不锈钢在建筑领域的应用前景

早期由于我国国力的不足及不锈钢产量、品种的匮乏，我国不锈钢在建筑方面的应用仅局限在某些没有适当材料的场合，而且主要是在建筑装饰业中使用。随着我国综合国力的提高，不锈钢生产规模及产品种类的扩大、质量的提高，不锈钢在建筑业的应用范围将得到扩展。其在建筑装饰业上的应用在突飞猛进地扩大，在建筑业的其它领域也开始得到推广。     

薄矿脉崩矿的夹制作用

在介质中每个药包的爆破作用半径主要取决于药包的药量、炸药的威力和岩石的性质等。在试验中,若爆破在自由面不受限制的条件下进行,则在工作面可形成标准爆破漏斗;在薄矿脉窄幅采场自由面受限制条件下,由于爆破时爆破漏斗底宽在自由面以外部分的发育受到极大的夹制作用,所以在工作面形成不了标准爆破漏斗,而只能形成萎缩的爆破漏斗。     

泛在网技术产业发展与用户参与的Living Lab创新模式

一、泛在网 1、泛在网的由来泛在计算（Ubiquitous Computing）的概念最早是由施乐公司首席科学家MarkWeiser在1991年提出的。在他发表在《科学美国人》杂志的文章“21世纪的计算机”中，Mark预言泛在计算将成为下一代的计算模式。他认为“最具有深远意义的技术是那些从人们注意力中消失的技术，     

计算机技术在化学实验室的应用

介绍了计算机技术在化学实验室的应用,包括计算机在化学分析过程中的应用、计算机网络在化学分析管理中的应用以及计算机在实验室仪器设备与材料的自动化管理方面的应用。     

金属在其合金相中扩散系数的测定

本文提出一种测定金属在其合金相中扩散系数的方法。推出在电位阶跃条件下电流达到稳态时形成合金所需的电量与扩散系数的关系式。在含稀土氯化物熔体中,用铜电极、铁电极、镍电极分别测定了镧在LaCu_2与LaCu_5、钇在YCu_4、钕在NdFe_2、镨在PrNi_5中的扩散系数。     

草分枝杆菌在黄铁矿和闪锌矿表面的选择性吸附研究

研究了草分枝杆菌在不同的影响因素条件下，在黄铁矿和闪锌矿表面的选择性吸附情况。实验结果表明，草分枝杆菌在黄铁矿和闪锌矿表面可发生明显的选择性吸附，在黄铁矿表面的最大吸附率可达到96．99％。而在闪锌矿表面的吸附率均在20％左右；草分枝杆菌在两种矿物表面的吸附在较短的时间内即可达到平衡；pH值是影响草分枝杆菌在两种矿物表面发生选择性吸附的关键因素，pH大于4．95后，选择性吸附现象明显；矿浆浓度超过6g／L和菌液浓度在0．5～4g／L之间利于选择性吸附；温度对吸附效果影响不大。扫描电镜检测结果表明，Mycobacterium Phlei细胞外膜表面的菌丝是重要的吸附位。     

关于树根桩的应用

树根桩在我国最早应用于工程,是在1981年苏州虎丘塔的地基托换加固,1983又在上海新卫机器厂做了各种长短不一的桩进行试验研究.1985在上海东湖宾馆加层时被称为在国内第一次使用,然后又在上海外滩天文台以及地铁穿越建筑物下面时的托换工程中相继使用并得到推广. 据资料记载,事实上树根桩最早是在1930年     

钛材在医学方面的应用

钛及其合金作为耐蚀和生物相容材料在医用方面已久负盛名.早在七十年代,前苏联就进行了大量的研究,直到目前,钛在该领域应用的研究兴趣仍在不断地增长.世界钛会上以及在非航空领域的应用方面有不少文章涉及到钛在医疗方面的应用,在国际钛协会组织的专业会议和展览会上与会代表们也十分关注这个问题.这必将促进钛及其合金在医学方面应用的深入研究以及生产工艺的不断发展.钛在医学方面的应用领域相当广,现已取得了长足的进展并得到了广泛的应用,诸如在人体髋关节的修复方面,现在每年大约有40万个钛制髋关节用于病人身上,这为人类健康、解除病痛做出了贡献.     

