubit System

We investigate the entanglement transfer in a four-qubit system and calculate the concurrence between any two qubits in different initial states. We show that both the pure entangled state and mixed entangled state can be transferred. For some special coupling constants and some evolution time, entanglement can be completely transferred from one pair particles to another.

水溶液中银表面自组装膜工艺

采用银在水溶液表面形成C18SH自组装膜(SAMs)的工艺,在银表面得到致密、平整,表现出明显疏水性的SAMs。EMPA和XPS测试表明,表面活性剂分别作为C18SH的分散剂,自组装过程中起到传输作用,本身不参与成膜,但影响SAMs的厚度和倾斜角。银试样表面的Ag2O在成膜过程中被硫醇中的H-S键还原为Ag,同时有Ag-S-C18H37键的形态形成。

Italicized carbon nanotube facilitating water transport:a molecular dynamics simulation

While the preferential movement of water inside carbon nanotube is appealing for water purification,our understanding of the water transport mechanism through carbon nanotube(CNT)-based membrane is far from adequate. Here we conducted molecular dynamics simulations to study how the alignment of the CNTs in the membrane affects the water transport through the CNT membrane. It was shown that compared to the conventional CNT membrane where the alignment of CNTs was vertical to membrane surface, the ‘‘italicized CNT membrane'' in which the contact angel between membrane surface and the CNT alignment is not 90° offered a higher transmembrane flux of water. The expanded exposure of more carbon atoms to water molecules reduced the energy barrier near the entrance of this italicized CNT membrane, compared to the vertical one. For water flows through the italicized CNT membrane, the Lennard-Jones interaction between water and nanotube as function of central path of the CNT changes from ‘‘U'' to ‘‘V'' pattern, which significantly lowers energy barrier for filling water into the CNT,favoring the water transport inside carbon nanotube. Above simulation indicates new opportunities for applying CNT in water purification or related fields in which water transport matters.

Decorating graphdiyne on ultrathin bismuth subcarbonate nanosheets to promote CO_(2)electroreduction to formate

Electrocatalytic reduction of CO_(2)is one of the most attractive approaches for converting CO_(2)into valuable chemical feedstocks and fuels.This work reports a catalyst comprising graphdiyne-decorated bismuth subcarbonate(denoted as BOC@GDY)for efficient electroreduction of CO_(2)to formate.The BOC@GDY shows a stable current density of 200 mA cm^(-2)at–1.1 V in a flow cell configuration,with a faradaic efficiency of 93.5%for formate.Experimental results show that the synergistic effect in BOC@GDY is beneficial for the CO_(2)adsorption affinity,the reaction kinetics and the selectivity for formate.In addition,in-situ X-ray absorption and Raman spectroscopy indicate that the electron-rich GDY could facilitate the reduction from Bi(Ⅲ)to Bi(0),thus leading to more active sites.We also demonstrate that the promoting effect of GDY in CO_(2)electroreduction can be further extended to other metal catalysts.To the best of our knowledge,such general promoting functions of GDY for CO_(2)electroreduction have not been documented thus far.

Electronics and Structural Properties of Single-Walled Carbon Nanotubes Interacting with a Glucose Molecule: ab initio Calculations

The adsorption of glucose molecule on single-walled carbon nanotubes(SWCNTs)is investigated by density functional theory calculations.Adsorption energies and equilibrium distances are evaluated,and glucose binding to the typical semiconducting and metallic nanotubes with various diameters and chirality are compared.We also investigated the role of the structural defects on the adsorption capability of the SWCNTs.We could observe larger adsorption energies for the larger diameters semiconducting CNTs,while the story is paradoxical for the metallic CNTs.The obtained results reveal that the adsorption energy is significantly higher for nanotubes with higher chiral angles.Finally,the adsorption energies are calculated for defected nanotubes for various configurations such as glucose molecule approaching to the pentagon,hexagon,and heptagon sites in the tube surface.We find that the respected defects have a minor contribution to the adsorption mechanism of the glucose on SWNTs.The calculation of electron transfers and the density of states supports that the electronic properties of SWCNTs do not change significantly after the gluycose molecular adsorption.Consequently,one can predict that presence of glucose would neither modify the electronic structure of the SWCNTs nor direct to a change in the conductivity of the intrinsic nanotubes.