management systems a nd meas ures esta blis hed by, a nd a num ber of pragmatic, com bine d part-time w orkforce e ducation information, the prote ction of the digital campus constructi on a nd sustai nabl e devel opme nt. Six Bureau attaches great importance to i nformation te chnol ogy se curity, i nfor mation technology se curit y, entr ust XX City Cente r for e ducational information and equipme nt de dicate d to the w ork. Network s ecurity leadi ng group was s et up, chaired by t he Educati on Burea u Chief, head, for XX education Metr o-network a nd i nformation security emergency response leadership. De puty group lea der for XX e ducati ona l metropolitan area network a nd i nformation security emergency response coor dinati on, command. T he team assist lea der a nd deputy leade r, res ponsi ble for netw ork XX network se curity a nd i nformation ... Team. Information se curity w ork Conference held each semeste r, a nd depl oyment of information se curity of document s iss ued on a reg ular ba sis. I nformation sec urity ass essme nt is included i n the a nnual index. Strictly im plement the information se curity budget t o e nsure information se curity of investment . By XX, educati on i nformation and e qui pment Centre XX netw ork netw ork se curity and information se curit y. A ccor ding t o the information technology security requirements , iss ue d a document re quire s s chools (units) impl ement, defined t he inf ormati on security gui deline s, s pe cific w ork pra ctices , pr oce dures , and requirement s. Clear industry i nformation se curity i nci dents (acci dent s) to dete ct, re port a nd dis pos al pr oces ses. Accordi ng to self -examinati on, t he s chool (units) basic establi she d ha s net work s ecurity management system; the s chool (units) accor ding t o this units a ctual, e stablis he d ha s units personnel ma nageme nt, information system r oom management, a nd equipment ma nagement, and media ma nagement, and netw ork s ecurity construction manag ement, a nd shi ppe d dime nsi on ma nagement, and service outsourci ng, management system; devel ope d has computer and the netw or k of network security res ponsi bility held sy stem, signed has network security res ponsi bility; w ebsite of information management personnel is res ponsi ble for confi dential ma nagement, passw ord ma nagement, on com puter e njoy s indepe ndent right, User name and pa ssw ord of t he computer for its pr oprietar y, and relea se of pr ovisi ons i s pr ohi bited, such a s leaks, investigated for re spons ibilit y. Accor di ng to w ho is in charge of who's in charge, who is r unning a nd who is res ponsi ble for, who uses principle s of w ho i s in charge of management schools (units) define d the r oles a nd re spons ibilitie s of i nformation security, a ssura nce respon sibilities to schools. XX city s chool s (units) total site 20, 19 of which were not cla ssified security pr otection as sessme nt, of w hich 1 (XX e ducati on and resource netw ork) for class ified se curity protecti on l evels, w ithout thir d-level information systems. Total education information systems 1 (XX educati on cloud platform), contai ns feature s with e-G overnment, res our ce li brary, test databas e, mail s ervice s, s uch as e -book s, all intra net servi ces. No for grade protecti on gra ding re cord and evaluati on of sc hool (unit s), requireme nts the s chool (units) according t o information se curity grade prote ction about policy a nd standar d, orga nization carrie d out information se curity g rade prote ction se curity manageme nt system constr uction, a nd te chnol ogy measures construction and grade eval uation, impleme ntation gra de pr otection system of the re quirement s, makes information system se curity ma nagement level obvi ouslyfa cility up to 160 mill ion Y uan, accordi ng to the standard, high quality planning XX e ducational metropolitan are a netw ork realizes Wan Z haok uan to schools, hundreds of megabytes of broa dba nd t o the tabl e, ' wire ' (ie: Web, video, a udi o) to the target, ele ctronic w hiteboards , multimedia classr ooms , remote intera ctive vide o teaching system of modern edu cational e qui pment in t he cla ssroom. .. . With I ntel com pany on XX Educati on City domai n net work of topic case desig n, relies on Cisco company t hought Shu aid chua n proj ect staff free provides ha s three year s technol ogy s upport, from 200 9 bega n, accor ding t o high sta ndar ds, a nd high of work thought, and ma npower planning, a nd poi nts step implementati on, using school earthquake H ou r econstruction of opportunities, agai n pla nni ng eleme ntary and middle s chool s campus network a nd e ducation city domai n netw ork, and local broadcasting netw ork company cooperation, using broa dcast TV network , will physi cal fiber layi ng to ea ch school, to mini mum of cost a chieve d ha s physical fiber s chool school pas s; Ea ch s chool construction standards of cam pus netw ork and netw ork ac ces s to all rooms; XX educati on metropolita n area network center ma chi ne room equipment i n the Mini stry of education sta ndardi zation manageme nt platform, the Central Library of a udi o-vis ual e ducation re sources , set up a Chi nese tea cher e ducation cl oud platform, impl emented li nks t he two platforms. At pres ent, the city's primary and middle s chool students to com puter 3 198, vitality than 10 :1; 809 e qui pment cl asse s through t he cla ssroom (pr imary and s econdary); 36 of the campus network. The e stablis hment of an adva nce d, pra ctical Gigabit e ducational metropolitan are a netw ork, the city's s chool s have a cce ss to educational metropolita n area network, school s have computer netw orks, closed -cir cuit televisi on network , broa dca st netw orks into t he cla ssrooms, reali ze the tri ple pla y. Schools share I nternet bandwidt h, ca n meet the nee ds of teaching of the s chool office and at a ny time. Accordi ng to Mi nistry of e ducati on on full started implementati on tea ching poi nts digital e ducation resource s full cover project of notificati on (taught te chnical letter (201 2) 74th,) and XX Provi nce Departme nt of education on iss ued XX provi nce tea chi ng points digital educati on res our ces full cover proje ct implementati on view s of notificati on (chua n taught letter (2013) 18t h,) requirements, I city 6 a teaching poi nts impleme ntation teaching points digital educati on res our ces full cover proje ct, combined I city specific situation, developed i ssue d ha s XX City Burea u on teaching point s digital res our ces full cover pr oje ct of implementati on pr ogramme, Establi she d XX, full coverage of digital re sources i n modern distance educati on tea chi ng project lea ding group, XX, chaired t he Secretary for e ducation. Establ ishe d, digital resources i n modern distance educati on tea chi ng, XX full coverage pro ject group, XX, Direct or of the Ce nter for educational informati on a nd e qui pment chaired Z hu G uiyan, re sponsi ble for di stance educati on digital re sources coveri ng proj ect work . Projects in XX city s chool digital resource s in modern distance education t ea chi ng full-coverage proje ct leadi ng group, digital re sour ces i n moder n di stance education teaching , and XX full coverage proje ct group leadershi p and organi zation, in a ccordance wit h the unified arra ngement of the w hol e provi nce , respons ible for university e ducation digital res ource s coveri ng proj ect manageme nt and implementati on. A ccording t o provi nce s arrangement s, I Ce nter has arra ngements G ong gei 黄瓜和番茄温室土壤 Olsen-P 阈值研究 张彦才 , 李若楠 1,王丽英 1,翟彩霞 1,李巧云 1,陈丽莉 1,武雪萍*2,吴会军 2 (1 河北省农林科学院农业资源环境研究所,河北,石家庄 ; 2 中国农业科学院农业资源与农业区划研究所,北京) 介绍 磷是植物生长发育所必需的大量营养元素之一,主要因为其在能量代谢、糖分代谢、酶促反应 和光合作用等过程中起着至关重要的作用,并且是核酸、植素和卵磷脂的重要组成成分,在很大程 度上决定了作物的产量和品质(Lynch and Beebe,1995)。植物根构型对磷吸收起着重要作用。同时在 众多种类的根分泌物中,质子、有机酸和酸性磷酸酶被普遍认为以直接或间接的方式影响土壤磷的 有效性,与植物吸收磷的效率有关。磷酸酶是土壤中最活跃的酶类之一,在土壤磷素循环中起重要 作用。植物根系及其残体、土壤动物及其遗骸和为生物所分泌的磷酸酶是其主要来源。 磷肥的当季利用率只有 10~25%。其施入土壤的磷肥很快转化为 Ca2-P、Ca8-P、Al-P、Fe-P 等 形态无机磷。长期大量施用磷肥不仅使 0~20cm 耕层土壤磷素大量积累,20~40cm 土层磷素均有不同 程度的增加。在中国,无论是在大田还是种植蔬菜的温室,因为不断增加的磷肥施用量,导致磷素 在土壤中过分积累。