高岭石表面上铵离子吸附的量子化学研究

在离子型稀土矿浸取过程中,浸取剂铵离子通过在黏土矿物表面的吸附作用交换出被吸附的稀土离子.采用基于密度泛函理论的量子化学计算方法,研究铵离子在无水和有水高岭石的铝氧面和硅氧面上的吸附机理.结果表明:铵离子主要通过静电作用和氢键作用吸附到高岭石表面上.在高岭石铝氧面上,铵离子最容易吸附在平躺的羟基组分周围,而在硅氧面上铵离子更容易吸附在表面六元环中心处.水分子的存在会使铵离子在铝氧面上吸附能显著降低,在硅氧面上变化不大,铵离子更易吸附在硅氧面上.在有水的高岭石铝氧面和硅氧面上,铵离子的吸附能均小于稀土镧离子的吸附能.      

敌敌畏在萝卜中的残留研究

[目的]了解敌敌畏在萝卜上的残留动态,为其在萝卜上的安全使用提供理论依据.[方法]在萝卜上喷施3种不同浓度的敌敌畏,测定不同时期采收的萝卜根和叶中敌敌畏的残留量.[结果]敌敌畏在萝卜根中降解速度明显大于在萝卜叶中.敌敌畏在萝卜叶上半衰期为4～6 d,在萝卜根中的半衰期在2～4 d.按推荐药量喷施时,施药15 d后萝卜根中敌敌畏的最终残留量才会在FAO/WHO规定的允许范围之内.[结论]敌敌畏在萝卜上的安全施用浓度为1:2 000～1:1 000倍,安全采收间隔期为15～20 d.     

重毒性铅污染土壤清洁高效修复研究进展

在介绍了铅元素污染背景、现状与危害的基础上,对土壤中铅的来源、赋存形式及其提取方法进行了详细介绍。结合土壤修复技术研究现状,对三大修复方法如物理、化学及生物修复法进行了系统综述,并从效率、适用性、经济性等方面评估了3种修复方法的优势与劣势,发现化学修复最适合重毒性铅污染治理。随之对化学淋洗法和固定化/稳定法作了详细介绍,探讨并评价了不同种类淋洗剂和固化剂的修复机制、修复效果、适用性和应用前景等。最后对未来重毒性铅污染土壤清洁高效修复提出了展望,修复方法应尽量减少对土壤的破坏;对高铅污染土壤来说联合修复技术的发展是土壤修复富有潜力的发展方向;应当尽可能地确定铅污染土壤修复机制,实现定向修复;同时应加强多功能复合材料的研发。      

Trigeminal nuclear complex of the ferret: anatomical and immunohistochemical studies

In order to establish the ferret as an animal model for studies of trigeminal pain, we describe the cytoarchitecture and neurochemistry of the trigeminal nuclear complex in the ferret and compare them to those of the cat and rat. The complex was divided as previously described, but the ferret differed in the extent of the nuclear boundaries. The neuroanatomical istribution of substance P-, calcitonin gene-related peptide-, galanin-, enkephalin-, serotonin-, somatostatin-, neuropeptide Y-, and neurotensin-immunoreactivity was determined throughout the rostrocaudal extent of the complex. In subnucleus caudalis, substance P-, calcitonin gene-related peptide-, enkephalin-, serotonin-, somatostatin-, neuropeptide Y-, and galanin-immunoreactivity was densest in laminae I and II. In subnucleus interpolaris, immunoreactivity for all the above neurochemicals was most dense along the lateral border and the ventral third of the caudal part of the subnucleus. Enkephalin-immunoreactive cell bodies were present in subnucleus caudalis and interpolaris. In subnucleus oralis, labelling for substance P, calcitonin gene-related peptide, galanin, enkephalin, and serotonin was most prominent in the dorsomedial part of the subnucleus. Somatostatin-immunoreactive cell bodies were distributed throughout the spinal nucleus. Labelling of serotonin, substance P, calcitonin gene-related peptide, galanin, enkephalin, and somatostatin was present in the main sensory nucleus. The motor nucleus contained fibers immunoreactive for substance P, enkephalin, serotonin and neuropeptide Y, and cell bodies immunoreactive for calcitonin gene-related peptide. The majority of neurotensin-immunoreactivity was found at the level of subnucleus caudalis, where it was densest in the trigeminal extension of the lateral cervical nucleus. The distribution of peptides in this species throughout the spinal nucleus is consistent with the notion that all the subnuclei may be involved in the processing of nociceptive inputs.     

元宇宙技术综述

元宇宙作为一个新兴的概念受到了产业界、学术界、媒体界及公众的广泛关注,国内外众多公司也纷纷在“元宇宙”领域布局,但布局的背后离不开强大的技术支持。本文从技术维度深入剖析元宇宙。首先,从科学与技术的角度论述元宇宙的概念及内涵,并总结了目前从业者、专家以及学者对元宇宙的不同见解。其次,概述了元宇宙相关关键技术,包括网络及运算技术（5G、6G、物联网、云计算、雾计算及边缘计算）、管理技术（能耗管理、资源管理、会话管理及时空一致性管理）、虚实对象连接、建模与管理技术（X联网、身份建模、社会计算、去中心化管理技术）、虚实空间交互与融合技术（拓展现实、电子游戏技术、脑机接口技术）等。元宇宙不宜称为新技术,而是IT新技术的综合运用。技术的进步与发展,将为元宇宙的实现和应用奠定坚实的基础,同时元宇宙的发展也会促进现有技术的升级换代。最后,展望了元宇宙发展面临的诸多挑战,以清晰认识、理智决策、稳步探索元宇宙。      

Genetic and environmental parameters for mature weight and other growth measures in Polled Hereford cattle

Variances and covariances were estimated for birth weight (BWT), weaning weight (WW), yearling gain (YG), yearling weight (YW), yearling height (YH), relative growth from birth to weaning (RGW) and weaning to yearling (RGY), and mature weight (MW). Field records on 572,446 Polled Hereford cattle were analyzed. Because multiple dam weights were collected on a cow the MW used in the analysis was calculated using a nonlinear regression correction factor computed by fitting a quadratic with a plateau to the data. If the cow had an observation(s) beyond the inflection point (IP), the closest weight to that point was used. If the cow only had observation(s) before the IP the closest weight to that point was nonlinearly adjusted to the plateau. The IP for this data set was 1,506 d and the plateau was 554.7 kg. Heritabilities and genetic and environmental correlations were calculated from the appropriate (co)variances and phenotypic correlations were computed. Heritability estimates for BWT, WW, YG, YW, YH, RGW, RGY, and MW were .49, .24, .23, .30, .59, .24, .15, and .52, respectively. Genetic correlations between MW with BWT, WW, YG, YW, YH, RGW, and RGY were .64, .80, .76, .89, .73, -.29, and .35, respectively, environmental correlations were .15, .43, .05, .40, 1.03, .32, and -.10, respectively, and phenotypic correlations were .33, .32, .28, .46, .70, .00, and .07, respectively.     

太行山北段梨园金矿构造地球化学特征

梨园金矿隶属太行山北段多金属成矿带,是山西省灵丘地区发现的一处中型金矿床,矿区内已发现的金矿体均赋存于NNE向断裂带中。本研究共采集677件岩石样品进行微量元素分析测试,利用迭代法计算各元素异常下限。通过相关性分析、R型聚类分析和斜交因子分析,研究各元素之间的相关关系,分析矿床成矿地质地球化学环境,厘定矿床成矿元素为Au,成矿直接指示元素组合为Cu-Pb-Zn-Ag,间接指示元素组合为As-Sb-Hg。Au元素异常主要分布在发育强烈褐铁矿化的花岗岩体、岩脉和地层中,展布方向为NE-SW向,与区域构造线方向相吻合,矿化受岩体及破碎带控制明显;指示元素异常组合分布范围与成矿元素叠合程度高,对金成矿指示作用明显。综上得到梨园金矿的构造地球化学特征,以用于本区的成矿预测,对于丰富和完善该区金矿地球化学模型有一定的指示意义。     

A model for self-sustained potential oscillation of lipid bilayer membranes induced by the gel-liquid crystal phase transitions

To clarify the mechanism of self-sustained oscillation of the electric potential between the two solutions divided by a lipid bilayer membrane, a microscopic model of the membrane system is presented. It is assumed, on the basis of the observed results (Yoshikawa, K., T. Omachi, T. Ishii, Y. Kuroda, and K. liyama. 1985. Biochem. Biophys. Res. Commun. 133:740-744; Ishii, T., Y. Kuroda, T. Omochi, and K. Yoshikawa. 1986. Langmuir. 2:319-321; Toko, K., N. Nagashima, S. liyama, K. Yamafuji, and T. Kunitake. Chem. Lett. 1986:1375-1378), that the gel-liquid crystal phase transition of the membrane drives the potential oscillation. It is studied, by using the model, how and under what condition the repetitive phase transition may occur and induce the potential oscillation. The transitions are driven by the repetitive adsorption and desorption of proton by the membrane surface, actions that are induced the periodic reversal of the direction of protonic current. The essential conditions for the periodic reversal are (a) at least one kind of cations such as Na+ or K+ are included in the system except for proton, and the variation of their permeability across the membrane due to the phase transition is noticeably larger than that of proton permeability; and (b) the phase transition has a hysteresis. When these conditions are fulfilled, the self-sustained potential oscillation may be brought about by adjusting temperature, pH, and the cation concentration in the solutions on both sides of the membrane. Application of electric current across the membrane also induces or modifies the potential oscillation. Periodic, quasiperiodic, and chaotic oscillations appear especially, depending on the value of frequency of the applied alternating current.     

Angiosomes of the leg: anatomic study and clinical implications

In 1987, Taylor and Palmer introduced the angiosome concept. This anatomical study defined the three-dimensional vascular territories supplied by source arteries and veins to each tissue layer between the skin and the bone. This report, however, was an overview investigation and did not study each region of the body in fine detail. In 1996, Inoue and Taylor studied the angiosomes of the forearm in much greater detail. They showed, among other findings, that the zone between the angiosomes, formed by reduced caliber (choke) vessels or similar caliber (true) anastomotic arteries, occurred usually within tissues, especially the muscles, not between them. This study focuses on the same region in the lower limb to draw a comparison and to fill certain voids in our knowledge--the leg. Twelve lower limbs from fresh cadavers were investigated over a 2-year period after perfusing each with a mixture containing radio-opaque lead oxide. The anatomy of the arterial supply to the skin, the muscles, and the periosteum of the bones of the leg was examined. The contribution to each tissue was defined by dissection, by metal clip tagging of vessels, by radiography, and by mapping the branches with colored pins, coded to match the respective source arteries. A subtraction technique was used to study the muscles whereby the bones of the limb were replaced with radiolucent balloons to obtain an unobscured picture of the vasculature of the leg. The muscles were then segregated one by one from the muscle mass and x-rayed again. Next, cross-section studies were made in two legs to complete the three-dimensional picture, tracing the branches from the source arteries to each layer. Finally, the contribution to each tissue from the popliteal, sural, anterior tibial, posterior tibial, and peroneal vessels were color coded to match these source arteries, thus defining the angiosomes of the leg. Results, as in the forearm, showed that in most cases the connections between adjacent angiosomes occurred within tissues, not between them. The skin, the bones, and most muscles received branches from two or more angiosomes, thus revealing one of the important anastomotic pathways through which the circulation is reconstituted when a source artery is interrupted by disease or trauma. Notably, however, the muscles of the anterior compartment of the leg were supplied from one angiosome. This finding, coupled with the anatomy of the rigid fascial compartments of the leg, helps explain the variable clinical pictures and syndromes seen in cases in which the circulation is compromised or interrupted. Finally, this anatomical study adds further information to help design or redesign flaps in the leg for local or free transfer. Similarly, the information reveals the pathways through which the supply to the remaining tissues is reconstituted when one of the source arteries is harvested with a free flap, especially when multiple tissues are included in the transplant.     

Functional morphology of insect mechanoreceptors

This paper reviews the structure and function of insect mechanoreceptors with respect to their cellular, subcellular, and cuticular organization. Four types are described and their function is discussed: 1, the bristles; 2, the trichobothria; 3, the campaniform sensilla; and 4, the scolopidia. Usually, bristles respond to touch, trichobothria to air currents and sound, campaniform sensilla to deformation of the cuticle, and scolopidia to stretch. Mechanoreceptors are composed of four cells: a bipolar sensory neuron, which is enveloped by the thecogen, the trichogen, and the tormogen cells. Apically, the neuron gives off a ciliary dendrite which is attached to the stimulus-transmitting cuticular structures. In types 1-3, the tip of the dendrite contains a highly organized cytoskeletal complex of microtubules, the "tubular body," which is connected to the dendritic membrane via short rods, the "membrane-integrated cones" (MICs). The dendritic membrane is attached to the cuticle via fine attachment fibers. The hair-type sensilla (types 1, 2) are constructed as first-order levers, which transmit deflection of the hair directly to the dendrite tip. In campaniform sensilla (type 3), there is a cuticular dome instead of a hair and the dendrite is stimulated by deformation of the cuticle. In these three types, a slight lateral compression of the dendrite tip is most probably the effective stimulus. In scolopidia, the dendritic membrane is most probably stimulated by stretch. On the subcellular level, connectors between the cytoskeleton, the dendritic membrane, and extracellular (cuticular) structures are present in all four types and are thought to be engaged in membrane depolarization.     

Characterization of and correction for artifacts in linogram MRI

The distribution of neuropeptide Y (NPY)-like immunoreactivity in the brain of the bichir, Polypterus senegalus, was examined immunohistochemically. NPY-like immunoreactivity was distributed widely in the brain, with the highest density in the diencephalon. NPY-positive perikarya were found in various areas, including the terminal nerve, the pallial zones of the telencephalon, the periventricular preoptic nucleus, the thalamic nucleus, the ventral hypothalamus of the diencephalon, the tegmentum of the mesencephalon, and the area intermedioventralis of the rhombencephalon. In the hypothalamus, NPY-positive liquor-contacting neurons were frequently observed. Immunoreactive neuron-like cells also appeared in the distal lobe of the hypophysis. NPY fibers were densely distributed in the ventral telencephalon, the hypothalamus, and the ventrolateral area of the rhombencephalon. They were also demonstrated in the terminal nerve. In the hypophysis, NPY fibers were dense in the median eminence, but sparse in the neural lobe. Electron-microscopic double immunostaining of the terminal nerve revealed the coexistence of NPY-like antigen with gonadotropin-releasing hormone-like and molluscan cardioexcitatory tetrapeptide-like antigens in the same cytoplasmic granules. These results suggest that NPY or a related substance is involved in neuroregulation of various areas of the bichir brain, by mainly acting as a neurotransmitter or neuromodulator.     

Basic epidemiology of fractures of the upper and lower limb among Americans over 65 years of age

Current knowledge regarding the basic epidemiology of fractures is largely limited to a few fracture sites, notably those of the hip and distal forearm. To clarify the patterns of incidence of limb fractures in the elderly, we used data from a 5% sample of the U.S. Medicare population over age 65 years during the years 1986-1990. We identified incident fractures of the proximal humerus, other parts of the humerus, proximal radius/ ulna, shaft of the radius/ulna, distal radius/ulna, pelvis, hip, other parts of the femur, patella, ankle, and other parts of the tibia/fibula from diagnoses and procedures coded on claims for inpatient services, outpatient facility use, and physician services. We used Poisson regression to investigate the relation between demographic factors and fracture risk at these sites. Fractures at the hip were the most common, accounting for 38% of the fractures identified. The proximal humerus, distal radius/ulna, and ankle also were common fracture sites. A pattern of rapidly rising rates with age was seen for fractures of the pelvis, hip, and other parts of the femur among women. Fractures distal to the elbow or knee, however, had, at most, modest increases in incidence with age over 65 years. For each of the fractures studied, women had higher rates than men of the same race, and whites generally had higher rates than blacks of the same gender. Gender-related differences in risk were larger among whites than among blacks, and racial differences in risk were more marked among women than among men.